US20110165847A1 - Millimiter wave transmission device, millimiter wave transmission method, and millimiter wave transmission system - Google Patents

Abstract

The device includes: a signal generating unit generating a millimeter wave signal by signal processing of an input signal; a coupling circuit transmitting an electromagnetic wave from the millimeter wave signal generated by the signal generating unit to one end of a circuit board; a coupling circuit receiving the electromagnetic wave from the millimeter wave signal from the other end of the circuit board; and a signal generating unit that generates an output signal by signal processing of the millimeter wave signal from the electromagnetic wave received by the coupling circuit. Preferably, the circuit board is constituted by a dielectric material whose the dielectric loss tangent is relatively large, and a transmission line functioning as a millimeter wave transmission path is constituted within this circuit board. With this construction, extremely high-speed signals can be transmitted through a circuit board having a prescribed dielectric constant representing a large loss.

Description

TECHNICAL FIELD
• The present invention relates to a millimeter wave transmission device, a millimeter wave transmission method, and a millimeter wave transmission system.
BACKGROUND ART
• Regarding a technique for transmitting/receiving a millimeter wave signal,Patent Literature 1 discloses a dielectric waveguide line. This dielectric waveguide line includes a pair of main conductor layers, two lines of via hole groups, and sub-conductor layers, wherein the main conductor layers are formed in parallel with a dielectric interposed between them. The via hole groups are formed at an interval equal to or shorter than a cutoff wavelength in the direction of signal transmission to electrically connect the main conductor layers. The sub-conductor layer is connected to the via hole groups and formed in parallel with the main conductor layers.
• When an electric signal is transmitted by a waveguide region enclosed by the main conductor layers, the via hole groups, and the sub-conductor layers in the dielectric waveguide line, at least one of the main conductor layers is formed with slot holes for electromagnetically coupling with a high frequency transmission line. The high frequency transmission line is constituted by a microstrip line, and is formed at a position opposite to the slot holes. When the dielectric waveguide line is made as described above, it is easy to electromagnetically couple with another high frequency transmission line, and a signal can be transmitted. In addition, a waveguide line having stable characteristics from a microwave to a millimeter wave can be provided.
• Regarding a technique for transmitting/receiving a millimeter wave signal,Patent Literature 2 discloses a wireless-type millimeter wave communication system. The millimeter wave communication system includes millimeter wave transmission means, millimeter wave reception means, and reflection means, wherein the millimeter wave transmission means includes a transmission antenna having a predetermined directivity and light emission means. The millimeter wave transmission means transmits a signal in a millimeter wave band. The millimeter wave reception means receives the millimeter wave signal from the millimeter wave transmission means. The reflection means is arranged to reflect the signal wave radiated from the millimeter wave transmission means and reflect a light, so that the reflected signal wave is incident to the millimeter wave reception means. With the above conditions, the millimeter wave transmission means is arranged with the light emission means almost in parallel with an output axis of the transmission antenna, so that the light emission means emits a light ray in the same direction as the signal wave.
• In order to adjust an initial position of the reflection means, the angle of the transmission antenna is adjusted by means of visual check so that the light ray emitted in parallel with the output axis of the transmission antenna is incident upon the reflection means. Accordingly, the angle of the reflection means can be adjusted so that the light ray reflected by the reflection means is incident upon the reception antenna. When the millimeter wave communication system is configured as described above, the initial direction of the reflection means can be adjusted easily by only one person.
CITATION LISTPatent Literature
• • Patent Literature 1: JP 2004-104816 (A) (page 4, FIG. 1)
  • Patent Literature 2: JP 2005-244362 (A) (page 5, FIG. 1)
SUMMARY OF INVENTIONTechnical Problem
• A purpose of the present invention is to provide a mechanism for transmitting a signal in a millimeter wave band without inconvenience while reducing interference in an electronic apparatus.
Solution to Problem
• A millimeter wave transmission device according to the present invention includes a first signal generation unit for generating a millimeter wave signal upon performing frequency conversion on an input signal to be transmitted and a second signal generation unit for demodulating the received millimeter wave signal and generating an output signal corresponding to the input signal to be transmitted.
• A circuit board is constituted by a dielectric material and includes the first signal generation unit and the second signal generation unit. Further, the circuit board is used as a millimeter wave transmission path between the first signal generation unit and the second signal generation unit
• In short, in the millimeter wave transmission device according to the present invention, members at the transmission side and the reception side relating to the millimeter wave transmission are mounted on the same circuit board, and the circuit board is configured to be also used as the millimeter wave transmission path.
• For example, the millimeter wave transmission path for transmitting the electromagnetic wave based on the millimeter wave signal is configured such that a transmission region is defined on the circuit board, and the millimeter wave signal is transmitted in such a manner that the millimeter wave signal is shielded in this defined transmission region of the circuit board.
• The millimeter wave transmission device includes a first signal coupling unit for transmitting the millimeter wave signal generated by the first signal generation unit to one end of the circuit board and a second signal coupling unit for receiving the millimeter wave signal from the other end of the circuit board. Each of the first signal coupling unit and the second signal coupling unit is constituted by an antenna member having a predetermined length based on the millimeter wave signal wavelength.
• The first signal generation unit and the first signal coupling unit are preferably arranged in the first electronic component. The second signal coupling unit and the second signal generation unit are preferably arranged in the second electronic component. The first electronic component and the second electronic component are preferably mounted on the same circuit board.
• An electronic component used for signal processing in baseband region of the input signal and the output signal may be mounted on the circuit board between the first region of the circuit board including the first signal generation unit and the first signal coupling unit and the second region of the circuit board including the second signal generation unit and the second signal coupling unit.
• For example, the first signal generation unit includes the modulating circuit, and the modulating circuit modulates the input signal. The first signal generation unit performs frequency modulation on the signal modulated by the modulating circuit, and generates the millimeter wave signal. The first signal coupling unit transmits the millimeter wave signal generated by the first signal generation unit to one end of the tangible object.
• The second signal coupling unit receives the millimeter wave signal from the other end of the tangible object. The signal is transmitted within the tangible object from the antenna member constituting the first signal coupling unit and having a predetermined length based on the millimeter wave signal wavelength, and the electromagnetic wave based on the signal is received by the antenna member constituting the second signal coupling unit and having the same length.
• For example, the second signal generation unit has the demodulating circuit, and performs frequency conversion on the millimeter wave signal. Thereafter, the second signal generation unit generates the output signal corresponding to the input signal demodulated by the demodulating circuit.
• The circuit board is preferably constituted by at least one of a glass epoxy resin, an acrylic resin, and a polyethylene resin. These resins have relatively large dielectric loss tangents.
• In the tangible object having a large loss, the transmission loss increases but the reflected wave is attenuated as the carrier frequency increases. Therefore, an extremely high-speed signal can be transmitted via the tangible object having a large loss.
• A millimeter wave transmission method according to the present invention includes the steps of generating a millimeter wave signal upon performing frequency conversion on an input signal to be transmitted, transmitting the millimeter wave signal to one end of the tangible object, and transmitting an electromagnetic wave based on the millimeter wave signal within the tangible object, receiving a millimeter wave signal based on the electromagnetic wave obtained from the other end of the tangible object, and demodulating the received millimeter wave signal and generating an output signal corresponding to the input signal to be transmitted.
• In the millimeter wave transmission method according to the present invention, the tangible object transmitting the electromagnetic wave based on the millimeter wave signal is formed with the same dielectric material as the circuit board in the circuit board constituted by the dielectric material having a circuit member for treating the millimeter wave signal.
• A millimeter wave transmission system according to the present invention includes a first millimeter wave transmission body including a first signal generation unit for generating a millimeter wave signal by performing frequency conversion on a first input signal to be transmitted, a second signal generation unit for demodulating the received millimeter wave signal and generating a first output signal corresponding to the first input signal to be transmitted, and a first circuit board constituted by a dielectric material and including the first signal generation unit and the second signal generation unit, wherein the first circuit board is used as a millimeter wave transmission path between the first signal generation unit and the second signal generation unit, a second millimeter wave transmission body including a third signal generation unit for generating a millimeter wave signal by performing frequency conversion on a second input signal to be transmitted, a fourth signal generation unit for demodulating the received millimeter wave signal and generating a second output signal corresponding to the second input signal to be transmitted, and a second circuit board constituted by a dielectric material and including the third signal generation unit and the fourth signal generation unit, wherein the second circuit board is used as a millimeter wave transmission path between the third signal generation unit and the fourth signal generation unit, and a coupling medium for connecting the first millimeter wave transmission body and the second millimeter wave transmission body and propagating an electromagnetic wave based on the millimeter wave signal.
• In short, the millimeter wave transmission system according to the present invention includes a plurality of millimeter wave transmission devices according to the present invention and a coupling medium for combining them and transmitting an electromagnetic wave based on the millimeter wave signals.
Advantageous Effects of Invention
• According to the present invention, a signal in a millimeter wave band can be transmitted within an electronic apparatus with a lower degree of interference and without any inconvenience. A circuit board having members at the transmission side and the reception side relating to the millimeter wave transmission is also used as a tangible object functioning as a millimeter wave transmission path, because an electromagnetic wave between transmission and reception based on a millimeter wave signal is transmitted while being shielded within the circuit board.
BRIEF DESCRIPTION OF DRAWINGS
• FIG. 1 is a block diagram illustrating an exemplary configuration of a millimeterwave transmission device100 as a first embodiment.
• FIG. 2A is an explanatory diagram illustrating an exemplary configuration of the millimeterwave transmission device100 on acircuit board10.
• FIG. 2B is a cross sectional view illustrating an exemplary configuration of the millimeterwave transmission device100 on thecircuit board10.
• FIG. 3 is a circuit diagram illustrating an exemplary internal configuration of anamplifier204 and the like.
• FIG. 4 is a frequency characteristic diagram illustrating example of bandpass characteristic Ia′ of theamplifier204.
• FIG. 5 is a simulation circuit diagram illustrating an example of a millimeter wave transmission in the millimeterwave transmission device100.
• FIG. 6 is a frequency characteristic diagram illustrating an example of loss and an example of reflection of atransmission line206 on thecircuit board10 made of Teflon (registered trademark) resin.
• FIG. 7 is a frequency characteristic diagram illustrating an example of loss and an example of reflection of thetransmission line206 on thecircuit board10 made of glass epoxy resin.
• FIG. 8A is an operation flowchart illustrating an example of communication from an electronic component #A to an electronic component #B in the millimeterwave transmission device100.
• FIG. 8B is a block diagram illustrating an exemplary configuration of a highfrequency transmission apparatus1 according to a first comparative example.
• FIG. 8C is a waveform diagram illustrating an example of transmission of a high-speed baseband signal.
• FIG. 8D is a baseband spectrum (frequency characteristics) of the high-speed baseband signal.
• FIG. 9A is a waveform diagram illustrating an example of transmission of a signal S in a millimeter wave band after frequency conversion.
• FIG. 9B is a spectrum (frequency characteristics) of the signal S in a millimeter wave band after frequency conversion.
• FIG. 10 is a block diagram illustrating an exemplary configuration of a millimeterwave transmission system200 according to a second embodiment.
• FIG. 11 is a top view illustrating an exemplary arrangement of four electronic components #A, #B, #C, #D in the millimeterwave transmission system200.
• FIG. 12A is a perspective view illustrating an exemplary implementation oftransmission lines206,226 and the electronic components #A, #B, #C, #D in the millimeterwave transmission system200.
• FIG. 12B is a block diagram illustrating an exemplary configuration of a high frequencysignal transmission system20 according to the second comparative example.
• FIG. 13 is a block diagram illustrating an exemplary configuration of a millimeterwave transmission system300 according to a third embodiment.
• FIG. 14 is a top view illustrating an exemplary arrangement of awaveguide structure341 and the four electronic components #A, #B, #C, #D in the millimeterwave transmission system300.
• FIG. 15 is a perspective view illustrating an exemplary implementation of thewaveguide structure341,transmission lines306,326, and the electronic components #A, #B, #C, #D, in the millimeterwave transmission system300.
• FIG. 16 is a block diagram illustrating an exemplary configuration of a millimeterwave transmission device400 according to a fourth embodiment.
• FIG. 17 is a graph chart illustrating an example of a frequency band in the millimeterwave transmission device400.
• FIG. 18 is a block diagram illustrating an exemplary configuration of a millimeterwave transmission device500 according to a fifth embodiment.
• FIG. 19 is an operation flowchart illustrating an example of gain control in the millimeterwave transmission device500.
• FIG. 20 includes a top view illustrating an exemplary configuration (part I) of a millimeterwave transmission device600 according to a sixth embodiment and a cross sectional view taken along arrow line X1-X.
• FIG. 21 is a perspective view illustrating an exemplary configuration (part II) of the millimeterwave transmission device600.
• FIG. 22 is a frequency characteristic diagram illustrating an example of reflection characteristic and an example of bandpass characteristic of a high-pass filter device255 of the millimeterwave transmission device600.
• FIG. 23 includes a top view illustrating an exemplary configuration of a millimeterwave transmission device700 according to a seventh embodiment and a cross sectional view taken along arrow line X2-X2.
• FIG. 24 includes a top view illustrating an exemplary configuration (part I) of a millimeterwave transmission device800 according to an eighth embodiment and a cross sectional view taken along arrow line X3-X3.
• FIG. 25 is a top view illustrating an exemplary configuration (part II) of the millimeterwave transmission device800.
• FIG. 26 is a cross sectional view taken along arrow line X4-X4 for illustrating an exemplary configuration (part III) of the millimeterwave transmission device800.
• FIG. 27A is a cross sectional view illustrating an exemplary propagation (part I) of an electromagnetic wave S′ in a high-pass filter device255′.
• FIG. 27B is a cross sectional view illustrating the exemplary propagation (part I) of the electromagnetic wave S′ in the high-pass filter device255′.
• FIG. 28A is a cross sectional view illustrating an exemplary propagation (part II) of the electromagnetic wave S′ in the high-pass filter device255′.
• FIG. 28B is a cross sectional view illustrating the exemplary propagation (part II) of the electromagnetic wave S′ in the high-pass filter device255′.
• FIG. 29 is a frequency characteristic diagram illustrating an example of reflection characteristic and an example of bandpass characteristic of the high-pass filter device255′ of the millimeterwave transmission device800.
DESCRIPTION OF EMBODIMENTS
• Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the appended drawings. Note that, in this specification and the drawings, elements that have substantially the same function and structure are denoted with the same reference signs, and repeated explanation is omitted.
• The following explanation will be made in the order listed below.
• 1. First embodiment: basic
• 2. Second embodiment: multiple transmission paths
• 3. Third embodiment: coupling with coupling medium
• 4. Fourth embodiment: adder circuit (frequency multiplexing)
• 5. Fifth embodiment: with feedback path
• 6. Sixth embodiment: microstrip line and waveguide structure
• 7. Seventh embodiment: upper ground layer and antenna structure
• 8. Eighth embodiment: coupling circuit has multiple-layer structure
First Embodiment
• FIG. 1 is a block diagram illustrating an exemplary configuration of a millimeterwave transmission device100 as a first embodiment. The millimeterwave transmission device100 shown inFIG. 1 can be applied to an image processing apparatus for transmitting a millimeter wave signal having a carrier frequency of 30 GHz to 300 GHz at a high speed.
• The millimeterwave transmission device100 includes a firstsignal generation unit21, a secondsignal generation unit22, asignal input terminal201, acoupling circuit205 for coupling with acircuit board10 as shown inFIG. 2B, atransmission line206 using a tangible object (such as a circuit board) made of a dielectric material, acoupling circuit207 for coupling with thecircuit board10, and asignal output terminal211. Thesignal generation unit21 and thesignal generation unit22 are constituted by CMOS-IC devices, i.e., examples of semiconductor integrated circuits. These members are arranged in an electronic apparatus.
• The firstsignal generation unit21 connected to thesignal input terminal201 includes, for example, a modulatingcircuit202, afrequency converting circuit203, and anamplifier204, in order to generate a millimeter wave signal S by processing an input signal Sin. Thesignal input terminal201 is connected to the modulatingcircuit202, so that the input signal Sin is modulated. The modulatingcircuit202 uses, for example, a phase modulating circuit. Alternatively, the modulatingcircuit202 as well as thefrequency converting circuit203 may use a so-called direct conversion method.
• The modulatingcircuit202 is connected to thefrequency converting circuit203. Accordingly, the input signal Sin modulated by the modulatingcircuit202 is subjected to frequency conversion, so that the millimeter wave signal S is generated. In this case, the millimeter wave signal S is a signal having a frequency of 30 GHz to 300 GHz. Thefrequency converting circuit203 is connected to theamplifier204. Accordingly, after the millimeter wave signal S is subjected to frequency conversion, the signal S is amplified.
• Theamplifier204 is connected to thecoupling circuit205 constituting an example of a first signal coupling unit. Theamplifier204 transmits the millimeter wave signal generated by thesignal generation unit21 to an end of a tangible object (tangible object made of a dielectric material) having a predetermined dielectric constant ε. Thecoupling circuit205 is constituted by an antenna member having a predetermined length based on a wavelength λ of the millimeter wave signal S, i.e., about 600 μm, and is coupled to the tangible object having the dielectric constant ε. When thecoupling circuit205 has a fractional bandwidth (=signal band/operation center frequency) of about 10% to 20%, thecoupling circuit205 can also be easily realized using a resonance structure. In this embodiment, a region of thecircuit board10 having the dielectric constant ε is used for the tangible object. The region of thecircuit board10 having the dielectric constant ε constitutes thetransmission line206. Accordingly, a millimeter wave electromagnetic wave S′ propagates in thetransmission line206. When a dielectric loss tangent δ is large, thetransmission line206 has a relatively large loss, which also reduces the reflection. Therefore, a large dielectric loss tangent δ is preferable to a small dielectric loss tangent δ.
• In this specification, the magnitude of the dielectric loss tangent δ in a used frequency band is distinguished as follows. The dielectric material having a small dielectric loss tangent δ corresponds to a material having a tan δ equal to or less than about 0.001, for example, Teflon (registered trademark) resin and silicone resin. On the other hand, the dielectric material having a large dielectric loss tangent δ corresponds to a material having a tan δ equal to or more than about 0.01, for example, glass epoxy resin (tan δ≈0.02 to 0.03), acrylic resin, and polyethylene resin.
• Thetransmission line206 is connected to thecoupling circuit207 constituting an example of a second signal coupling unit. Thetransmission line206 receives an electromagnetic wave S′ based on the millimeter wave signal S from the other end of thetransmission line206. Thecoupling circuit207 is constituted by an antenna member having a predetermined length based on the wavelength λ of the millimeter wave signal S, i.e., about 600 μm. The antenna member is, for example, a probe antenna (dipole), a loop antenna, and a small aperture-coupled device (such as slot antenna).
• Thecoupling circuit207 is connected to the secondsignal generation unit22. The secondsignal generation unit22 processes the millimeter wave signal received by thecoupling circuit207. More particularly, the secondsignal generation unit22 demodulates the millimeter wave signal. Thereby, the secondsignal generation unit22 generates an output signal Sout corresponding to the input signal Sin to be transmitted. Thesignal generation unit22 includes, for example, anamplifier208, afrequency converting circuit209, and ademodulating circuit210. Alternatively, thefrequency converting circuit209 as well as thedemodulating circuit210 may use a so-called direct conversion method. Thecoupling circuit207 is connected to theamplifier208, so that theamplifier208 can amplify the received millimeter wave signal.
• Theamplifier208 is connected to thefrequency converting circuit209. Thefrequency converting circuit209 converts the frequency of the amplified millimeter wave signal S. Thefrequency converting circuit209 is connected to thedemodulating circuit210. Thedemodulating circuit210 demodulates the output signal having been subjected to the frequency conversion.
• In this millimeterwave transmission device100, thesignal input terminal201, thesignal generation unit21, and thecoupling circuit205 shown inFIG. 1 constitute a signal-transmission first electronic component #A. On the other hand, thecoupling circuit207, thesignal generation unit22, and thesignal output terminal211 constitute a signal-reception second electronic component #B.
• Thesignal generation unit21 and thesignal generation unit22 are respectively provided as the millimeter wave communication electronic components #A, #B constituted by CMOS-IC devices, i.e., examples of semiconductor integrated circuits. The electronic component #A and the electronic component #B are mounted on thecircuit board10 having the dielectric constant ε. The electronic components #A, #B may not be necessarily arranged on the same surface of thesame circuit board10. Alternatively, the electronic components #A, #B may be arranged on surfaces different from each other (i.e., on the front surface and the back surface, respectively).
• Although not shown in the figure, thecircuit board10 may be arranged with not only the millimeter wave communication electronic components #A, #B but also passive elements such as resistor devices, capacitor devices, and transformers, and active elements such as transistors and semiconductor integrated circuits, which are used for signal processing in a baseband region.
• In this case, in this mechanism of the first embodiment, thecircuit board10 is arranged with thetransmission line206 between the first region of thecircuit board10 including the electronic component #A having thecoupling circuit205 constituting an example of the first signal coupling unit and the firstsignal generation unit21 and the second region of thecircuit board10 including the electronic component #B having thecoupling circuit207 constituting an example of the second signal coupling unit and the secondsignal generation unit22. Accordingly, in this mechanism of the first embodiment, it is not necessary to consider a millimeter wave transmission therebetween on thecircuit board10. Therefore, for example, electronic components (passive elements and active elements) used for signal processing in a baseband region can be mounted in a space between the electronic components #A, #B on thecircuit board10 regardless of the sizes of the components (seeFIG. 12A explained below).
• The above-explained method for transmitting data upon converting the frequency of the input signal Sin is generally used for broadcast and wireless communication. For this purpose, relatively complicated transmitters and receivers are used to cope with issues, for example, (1) to what extent communication can be performed (issue of S/N ratio with respect to thermal noise), (2) how reflection and multi-pass can be treated, and (3) how interference with other channels can be suppressed. Thesignal generation unit21 and thesignal generation unit22 used in the present embodiment are used in a millimeter wave band, which is in a frequency band higher than the frequency used by the complicated transmitters and receivers generally used for broadcast and wireless communication. Thesignal generation unit21 and thesignal generation unit22 use the millimeter wave having a short wavelength λ. Therefore, the frequency can be easily reused, and the used frequency is suitable for a case where many devices arranged in proximity communicate with each other.
• FIGS. 2A and 2B are explanatory diagrams each illustrating an exemplary configuration of the millimeterwave transmission device100 on thecircuit board10. In this embodiment, a glass epoxy resin circuit board having a large loss, which is not usually used in the millimeter wave band, is used in order to increase the margin of the S/N ratio with respect to thermal noise. Therefore, reflection, multi-pass, and interferences are reduced.
• In the millimeterwave transmission device100 shown inFIG. 2, the signal is transmitted from the electronic component #A to the electronic component #B. This millimeterwave transmission device100 has thecircuit board10 having the dielectric constant ε, which includes the signal-transmission first electronic component #A including thesignal generation unit21, thecoupling circuit205, and thesignal input terminal201, and the signal-reception second electronic component #B including thecoupling circuit207, thesignal generation unit22, and thesignal output terminal211 as shown inFIG. 1. Thecircuit board10 has a both-side copper foil circuit board in which a glass epoxy resin is used as an insulating base. The dielectric constant ε of the glass epoxy resin is about 4.0 to 5.0 (1 MHz).
• Thetransmission line206 is constituted by a transmission region I defined on the glass epoxy resin circuit board including the electronic component #A and the electronic component #B mounted thereon. Thetransmission line206 uses thecircuit board10 having a large loss, such as a glass epoxy circuit board usually used for an ordinary print circuit board, wherein thecircuit board10 has a dielectric loss tangent δ of 0.01 or more, and thecircuit board10 has a large transmission loss in the millimeter wave band and is not considered to be suitable for millimeter wave transmission in the past.
