US20130328739A1

Movatterモバイル変換

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Publication number: US20130328739A1
Application number: US13/963,363
Authority: US
Inventors: Ahmadreza Rofougaran; Maryam Rofougaran
Original assignee: Broadcom Corp
Current assignee: Avago Technologies International Sales Pte Ltd
Priority date: 2009-06-09
Filing date: 2013-08-09
Publication date: 2013-12-12
Also published as: TW201145668A; HK1154435A1; US20100309078A1; EP2267835B1; CN101980449B; EP2267835A1; TWI499125B; US8508422B2; CN101980449A

Abstract

Methods and systems for converting RF power to DC power utilizing a leaky wave antenna (LWA) are disclosed and may include receiving RF wireless signals utilizing one or more LWAs in a wireless device, and generating one or more DC voltages from the received RF signals utilizing cascaded rectifier cells. A resonant frequency of the LWAs may be configured utilizing micro-electro-mechanical systems (MEMS) deflection. The LWAs may be configured to receive the RF signals from a desired direction. The LWAs may comprise microstrip or coplanar waveguides, wherein a cavity height of the LWAs is dependent on a spacing between conductive lines in the waveguides. The LWAs may be integrated in one or more integrated circuits, integrated circuit packages, and/or printed circuit boards. The packages may be affixed to one or more printed circuit boards and the integrated circuits may be flip-chip-bonded to the packages.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This application makes reference to, claims the benefit from, and claims priority to U.S. Provisional Application Ser. No. 61/246,618 filed on Sep. 29, 2009, and U.S. Provisional Application Ser. No. 61/185,245 filed on Jun. 9, 2009.

This application also makes reference to:

U.S. patent application Ser. No. 12/650,212 filed on Dec. 30, 2009;
U.S. patent application Ser. No. 12/650,295 filed on Dec. 30, 2009;
U.S. patent application Ser. No. 12/650,277 filed on Dec. 30, 2009;
U.S. patent application Ser. No. 12/650,192 filed on Dec. 30, 2009;
U.S. patent application Ser. No. 12/650,224 filed on Dec. 30, 2009;
U.S. patent application Ser. No. 12/650,176 filed on Dec. 30, 2009;
U.S. patent application Ser. No. 12/650,246 filed on Dec. 30, 2009;
U.S. patent application Ser. No. 12/650,292 filed on Dec. 30, 2009;
U.S. patent application Ser. No. 12/650,324 filed on Dec. 30, 2009;
U.S. patent application Ser. No. 12/708,366 filed on Feb. 18, 2010;
U.S. patent application Ser. No. 12/751,550 filed on Mar. 31, 2010;
U.S. patent application Ser. No. 12/751,768 filed on Mar. 31, 2010;
U.S. patent application Ser. No. 12/751,759 filed on Mar. 31, 2010;
U.S. patent application Ser. No. 12/751,593 filed on Mar. 31, 2010;
U.S. patent application Ser. No. 12/751,772 filed on Mar. 31, 2010;
U.S. patent application Ser. No. 12/751,777 filed on Mar. 31, 2010;
U.S. patent application Ser. No. 12/751,782 filed on Mar. 31, 2010;
U.S. patent application Ser. No. 12/751,792 filed on Mar. 31, 2010;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21204US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21212US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21215US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21216US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21217US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21219US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21221US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21223US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21224US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21225US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21226US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21228US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21229US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21234US02) filed on ______;
U.S. patent application Ser. No. ______ (Attorney Docket No. 21235US02) filed on ______; and
U.S. patent application Ser. No. ______ (Attorney Docket No. 21236US02) filed on ______.

Each of the above stated applications is hereby incorporated herein by reference in its entirety.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[Not Applicable]

[MICROFICHE/COPYRIGHT REFERENCE]

[Not Applicable]

FIELD OF THE INVENTION

Certain embodiments of the invention relate to wireless communication. More specifically, certain embodiments of the invention relate to a method and system for converting RF power to DC power utilizing a leaky wave antenna.

BACKGROUND OF THE INVENTION

Mobile communications have changed the way people communicate and mobile phones have been transformed from a luxury item to an essential part of every day life. The use of mobile phones is today dictated by social situations, rather than hampered by location or technology. While voice connections fulfill the basic need to communicate, and mobile voice connections continue to filter even further into the fabric of every day life, the mobile Internet is the next step in the mobile communication revolution. The mobile Internet is poised to become a common source of everyday information, and easy, versatile mobile access to this data will be taken for granted.