• The transmission region I of this example is defined by a plurality of opening portions (hereinafter referred to as throughholes10a) in a cylindrical hollow form penetrating thecircuit board10 as shown inFIG. 2A. For example, the plurality of throughholes10aare formed in a linear manner in two rows in a direction of propagation of the electromagnetic wave S′ based on the millimeter wave signal S between the electronic component #A and the electronic component #B on the circuit board10 (directionality). An arrangement pitch p between one of the throughholes10aand an adjacent throughhole10ais set at λ/2 or less, for example. When the width between one of the throughholes10aand an opposing throughhole10ais defined as a width w of the transmission region I, the width w is set at λ/2 or more. The throughhole10ais not limited to a cylindrical hollow member, and may be a column-shaped member having a conducting property. When a column-shaped member having a conducting property is grounded, a phase can be adjusted as a dielectric waveguide path.
• As described above, the transmission region I is defined by opening portions arranged in two rows (hereinafter referred to as throughhole fence portions10b). It is to be understood that a fence member such as a repeater may be arranged on thecircuit board10, so that the transmission range of the electromagnetic wave S′ based on the millimeter wave signal S may be controlled. It is to be understood that, when the electronic component #B or a plurality of other electronic components #B arranged around the electronic component #A are configured to receive the electromagnetic wave S′ based on the millimeter wave signal S at a time, the throughhole fence portions10bmay be omitted so that the transmission direction of the electromagnetic wave S′ becomes omnidirectional.
• In the millimeterwave transmission device100, the electromagnetic wave S′ based on the signal transmitted within thecircuit board10 from theantenna member11 shown inFIG. 2B, constituting thecoupling circuit205, is received by theantenna member12 as shown inFIG. 2B, constituting thecoupling circuit207. Theantenna member11 is connected to theamplifier204 of the electronic component #A as shown inFIG. 1, and is arranged on thecircuit board10 or in thecircuit board10. Theantenna member11 is configured to emit the electromagnetic wave S′ within thecircuit board10. For example, theantenna member11 is arranged in ahole portion10cformed in thecircuit board10. Theantenna member11 uses an antenna body having a wavelength λ of about ½ or more. When an antenna body having a wavelength λ of about ½ or more can be mounted, a waveguide structure such as a waveguide and a dielectric line can be easily realized. When the waveguide structure is used, the issues (1), (2), and (3) associated with broadcast and wireless communication apparatuses can be significantly alleviated.
• Theantenna member12 is connected to theamplifier208 of the electronic component #B, and is arranged on thecircuit board10 or in thecircuit board10. Theantenna member12 is configured to receive the electromagnetic wave S′ from within thecircuit board10. Theantenna member12 is also arranged in ahole portion10dformed in thecircuit board10. Therefore, the electromagnetic wave S′ transmitted from the electronic component #A can be shielded within the transmission region I defined by the throughhole fence portions10b. Moreover, theantenna member12 of the electronic component #B can receive the electromagnetic wave S′ shielded within the transmission region I.
• Subsequently, exemplary internal configurations of theamplifier204 of thesignal generation unit21 and theamplifier208 of thesignal generation unit22 will be explained.FIG. 3 is a circuit diagram illustrating the exemplary internal configuration of theamplifier204 and the like. In this embodiment, theamplifier204 shown inFIG. 3 is an amplification circuit which can be applied to thesignal generation units21,22 shown inFIG. 1, and includes three driver amplifiers AMP1 to AMP3 and a final amplifier AMP4, which are connected in series.
• The amplifier AMP1 includes two n-channel field effect transistors (hereinafter referred to as transistors FET1, FET2), a resistor R11, a coupling capacitor (hereinafter simply referred to as capacitor C11), two electrolytic capacitors (hereinafter simply referred to as capacitors C12, C13), a gate discharge capacitor (hereinafter simply referred to as capacitor C14), an input (load) inductance L12, and an output (load) inductance L13.
• One end of the capacitor C11 is connected to thefrequency converting circuit203. The millimeter wave signal S having been subjected to the frequency conversion is provided to the one end of the capacitor C11. The other end of the capacitor C11 is connected to a gate of the transistor FET1 and is also connected to one end of the inductance L12. The other end of the inductance L12 is connected to a gate voltage supply source Vg and is also connected to one end of the capacitor C12. The other end of the capacitor C12 and the source of the transistor FET1 are grounded.
• The drain of the transistor FET1 and the source of the transistor FET2 are connected. The drain of the transistor FET2 is connected to one end of the inductance L13. The other end of the inductance L13 is connected to Vdd power supply and one end of the capacitor C13, so that the drain voltage is provided to the drain of the transistor FET2. The other end of the capacitor C13 is grounded, so that the capacitor C13 accumulates charge.
• The resistor R11 is connected between the gate of the transistor FET2 and the Vdd power supply. The gate voltage divided by the resistor R11 is provided to the transistor FET2. The capacitor C14 is connected between the gate of the transistor FET2 and the ground, so that the capacitor C14 charges and discharges the gate voltage. The drain of the transistor FET2 is connected to one end of a coupling capacitor (hereinafter simply referred to as capacitor C21).
• The other end of the capacitor C21 is connected to the amplifier AMP2 of the subsequent stage. Likewise, the amplifier AMP2 includes two n-channel field effect transistors (hereinafter simply referred to as transistors FET3, FET4), a resistor R21, a capacitor C21, two electrolytic capacitors (hereinafter simply referred to as capacitors C22, C23), a gate discharge capacitor (hereinafter simply referred to as capacitor C24), an input (load) inductance L22, and an output (load) inductance L23.
• The other end of the capacitor C21 connected to the drain of the transistor FET2 in the previous stage is connected to the gate of the transistor FET3, and is also connected to one end of the inductance L22. The other end of the inductance L22 is connected to the gate voltage supply source Vg, and is also connected to one end of the capacitor C22. The other end of the capacitor C22 and the source of the transistor FET3 are grounded.
• The drain of the transistor FET3 is connected to the source of the transistor FET4. The drain of the transistor FET4 is connected to one end of the inductance L33. The other end of the inductance L33 is connected to the Vdd power supply and one end of the capacitor C33, so that the drain voltage is provided to the drain of the transistor FET4. The other end of the capacitor C23 is grounded, so that the capacitor C23 accumulates charge.
• The resistor R21 is connected between the gate of the transistor FET2 and the Vdd power supply. The gate voltage divided by the resistor R21 is provided to the transistor FET4. The capacitor C24 is connected between the gate of the transistor FET4 and the ground, so that the capacitor C24 charges and discharges the gate voltage. The drain of the transistor FET2 is connected to one end of a coupling capacitor (hereinafter simply referred to as capacitor C31).
• The other end of the capacitor C31 is connected to the amplifier AMP3 of the subsequent stage. Likewise, the amplifier AMP3 includes two n-channel field effect transistors (hereinafter simply referred to as transistors FET5, FET6), a resistor R31, a capacitor C31, two electrolytic capacitors (hereinafter simply referred to as capacitors C32, C33), a gate discharge capacitor (hereinafter simply referred to as capacitor C34), an input (load) inductance L32, and an output (load) inductance L33.
• The other end of the capacitor C31 connected to the drain of the transistor FET4 in the previous stage is connected to the gate of the transistor FET5, and is also connected to one end of the inductance L32. The other end of the inductance L32 is connected to the gate voltage supply source Vg, and is also connected to one end of the capacitor C32. The other end of the capacitor C32 and the source of the transistor FET5 are grounded.
• The drain of the transistor FET5 is connected to the source of the transistor FET6. The drain of the transistor FET6 is connected to one end of the inductance L33. The other end of the inductance L33 is connected to the Vdd power supply and one end of the capacitor C33, so that the drain voltage is provided to the drain of the transistor FET6. The other end of the capacitor C33 is grounded, so that the capacitor C33 accumulates charge.
• The resistor R31 is connected between the gate of the transistor FET6 and the Vdd power supply. The gate voltage divided by the resistor R31 is provided to the transistor FET6. The capacitor C34 is connected between the gate of the transistor FET6 and the ground, so that the capacitor C34 charges and discharges the gate voltage. The drain of the transistor FET6 is connected to one end of a coupling capacitor (hereinafter simply referred to as capacitor C41).
• The other end of the capacitor C41 is connected to the amplifier AMP4 of the final stage. The amplifier AMP4 includes an n-channel field effect transistor (hereinafter simply referred to as transistor FET7),capacitors41, C51, two electrolytic capacitors (hereinafter simply referred to as capacitors C42, C43), input (load) inductances L41, L42, an output (load) inductance L33, and a bias voltage generation inductance L44.
• The other end of the capacitor C41 connected to the drain of the transistor FETE in the previous stage is connected to the inductance L41. The other end of the inductance L41 is connected to the gate of the transistor FET7, and is also connected to one end of the inductance L42. The other end of the inductance L42 is connected to the gate voltage supply source Vg, and is also connected to one end of the capacitor C42. The source of the transistor FET7 is connected to one end of the inductance L44. The other end of the inductance L44 and the other end of the capacitor C42 are grounded.
• The drain of the transistor FET7 is connected to one end of the inductance L43. The other end of the inductance L43 is connected to the Vdd power supply and one end of the capacitor C43, so that the drain voltage is provided to the drain of the transistor FET7. The other end of the capacitor C43 is grounded, so that the capacitor C43 accumulates charge. The drain of the transistor FET7 is connected to one end of the capacitor C51. The other end of the capacitor C51 is connected to theantenna member11 and the like of the coupling circuit206 (seeFIG. 2B).
• Theamplifier204 is constituted by the above elements. Theamplifier204 uses the amplifiers AMP1 to AMP3 to successively amplify the millimeter wave signal S having been subjected to the frequency conversion, and is configured to transmit the amplified millimeter wave signal S from the final amplifier AMP4 to theantenna member11 and the like of thecoupling circuit205. Accordingly, the amplified millimeter wave signal can be transmitted via theantenna member11 and the like to one end of the tangible object (tangible object made of a dielectric material) having the predetermined dielectric constant ε.
• FIG. 4 is a frequency characteristic diagram illustrating example of bandpass characteristic Ia′ of theamplifier204. InFIG. 4, the vertical axis represents bandpass characteristic dB (S(2,1)) of theamplifier204, and the horizontal axis represents a carrier frequency (freq, GHz). The unit of the scale is 10 GHz.
• The example of bandpass characteristic Ia′ of theamplifier204 shown inFIG. 4 represents bandpass characteristic dB (S(2,1)) of the millimeter wave signal successively amplified by the three-stage driver amplifiers AMP1 to AMP3 and the final amplifier AMP4 of theamplifier204 shown inFIG. 3. When the carrier frequency is increased from 1 GHz to 100 GHz by 1 GHz, the bandpass characteristic dB (S(2,1)) of theamplifier204 indicates that the bandpass gain increases. According to an actual measurement result, the bandpass gain (gain) of the bandpass characteristic dB (S(2,1)) at a carrier frequency of 60 GHz is 21.764 dB as shown by S21 in the figure.
• Subsequently, two circuit boards, i.e., acircuit board10 made of Teflon (registered trademark) resin and acircuit board10 made of glass epoxy resin, are applied to the millimeterwave transmission device100, and the magnitudes of the losses and reflection characteristic thereof are compared based on a simulation using Agilent Advanced Design System (ADS).FIG. 5 is a simulation circuit diagram illustrating an example of a millimeter wave transmission in the millimeterwave transmission device100.
• In the simulation as shown inFIG. 5, the magnitude of the loss of thetransmission line206 and the result of examination of the reflection characteristic are compared between a case where thetransmission line206 is made as a microstrip line having a thickness t of 18 μm, a length L of 100 mm, and a width W of 170 μm formed on acircuit board10 made of glass epoxy resin having a thickness of 100 μm, and a case where thetransmission line206 is made as a microstrip line having the same thickness t, the same length L, and a width W of 170 μm+α formed on acircuit board10 made of Teflon (registered trademark) resin having a thickness of 100 μm. In the simulation, the output impedance of thecoupling circuit205 of the electronic circuit #A is set at characteristic impedance Zo=50Ω, and the input impedance of thecoupling circuit207 of the electronic circuit #B is set at characteristic impedance Zo=50Ω, and the carrier frequency is increased from 1 GHz to 100 GHz by 1 GHz.
• FIG. 6 is a frequency characteristic diagram illustrating an example of bandpass characteristic and an example of reflection characteristic of thetransmission line206 on thecircuit board10 made of Teflon (registered trademark) resin. Thecircuit board10 made of Teflon (registered trademark) resin is configured such that the dielectric loss tangent δ is 0.001 and thetransmission line206 is made with the microstrip line. δ is the loss angle of the dielectric material. InFIG. 6, the vertical axis represents bandpass characteristic dB (S(2,1)) and reflection characteristic dB (S(1,1)). The horizontal axis represents a carrier frequency (freq, GHz). The unit of the scale is 5 GHz.
• The example of bandpass characteristic Ia of thetransmission line206 shown inFIG. 6 is the bandpass characteristic dB (S(2,1)) of the electromagnetic wave S′ based on the millimeter wave signal S from the electronic circuit #A to the electronic circuit #B on thecircuit board10 made of Teflon (registered trademark) resin. When the carrier frequency is increased from 1 GHz to 100 GHz by 1 GHz, the bandpass characteristic dB (S(2,1)) of thetransmission line206 on thecircuit board10 made of Teflon (registered trademark) resin indicates that the loss hardly exists. According to the simulation result, the bandpass gain (gain) of the bandpass characteristic dB (S(2,1)) at a carrier frequency of 60 GHz (2 Gbps) is −5.150 dB as shown by ml in the figure.
• The example of reflection characteristic IIa shown inFIG. 6 is the reflection characteristic dB(S(1,1)) of the electromagnetic wave S′ based on the millimeter wave signal S reflected to the electronic circuit #A when the electronic circuit #B is seen from the electronic circuit #A on thecircuit board10 made of Teflon (registered trademark) resin. When the carrier frequency of thetransmission line206 on thecircuit board10 made of Teflon (registered trademark) resin is increased from 1 GHz to 100 GHz by 1 GHz, the example of reflection characteristic IIa appears to have a wave-shaped standing wave in the figure. As described above, thecircuit board10 made of Teflon (registered trademark) resin having a dielectric loss tangent δ of 0.001 has a small loss as shown by the example of bandpass characteristic Ia but is likely to cause the standing wave as shown in the example of reflection characteristic IIa.
• FIG. 7 is a frequency characteristic diagram illustrating an example of bandpass characteristic and an example of reflection characteristic of thetransmission line206 on thecircuit board10 made of glass epoxy resin. Thecircuit board10 made of glass epoxy resin used for an ordinary print circuit board is configured such that the dielectric loss tangent δ is, for example, 0.03, and thetransmission line206 is made with a microstrip line. δ is the loss angle of the dielectric material. InFIG. 7, the vertical axis also represents bandpass characteristic dB (S(2,1)) and reflection characteristic dB(S(1,1)). The horizontal axis represents a carrier frequency (freq, GHz). The unit of the scale is 10 GHz.
• The example of bandpass characteristic Ib shown inFIG. 7 is the bandpass characteristic dB (S(2,1)) of the electromagnetic wave S′ based on the millimeter wave signal S from the electronic circuit #A to the electronic circuit #B on thecircuit board10 made of glass epoxy resin. When the carrier frequency of the bandpass characteristic dB (S(2,1)) of thetransmission line206 on thecircuit board10 made of glass epoxy resin is increased from 1 GHz to 100 GHz by 1 GHz, the loss in this case is larger than the loss in the case of thecircuit board10 made of Teflon (registered trademark) resin. According to the simulation result, the bandpass gain (gain) at a carrier frequency of 60 GHz is −31.141 dB as shown by ml in the figure.
• The example of reflection characteristic IIb shown inFIG. 7 is the reflection characteristic dB(S(1,1)) of the electromagnetic wave S′ based on the millimeter wave signal S reflected to the electronic circuit #A when the electronic circuit #B is seen from the electronic circuit #A on thecircuit board10 made of glass epoxy resin. When the carrier frequency is increased from 1 GHz to 100 GHz by 1 GHz, the example of reflection characteristic IIb of thetransmission line206 on thecircuit board10 made of glass epoxy resin indicates that a reflected wave is attenuated and a standing wave is hardly generated in the figure. As described above, thecircuit board10 made of glass epoxy resin having a dielectric loss tangent δ of 0.03 is less likely to cause a standing wave as shown in the example of reflection characteristic IIb, and has a large loss as shown in the example of transmission loss characteristic Ib. Therefore, thecircuit board10 made of glass epoxy resin has not been used for signal transmission in the millimeter wave band in the past.
• However, in the following case, a sufficient signal strength, compared to thermal noise, can be obtained to execute communication processing in the millimeter wave circuit board. Thecircuit board10 has a large loss, i.e., a dielectric loss tangent of about 0.03, and the length L of thetransmission line206 is about 10 cm. The CMOS-IC device having thesignal generation unit21 for transmitting the millimeter wave signal and the CMOS-IC device having thesignal generation unit22 for receiving the millimeter wave signal are mounted on thecircuit board10.
• On the other hand, it is assumed that thetransmission line206 has a BHz-transmission band, a Boltzmann constant k, a temperature T, and a noise power P due to thermal noise. In such case, the noise power P is kTB, and the noise power per 1 GHz is −84 dBm in an RMS value. The RMS value can be obtained from an equivalent noise current and a thermal noise voltage of a resistor device obtained from a function of a measurement frequency band width, a temperature, and a resistor. For example, when theamplifiers204,208 having low noise in 60 GHz band are made with the CMOS-IC devices, theamplifiers204,208 can easily achieve a noise factor of about 6 dB. When thesignal generation unit22 for receiving the millimeter wave signal is actually made, and a margin of 10 dB is set, there is a noise floor of −84 dBm+10 dB+6 dB=−68 dB.
• It is easy to design theamplifiers204,208 with an output of 0 dBm at a carrier frequency of 60 GHz with the CMOS-IC devices. Therefore, even when the transmission loss of thetransmission line206 on thecircuit board10 made of glass epoxy resin as shown inFIG. 7 is 31 dB, the S/N ratio is (0 dBm−31 dB)−68 dB=37 dB, which is sufficient for communication when the length L of thetransmission line206 is about 10 cm.
• When this output of 0 dBm is controlled to achieve the minimal S/N ratio, interference with peripheral circuits (regions) can be reduced to the minimum. In a case where the dielectric loss tangent δ is large, e.g., a case where thecircuit board10 made of glass epoxy resin is used, the millimeter wave electromagnetic wave S′ propagating in thetransmission line206 formed on thecircuit board10 is attenuated by the circuit board. Therefore, interferences with other electronic components not related to the signal can be greatly reduced. In addition, the power consumption at the transmission side can also be reduced.
• When the carrier frequency is increased, the transmission loss increases but the reflected wave is attenuated in thistransmission line206 having a large loss. Therefore, a standing wave caused by the reflected wave is less likely to cause adverse effects. In this example, thefrequency converting circuit203 performs frequency conversion on the input signal Sin into the millimeter wave signal S, and thereafter, thefrequency converting circuit209 performs frequency conversion on the millimeter wave signal amplified by theamplifier208. Accordingly, a ratio of (signal band)/(center frequency) can be reduced. Therefore, it is easy to make thesignal generation unit21 for transmitting the millimeter wave signal and thesignal generation unit22 for receiving the millimeter wave signal.
• Subsequently, the millimeter wave transmission method will be explained.FIG. 8A is an operation flowchart illustrating an example of communication from the electronic component #A to the electronic component #B in the millimeterwave transmission device100. In this example, the millimeterwave transmission device100 for transmitting the millimeter wave to thecircuit board10 having the dielectric loss tangent δ (dielectric constant ε) includes the electronic component #A and the electronic component #B, which are made of CMOS-IC devices, mounted in the region (a) on thecircuit board10 made of glass epoxy resin as shown inFIG. 2, wherein the electronic component #A and the electronic component #B are joined by thetransmission line206 having a large loss.
• Using the above as the operation condition, in the electronic component #A of the millimeterwave transmission device100, the modulatingcircuit202 of thesignal generation unit21 performs phase modulation processing based on the input signal Sin in step ST11 of the flowchart shown inFIG. 8A in order to generate the millimeter wave signal S by processing the input signal Sin. The input signal Sin is provided to the terminal201 from a lower signal processing circuit, not shown.
• Subsequently, in step ST12, thefrequency converting circuit203 generates the millimeter wave signal S by performing frequency conversion on the input signal Sin phase-modulated by the modulatingcircuit202. Thereafter, in step ST13, theamplifier204 amplifies the millimeter wave signal S. Then, in step ST14, thecoupling circuit205 transmits the signal of the millimeter wave (millimeter wave having been subjected to the signal processing) amplified by theamplifier204 to one end of thetransmission line206 defined on thecircuit board10 having the dielectric loss tangent S. The electromagnetic wave S′ based on the millimeter wave signal S propagates through thetransmission line206.
• On the other hand, in the electronic component #B, thecoupling circuit207 receives the electromagnetic wave S′ based on the millimeter wave signal S from the other end of thetransmission line206 on thecircuit board10 having the dielectric loss tangent δ in step ST21 of the flowchart shown inFIG. 8A in order to generate the output signal Sout by receiving the electromagnetic wave S′ based on the millimeter wave signal S. Thereafter, in step ST22, theamplifier208 amplifies the millimeter wave signal. Then, in step ST23, thefrequency converting circuit208 performs frequency conversion on the millimeter wave signal S amplified by theamplifier208. Thereafter, in step ST24, thedemodulating circuit210 demodulates the output signal having been subjected to the frequency conversion. The demodulated output signal Sout is output from the terminal211 to a host signal processing circuit, not shown.
• As described above, according to the millimeterwave transmission device100 and the millimeter wave transmission method of the first embodiment, MOS-IC devices for performing frequency conversion on the input signal Sin into the signal in the millimeter wave band are mounted on thecircuit board10 constituted by the tangible object made of a dielectric material, and in the millimeterwave transmission device100, thesignal generation unit21 performs frequency conversion on the input signal Sin into the signal in the millimeter wave band, so that the electromagnetic wave S′ based on the millimeter wave signal S is transmitted to thetransmission line206 on thecircuit board10 having a large loss in the millimeter wave band.
• Preferably, the tangible object made of a dielectric material constituting thecircuit board10 does not have a small dielectric loss tangent δ but has a large dielectric loss tangent δ, so that thetransmission line206 has a large loss. As the carrier frequency increases, the transmission loss increases but the reflected wave is attenuated in thetransmission line206 having a large loss. Therefore, the signal can be transmitted at an extremely high speed via thecircuit board10 having the dielectric constant ε having a large loss. Moreover, when only a limited range of thecircuit board10 having the dielectric constant ε (in this example, thetransmission line206 made as the circuit board10) is used as a transmission path, fast communication processing can be performed. The attenuation increases in regions other than the limited range of thecircuit board10 having the dielectric constant ε, i.e., an example of tangible object made of a dielectric material, and this reduces interferences with locations of thecircuit board10 other than those for communication, i.e., regions other than the communication region of thecircuit board10 having the dielectric constant ε. In addition, because the loss of thecircuit board10 is large, interferences with components other than thecircuit board10 are reduced. Therefore, the high-speed signal transmission system which causes lower degree of interferences and reflections can be achieved.
• In particular, the mechanism of the first embodiment has a great deal of effect in that the signal transmission in the millimeter wave band can be achieved without any issue even when the system incorporates transmission/reception electronic components mounted on a circuit board made of glass epoxy resin and the like including a dielectric material having a not-so-small loss (dielectric loss tangent δ is medium to large) which can be easily obtained at low cost.
First Comparative Example
• FIGS. 8B to 8D are diagrams illustrating a first comparative example corresponding to the first embodiment. In this case,FIG. 8B is a block diagram illustrating an exemplary configuration of a high-speed baseband signal transmission apparatus according to the first comparative example.FIGS. 8C and 8D are diagrams each illustrating an example of transmission of a high-speed baseband signal.
• With the recent tremendous increase in the amount of information such as movie images and computer images, apparatuses transmitting baseband signals at a high speed are often used. These kinds of high-speed baseband signal transmission apparatuses need to transmit high-speed baseband signals such as millimeter waves without any error.
• For example, in a highfrequency transmission apparatus1 according to the first comparative example shown inFIG. 8B, a signaltransmission IC component2 and a signalreception IC component3 are mounted on a circuit board having a small dielectric material loss in order to reduce the transmission loss. TheIC component2 includes asignal input terminal101, awaveform formation unit102, and acoupling circuit103 for coupling with the circuit board.
• TheIC component3 includes acoupling circuit105 for coupling with the circuit board, awaveform formation unit106, and thesignal output terminal107. Atransmission line104 having a small loss is arranged between thecoupling circuit103 of theIC component2 and thecoupling circuit105 of theIC component3. For example, high-speed baseband signals for an enormous amount of information such as movie images and computer images are transmitted from theIC component2 to theIC component3.
• The “transmission line104 having a small loss” means that the dielectric loss tangent δ of the member forming the transmission line104 (in this example, circuit board) is smaller than the dielectric loss tangent δ of the dielectric material constituting thecircuit board10 used in the first embodiment.
• FIG. 8C illustrates a waveform diagram showing an example of transmission of a high-speed baseband signal.FIG. 8D illustrates a baseband spectrum (frequency characteristics). In the exemplary waveform as shown inFIG. 8C, the horizontal axis represents a time t, and the vertical axis represents an amplitude a. In the figure, Ts represents a symbol section. Where a temporal waveform of the baseband signal is defined as S(t), the temporal waveform S(t) is represented by the following expression (1).
• [Expression 1]

  
• The temporal waveform S(t) of the expression (1) is defined by the expression (2) using a Fourier transform pair.
• [Expression 2]

  
• In the base spectrum shown inFIG. 8D, the horizontal axis represents a frequency t, and the vertical axis represents an amplitude. The frequency characteristic of the temporal waveform S(t) is represented by the expression (3).
• [Expression 3]

  
• In the figure, Fs represents a symbol frequency. The signaltransmission IC component2 transmits at least a signal of 0 Hz to (½)·(1/Ts) Hz to theIC component3 so as to avoid intersymbol interference in the signal reception IC component3 (Nyquist stability theorem). For example, when binary data are transmitted from theIC component2 to theIC component3 with a transmission data rate of 10 Gbps, the symbol frequency Fs is given as 1/Ts, and therefore, Fs is 10 GHz.
• In the baseband signal transmission, a signal of 0 Hz to (½)·(10 GHz), i.e., 0 Hz to 5 GHz, is transmitted to avoid intersymbol interference. In this case, where the signal of 0 Hz has an infinite wavelength λ, and the light speed in vacuum c is 3×108 m/s, the wavelength λ of the signal of 5 GHz is given as c/Fs. Therefore, λ is 3×108/5×109=6 cm. The highfrequency transmission apparatus1 can accept a wide range of wavelength λ, and is configured to transmit a high-speed baseband signal.
• As the signal processing speed on the circuit board increases, the following issues are expected when the highfrequency transmission apparatus1 according to the first comparative example and the signal transmission technique for millimeter wave band are applied to make a high-speed millimeter wave signal transmission system on the circuit board or in the circuit board so as to reduce the interference.
• i. According to the highfrequency transmission apparatus1 of the first comparative example, the signaltransmission IC component2 and the signalreception IC component3 should be mounted on the circuit board having a small dielectric material loss in order to reduce the transmission loss. Therefore, there is an issue in that the circuit board having a small dielectric material loss is peculiar and expensive.
• ii. It appears that signals on circuit boards are transmitted at a higher speed than ever before. Accordingly, signals generated by theIC components2 and the like on the circuit board are expected to interfere with each other. Therefore, it is becoming difficult to transmit high-speed baseband signals such as a millimeter wave from theIC component2 to theIC component3 without any error.
• According to the example of transmission of binary data of 10 Gbps shown inFIGS. 8C and 8D, it is not easy, in terms of mechanical design and electric design, to reduce electric resonance and reflection and structural resonance in units of multiples of ½ wavelength, throughout the wavelength from the infinite wavelength (0 Hz) to 6 cm (5 GHz). In this issue, the higher the transmission data rate, the more difficult the design thereof. Therefore, it is difficult to design a circuit board processing a high-speed signal.
• iii. As the amount of information such as movie images and computer images increases, the bandwidth of the baseband signal becomes wider. Therefore, there are issues not only in (1) spurious emission to the outside of the circuit board but also in (2) transmission error caused by interference between symbols at the reception side when there is a reflection and (3) transmission error caused by intrusive interference.
• In general, the spurious emission in the baseband signal band is caused not only by a limitation of a noise floor due to thermal noise but also by various kinds of signal interference sources other than the transmission signal. Examples of primary causes of spurious emissions include interference caused by a clock signal of a CPU, interference with broadcast, communication, and the like, interference signal such as surge caused by a noise discharge of a motor, and reflection caused by impedance mismatch on a signal line (transmission line). When there are resonance and reflection, the resonance and the reflection are likely to cause radiation, which results in a serious issue of Electro-Magnetic Interference (EMI).
• v. Further, when a new millimeter wave signal transmission apparatus according to a new intra-tangible object transmission method is made in view of a dielectric waveguide line as shown inPTL1 and a wireless millimeter wave communication system as shown inPTL2, it is difficult to achieve a high-speed communication processing in a limited range of a dielectric waveguide line and reduce interference with regions other than the limited range of the dielectric waveguide line, by simply combining a dielectric waveguide line having a small loss and a millimeter wave communication system having a transmission/reception function of a millimeter wave signal without devising any new idea.
• vi. In a dielectric waveguide line in which transmission loss does not increase according to increase of a carrier frequency, a reflected wave tends to increase. When this reflected wave is reduced, the structure of the dielectric waveguide line becomes more complicated.
• [Comparison Between First Comparative Example and First Embodiment]
• FIG. 9 is a diagram illustrating effects of millimeter wave transmission of the millimeterwave transmission device100 according to the first embodiment, as compared with the first comparative example. In this case, the highfrequency transmission apparatus1 according to the first comparative example does not transmit a high-speed data band signal. Instead, the high-speed baseband signal is frequency-converted into the millimeter wave signal S by the millimeterwave transmission device100 according to the first embodiment and the millimeter wave signal S is transmitted. Advantages of this configuration will be hereinafter explained.
• FIG. 9A is a waveform diagram illustrating an example of transmission of the signal S in the millimeter wave band after the frequency conversion.FIG. 9B is a spectrum (frequency characteristics) of the signal S in the millimeter wave band.
• In the exemplary waveform shown inFIG. 9A, the horizontal axis represents a time t, and the vertical axis represents an amplitude a. S represents a signal waveform in the millimeter wave band after the frequency conversion. In the spectrum of the signal S in the millimeter wave band shown inFIG. 9B, the horizontal axis represents a frequency t, and the vertical axis represents an amplitude. In the figure, Fs represents a symbol frequency. In the figure, Fs is 10 GHz.
• In this example, the highfrequency transmission apparatus1 according to the first comparative example and the millimeterwave transmission device100 according to the first embodiment are compared when exemplary transmission of binary data is carried out at a transmission data rate of 10 Gbps. As explained inFIG. 8D, according to the highfrequency transmission apparatus1, structures such as an antenna and electronics can be designed while attention is given to a wavelength λ from the infinite wavelength (0 Hz) to 6 cm (5 GHz) with the binary data serving as the baseband.
• In contrast, in the millimeterwave transmission device100 according to the first embodiment, binary data are frequency-converted into the millimeter wave band, and the millimeter wave signal is transmitted from the electronic component #A to the electronic component #B. For example, when a center frequency F0 is set at 60 GHz, a signal S ranging from a symbol frequency Fs of 55 GHz ((=60 GHz−(Fs/2)) to a symbol frequency Fs of 65 GHz (=60 GHz+(Fs/2)) is transmitted in order to perform transmission without any intersymbol interference according to Nyquist stability theorem.
• Where the light speed in vacuum c is 3×108 m/s, and Fs is 55 GHz, the wavelength λ in vacuum is obtained as follows: c/Fs=3×108/55×109≈5.5 mm. When Fs is 65 GHz, it is obtained as follows: 3×108/65×109=4.6 mm. Therefore, according to the millimeterwave transmission device100, structures such as an antenna and electronics can be designed with attention given to a wavelength λ from 4.6 mm to 5.5 mm. Therefore, it is easier to handle the millimeterwave transmission device100 than the highfrequency transmission apparatus1.
• As described above, according to the first embodiment, the millimeter wave transmission system can be structured between the electronic component #A and the electronic component #B. When the communication distance between the electronic component #A and the electronic component #B is short, theamplifier208 at the reception side and theamplifier204 at the providing side shown inFIG. 1 may be omitted.
Second Embodiment
• Subsequently, a millimeterwave transmission system200 serving as the second embodiment will be explained with reference toFIGS. 10 to 12A.FIG. 10 is a block diagram illustrating an exemplary configuration of the millimeterwave transmission system200 according to the second embodiment. The millimeterwave transmission system200 shown inFIG. 10 includes a millimeterwave transmission device100aconstituting an example of a first millimeter wave transmission body and a millimeterwave transmission device100bconstituting an example of a second millimeter wave transmission body.
• The millimeterwave transmission device100aincludes an electronic component #A and an electronic component #B. The explanation about the millimeterwave transmission device100ais omitted since the millimeterwave transmission device100 explained in the first embodiment is used. The millimeterwave transmission device100bincludes an electronic component #C and an electronic component #D. The millimeterwave transmission system200 shown inFIG. 10 is configured as a system such that an electromagnetic wave S′ based on the millimeter wave signal S is transmitted from the electronic component #A to the electronic component #B, and an electromagnetic wave S′ based on the millimeter wave signal S is transmitted from the electronic component # C to the electronic component #D located at separate, independent locations on thesame circuit board10.
• The millimeterwave transmission device100bincludes a thirdsignal generation unit23 and asignal input terminal221 constituting the signal transmission electronic component #C, acoupling circuit225 for coupling with thecircuit board10, atransmission line226 using a tangible object made of a dielectric material (such as a circuit board), acoupling circuit227 for coupling with thecircuit board10, a fourthsignal generation unit24 and asignal output terminal231 constituting the signal reception electronic component #D.
• Thesignal generation unit23 and thesignal generation unit24 are respectively provided as the millimeter wave communication electronic components #A, #B constituted by CMOS-IC devices, i.e., examples of semiconductor integrated circuits. The electronic component #A and the electronic component #B are mounted on thecircuit board10 having the dielectric constant ε. The electronic components #A, #B may not be necessarily arranged on the same surface of thesame circuit board10. Alternatively, the electronic components #A, #B may be arranged on surfaces different from each other (i.e., on the front surface and the back surface, respectively).
• The thirdsignal generation unit23 connected to thesignal input terminal221 includes, for example, a modulatingcircuit222, afrequency converting circuit223, and anamplifier224, in order to generate a millimeter wave signal S by processing an input signal Sin. Thesignal input terminal221 is connected to the modulatingcircuit222, so that the input signal Sin is modulated. Like the millimeterwave transmission device100a, the modulatingcircuit222 uses, for example, a phase modulating circuit. Alternatively, the modulatingcircuit222 as well as thefrequency converting circuit223 may use a so-called direct conversion method.
• The modulatingcircuit222 is connected to thefrequency converting circuit223. Accordingly, the input signal Sin modulated by the modulatingcircuit222 is converted into a frequency in a range of 30 GHz to 300 GHz, so that the millimeter wave signal S is generated. Thefrequency converting circuit223 is connected to theamplifier224. Accordingly, after the millimeter wave signal S is subjected to frequency conversion, the signal S is amplified.
• Theamplifier224 is connected to thecoupling circuit225 constituting an example of a third signal coupling unit. Theamplifier224 transmits the millimeter wave signal generated by thesignal generation unit23 to an end of a tangible object (tangible object made of a dielectric material) having a predetermined dielectric constant ε. Thecoupling circuit225 is constituted by an antenna member having a predetermined length based on a wavelength λ of the millimeter wave signal S, i.e., about 600 μm, and is coupled to the tangible object having the dielectric constant ε. In this embodiment, a region of thecircuit board10 having the dielectric constant ε is also used for the tangible object. The region of thecircuit board10 having the dielectric constant ε constitutes thetransmission line226. Accordingly, a millimeter wave electromagnetic wave S′ propagates in thetransmission line226. When a dielectric loss tangent δ is large, thetransmission line226 has a relatively large loss, which also reduces the reflection. Therefore, a large dielectric loss tangent δ is preferable than a small dielectric loss tangent S.
• Thetransmission line226 is connected to thecoupling circuit227 constituting an example of a fourth signal coupling unit. Thetransmission line226 receives an electromagnetic wave S′ based on the millimeter wave signal S from the other end of thetransmission line226. Thecoupling circuit227 is constituted by an antenna member having a predetermined length based on the wavelength λ of the millimeter wave signal S, i.e., about 600 μm. Like the first embodiment, the antenna member is, for example, a probe antenna (dipole), a loop antenna, and a small aperture-coupled device (such as slot antenna).
• Thecoupling circuit227 is connected to the fourthsignal generation unit24. The fourthsignal generation unit24 processes the electromagnetic wave S′ based on the millimeter wave signal S received by thecoupling circuit227. More particularly, the fourthsignal generation unit24 demodulates the electromagnetic wave S′. Thereby, the fourthsignal generation unit24 generates an output signal Sout corresponding to the input signal Sin to be transmitted and processed by the electronic component #C. Thesignal generation unit24 includes, for example, anamplifier228, afrequency converting circuit229, and ademodulating circuit230. Alternatively, thefrequency converting circuit229 as well as thedemodulating circuit230 may use a so-called direct conversion method. Thecoupling circuit227 is connected to theamplifier228, so that theamplifier228 can amplify the received millimeter wave signal.
• Theamplifier228 is connected to thefrequency converting circuit229. Thefrequency converting circuit229 converts the frequency of the amplified millimeter wave signal S. Thefrequency converting circuit229 is connected to thedemodulating circuit230. Thedemodulating circuit230 demodulates the output signal having been subjected to the frequency conversion.
• In this example, thesignal generation unit23 and thesignal generation unit24 are also respectively provided as the millimeter wave communication electronic components #C, #D constituted by CMOS-IC devices, i.e., examples of semiconductor integrated circuits. The electronic component #C and the electronic component #D as well as the electronic component #A and the electronic component #B constituting the millimeterwave transmission device100aare mounted on thecircuit board10 having the dielectric constant ε. The electronic components #C, #D may not be necessarily arranged on the same surface of thesame circuit board10. Alternatively, the electronic components #C, #D may be arranged on surfaces different from each other (i.e., on the front surface and the back surface, respectively).
• Although not shown in the figure, thecircuit board10 may be arranged not only with the millimeter wave communication electronic components #A, #B, #C, #D but also with passive elements such as resistor devices, capacitor devices, and transformers, and active elements such as transistors and semiconductor integrated circuits, which are used for signal processing in a baseband region.
• For example, electronic components (passive elements and active elements) used for signal processing in a baseband region can be mounted in a space between the electronic components #A, #B on thecircuit board10 regardless of the sizes of the components (seeFIG. 12A explained below). Likewise, thetransmission line226 is formed within thecircuit board10 in such a manner that thetransmission line226 is formed between a third region of thecircuit board10 including the electronic component #C including thecoupling circuit225 constituting an example of the third signal coupling unit and the thirdsignal generation unit23 and a fourth region of thecircuit board10 including the electronic component #D including thecoupling circuit227 constituting an example of the fourth signal coupling unit and the fourthsignal generation unit24. Therefore, it is not necessary to consider the millimeter wave transmission therebetween on thecircuit board10. Therefore, for example, electronic components (passive elements and active elements) used for signal processing in a baseband region can be mounted in a space between the electronic components #C, #D on thecircuit board10 regardless of the sizes of the components (seeFIG. 12A explained below).
• As can be understood from the explanation above, the millimeterwave transmission system200 according to the second embodiment includes the millimeterwave transmission device100aand the millimeterwave transmission device100b, which are mounted on thesame circuit board10. In this case, a space therebetween and a region of thecircuit board10 form acoupling medium243 between thetransmission line206 of the millimeterwave transmission device100aand thetransmission line226 of the millimeterwave transmission device100b. Therefore, interference (communication interference) may occur between the millimeterwave transmission device100aand the millimeterwave transmission device100b.
• However, when the dielectric loss tangent δ of thecircuit board10 is not small (i.e., large), a large loss in thecircuit board10 can reduce the leak of the millimeter wave from thetransmission line206 of the millimeterwave transmission device100avia thecoupling medium243 to thetransmission line226 of the millimeterwave transmission device100b. In this case, it is considered that the coupling state via thecoupling medium243 formed in the space therebetween is small. Therefore, when the dielectric loss tangent δ of thecircuit board10 is not small (i.e., large) in the second embodiment, it is possible to significantly reduce the interference caused by the millimeter wave.
• In addition, according to the mechanism of the second embodiment, the millimeterwave transmission device100aand the millimeterwave transmission device100bmounted on thesame circuit board10 are arranged spaced apart by a certain distance, and it is not necessary to consider the millimeter wave transmission in a free section in the space therebetween. Therefore, for example, passive elements (such as resistor devices, capacitor devices, and transformers) and active elements (such as transistors and semiconductor integrated circuits), which are used for signal processing in a baseband region, can be mounted in the space between the millimeterwave transmission devices100a,100bregardless of the sizes of the components (seeFIG. 12A explained below).
• FIG. 11 is a top view illustrating an exemplary arrangement of four electronic components #A, #B, #C, #D in the millimeterwave transmission system200. Two regions (α) and (β) are allocated on thecircuit board10 shown inFIG. 11. In the region (α), the electronic component #A and the electronic component #B are arranged spaced apart in the longitudinal direction by a predetermined distance, i.e., about several millimeters to several dozen centimeters.
• In the region (β) shown in the figure, the electronic component #C and the electronic component #D are arranged spaced apart in the longitudinal direction by a predetermined separating distance L, i.e., about several millimeters to several dozen centimeters. An arrangement gap Lab between the electronic component #A of the region (α) and the electronic component #C of the region (β) is set at a value about three times larger than the separating distance L in the longitudinal direction. The electronic component #A is arranged in the region (α), and the electronic component #C is arranged in the region (β) in a lateral direction thereto. Further, an arrangement gap between the electronic component #B of the region (α) and the electronic component #D of the region (β) is also set at a value about three times larger than the separating distance L in the longitudinal direction, and the electronic component #B and the electronic component #D are arranged in the lateral direction. As described above, when they are arranged spaced apart by the gap about three times larger than the separating distance L, even if the electromagnetic wave S′ based on the millimeter wave signal S leaks from the line between the electronic components #A, #B to the line between the electronic components #C, #D, the leak can be attenuated while it propagates.
• In the millimeterwave transmission system200 as described above, it is possible to reduce the coupling state via thecoupling medium243 such as the inside of thecircuit board10 having a large loss and the space thereof. Compared with a circuit board having a small loss, it is possible to greatly improve isolation between the electronic components #A, #B and between the electronic components #C, #D during communication therebetween.
• Although not shown inFIG. 11, electronic components (passive elements and active elements), used for signal processing in a baseband region, can be mounted between the electronic component #A of the region (α) and the electronic component #C of the region (β) as shown inFIG. 12A explained later.
• FIG. 12A is a perspective view illustrating an exemplary implementation oftransmission lines206,226 and the electronic components #A, #B, #C, #D in the millimeterwave transmission system200. In the millimeterwave transmission device100ashown inFIG. 12A, the signal transmission electronic component #A and the signal reception electronic component #B are mounted in the region (α), so that the millimeter wave signal is transmitted from the electronic component #A to the electronic component #B.