As the number of electronic devices enabled for wireline and/or mobile communications continues to increase, significant efforts exist with regard to making such devices more power efficient. For example, a large percentage of communications devices are mobile wireless devices and thus often operate on battery power. Additionally, transmit and/or receive circuitry within such mobile wireless devices often account for a significant portion of the power consumed within these devices. Moreover, in some conventional communication systems, transmitters and/or receivers are often power inefficient in comparison to other blocks of the portable communication devices. Accordingly, these transmitters and/or receivers have a significant impact on battery life for these mobile wireless devices.

Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.

BRIEF SUMMARY OF THE INVENTION

A system and/or method for converting RF power to DC power utilizing a leaky wave antenna as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.

Various advantages, aspects and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary wireless system with leaky wave antennas for receiving RF signals to convert to DC voltages, which may be utilized in accordance with an embodiment of the invention.

FIG. 2 is a block diagram illustrating an exemplary leaky wave antenna, in accordance with an embodiment of the invention.

FIG. 3 is a block diagram illustrating a plan view of exemplary partially reflective surfaces, in accordance with an embodiment of the invention.

FIG. 4 is a block diagram illustrating an exemplary phase dependence of a leaky wave antenna, in accordance with an embodiment of the invention.

FIG. 5 is a block diagram illustrating exemplary in-phase and out-of-phase beam shapes for a leaky wave antenna, in accordance with an embodiment of the invention.

FIG. 6 is a block diagram illustrating a leaky wave antenna with variable input impedance feed points, in accordance with an embodiment of the invention.

FIG. 7 is a block diagram illustrating a cross-sectional view of coplanar and microstrip waveguides, in accordance with an embodiment of the invention.

FIG. 8 is a diagram illustrating a cross-sectional view of an integrated circuit package with integrated leaky wave antennas for receiving RF signals, in accordance with an embodiment of the invention.

FIG. 9 is a block diagram illustrating an exemplary RF to DC module, in accordance with an embodiment of the invention.

FIG. 10 is a block diagram illustrating exemplary steps for converting RF power received by leaky wave antennas to DC power, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a block diagram of an exemplary wireless system with leaky wave antennas for receiving RF signals to convert to DC voltages, which may be utilized in accordance with an embodiment of the invention. Referring toFIG. 1, thewireless device150 may comprise anantenna151, atransceiver152, abaseband processor154, aprocessor156, asystem memory158, alogic block160, achip162,leaky wave antennas164, switches165, anexternal headset port166, anintegrated circuit package167, and an RF-to-DC module169. Thewireless device150 may also comprise ananalog microphone168, integrated hands-free (IHF)stereo speakers170, a printedcircuit board171, a hearing aid compatible (HAC)coil174, a dual digital microphone176, avibration transducer178, a keypad and/ortouchscreen180, and adisplay182.

Thetransceiver152 may comprise suitable logic, circuitry, interface(s), and/or code that may be enabled to modulate and upconvert baseband signals to RF signals for transmission by one or more antennas, which may be represented generically by theantenna151. Thetransceiver152 may also be enabled to downconvert and demodulate received RF signals to baseband signals. The RF signals may be received by one or more antennas, which may be represented generically by theantenna151, or theleaky wave antennas164. Different wireless systems may use different antennas for transmission and reception. Thetransceiver152 may be enabled to execute other functions, for example, filtering the baseband and/or RF signals, and/or amplifying the baseband and/or RF signals. Although asingle transceiver152 is shown, the invention is not so limited. Accordingly, thetransceiver152 may be implemented as a separate transmitter and a separate receiver. In addition, there may be a plurality of transceivers, transmitters and/or receivers. In this regard, the plurality of transceivers, transmitters and/or receivers may enable thewireless device150 to handle a plurality of wireless protocols and/or standards including cellular, WLAN and PAN. Wireless technologies handled by thewireless device150 may comprise GSM, CDMA, CDMA2000, WCDMA, GMS, GPRS, EDGE, WIMAX, WLAN, 3GPP, UMTS, BLUETOOTH, and ZigBee, for example.