• In this millimeterwave transmission device100a, the electronic component #A includes asignal generation unit21, acoupling circuit205, and asignal input terminal201 shown inFIG. 10, and the electronic component #B includes acoupling circuit207, asignal generation unit22, and asignal output terminal211. The electronic component #A and the electronic component #B are mounted on thecircuit board10 having the dielectric constant ε. In this example, a throughhole fence portion10bmay also be arranged to define the region (α) (SeeFIG. 2A).
• Thetransmission line206 is arranged between the electronic component #A and the electronic component #B on thecircuit board10. As shown inFIG. 2A, thetransmission line206 is constituted by a transmission region I defined in thecircuit board10 made of glass epoxy resin and having a large loss, which includes the electronic component #A and the electronic component #B. Although not shown inFIG. 12A, for example, thetransmission line206 is defined by a plurality of throughholes10apenetrating thecircuit board10 in this example (seeFIG. 2A). The above method for making thetransmission line206 is merely an example.
• In this millimeterwave transmission device100b, the electronic component #C includes asignal input terminal221, asignal generation unit23, and acoupling circuit225 shown inFIG. 10, and the electronic component #D includes acoupling circuit227, asignal generation unit24, and asignal output terminal231. Like the electronic component #A and the electronic component #B, the electronic component #C and the electronic component #D are mounted on thesame circuit board10 having the dielectric constant ε. In this example, a throughhole fence portion10bmay also be arranged to define the region (β) (SeeFIG. 2A).
• Thetransmission line226 is arranged between the electronic component #C and the electronic component #D on thecircuit board10. As shown inFIG. 2A, thetransmission line226 is constituted by a transmission region I defined in thecircuit board10 made of glass epoxy resin and having a large loss, which includes the electronic component #C and the electronic component #D mounted thereon. Although not shown inFIG. 12A, for example, thetransmission line226 is defined by a plurality of throughholes10apenetrating thecircuit board10 in this example (seeFIG. 2A). The above method for making thetransmission line226 is merely an example.
• Passive elements such asresistor devices280,capacitor devices282, andtransformers284 and active elements such astransistors290 and semiconductor integratedcircuits292, which are used for signal processing in a baseband region, are mounted in the space between the region (α) including the millimeterwave transmission device100aand the region (β) including the millimeterwave transmission device100bmounted on thesame circuit board10.
• As described above, according to the millimeterwave transmission system200 of the second embodiment, the millimeterwave transmission device100aand the millimeterwave transmission device100bare arranged on thesame circuit board10 made of glass epoxy resin having a large loss. In the region (α), the electromagnetic wave S′ based on the millimeter wave signal S is transmitted from the electronic component #A to the electronic component #B. In the region (β) located at separate, independent location on thesame circuit board10, the electromagnetic wave S′ based on the millimeter wave signal S is transmitted from the electronic component #C to the electronic component #D.
• Therefore, even when the setting of the carrier frequency from the electronic component #A to the electronic component #B in the region (α) and the setting of the carrier frequency from the electronic component #C to the electronic component #D in the region (β) are the same on thesame circuit board10 by making use of the loss of thecircuit board10, the issue of the communication interferences between the regions (α), (β) does not occur. Therefore, it is easy to reuse the carrier frequency.
Second Comparative Example
• FIG. 12B is a figure illustrating a second comparative example corresponding to the second embodiment.FIG. 12B is a block diagram illustrating an exemplary configuration of a high-speed baseband signal transmission system according to the second comparative example.
• A highfrequency transmission system20 according to the second comparative example includes a plurality of highfrequency transmission apparatuses1 according to the first comparative example shown inFIG. 8B on the same circuit board. In other words, the highfrequency transmission system20 according to the second comparative example includes the highfrequency transmission apparatus1 according to the first comparative example shown inFIG. 8B and another highfrequency transmission apparatus6 having the same functions as the highfrequency transmission apparatus1, wherein the highfrequency transmission apparatus1 and the highfrequency transmission apparatus6 are mounted on the same circuit board.
• AnIC component4 includes asignal input terminal111, awaveform formation unit112, and acoupling circuit113 for coupling with the circuit board. AnIC component5 includes acoupling circuit115 for coupling with the circuit board, awaveform formation unit116, and asignal output terminal117. Atransmission line114 having a small loss is arranged between thecoupling circuit113 of theIC component4 and thecoupling circuit115 of theIC component5. For example, high-speed baseband signals for an enormous amount of information such as movie images and computer images are transmitted from theIC component4 to theIC component5 independently from the highfrequency transmission apparatus1.
• The “transmission line114 having a small loss” means that a dielectric loss tangent δ of the member forming the transmission line114 (in this example, circuit board) is smaller than the dielectric loss tangent δ of the dielectric material constituting thecircuit board10 used in the first embodiment.
• As can be understood from the explanation above, the highfrequency transmission system20 according to the second comparative example includes the highfrequency transmission apparatus1 and a high-speed basebandsignal transmission apparatus2, which are mounted on the same circuit board having a small loss. In this case, a space therebetween and a region of the circuit board having a small loss form acoupling medium143 between thetransmission line104 of the highfrequency transmission apparatus1 and thetransmission line114 of the high-speed basebandsignal transmission apparatus2. Therefore, interference (communication interference) occurs between the high-speed baseband signal transmission apparatuses, when the plurality of high-speed baseband signal transmission apparatuses are mounted on the same circuit board having a small loss.
• Thetransmission line104 and thetransmission line114 are coupled via a free space and within the circuit board having a small loss. When a low frequency signal is transmitted, the loss of the free space is small, and the dielectric material loss makes little influence. A transmission loss in free space is proportional to a square of a frequency. However, on the side of theIC component4, theIC component5, and the like on the circuit board on which thetransmission line114 having a small loss is mounted, thetransmission line114 is easily affected by the interference caused by thetransmission line104, i.e., the interference caused by the signal transmitted from theIC component2. Moreover, interference caused by a baseband signal having a low frequency is less likely to be attenuated, which is also a cause of transmission error. As described above, in the second comparative example, the high-speed baseband signal has issues of reflection, interference, a large fractional bandwidth (=necessary bandwidth/operation center frequency).
• In contrast, the mechanism of the second embodiment is configured such that, preferably, the tangible object made of a dielectric material for making thecircuit board10 is not a material having a small dielectric loss tangent δ but is a material having a large dielectric loss tangent δ, so that thecoupling medium243 has a large loss. Therefore, even when the plurality of millimeterwave transmission devices100 are mounted on the same circuit board, the high-speed signal transmission system which causes lower degree of interferences and reflections can be realized.
Third Embodiment
• Subsequently, a millimeterwave transmission system300 serving as the third embodiment will be explained with reference toFIGS. 13 to 15. Elements having the same names as those of the first and second embodiments have the same functions, and therefore, description thereabout is omitted.
• FIG. 13 is a block diagram illustrating an exemplary configuration of the millimeterwave transmission system300 according to the second embodiment. In this embodiment, a plurality of millimeterwave transmission devices100 are arranged on the same circuit board, and are further coupled with a coupling medium transmitting a millimeter wave signal, so that an electromagnetic wave S′ based on the millimeter wave signal S is propagated.
• The millimeterwave transmission system300 shown inFIG. 13 includes a millimeterwave transmission device100cand a millimeter wave transmission device100dwhich are arranged on the same plane of thecircuit board10, and includes a low-loss waveguide structure341 constituting an example of a coupling medium, wherein thewaveguide structure341 is formed on a layer different from thecircuit board10 or the same layer. The millimeterwave transmission device100cand the millimeter wave transmission device100dare connected by a waveguide, for example (seeFIG. 15). Members such as the millimeterwave transmission devices100c,100dand the waveguide connecting therebetween are arranged in the same electronic apparatus.
• The “low-loss waveguide structure341” means that the dielectric loss tangent δ of the member forming the waveguide formed with the waveguide structure341 (including air when it is free space) is smaller than the dielectric loss tangent δ of the dielectric material constituting thecircuit board10 used in the third embodiment.
• The millimeterwave transmission device100cincludes the electronic component #A and the electronic component #B on thecircuit board10 having the dielectric constant ε. The signal transmission electronic component #A of the millimeterwave transmission device100cincludes asignal generation unit25, asignal input terminal301, and acoupling circuit305 for coupling with thecircuit board10. On thecircuit board10, atransmission line306 having a large loss is structured. Thesignal generation unit25 includes a modulatingcircuit302, afrequency converting circuit303, and anamplifier304.
• The signal reception electronic component #B includes acoupling circuit307 for coupling with thecircuit board10, asignal generation unit26, and asignal output terminal311. Thesignal generation unit26 includes anamplifier308, afrequency converting circuit309, and ademodulating circuit310. Thesignal generation unit25 and thesignal generation unit26 are constituted by CMOS-IC devices, i.e., examples of semiconductor integrated circuits.
• The millimeter wave transmission device100dincludes the electronic component #C and the electronic component #D on thecircuit board10 having a dielectric constant ε. The signal transmission electronic component #C includes asignal input terminal321, asignal generation unit27, and acoupling circuit325 for coupling with thecircuit board10. Thesignal generation unit27 includes a modulatingcircuit322, afrequency converting circuit323, and anamplifier324.
• Preferably, the tangible object made of a dielectric material for making thecircuit board10 is not a material having a small dielectric loss tangent δ but is a material having a large dielectric loss tangent δ (such as glass epoxy resin), so that thetransmission lines306,326 have large losses.
• The signal reception electronic component #D includes acoupling circuit327 for coupling with thecircuit board10, asignal generation unit28, and asignal output terminal331. Thesignal generation unit28 includes anamplifier328, afrequency converting circuit329, and ademodulating circuit330. Thesignal generation unit27 and thesignal generation unit28 are constituted by CMOS-IC devices, i.e., examples of semiconductor integrated circuits.
• The low-loss waveguide structure341 is made with, e.g., a waveguide. The low-loss waveguide structure341 is configured to connect between thecoupling circuit305 arranged at the side of the electronic component #A for coupling with thecircuit board10 and thecoupling circuit327 arranged at the side of the electronic component #D for coupling with thecircuit board10.
• As described above, the millimeterwave transmission system300 shown inFIG. 13 is configured as a system in which the electromagnetic wave S′ based on the millimeter wave signal S is transmitted from the electronic component #A to the electronic component #B, and the electromagnetic wave S′ based on the millimeter wave signal S is transmitted from the electronic component #C to the electronic component #D located at separate, independent locations on thesame circuit board10. Further, the electromagnetic wave S′ based on the millimeter wave signal S can be transmitted from the electronic component #A to the electronic component #D via the low-loss waveguide structure341.
• FIG. 14 is a top view illustrating an exemplary arrangement of awaveguide structure341 and the four electronic components #A, #B, #C, #D in the millimeterwave transmission system300. Two regions (α) and (β) are allocated on thecircuit board10 having a large loss as shown inFIG. 14. Like the second embodiment, in the region (α), the electronic component #A and the electronic component #B are arranged spaced apart in the longitudinal direction by a predetermined distance, i.e., about several millimeters to several dozen centimeters.
• Like the second embodiment, in the region (β) shown in the figure, the electronic component #C and the electronic component #D are arranged spaced apart in the longitudinal direction by a predetermined separating distance L, i.e., about several millimeters to several dozen centimeters. An arrangement gap Lab between the electronic component #A of the region (α) and the electronic component #C of the region (β) is set at a value about three times larger than the separating distance L in the longitudinal direction. The electronic component #A is arranged in the region (a), and the electronic component #C is arranged in the region (β) in a lateral direction thereto. Further, an arrangement gap between the electronic component #B of the region (α) and the electronic component #D of the region (β) is also set at a value about three times larger than the separating distance L in the longitudinal direction, and the electronic component #B and the electronic component #D are arranged in the lateral direction.
• Thewaveguide structure341 constitutes an example of the coupling medium, and is a layer different from thecircuit board10 having a large loss. Two regions (α) and (β) are arranged so that the waveguide links the two regions (α) and (β). The waveguide is a metal pipe or a conductive resin pipe having a space therein. The free space of the waveguide has a dielectric constant ε0 to propagate the electromagnetic wave S′ based on the millimeter wave signal S. ε0 is a dielectric constant in vacuum. ε0 is 8.854187817×10̂(−12) (F/m). Preferably the waveguide portion of thewaveguide structure341 is made with a material having a smaller (different) loss than the material of thecircuit board10 having a large loss in the millimeter wave band. As described above, the millimeterwave transmission system300 is configured as a system in which the electromagnetic wave S′ based on the millimeter wave signal S can be transmitted from the electronic component #A of the region (α) to the electronic component #D of the region (β) via the low-loss waveguide structure341. It is to be understood that thewaveguide structure341 may not be made of a hollow waveguide having a metal wall. Where the relative permittivity is εr, thewaveguide structure341 may be made of a dielectric material line having a dielectric constant ε=ε0·εr.
• FIG. 15 is a perspective view illustrating an exemplary implementation of thewaveguide structure341, thetransmission lines306,326, and the electronic components #A, #B, #C, #D, in the millimeterwave transmission system300. In the millimeterwave transmission system300 shown inFIG. 15, the millimeterwave transmission device100cincludes the signal transmission electronic component #A and the signal reception electronic component #B mounted in the region (α), so that the millimeter wave signal is transmitted from the electronic component #A to the electronic component #B.
• In this millimeterwave transmission device100c, the electronic component #A includes asignal input terminal301, asignal generation unit25, and acoupling circuit305 shown inFIG. 13, and the electronic component #B includes acoupling circuit307, asignal generation unit26, and asignal output terminal311. The electronic component #A and the electronic component #B are mounted on thecircuit board10 having the dielectric constant ε. Also in this example, through ahole fence portion10bmay be arranged to define the region (α) (SeeFIG. 2A).
• Thetransmission line306 is arranged between the electronic component #A and the electronic component #B on thecircuit board10. As shown inFIG. 2A, thetransmission line306 is constituted by a transmission region I defined in thecircuit board10 made of glass epoxy resin and having a large loss, which includes the electronic component #A and the electronic component #B mounted thereon. Although not shown inFIG. 15, thetransmission line306 is defined by a plurality of throughholes10apenetrating thecircuit board10 in this example (seeFIG. 2A).
• In the millimeter wave transmission device100d, the electronic component #C includes asignal input terminal321, asignal generation unit27, and acoupling circuit325 shown inFIG. 13, and the electronic component #D includes acoupling circuit327, asignal generation unit28, and asignal output terminal331. Like the electronic component #A and the electronic component #B, the electronic component #C and the electronic component #D are mounted on thesame circuit board10 having the dielectric constant ε. Also in this example, a throughhole fence portion10bmay be arranged to define the region (β) (SeeFIG. 2A).
• Thetransmission line326 is arranged between the electronic component #C and the electronic component #D on thecircuit board10. As shown inFIG. 2A, thetransmission line326 is constituted by a transmission region I defined in thesame circuit board10 made of glass epoxy resin and having a large loss, which includes the electronic component #C and the electronic component #D mounted thereon. Although not shown inFIG. 15, for example, thetransmission line326 is defined by a plurality of throughholes10apenetrating thecircuit board10 in this example (seeFIG. 2A). The throughhole10amay be a contact hole filled with conductive material for electrically connecting an upper conductive layer and a lower conductive layer. The contact hole filled with conductive material constitutes an example of a plurality of cylindrical conductive members for connecting conductive layers.
• Further, the low-loss waveguide structure341 is arranged between the electronic component #A and the electronic component #D on thecircuit board10.
• As described above, according to the millimeterwave transmission system300 of the third embodiment, the low-loss waveguide structure341 is arranged between the electronic component #A of the region (α) and the electronic component #D of the region (β) shown inFIG. 15, and the electromagnetic wave S′ based on the millimeter wave signal S is propagated through thewaveguide structure341 from the electronic component #A to the electronic component #D. Therefore, interference between the region (α) and the region (β) can be reduced. In addition, a high-speed millimeter wave signal S can be transmitted/received between the region (α) and the region (β).
• Accordingly, when several points in the limited communication range are desired to be linked, thewaveguide structure341 having a small loss in the millimeter wave band is arranged at an upper portion of thecircuit board10, in the inside of thecircuit board10, or at a lower portion thereof, so that high-speed millimeter wave communication can be performed between a plurality of local points. When thewaveguide structure341 arranged at the upper portion or the lower portion of thecircuit board10 is configured as movable or variable type, control is performed to select which two of the electronic components #A, #B, #C, #D on thecircuit board10 are selected, and communication processing can be performed based on the selection of the destination of communication.
Fourth Embodiment
• Subsequently, a millimeterwave transmission device400 serving as the fourth embodiment will be explained with reference toFIGS. 16 and 17.FIG. 16 is a block diagram illustrating an exemplary configuration of the millimeterwave transmission device400 according to the fourth embodiment. The signal multiplex-enabled millimeterwave transmission device400 shown inFIG. 16 includes a plurality of, i.e., three, millimeterwave transmission devices400a,400b,400c, anadder circuit431, acoupling circuit405 for coupling with thecircuit board10, and atransmission line432. Millimeter wave signals51, S2, S3 provided by the millimeterwave transmission devices400a,400b,400care added and output to thetransmission line432.
• Preferably, the tangible object made of a dielectric material for making thecircuit board10 is not a material having a small dielectric loss tangent δ but is a material having a large dielectric loss tangent δ, so that thetransmission line432 has a large loss.
• The millimeterwave transmission device400aincludes a terminal401 forsignal input1 and asignal generation unit41, so as to output a millimeter wave signal S1 in a frequency band F1 to theadder circuit431. Thesignal generation unit41 includes a modulatingcircuit402, afrequency converting circuit403, and anamplifier404.
• The modulatingcircuit402 modulates the input signal Sin1, and outputs the modulated input signal Sin1 to thefrequency converting circuit403. Like the first to third embodiments, the modulatingcircuit402 uses, for example, a phase modulating circuit. The modulatingcircuit402 is connected to thefrequency converting circuit403. The input signal Sin1 modulated by the modulatingcircuit402 is converted into a frequency in the range of the frequency band F1, so that the millimeter wave signal S1 is generated. Thefrequency converting circuit403 is connected to theamplifier404, so that theamplifier404 amplifies the millimeter wave signal S1 having been subjected to the frequency conversion.
• The millimeterwave transmission device400bincludes a terminal411 forsignal input2 and asignal generation unit42, so as to output a millimeter wave signal S2 in a frequency band F2, which is different from the frequency band F1, to theadder circuit431. Thesignal generation unit42 includes a modulatingcircuit412, afrequency converting circuit413, and anamplifier414.
• The modulatingcircuit412 modulates the input signal Sin2, and outputs the modulated input signal Sin2 to thefrequency converting circuit413. Like the first to third embodiments, the modulatingcircuit412 uses a phase modulating circuit and the like. The modulatingcircuit412 is connected to thefrequency converting circuit413. The input signal Sin2 modulated by the modulatingcircuit412 is converted into a frequency in the range of the frequency band F2, so that the millimeter wave signal S2 is generated. Thefrequency converting circuit413 is connected to theamplifier414, so that theamplifier414 amplifies the millimeter wave signal S2 having been subjected to the frequency conversion.
• The millimeterwave transmission device400cincludes a terminal421 forsignal input3 and asignal generation unit43, so as to output a millimeter wave signal S3 in a frequency band F3, which is different from the frequency bands F1, F2, to theadder circuit431. Thesignal generation unit43 includes a modulatingcircuit422, afrequency converting circuit423, and anamplifier424.
• The modulatingcircuit422 modulates the input signal Sin3, and outputs the modulated input signal Sin3 to thefrequency converting circuit423. Like the first to third embodiments, the modulatingcircuit422 uses a phase modulating circuit and the like. The modulatingcircuit422 is connected to thefrequency converting circuit423. The input signal Sin3 modulated by the modulatingcircuit422 is converted into a frequency in the range of the frequency band F3, so that the millimeter wave signal S3 is generated. Thefrequency converting circuit423 is connected to theamplifier424, so that theamplifier424 amplifies the millimeter wave signal S3 having been subjected to the frequency conversion.
• The above threeamplifiers404,414,424 are connected to theadder circuit431, which performs frequency multiplex processing on the millimeter wave signal S1 of the frequency band F1, the millimeter wave signal S2 of the frequency band F2, and the millimeter wave signal S3 of the frequency band F3. Theadder circuit431 is connected to thecoupling circuit405 for coupling with thecircuit board10, so that an electromagnetic wave S′ based on the millimeter wave signal S=S1+S2+S3 of the frequency bands F1+F2+F3 having been subjected to frequency multiplex processing is transmitted to thetransmission line432. Thecoupling circuit405 is arranged on thetransmission line432, which propagates the electromagnetic wave S′ of the frequency bands F1+F2+F3 based on the millimeter wave signal S. Thetransmission line432 is arranged in thecircuit board10.
• Preferably, the tangible object made of a dielectric material for making thecircuit board10 is not a material having a small dielectric loss tangent δ but is a material having a large dielectric loss tangent δ, so that thetransmission line432 has a large loss.
• FIG. 17 is a graph chart illustrating an example of a frequency band in the millimeterwave transmission device400. In the graph chart shown inFIG. 17, the vertical axis represents an amplitude of the millimeter wave signal S. The horizontal axis represents a carrier frequency in GHz. F1, F2, F3 are frequency bands. The millimeter wave signal S1 of the frequency band F1 is generated by thefrequency converting circuit403. Thereafter, it is output from theamplifier404 of the millimeterwave transmission device400ato theadder circuit431.
• The millimeter wave signal S2 of the frequency band F2 is generated by thefrequency converting circuit413. Thereafter, it is output from theamplifier414 of the millimeterwave transmission device400bto theadder circuit431. The millimeter wave signal S3 of the frequency band F3 is generated by thefrequency converting circuit423. Thereafter, it is output from theamplifier424 of the millimeterwave transmission device400cto theadder circuit431.
• As described above, according to the millimeterwave transmission device400 of the fourth embodiment, the millimeterwave transmission device400ais arranged with thefrequency converting circuit403, the millimeterwave transmission device400bis arranged with thefrequency converting circuit413, and the millimeterwave transmission device400cis arranged with thefrequency converting circuit423. Theadder circuit431 performs frequency multiplex processing on the millimeter wave signal S1 of the frequency band F1, the millimeter wave signal S2 of the frequency band F2, and the millimeter wave signal S3 of the frequency band F3.
• Therefore, frequency multiplex communication processing can be executed between the signal transmission millimeterwave transmission device400 and the signal reception millimeter wave transmission device. It is to be understood that a signal reception millimeter wave transmission device for receiving an electromagnetic wave S′ based on a bandpass-type millimeter wave signal S=S1+S2+S3 is arranged with a frequency separating circuit. When the signal reception millimeter wave transmission device receives the bandpass-type electromagnetic wave S′ based on the millimeter wave signal S, the signal reception millimeter wave transmission device can easily obtain the bandpass-type millimeter wave signal S=S1+S2+S3 by arranging the coupling circuit on thecircuit board10 for coupling with thecircuit board10 without any DC connection. Moreover, the transmission speed of thesame transmission line432 can be improved. Therefore, the signal multiplex-enabled millimeter wave transmission system can be structured.
Fifth Embodiment
• Subsequently, a millimeterwave transmission device500 serving as the fifth embodiment will be explained with reference toFIGS. 18 and 19.FIG. 18 is a block diagram illustrating an exemplary configuration of the millimeterwave transmission device500 according to the fifth embodiment. In this embodiment, a feed back path is arranged between a signal transmission electronic component #A and a signal reception electronic component #B which execute communication processing, so that the gain of anamplifier504 can be controlled.
• The millimeterwave transmission device500 shown inFIG. 18 includes electronic components #A, #B, atransmission line506, and a DC/low frequency transmission line522 (which is denoted as DC/low frequency transmission line in the figure).
• Preferably, the tangible object made of a dielectric material for making thecircuit board10 is not a material having a small dielectric loss tangent δ but is a material having a large dielectric loss tangent δ, so that thetransmission line506 has a large loss.
• The electronic component #A includes asignal input terminal501, asignal generation unit51, acoupling circuit505, and again control circuit521. Thesignal generation unit51 is connected to thesignal input terminal501. Thesignal generation unit51 includes, for example, a modulatingcircuit502, afrequency converting circuit503, anamplifier504, and again control circuit521 in order to process an input signal Sin and generate a millimeter wave signal S. The terminal501 is connected to the modulatingcircuit502, so that the input signal Sin is modulated. Like the first to fourth embodiments, the modulatingcircuit502 uses a phase modulating circuit.
• The modulatingcircuit502 is connected to thefrequency converting circuit503, which performs frequency conversion on the input signal Sin modulated by the modulatingcircuit502 to generate a millimeter wave signal S. Thefrequency converting circuit503 is connected to theamplifier504, so that theamplifier504 amplifies themillimeter wave signal51 having been subjected to the frequency conversion.
• Theamplifier504 is connected to thecoupling circuit505, which transmits the millimeter wave signal generated by thesignal generation unit51 to an end of a tangible object (tangible object made of a dielectric material) having a predetermined dielectric constant ε. Thecoupling circuit505 is constituted by an antenna member having a predetermined length based on a wavelength λ of the millimeter wave signal S, i.e., about 600 μm, and is coupled to thecircuit board10 having the dielectric constant ε. In this example, thecircuit board10 also makes thetransmission line506 having a large loss. The millimeter wave electromagnetic wave S′ propagates in thetransmission line506.
• The electronic component #B includes acoupling circuit507, asignal generation unit52, asignal output terminal511, and a signalquality determination circuit523. Thetransmission line506 is coupled with thecoupling circuit507, which receives the electromagnetic wave S′ based on the millimeter wave signal S from the other end of thetransmission line506. Thecoupling circuit507 is constituted by an antenna member having a predetermined length based on a wavelength λ of the millimeter wave signal S, i.e., about 600 μm. Like the first and second embodiments, the antenna member is, for example, a probe antenna (dipole), a loop antenna, and a small aperture-coupled device (such as slot antenna).
• Thecoupling circuit507 is connected to thesignal generation unit52, which generates an output signal Sout by processing the millimeter wave signal based on the electromagnetic wave S′ received by thecoupling circuit507. Thesignal generation unit52 includes, for example, anamplifier508, afrequency converting circuit509, ademodulating circuit510, and a signalquality determination circuit523. Thecoupling circuit507 is connected to theamplifier508. Theamplifier508 amplifies the received millimeter wave signal.
• Theamplifier508 is connected to thefrequency converting circuit509. Thefrequency converting circuit509 performs frequency conversion on the amplified millimeter wave signal S. Thefrequency converting circuit509 is connected to thedemodulating circuit510. Thedemodulating circuit510 demodulates the output signal having been subjected to the frequency conversion.
• In terms of principle, examples of signals monitored by the signalquality determination circuit523 are considered to include a first example: an output signal of the demodulating circuit510 (output signal Sout given to the terminal511), a second example: a signal being processed by thedemodulating circuit510, and a third example: an output signal of thefrequency converting circuit509. The configuration of the signalquality determination circuit523 is prepared accordingly. For example, in the second example, the demodulating circuit includes not only functional blocks for demodulation processing but also function blocks for amplitude determination, gain control, and the like. The control operation of the signalquality determination circuit523 corresponds thereto. In the explanation below, the third example is employed for the sake of ease of understanding and explanation.
• Thefrequency converting circuit509 is connected to the signalquality determination circuit523. The signalquality determination circuit523 monitors the output signal having been subjected to the frequency conversion to determine the signal quality. For example, the signalquality determination circuit523 compares an output level Vx of an output signal having been subjected to the frequency conversion and a threshold value level Vth serving as a reference for determination. When the output level Vx is determined to be equal to or less than the threshold value level Vth, the signalquality determination circuit523 outputs a quality determination signal Sf (information) so as to increase the current gain. When the output level Vx is determined to be more than the threshold value level Vth, the signalquality determination circuit523 outputs a quality determination signal Sf so as to reduce the current gain.
• The signalquality determination circuit523 is connected to thetransmission line522 capable of handling a direct current or low frequency, so that the quality determination signal Sf output from the signalquality determination circuit523 is given to the side of the electronic component #A as a feedback. Thetransmission line522 capable of handling a direct current or low frequency is made of an ordinary print circuit board. This is because the quality determination signal Sf does not need to be given as a feedback from the electronic component #B to the electronic component #A in real time at high speed, but is necessary regularly or irregularly when the signal input level of the side of the electronic component #B is adjusted. Therefore, an ordinary print circuit board capable of handling a direct current or low frequency signal can be used.
• Thetransmission line522 capable of handling a direct current or low frequency is connected to thegain control circuit521. Thegain control circuit521 controls the gain of theamplifier504 based on the quality determination signal Sf transmitted via thetransmission line522. For example, when the quality determination signal Sf is information for increasing the current gain, thegain control circuit521 adjusts a bias current so as to increase the gain of theamplifier504. On the other hand, when the quality determination signal Sf is information for decreasing the current gain, thegain control circuit521 adjusts the bias current so as to decrease the gain of theamplifier504.
• The abovesignal generation unit51, thesignal generation unit52, thegain control circuit521, and the signalquality determination circuit523 are constituted by CMOS-IC devices, i.e., examples of semiconductor integrated circuits. The electronic component #A, the electronic component #B, and the like are mounted on thecircuit board10 having the dielectric constant ε.
• Subsequently, an example of operation performed by the millimeterwave transmission device500 will be explained.FIG. 19 is an operation flowchart illustrating an example of gain control in the millimeterwave transmission device500. In this embodiment, an example will be explained where the signal reception electronic component #B responds information such as reception level and reception error, which is carried by a direct current or a low frequency, to the signal transmission electronic component #A via thetransmission line522, so that thegain control circuit521 optimizes the output level of theamplifier504.
• The electronic component #A of the millimeterwave transmission device500 adopts the above as the gain control conditions. In order to generate the millimeter wave signal S by processing the input signal Sin, the modulatingcircuit502 of thesignal generation unit51 executes phase modulation processing based on the input signal Sin in step ST31 of the operation flowchart shown inFIG. 19. The input signal Sin is provided from a lower signal processing circuit, not shown, to the terminal201.
• Subsequently, in step ST32, thefrequency converting circuit503 performs frequency conversion on the signal phase-modulated by the modulatingcircuit502. Thereafter, in step ST33, theamplifier504 amplifies the millimeter wave signal S. Then, in step ST34, thecoupling circuit505 transmits the signal of the millimeter wave (millimeter wave having been subjected to the signal processing) amplified by theamplifier504 to one end of thetransmission line506 defined on thecircuit board10 having the dielectric loss tangent S. The electromagnetic wave S′ based on the millimeter wave signal S propagates through thetransmission line506.
• On the other hand, in the electronic component #B, thecoupling circuit507 receives the electromagnetic wave S′ based on the millimeter wave signal S from the other end of thetransmission line506 on thecircuit board10 having the dielectric loss tangent δ in step ST41 of the flowchart shown inFIG. 19B in order to generate the output signal Sout by receiving the electromagnetic wave S′ based on the millimeter wave signal S. Thereafter, in step ST42, theamplifier508 amplifies the millimeter wave signal. Then, in step ST43, thefrequency converting circuit509 performs frequency conversion on the millimeter wave signal S amplified by theamplifier508. Thereafter, in step ST44, thedemodulating circuit510 demodulates the output signal having been subjected to the frequency conversion. The demodulated output signal Sout is output from the terminal511 to a host signal processing circuit, not shown.
• At the same time, in step ST45, the signalquality determination circuit523 monitors the output signal provided by thefrequency converting circuit509 to determine the signal quality. For example, the signalquality determination circuit523 compares an output level Vx of the signal having been subjected to the frequency conversion and a threshold value level Vth serving as a reference for determination. When the output level Vx is determined to be equal to or less than the threshold value level Vth, the signalquality determination circuit523 provides a quality determination signal Sf (information) to thegain control circuit521 via thetransmission line522 so as to increase the current gain. When the output level Vx is determined to be more than the threshold value level Vth, the signalquality determination circuit523 provides a quality determination signal Sf to thegain control circuit521 via thetransmission line522 so as to reduce the current gain.
• In the electronic component #A having received the quality determination signal Sf, thegain control circuit521 controls the gain of theamplifier504 based on the quality determination signal Sf transmitted via thetransmission line522 in step ST35. For example, when the quality determination signal Sf is information for increasing the current gain, thegain control circuit521 returns back to step ST33 to adjust a bias current so as to increase the gain of theamplifier504. On the other hand, when the quality determination signal Sf is information for decreasing the current gain, thegain control circuit521 adjusts the bias current so as to decrease the gain of theamplifier504. Therefore the output signal of theamplifier504 is maintained at an appropriate level at which the signal quality between the electronic components #A, #B is good, and interference with other electronic components is suppressed.
• As described above, according to the millimeterwave transmission device500 of the fifth embodiment, the electronic component #A includes thegain control circuit521, and the electronic component #B includes the signalquality determination circuit523. The signalquality determination circuit523 responds information such as reception level and reception error, which is carried by a direct current or a low frequency, to the signal transmission electronic component #A from the signal reception electronic component #B via the transmission line522 (feedback path), so that thegain control circuit521 controls the output level of theamplifier504.
• With this gain control, interference with communication between local regions such as other electronic components can be controlled. Therefore, the quality of connection between the electronic component #A and the electronic component #B is maintained at a preferable level, and interference with communication of other electronic components can be reduced to the minimum level. In addition to the above effects, communication power can be adjusted to an optimum level, and accordingly, communication range can be controlled. Further, theamplifier504 may be treated as an output enable switch.
• In the above explanation, at the signal transmissionsignal generation unit51, thegain control circuit521 controls theamplifier508 to perform the gain control. However, the mechanism of the gain control is not limited to this example. For example, in the millimeterwave transmission device500, a switchable attenuator may be arranged before the signal receptionsignal generation unit52, or a gain control circuit for changing (adjusting) the sensitivity of reception input by means of bias change (adjustment) of theamplifier508 may be arranged in the electronic component #B as a functional unit for adjusting input of thesignal generation unit52. The millimeterwave transmission device500 may be structured by combining an input adjustment (gain control at the reception side) of thesignal generation unit52 and a gain control (gain control at the transmission side) at the signal transmissionsignal generation unit51. It is to be understood that a multifunctional millimeter wave transmission system may be structured by combining millimeterwave transmission devices100,400,500 and millimeterwave transmission systems200,300.
• According to a wireless millimeter wave communication system described inPatent Literature 2, an adjustment can be performed to propagate the millimeter wave signal (signal wave) emitted by the antenna of the millimeter wave transmission means to the antenna of the millimeter wave reception means with a high reproducibility. In a case where a baseband signal such as millimeter wave is transmitted at high speed, a reflected wave may be one of the causes of transmission error.
• In contrast, in the fifth embodiment, the basic portion of the millimeter wave transmission uses the same mechanism as the first embodiment. The fifth embodiment achieves the same effects as the first embodiment with regard to the millimeter wave transmission of the transmission target signal (Sin). Therefore, the issues of transmission error caused by reflected wave can be alleviated or solved.
Sixth Embodiment
• Subsequently, a millimeterwave transmission device600 serving as the sixth embodiment will be explained with reference toFIGS. 20 and 22.FIG. 20 includes a top view (an upper figure ofFIG. 20) illustrating an exemplary configuration (part I) of the millimeterwave transmission device600 according to the sixth embodiment and a cross sectional view (a lower figure ofFIG. 20) taken along arrow line X1-X. In this embodiment, acoupling circuit205 of the millimeterwave transmission device600 includes amicrostrip line251 and awaveguide structure252 instead of theantenna member11 as shown inFIG. 2B.