Thebaseband processor154 may comprise suitable logic, circuitry, interface(s), and/or code that may be enabled to process baseband signals for transmission via thetransceiver152 and/or the baseband signals received from thetransceiver152. Theprocessor156 may be any suitable processor or controller such as a CPU, DSP, ARM, or any type of integrated circuit processor. Theprocessor156 may comprise suitable logic, circuitry, and/or code that may be enabled to control the operations of thetransceiver152 and/or thebaseband processor154. For example, theprocessor156 may be utilized to update and/or modify programmable parameters and/or values in a plurality of components, devices, and/or processing elements in thetransceiver152 and/or thebaseband processor154. At least a portion of the programmable parameters may be stored in thesystem memory158.

Control and/or data information, which may comprise the programmable parameters, may be transferred from other portions of thewireless device150, not shown inFIG. 1, to theprocessor156. Similarly, theprocessor156 may be enabled to transfer control and/or data information, which may include the programmable parameters, to other portions of thewireless device150, not shown inFIG. 1, which may be part of thewireless device150.

Theprocessor156 may utilize the received control and/or data information, which may comprise the programmable parameters, to determine an operating mode of thetransceiver152. For example, theprocessor156 may be utilized to select a specific frequency for a local oscillator, a specific gain for a variable gain amplifier, configure the local oscillator and/or configure the variable gain amplifier for operation in accordance with various embodiments of the invention. Moreover, the specific frequency selected and/or parameters needed to calculate the specific frequency, and/or the specific gain value and/or the parameters, which may be utilized to calculate the specific gain, may be stored in thesystem memory158 via theprocessor156, for example. The information stored insystem memory158 may be transferred to thetransceiver152 from thesystem memory158 via theprocessor156.

Thesystem memory158 may comprise suitable logic, circuitry, interface(s), and/or code that may be enabled to store a plurality of control and/or data information, including parameters needed to calculate frequencies and/or gain, and/or the frequency value and/or gain value. Thesystem memory158 may store at least a portion of the programmable parameters that may be manipulated by theprocessor156.

Thelogic block160 may comprise suitable logic, circuitry, interface(s), and/or code that may enable controlling of various functionalities of thewireless device150. For example, thelogic block160 may comprise one or more state machines that may generate signals to control thetransceiver152 and/or thebaseband processor154. Thelogic block160 may also comprise registers that may hold data for controlling, for example, thetransceiver152 and/or thebaseband processor154. Thelogic block160 may also generate and/or store status information that may be read by, for example, theprocessor156. Amplifier gains and/or filtering characteristics, for example, may be controlled by thelogic block160.

The BT radio/processor163 may comprise suitable circuitry, logic, interface(s), and/or code that may enable transmission and reception of Bluetooth signals. The BT radio/processor163 may enable processing and/or handling of BT baseband signals. In this regard, the BT radio/processor163 may process or handle BT signals received and/or BT signals transmitted via a wireless communication medium. The BT radio/processor163 may also provide control and/or feedback information to/from thebaseband processor154 and/or theprocessor156, based on information from the processed BT signals. The BT radio/processor163 may communicate information and/or data from the processed BT signals to theprocessor156 and/or to thesystem memory158. Moreover, the BT radio/processor163 may receive information from theprocessor156 and/or thesystem memory158, which may be processed and transmitted via the wireless communication medium a Bluetooth headset, for example.

The RF-to-DC module169 may comprise suitable circuitry, logic, interfaces, and/or code that may be operable to convert a received RF signal to one or more DC voltages. The RF-to-DC module169 may comprise on-chip, on-package, and/or on printed-circuit board components that may be operable to generate one or more DC voltages through rectification of RF AC signals and charging storage elements such as CMOS capacitors, for example.