• The millimeterwave transmission device600 shownFIG. 20 includes aCMOS chip250, amicrostrip line251, and a waveguidetop panel portion253, which are arranged on acircuit board10. TheCMOS chip250 is a semiconductor transistor circuit which integrates thesignal generation unit21 including the modulatingcircuit202, thefrequency converting circuit203, and theamplifier204 shown inFIG. 1. Thecoupling circuit205 and theCMOS chip250 constitute an electronic component #A.
• In the lower figure ofFIG. 20, aconductive ground layer10eis arranged on all over thecircuit board10. An insulatingdielectric material layer10fconstituting atransmission line206 having a large loss is arranged on theground layer10e. Thedielectric material layer10fis made of glass epoxy resin (FR4) whose dielectric constant is 4.9 and whose dielectric loss tangent is 0.025. A conductingmicrostrip line251, a waveguidetop panel portion253, and awiring pattern254 are arranged on thedielectric material layer10f. Thewiring pattern254 is made of a copper foil and the like, and is connected to a plurality of electrodes of theCMOS chip250. For example, thewiring pattern254 and theCMOS chip250 are bonded with bump electrodes by flip chip method.
• Thecoupling circuit205 of the millimeterwave transmission device600 includes themicrostrip line251 and thewaveguide structure252. Themicrostrip line251 is constituted by a copper foil and the like and is arranged on thecircuit board10. Themicrostrip line251 directly connects the waveguidetop panel portion253 and theamplifier204 of the electronic component #A shown inFIG. 1. Themicrostrip line251 is configured to transmit an electromagnetic wave S′ based on a millimeter wave signal S to thewaveguide structure252. The output terminal of theamplifier204 and themicrostrip line251 are bonded with bump electrodes by flip chip method. The method is not limited thereto. Other methods may also be used. For example, they may be bonded with wires.
• According to thewaveguide structure252 of this example, the wave guide includes a top panel portion projection region Ic of theground layer10e, the waveguidetop panel portion253, and contact holes10a′. The contact holes10a′ electrically connect the top panel portion projection region Ic and the waveguidetop panel portion253. For example, the contact holes10a′ are arranged in two rows in a comb form, so as to define the travelling direction of the electromagnetic wave S′. The travelling direction of the electromagnetic wave S′ is defined by the two rows of contact holes10a′ (hereinafter referred to as a contacthole fence portion10b′). In other words, the four sides of the waveguide are electrically shielded by the top panel portion projection region Ic of theground layer10e, the waveguidetop panel portion253, and the right and left contact holes10a′ and10a′. Thus, thewaveguide structure252 filled with dielectric material therein can be employed.
• Therefore, themicrostrip line251 and thewaveguide structure252 can be directly connected, and the electromagnetic wave S′ based on the millimeter wave signal S can be transmitted to thedielectric material layer10f. The portion of thedielectric material layer10fon thecircuit board10 in which the waveguidetop panel portion253 is not arranged serves as a dielectric material transmission path that constitutes thetransmission line206 having a large loss. Thewaveguide structure252 significantly alleviates the issues of spurious emission and transmission error associated with broadcast and wireless communication apparatuses explained in the first embodiment.
• FIG. 21 is a perspective view illustrating an exemplary configuration (part II) of the millimeterwave transmission device600. The millimeterwave transmission device600 shown inFIG. 21 is a perspective view illustrating an example of a millimeter wave transmission in which the electronic component #A and the electronic component #B are connected with thetransmission line206 having a large loss. In this example, the structure of the above-explainedcoupling circuit205 is applied to acoupling circuit207 at the side of the electronic component #B.
• Thecoupling circuit207 of the millimeterwave transmission device600 includes amicrostrip line251 and awaveguide structure252 instead of theantenna member11 shown inFIG. 2B. Themicrostrip line251 is constituted by a copper foil and the like and is arranged on thecircuit board10. Themicrostrip line251 directly connects the waveguidetop panel portion253 and theamplifier208 of the electronic component #B shown inFIG. 1. Themicrostrip line251 is configured to receive the millimeter wave signal S based on the electromagnetic wave S′ from thewaveguide structure252.
• As described above, the simple high-pass filter device255 can be structured on thecircuit board10 with thecoupling circuit205 including themicrostrip line251 and thewaveguide structure252 at the side of the electronic component #A, thetransmission line206, and thecoupling circuit207 including themicrostrip line251 and thewaveguide structure252 at the side of the electronic component #B. The high-pass filter device255 electrically connects the two electronic components #A, #B.
• FIG. 22 is a frequency characteristic diagram illustrating an example of reflection characteristic and an example of bandpass characteristic of the high-pass filter device255 of the millimeterwave transmission device600. InFIG. 22, the vertical axis represents bandpass characteristic S (2,1) dB and reflection characteristic S (1,1) dB of the high-pass filter device255. The horizontal axis represents carrier frequency (GHz). The unit of the scale is 1 GHz. In the figure, Ma represents an example of bandpass characteristic of the high-pass filter device255. In this example of bandpass characteristic, each of thecoupling circuits205,207 of the millimeterwave transmission device600 includes themicrostrip line251 and thewaveguide structure252, and thetransmission line206 is constituted by thedielectric material layer10f.
• The bandpass characteristic S (2,1) dB of the high-pass filter device255 is bandpass characteristic of the electromagnetic wave S′ based on the millimeter wave signal S transmitted from aCMOS chip250 at the side of the electronic component #A to aCMOS chip250′ at the side of the electronic component #B via the high-pass filter device255 (FR4) whose dielectric constant is 4.9 and whose dielectric loss tangent δ is 0.025. The bandpass characteristic S (2,1) dB represents a case where the carrier frequency is increased from 0 GHz to 80 GHz by 1 GHz. According to this simulation result, video data based on the millimeter wave signal S have a bandpass loss of about 4.0 dB between the electronic components #A, #B when the carrier frequency is in the range of 40.0 GHz to 75 GHz.
• In the figure, IIIb represents an example of reflection characteristic of the high-pass filter device255. The reflection characteristic S (1,1) dB of the high-pass filter device255 is reflection characteristic of the electromagnetic wave S′ based on the millimeter wave signal S transmitted from theCMOS chip250 at the side of the electronic component #A to theCMOS chip250′ at the side of the electronic component #B via the high-pass filter device255 whose dielectric constant is 4.9 and whose dielectric loss tangent δ is 0.025.
• The reflection characteristic S (1,1) dB represents a case where the carrier frequency is increased from 10 GHz to 80 GHz by 1 GHz. According to this simulation result, the reflection loss of 40 dB or more is achieved. Further, the reflection loss is 10 dB or more when the carrier frequency is in the range of 40.0 GHz to 75 GHz.
• As the carrier frequency increases, the transmission loss increases but the reflected wave decreases in the high-pass filter device255 having such a large loss. Therefore, the high-pass filter device255 reduces adverse effect of a standing wave caused by the reflected wave. In this example, thefrequency converting circuit203 performs frequency conversion to convert the input signal Sin into the millimeter wave signal S, and thefrequency converting circuit209 performs frequency conversion to convert the millimeter wave signal amplified by theamplifier208, so that the ratio of (signal band)/(center frequency) can be reduced. Therefore, it is easy to make thesignal generation unit21 for transmitting the millimeter wave signal and thesignal generation unit22 for receiving the millimeter wave signal.
• As described above, according to the millimeterwave transmission device600 of the sixth embodiment, each of thecoupling circuit205 at the side of the electronic component #A and thecoupling circuit207 at the side of the electronic component #B includes themicrostrip line251 and thewaveguide structure252 instead of theantenna member11 shown inFIG. 2B.
• Therefore, the simple high-pass filter device255 can be structured on thecircuit board10 with thecoupling circuit205 including themicrostrip line251 and thewaveguide structure252 at the side of the electronic component #A, thetransmission line206, and thecoupling circuit207 including themicrostrip line251 and thewaveguide structure252 at the side of the electronic component #B. As the carrier frequency increases, the transmission loss increases but the reflected wave decreases in the high-pass filter device255. Therefore, the high-pass filter device255 reduces adverse effect of a standing wave caused by the reflected wave.
Seventh Embodiment
• FIG. 23 includes a top view (an upper figure ofFIG. 23) illustrating an exemplary configuration of a millimeterwave transmission device700 according to the seventh embodiment and a cross sectional view (a lower figure ofFIG. 23) taken along arrow line X2-X2. In this embodiment, acoupling circuit205 of the millimeterwave transmission device700 includes anupper ground layer10g, anantenna structure256, aslot hole257 and awaveguide structure252, instead of themicrostrip line251 shown inFIG. 21.
• The millimeterwave transmission device700 shown in the upper diagram ofFIG. 23 includes alower ground layer10e, anupper ground layer10g, awaveguide structure252, and aCMOS chip259, which are arranged on acircuit board10. TheCMOS chip259 is a semiconductor transistor circuit which integrates thesignal generation unit21 including the modulatingcircuit202, thefrequency converting circuit203, and theamplifier204 shown inFIG. 1. Thecoupling circuit205 and theCMOS chip259 constitute an electronic component #A′.
• TheCMOS chip259 is different from theCMOS chip250 explained in the sixth embodiment in that theCMOS chip259 has theantenna structure256. Theantenna structure256 is constituted by anantenna member56 having a length of λ/2 where the wavelength of the carrier frequency is λ. Theantenna member56 is made on a predetermined surface of theCMOS chip259 in an exposed manner.
• In the lower figure ofFIG. 23, a conductiveinterlayer ground layer10eis arranged on all over thecircuit board10. An insulatingdielectric material layer10fconstituting atransmission line206 having a large loss is arranged on theground layer10e. Thedielectric material layer10fis made of glass epoxy resin (FR4) whose dielectric constant is 4.9 and whose dielectric loss tangent is 0.025. A conductingupper ground layer10gis arranged on thedielectric material layer10f.
• Aslot hole257 constituted by an opening portion having a predetermined width and a predetermined length is arranged in theupper ground layer10g. TheCMOS chip259 is adhered to theupper ground layer10gwith an adhesive258 and is fixed to thecircuit board10 such that theantenna member56 is perpendicular to theslot hole257.
• Thecoupling circuit205 of the millimeterwave transmission device700 includes theantenna member56, theslot hole257 formed in theupper ground layer10g, and thewaveguide structure252. Theinterlayer ground layer10eand theupper ground layer10gare constituted by a copper foil and the like and is arranged on thecircuit board10. Theinterlayer ground layer10eand theupper ground layer10gare configured to transmit the electromagnetic wave S′ based on the millimeter wave signal S to thewaveguide structure252 via theslot hole257 from theantenna member56 connected to the amplifier204 (seeFIG. 1) of the electronic component #A′. The output terminal of theamplifier204 and theantenna member56 are bonded with wires, for example.
• According to thewaveguide structure252 of this example, the waveguide includes theinterlayer ground layer10e, theupper ground layer10g, and the contact holes10a′. The contact holes10a′ electrically connect theinterlayer ground layer10eand theupper ground layer10g. Like the sixth embodiment, the contact holes10a′ are arranged in two rows in a comb form, so as to define the travelling direction of the electromagnetic wave S′. The travelling direction of the electromagnetic wave S′ is defined by the two rows of contact holes10a′ (hereinafter referred to as a contacthole fence portion10b′).
• In other words, like the sixth embodiment, the four sides of the waveguide are electrically shielded by theinterlayer ground layer10e, theupper ground layer10g, and the right and left contact holes10a′ and10a′. Thus, thewaveguide structure252 filled with dielectric material therein can be employed. The portion of thedielectric material layer10fon thecircuit board10 in which theupper ground layer10gis not arranged serves as a dielectric material transmission path that constitutes thetransmission line206 having a large loss.
• As described above, according to the millimeterwave transmission device700 of the seventh embodiment, thecoupling circuit205 at the side of the electronic component #A includes theupper ground layer10g, theantenna structure256, theslot hole257, and thewaveguide structure252, instead of themicrostrip line251 shown inFIG. 21.
• Therefore, thewaveguide structure252 can be spatially connected via theslot hole257 to theantenna member56 connected to the amplifier204 (seeFIG. 1) of the electronic component #A′. Therefore, the electromagnetic wave S′ based on the millimeter wave signal S can be transmitted to thedielectric material layer10f. Like the sixth embodiment, thewaveguide structure252 significantly alleviates the issues of spurious emission and transmission error associated with broadcast and wireless communication apparatuses.
Eighth Embodiment
• Subsequently, a millimeterwave transmission device800 serving as the eighth embodiment will be explained with reference toFIGS. 24 to 29.FIG. 24 includes a top view (an upper figure ofFIG. 24) illustrating an exemplary configuration (part I) of the millimeterwave transmission device800 according to the eighth embodiment and a cross sectional view (a lower figure ofFIG. 24) taken along arrow line X3-X3. In this embodiment,coupling circuits205,207 have a multi-layer structure, so that an electromagnetic wave S′ can be propagated in the thickness direction of thecircuit board10 via aslot hole257.
• The millimeterwave transmission device800 shown in the upper figure ofFIG. 24 includes aninterlayer ground layer10e, aCMOS chip250, amicrostrip line251, and a waveguidetop panel portion253, which are arranged on acircuit board10. Like the sixth embodiment, theCMOS chip250 is a semiconductor transistor circuit which integrates thesignal generation unit21 including the modulatingcircuit202, thefrequency converting circuit203, and theamplifier204 shown inFIG. 1. Thecoupling circuit205 and theCMOS chip250 constitute an electronic component #A.
• In the lower figure ofFIG. 24, a conductiveinterlayer ground layer10eis arranged on all over thecircuit board10. An insulatingdielectric material layer10fconstituting atransmission line206 having a large loss is arranged on theinterlayer ground layer10e. A conductive lower ground layer10his arranged on the lower surface of thecircuit board10. An insulatingdielectric material layer10iis interposed between theinterlayer ground layer10eand the lower ground layer10h. Each of the dielectric material layers10f,10iis made of glass epoxy resin (FR4) whose dielectric constant is 4.9 and whose dielectric loss tangent is 0.025.
• Aconductive microstrip line251, a waveguidetop panel portion253, and awiring pattern254 are arranged on thedielectric material layer10f. Thewiring pattern254 is constituted by a copper foil, and is connected to a plurality of electrodes of theCMOS chip250. Like the sixth embodiment, thewiring pattern254 and theCMOS chip250 are bonded with bump electrodes by flip chip method.
• Thecoupling circuit205 of the millimeterwave transmission device800 includes themicrostrip line251, awaveguide structure252′ and theslot hole257. Like the sixth embodiment, themicrostrip line251 is constituted by a copper foil and the like and is arranged on thecircuit board10. Themicrostrip line251 directly connects the waveguidetop panel portion253 and theamplifier204 of the electronic component #A shown inFIG. 1. Themicrostrip line251 is configured to transmit an electromagnetic wave S′ based on a millimeter wave signal S to thewaveguide structure252′. The output terminal of theamplifier204 and themicrostrip line251 are bonded with bump electrodes by flip chip method. The method is not limited thereto. Other methods may also be used. For example, they may be bonded with wires.
• In thewaveguide structure252′ of this example, a top panel portion projection region Ic of theinter-layer ground layer10e, a top panel portion projection region Ic of the lower ground layer10h, and the waveguidetop panel portion253 are constituted by a two-layer wave guide connected via contact holes10a′. The contact holes10a′ electrically connect the waveguidetop panel portion253 with the top panel portion projection region Ic of theinterlayer ground layer10eand the top panel portion projection region Ic of the lower ground layer10h. For example, the contact holes10a′ are arranged in two rows in a comb form, so as to define the travelling direction of the electromagnetic wave S′.
• A two-layer structure including an upper layer and a lower layer is defined by the contact holes10a′ arranged in two rows (contacthole fence portion10b′). In other words, the seven or eight sides of the waveguide are electrically shielded by the top panel portion projection region Ic of theinterlayer ground layer10e, the top panel portion projection region Ic of the lower ground layer10h, the waveguidetop panel portion253, and the right and left contact holes10a′ and10a′. Thus, thewaveguide structure252′ filled with dielectric material therein can be employed.
• In this example, theslot hole257 is formed at a predetermined position of theinterlayer ground layer10e, so as to guide the electromagnetic wave S′ from the upperdielectric material layer10fto the lowerdielectric material layer10ior from the lowerdielectric material layer10ito the upperdielectric material layer10f. Therefore, themicrostrip line251 and thewaveguide structure252′ can be directly connected, and the electromagnetic wave S′ based on the millimeter wave signal S can be transmitted to thedielectric material layer10f. Moreover, thecoupling circuit205 has a two-layer structure, and the electromagnetic wave S′ can be guided to lowerdielectric material layer10i(in the direction of the thickness of the circuit board10) via theslot hole257.
• The portion of thedielectric material layer10fon thecircuit board10 in which the waveguidetop panel portion253 is not arranged and thedielectric material layer10ibetween theinterlayer ground layer10eand the lower ground layer10hserve as a dielectric material transmission path that constitutes thetransmission line206 having a large loss. Thewaveguide structure252′ significantly alleviates the issues of spurious emission and transmission error explained in the first embodiment.
• FIG. 25 is a top view illustrating an exemplary configuration (part II) of the millimeterwave transmission device800.FIG. 26 is a cross sectional view taken along arrow line X4-X4 for illustrating an exemplary configuration (part III) of the millimeterwave transmission device800.
• In this embodiment, two electronic components #A, #B are arranged on one surface of thecircuit board10, and two electronic components #C, #D are arranged on the other surface thereof. The fourelectronic components #1 to #4 are connected by themulti-layer coupling circuits205,207 and thetransmission line206 having a large loss. The electromagnetic wave S′ is propagated to the lowerdielectric material layer10ivia theslot hole257 of the interlayer ground layer at the side of the electronic component #A. Further, the electromagnetic wave S′ is propagated to the original upperdielectric material layer10fvia theslot hole257 of the interlayer ground layer at the side of the electronic component #D. In this example, the waveguidetop panel portion253 is omitted.
• In the millimeterwave transmission device800 shown inFIG. 25, themulti-layer coupling circuit205 at the side of the electronic component #A shown inFIG. 24 is applied not only to thecoupling circuit205 at the side of the electronic component #C but also to thecoupling circuit207 at the side of the electronic components #B, #D.
• Thecoupling circuit207 at the side of the electronic component #B of the millimeterwave transmission device800 includes themicrostrip line251 and thewaveguide structure252′ instead of theantenna member11 shown inFIG. 2B. Themicrostrip line251 is constituted by a copper foil and the like and arranged on thecircuit board10. Themicrostrip line251 directly connects the waveguidetop panel portion253 and the amplifier208 (seeFIG. 10) of the electronic component #B shown inFIG. 1. Themicrostrip line251 is configured to receive the millimeter wave signal S based on the electromagnetic wave S′ from thewaveguide structure252.
• Thecoupling circuit205 at the side of the electronic component #C of the millimeterwave transmission device800 includes themicrostrip line251 and thewaveguide structure252′ as shown inFIG. 26. Themicrostrip line251 is constituted by a copper foil and the like and arranged under thecircuit board10. For example, themicrostrip line251 is directly connected to the amplifier224 (seeFIG. 10) of the electronic component #C shown inFIG. 10. Themicrostrip line251 is configured to transmit the electromagnetic wave S′ based on the millimeter wave signal S from thewaveguide structure252′.
• Thecoupling circuit207 at the side of the electronic component #D of the millimeterwave transmission device800 includes themicrostrip line251 and thewaveguide structure252′ as shown inFIG. 26. Themicrostrip line251 is constituted by a copper foil and the like and arranged under thecircuit board10. For example, themicrostrip line251 is directly connected to the amplifier228 (seeFIG. 10) of the electronic component #D shown inFIG. 10. Themicrostrip line251 is configured to receive the millimeter wave signal S based on the electromagnetic wave S′ from thewaveguide structure252′.
• As described above, a multi-layer high-pass filter device255′ includes thecoupling circuit205 constituted by thewaveguide structure252′ and themicrostrip line251 at the side of the electronic component #A, thetransmission line206 made with the upperdielectric material layer10f, thecoupling circuit207 constituted by thewaveguide structure252′ and themicrostrip line251 at the side of the electronic component #B, thecoupling circuit205 constituted by thewaveguide structure252′ and themicrostrip line251 at the side of the electronic component #C, thetransmission line206 made with the upperdielectric material layer10i, thecoupling circuit207 constituted by thewaveguide structure252′ and themicrostrip line251 at the side of the electronic component #D, theslot hole257 formed in theinterlayer ground layer10eat the side of the electronic components #A, #C, and theslot hole257 formed in theinterlayer ground layer10eat the side of the electronic components #B, #D.
• In the multi-layer high-pass filter device255′, the electromagnetic wave S′ is propagated to the lowerdielectric material layer10ivia theslot hole257 of the interlayer ground layer at the side of the electronic component #A. Further, the electromagnetic wave S′ is propagated to the original upperdielectric material layer10fvia theslot hole257 of the interlayer ground layer at the side of the electronic component #D.
• Reflection prevention slot holes260 shown inFIG. 25 are formed in theinterlayer ground layer10eas shown inFIG. 26. In this example, the reflection prevention slot holes260 are arranged on the outside of theslot hole257 at the side of the electronic components #A, #C and the outside of theslot hole257 at the side of the electronic components #B, #D. Like theslot hole257, theslot hole260 has a rectangular shape, and theslot hole260 has a longer width and a longer length than theslot hole257. Theslot hole260 is configured to prevent diffusion (reflection) of the electromagnetic wave S′ propagated to the upperdielectric material layer10fand the electromagnetic wave S′ propagated to the lowerdielectric material layer10i.
• FIGS. 27 and 28 are cross sectional views illustrating an exemplary propagation (part I and part II) of the electromagnetic wave S′ in the high-pass filter device255′. In this example, the electromagnetic wave S′ is propagated from the electronic component #A to a different port (electronic components #B, #C, #D and the like) according to a carrier frequency.
• In the high-pass filter device255′ shown inFIG. 27A, when the carrier frequency is 40 GHz, the electromagnetic wave S′ is propagated from the electronic component #A to the electronic component #B. When the millimeter wave signal flows in themicrostrip line251 constituting thecoupling circuit205 at the side of the electronic component #A, the electromagnetic wave S′ based on this millimeter wave signal is propagated from thewaveguide structure252′ to thetransmission line206 constituted by the upperdielectric material layer10f.
• In thecoupling circuit207 at the side of the electronic component #B, thewaveguide structure252′ receives the electromagnetic wave S′, which is to be propagated to the upperlayer transmission line206, and the millimeter wave signal based on the electromagnetic wave S′ flows to themicrostrip line251. The millimeter wave signal is input from themicrostrip line251 to the amplifier208 (seeFIG. 10) at the side of the electronic component #B.
• In the high-pass filter device255′ shown inFIG. 27B, when the carrier frequency is 60 GHz, the electromagnetic wave S′ is propagated from the electronic component #A to the electronic component #B via theslot hole257 formed in theinterlayer ground layer10eat the side of the electronic components #A, #C and theslot hole257 formed in theinterlayer ground layer10eat the side of the electronic components #B, #D.
• When the millimeter wave signal flows in themicrostrip line251 constituting thecoupling circuit205 at the side of the electronic component #A, the electromagnetic wave S′ based on the signal S is propagated from thewaveguide structure252′ to thetransmission line206 constituted by the lowerdielectric material layer10ivia theslot hole257 at the side of the electronic components #A, #C.
• In thecoupling circuit207 at the side of the electronic component #B, thewaveguide structure252′ receives the electromagnetic wave S′, which is to be propagated to the lowerlayer transmission line206, via theslot hole257 at the side of the electronic components #B, #D, and the millimeter wave signal based on the electromagnetic wave S′ flows to themicrostrip line251. The millimeter wave signal is input from themicrostrip line251 to the amplifier208 (seeFIG. 10) at the side of the electronic component #B.
• As described above, when the carrier frequencies such as 40 GHz and 60 GHz are selected in the multi-layer high-pass filter device255′, the electromagnetic wave S′ is propagated to the lowerdielectric material layer10ivia theslot hole257 at the side of the electronic components #A, #C. Further, the electromagnetic wave S′ can be propagated to the original upperdielectric material layer10fvia theslot hole257 of the interlayer ground layer at the side of the electronic components #B, #D.
• In the high-pass filter device255′ shown inFIG. 28A, when a predetermined carrier frequency fx (20 GHz<fx<80 GHz) is selected, the electromagnetic wave S′ is propagated from the electronic component #A to the electronic component #D. When the millimeter wave signal flows in themicrostrip line251 constituting thecoupling circuit205 at the side of the electronic component #A, the electromagnetic wave S′ based on this millimeter wave signal is propagated from thewaveguide structure252′ to thetransmission line206 constituted by the lowerdielectric material layer10ivia theslot hole257 at the side of the electronic components #A, #C.
• In thecoupling circuit207 at the side of the electronic component #D, thewaveguide structure252′ receives the electromagnetic wave S′, which is to be propagated to the lowerlayer transmission line206, and the millimeter wave signal based on the electromagnetic wave S′ flows to themicrostrip line251. The millimeter wave signal is input from themicrostrip line251 to the amplifier228 (seeFIG. 10) at the side of the electronic component #D.
• When a predetermined carrier frequency fx (20 GHz<fx<80 GHz) is selected in the multi-layer high-pass filter device255′ shown inFIG. 28B, the electromagnetic wave S′ is successively propagated from the electronic component #A to the electronic components #B, #D and further from the electronic component #C to the electronic components #B, #D. When the millimeter wave signal flows in themicrostrip line251 constituting thecoupling circuit205 at the side of the electronic component #A, the electromagnetic wave S′ based on this millimeter wave signal is propagated from thewaveguide structure252′ to thetransmission line206 constituted by the upperdielectric material layer10f, and is propagated from thewaveguide structure252′ to thetransmission line206 constituted by the lowerdielectric material layer10ivia theslot hole257 at the side of the electronic components #A, #C.
• In thecoupling circuit207 at the side of the electronic component #B, thewaveguide structure252′ receives the electromagnetic wave S′, which is to be propagated to the upperlayer transmission line206, and the millimeter wave signal based on the electromagnetic wave S′ flows to themicrostrip line251. The millimeter wave signal is input from themicrostrip line251 to the amplifier208 (seeFIG. 10) at the side of the electronic component #B.
• In thecoupling circuit207 at the side of the electronic component #D, thewaveguide structure252′ receives the electromagnetic wave S′, which is to be propagated to the lowerlayer transmission line206, and the millimeter wave signal based on the electromagnetic wave S′ flows to themicrostrip line251. The millimeter wave signal is input from themicrostrip line251 to the amplifier228 (seeFIG. 10) at the side of the electronic component #D.
• When the millimeter wave signal flows in themicrostrip line251 in thecoupling circuit205 at the side of the electronic component #C, the electromagnetic wave S′ based on this millimeter wave signal is propagated from thewaveguide structure252′ to thetransmission line206 constituted by the lowerdielectric material layer10i, and is propagated from thewaveguide structure252′ to thetransmission line206 constituted by the upperdielectric material layer10fvia theslot hole257 at the side of the electronic components #B, #D. Therefore, the millimeter wave signal flowing in the upperlayer microstrip line251 is input to theamplifier208 at the side of the electronic component #B, and the millimeter wave signal flowing in the lowerlayer microstrip line251 is input to theamplifier228 at the side of the electronic component #D (seeFIG. 10).
• FIG. 29 is a frequency characteristic diagram illustrating an example of reflection characteristic and an example of bandpass characteristic of the high-pass filter device255′ of the millimeterwave transmission device800. InFIG. 29, the vertical axis represents bandpass characteristic S (2,1) dB and reflection characteristic S (1,1) dB of the high-pass filter device255′. The horizontal axis represents carrier frequency (GHz). The unit of the scale is 1 GHz. In the figure, IVa represents an example of bandpass characteristic of the high-pass filter device255′. In this example of bandpass characteristic, thecoupling circuits205,207 of the millimeterwave transmission device800 are respectively constituted by themicrostrip line251 and thewaveguide structure252′, the upperlayer transmission line206 is constituted by thedielectric material layer10f, and the lowerlayer transmission line206 is constituted by thedielectric material layer10i.
• The bandpass characteristic S (2,1) dB of the high-pass filter device255′ is bandpass characteristic of the millimeter wave signal transmitted from aCMOS chip250 at the side of the electronic component #A to aCMOS chip250′ at the side of the electronic component #B (#D) via the high-pass filter device255′ (FR4) whose dielectric constant is 4.9 and whose dielectric loss tangent δ is 0.025. The bandpass characteristic S (2,1) dB represents a case where the carrier frequency is increased from 0 GHz to 80 GHz by 1 GHz. According to this simulation result, video data based on the millimeter wave signal have a bandpass loss of about 4.0 dB between the electronic components #A, #B (#D) when the carrier frequency is in the range of 44.0 GHz to 56 GHz.
• In the figure, IVb represents an example of reflection characteristic of the high-pass filter device255′. The reflection characteristic S (1,1) dB of the high-pass filter device255′ is reflection characteristic of the millimeter wave signal transmitted from theCMOS chip250 at the side of the electronic component #A to theCMOS chip250′ at the side of the electronic component #B (#D) via the high-pass filter device255′ whose dielectric constant is 4.9 and whose dielectric loss tangent δ is 0.025.
• The reflection characteristic S (1,1) dB represents a case where the carrier frequency is increased from 0 GHz to 80 GHz by 1 GHz. According to this simulation result, the reflection loss of 35 dB or more is achieved. Further, the reflection loss is 5 dB or more when the carrier frequency is in the range of 40.0 GHz to 60 GHz.
• As the carrier frequency increases, the transmission loss increases but the reflected wave decreases in the high-pass filter device255′ having such a large loss. Therefore, the high-pass filter device255′ can reduce adverse effect of a standing wave caused by the reflected wave. In this example, thefrequency converting circuit203 performs frequency conversion to convert the input signal Sin into the millimeter wave signal S, and thefrequency converting circuit209 performs frequency conversion to convert the millimeter wave signal amplified by theamplifier208, so that the ratio of (signal band)/(center frequency) can be reduced. Therefore, it is easy to make thesignal generation unit21 for transmitting the millimeter wave signal and thesignal generation unit22 for receiving the millimeter wave signal.
• In the millimeterwave transmission device800 according to the eighth embodiment, thecoupling circuit205 at the side of the electronic components #A, #C and thecoupling circuit207 at the side of the electronic components #B, #D have a multi-layer structure. Theslot hole257 is formed in theinterlayer ground layer10e, and is configured to guide the electromagnetic wave S′ from the upperdielectric material layer10fto the lowerdielectric material layer10ior from the lowerdielectric material layer10ito the upperdielectric material layer10f.
• Therefore, the upperlayer microstrip line251 and thewaveguide structure252′ can be directly connected. The electromagnetic wave S′ based on the millimeter wave signal S can be transmitted to thedielectric material layer10f. The lowerlayer microstrip line251 and thewaveguide structure252′ can be directly connected. The electromagnetic wave S′ based on the millimeter wave signal S can be transmitted to thedielectric material layer10i. In addition, thecoupling circuit205 has the two-layer structure. The electromagnetic wave S′ can be transmitted to the lowerdielectric material layer10i(in the direction of the thickness of the circuit board10) via theslot hole257. The electromagnetic wave S′ can be propagated to the upperdielectric material layer10f(in the direction of the thickness of the circuit board10) via theslot hole257.
• The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, whilst the present invention is not limited to the above examples, of course. A person skilled in the art may find various alternations and modifications within the scope of the appended claims, and it should be understood that they will naturally come under the technical scope of the present invention.
• The invention set forth in claims is not limited by the above embodiments. All of the combinations of the features explained in the embodiments are not absolutely necessary for the solution means of the invention. The above embodiments include various stages of the invention, from which various kinds of inventions can be extracted using an appropriate combination of a plurality of disclosed constituent elements. Even when some of the constituent elements are deleted from all the constituent elements of the embodiments, a constitution from which some of the constituent elements are deleted may be extracted as the invention as long as the effects can be obtained.
• In the mechanism of the embodiments, for example, members at the transmission side and the reception side relating to the millimeter wave transmission are mounted on the same circuit board, and the circuit board is configured to be also used as the tangible object serving as the millimeter wave transmission path. Since the electromagnetic wave between the transmission and the reception based on the millimeter wave signal is transmitted while being shielded within the circuit board, the signal in the millimeter wave band can be transmitted within the electronic apparatus with a lower degree of interference and without any inconvenience.
• This is particularly effective when the dielectric loss tangent of the dielectric material constituting the circuit board also used as the tangible object serving as the millimeter wave transmission path is relatively large.
• In other words, according to the millimeter wave transmission device and the millimeter wave transmission method explained in the embodiments, the millimeter wave signal provided from one end of the tangible object made of the dielectric material (tangible object having the predetermined dielectric constant ε) is received from the other end of the tangible object, and the millimeter wave signal is processed to generate the output signal.
• In the tangible object having a large loss and having a relatively large dielectric loss tangent of the dielectric material, the transmission loss increases but the reflected wave is attenuated as the carrier frequency increases. Therefore, an extremely high-speed signal can be transmitted via the tangible object made of the dielectric material having a large loss. In addition, high-speed communication processing can be achieved with only the limited range of the tangible object. In ranges other than the limited range of the tangible object made of the dielectric material, the attenuation is large, which can greatly reduce interference with those outside of the tangible object.
• According to the millimeter wave transmission system explained in the above embodiments, the millimeter wave transmission device and the millimeter wave transmission method explained in the above embodiments are arranged, and the millimeter wave signal provided from one end of the tangible object made of the dielectric material (tangible object having the predetermined dielectric constant) is received from the other end of the tangible object, and the millimeter wave signal is processed to generate the output signal.
• According to this configuration, in the tangible object having a large loss, the transmission loss increases but the reflected wave is attenuated as the carrier frequency increases. Therefore, an extremely high-speed signal can be transmitted via the tangible object made of the dielectric material having a large loss. In addition, a high-speed baseband signal and the like can be transmitted, and therefore, high-speed bidirectional communication processing can be achieved with only the limited range of the tangible object. In ranges other than the limited range of the tangible object made of the dielectric material, the attenuation is large, which can greatly reduce interference with those outside of the tangible object.
• In the embodiments, the tangible object (tangible object made of the dielectric material) having the predetermined dielectric constant ε has been explained about thecircuit board10 made of glass epoxy resin. However, the tangible object made of a dielectric material is not limited thereto. The inventors of the present application have confirmed that tangible objects made of dielectric material such as a light-gathering sheet and a conducting/insulating sheet made of acrylic and polyethylene resin, an acrylic stick and an acrylic plate, a ballpoint pen in which an ink containing tube and a ballpoint pen body (tube) is made of polyethylene synthetic resin such as polyethylene and polyethylene terephthalate also function as the transmission line for the millimeter wave. The dielectric loss tangent δ of the acrylic and polyethylene resin is generally close to a dielectric loss tangent δ of glass epoxy resin. Therefore, thecircuit board10 explained in the embodiments is not limited to glass epoxy resin, and may be acrylic and polyethylene resin.
• In the explanation of the above embodiments, the dielectric loss tangent δ in the used frequency band is considered to be two levels of magnitudes, i.e., a dielectric loss tangent δ of about 0.001 or less and a dielectric loss tangent δ of about 0.01 or more. However, the above levels are merely examples. An example of a dielectric material having a dielectric loss tangent δ in between these two levels, i.e., a tangent δ of about 0.01 to 0.001, includes a BT resin (tan δ is about 0.004) (see thedocument 1 below). The dielectric material having a tangent δ of about 0.01 to 0.001 is referred to as having “a moderate loss”. For example, a material having “a moderate loss” using the BT resin has characteristic in between the material having “large loss” and the material having “small loss” explained in the above embodiments.
• Reference document 1: “high frequency BT resin glass cloth base copper-clad lamination”, [online], [searched on Sep. 2, 2009], the Internet <URL:http://www.tripleone.net/ENG/img_business/1_2_LX67.pdf>
• It should be noted that linearlity is not necessary for thetransmission lines206,226 and the like. An electromagnetic wave is known to be propagated even intransmission lines206,226 bent 90 degrees (for example, seeFIGS. 12A,15 and the like).
• The mechanism of the present embodiment is extremely suitable for an apparatus in a millimeter wave circuit board, a millimeter wave transmission method, a millimeter wave transmission system, and the like, for transmitting a millimeter wave signal whose carrier frequency is 30 GHz to 300 GHz at a high speed to carry movie images, computer images, and the like.
• As can be understood from the explanation about the embodiments, an aspect of the present embodiment enables execution of high-speed communication processing in the limited range of the tangible object made of the dielectric material, and reduces interference with ranges other than the limited range of the tangible object.
• The mechanisms of the millimeter wave tangible object transmission device, the millimeter wave transmission method, and the millimeter wave transmission system according to the embodiments are applied to, for example, apparatuses and systems for transmitting a millimeter wave signal whose carrier frequency is 30 GHz to 300 GHz at a high speed to carry movie images, computer images, and the like. The millimeter wave signal transmitted from one end of the tangible object made of the dielectric material is received from the other end of the tangible object, and the millimeter wave signal is processed to generate the output signal. The signal can be transmitted at a high speed via the tangible object, and interference with regions outside of the tangible object is reduced.
REFERENCE SIGNS LIST
• 10 circuit board made of glass epoxy resin
• 11,12 antenna member
• 21-28 signal generation unit
• 100,400,500,600,700,800 the millimeter wave transmission device
• 201,221,301,421,401,421,501 signal input terminal
• 202,222,302,322,402,412,422,502 modulating circuit
• 203,223,303,323,403,413,423,503 frequency converting circuit
• 204,304,404,504 amplifier
• 205,207,227,305,307,327,405,407,505 the coupling circuit for coupling with the circuit board
• 206,226,306,326,406,432,506 transmission line
• 208,228,308,328,404,408,414,424,508 amplifier
• 209,223,309,323,403,409,413,423 frequency converting circuit
• 210,230,310,330,410,510 demodulating circuit
• 211,311,411,511 signal output terminal
• 250,250′,259 CMOS chip
• 251 microstrip line
• 252,252′ waveguide structure
• 253 waveguide top panel portion
• 254 wiring pattern
• 255,255′ high-pass filter device
• 256 antenna structure
• 256′ antenna member
• 257,260 slot hole
• 341 waveguide structure
• 431 adder circuit
• 200,300 millimeter wave transmission systems

Claims (19)

1. A millimeter wave transmission device comprising:

a first signal generation unit for generating a millimeter wave signal by performing frequency conversion on an input signal to be transmitted;

a second signal generation unit for demodulating the received millimeter wave signal and generating an output signal corresponding to the input signal to be transmitted; and

a circuit board which is constituted by a dielectric material and including the first signal generation unit and the second signal generation unit,

wherein the circuit board is used as a millimeter wave transmission path between the first signal generation unit and the second signal generation unit.

2. The millimeter wave transmission device according toclaim 1, further comprising:

a first signal coupling unit for transmitting the millimeter wave signal generated by the first signal generation unit to one end of the circuit board; and

a second signal coupling unit for receiving the millimeter wave signal from the other end of the circuit board,

wherein each of the first signal coupling unit and the second signal coupling unit is constituted by an antenna member having a predetermined length based on the millimeter wave signal wavelength.

3. The millimeter wave transmission device according toclaim 2,

wherein the antenna member constituting the second signal coupling unit receives an electromagnetic wave based on the millimeter wave signal transmitted within the tangible object by the antenna member constituting the first signal coupling unit.

4. The millimeter wave transmission device according toclaim 1,

wherein the first signal generation unit includes a modulating circuit for modulating the input signal and a first frequency converting circuit for performing frequency conversion on the signal modulated by the modulating circuit and generating the millimeter wave signal, and

the second signal generation unit includes a second frequency converting circuit for performing frequency conversion on the millimeter wave signal and a demodulating circuit for demodulating the signal output from the second frequency converting circuit and generating the output signal.

5. The millimeter wave transmission device according toclaim 1,

wherein the millimeter wave transmission path is configured such that a transmission region is defined on the circuit board, and the millimeter wave signal is transmitted in such a manner that the millimeter wave signal is shielded in this defined transmission region of the circuit board.

6. The millimeter wave transmission device according toclaim 5,

wherein the transmission region is defined by a plurality of hollow cylindrical opening portions penetrating through the circuit board or a plurality of cylindrical conductive members connecting conductive layers.

7. The millimeter wave transmission device according toclaim 4,

wherein each of the first signal generation unit and the second signal generation unit has an amplifier for amplifying the millimeter wave signal.

8. The millimeter wave transmission device according toclaim 7, further comprising:

a signal quality determination circuit for determining a signal quality by monitoring the output signal provided by the demodulating circuit;

a direct current or low frequency transmission line for transmitting a quality determination signal output from the signal quality determination circuit; and

a gain control circuit for controlling a gain of the amplifier based on the quality determination signal transmitted by the direct current or low frequency transmission line.

9. The millimeter wave transmission device according toclaim 2, comprising:

a first electronic component including the first signal generation unit and the first signal coupling unit; and

a second electronic component including the second signal coupling unit and the second signal generation unit,

wherein the first electronic component and the second electronic component are mounted on the same circuit board.

10. The millimeter wave transmission device according toclaim 1,

wherein the circuit board is constituted by at least one of a glass epoxy resin, an acrylic resin, and a polyethylene resin.

11. The millimeter wave transmission device according toclaim 2,

wherein an electronic component used for signal processing in baseband region of the input signal and the output signal is mounted on the circuit board between a first region of the circuit board including the first signal generation unit and the first signal coupling unit and a second region of the circuit board including the second signal generation unit and the second signal coupling unit.

12. A millimeter wave transmission method,

wherein a circuit board constituted by a dielectric material includes a first signal generation unit for generating a millimeter wave signal by performing frequency conversion on an input signal to be transmitted and a second signal generation unit for demodulating the received millimeter wave signal and generating an output signal corresponding to the input signal to be transmitted, and

the millimeter wave transmission method comprises the steps of:

causing the first signal generation unit to generate the millimeter wave signal by performing frequency conversion on the input signal to be transmitted;

transmitting the millimeter wave signal to one end of the circuit board, and transmitting an electromagnetic wave based on the millimeter wave signal within the circuit board;

receiving a millimeter wave signal based on the electromagnetic wave obtained from the other end of the circuit board; and

causing the second signal generation unit to demodulate the received millimeter wave signal and generating an output signal corresponding to the input signal to be transmitted.

13. The millimeter wave transmission method according toclaim 12,

wherein when the millimeter wave signal is generated, the method includes the steps of:

modulating the input signal; and

performing frequency conversion on the modulated signal, and

when the output signal is generated, the method includes the steps of:

performing frequency conversion on the received millimeter wave signal; and

demodulating the signal having been subjected to the frequency conversion, and generating the output signal.

14. A millimeter wave transmission system comprising:

a first millimeter wave transmission body including a first signal generation unit for generating a millimeter wave signal by performing frequency conversion on a first input signal to be transmitted, a second signal generation unit for demodulating the received millimeter wave signal and generating a first output signal corresponding to the first input signal to be transmitted, and a first circuit board constituted by a dielectric material and including the first signal generation unit and the second signal generation unit, wherein the first circuit board is used as a millimeter wave transmission path between the first signal generation unit and the second signal generation unit;

a second millimeter wave transmission body including a third signal generation unit for generating a millimeter wave signal by performing frequency conversion on a second input signal to be transmitted, a fourth signal generation unit for demodulating the received millimeter wave signal and generating a second output signal corresponding to the second input signal to be transmitted, and a second circuit board constituted by a dielectric material and including the third signal generation unit and the fourth signal generation unit, wherein the second circuit board is used as a millimeter wave transmission path between the third signal generation unit and the fourth signal generation unit; and

a coupling medium for connecting the first millimeter wave transmission body and the second millimeter wave transmission body and propagating an electromagnetic wave based on the millimeter wave signal.

15. The millimeter wave transmission system according toclaim 14,

wherein the first circuit board including the first millimeter wave transmission body and the second circuit board including the second millimeter wave transmission body are the same circuit board, and

the first millimeter wave transmission body and the second millimeter wave transmission body are connected via the coupling medium.

16. The millimeter wave transmission system according toclaim 14,

wherein the coupling medium propagates the millimeter wave signal constituted by a dielectric material different from the first circuit board and the second circuit board.

17. The millimeter wave transmission system according toclaim 14,

wherein the coupling medium is constituted by a waveguide structure for propagating the millimeter wave signal.

18. The millimeter wave transmission system according toclaim 14, comprising:

a plurality of first millimeter wave transmission bodies; and

an adder circuit for adding millimeter wave signals provided from the plurality of first millimeter wave transmission bodies.

19. The millimeter wave transmission system according toclaim 14,

wherein the first circuit board including the first millimeter wave transmission body and the second circuit board including the second millimeter wave transmission body are the same circuit board, and

an electronic component used for signal processing in baseband region of the input signal and the output signal is mounted on the circuit board between a first region of the circuit board including the first millimeter wave transmission body and a second region of the circuit board including the second millimeter wave transmission body.

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