TheCODEC172 may comprise suitable circuitry, logic, interface(s), and/or code that may process audio signals received from and/or communicated to input/output devices. The input devices may be within or communicatively coupled to thewireless device150, and may comprise theanalog microphone168, thestereo speakers170, the hearing aid compatible (HAC)coil174, the dual digital microphone176, and thevibration transducer178, for example. TheCODEC172 may be operable to up-convert and/or down-convert signal frequencies to desired frequencies for processing and/or transmission via an output device. TheCODEC172 may enable utilizing a plurality of digital audio inputs, such as 16 or 18-bit inputs, for example. TheCODEC172 may also enable utilizing a plurality of data sampling rate inputs. For example, theCODEC172 may accept digital audio signals at sampling rates such as 8 kHz, 11.025 kHz, 12 kHz, 16 kHz, 22.05 kHz, 24 kHz, 32 kHz, 44.1 kHz, and/or 48 kHz. TheCODEC172 may also support mixing of a plurality of audio sources. For example, theCODEC172 may support audio sources such as general audio, polyphonic ringer, I²S FM audio, vibration driving signals, and voice. In this regard, the general audio and polyphonic ringer sources may support the plurality of sampling rates that theaudio CODEC172 is enabled to accept, while the voice source may support a portion of the plurality of sampling rates, such as 8 kHz and 16 kHz, for example.

Thechip162 may comprise an integrated circuit with multiple functional blocks integrated within, such as thetransceiver152, theprocessor156, thebaseband processor154, the BT radio/processor163, and theCODEC172. The number of functional blocks integrated in thechip162 is not limited to the number shown inFIG. 1. Accordingly, any number of blocks may be integrated on thechip162 depending on chip space andwireless device150 requirements, for example. Thechip162 may be flip-chip bonded, for example, to thepackage167, as described further with respect toFIG. 8.

Theleaky wave antennas164 may comprise a resonant cavity with a highly reflective surface and a lower reflectivity surface, and may be integrated in and/or on thepackage167. In addition, leaky wave antennas may be integrated on thechip162 and/or the printedcircuit board171. The lower reflectivity surface may allow the resonant mode to “leak” out of the cavity. The lower reflectivity surface of theleaky wave antennas164 may be configured with slots in a metal surface, or a pattern of metal patches, as described further inFIGS. 2 and 3. The physical dimensions of theleaky wave antennas164 may be configured to optimize bandwidth of transmission and/or the beam pattern radiated. By integrating theleaky wave antennas164 on thepackage167 and/or the printedcircuit board171, the dimensions of theleaky wave antennas164 may not be limited by the size of thechip162.

In an exemplary embodiment of the invention, theleaky wave antennas164 may be operable to transmit and/or receive RF signals, and may enable the generation of DC voltages for use in thewireless device150 by converting received RF signals utilizing the RF-to-DC module169.

Theswitches165 may comprise switches such as CMOS or MEMS switches that may be operable to switch different antennas of theleaky wave antennas164 to thetransceiver152 and/or switch elements in and/or out of theleaky wave antennas164, such as the patches and slots described inFIG. 3.

Theexternal headset port166 may comprise a physical connection for an external headset to be communicatively coupled to thewireless device150. Theanalog microphone168 may comprise suitable circuitry, logic, interface(s), and/or code that may detect sound waves and convert them to electrical signals via a piezoelectric effect, for example. The electrical signals generated by theanalog microphone168 may comprise analog signals that may require analog to digital conversion before processing.

Thepackage167 may comprise a ceramic package, a printed circuit board, or other support structure for thechip162 and other components of thewireless device150. In this regard, thechip162 may be bonded to thepackage167. Thepackage167 may comprise insulating and conductive material, for example, and may provide isolation between electrical components mounted on thepackage167.

Thestereo speakers170 may comprise a pair of speakers that may be operable to generate audio signals from electrical signals received from theCODEC172. TheHAC coil174 may comprise suitable circuitry, logic, and/or code that may enable communication between thewireless device150 and a T-coil in a hearing aid, for example. In this manner, electrical audio signals may be communicated to a user that utilizes a hearing aid, without the need for generating sound signals via a speaker, such as thestereo speakers170, and converting the generated sound signals back to electrical signals in a hearing aid, and subsequently back into amplified sound signals in the user's ear, for example.

The dual digital microphone176 may comprise suitable circuitry, logic, interface(s), and/or code that may be operable to detect sound waves and convert them to electrical signals. The electrical signals generated by the dual digital microphone176 may comprise digital signals, and thus may not require analog to digital conversion prior to digital processing in theCODEC172. The dual digital microphone176 may enable beamforming capabilities, for example.

Thevibration transducer178 may comprise suitable circuitry, logic, interface(s), and/or code that may enable notification of an incoming call, alerts and/or message to thewireless device150 without the use of sound. The vibration transducer may generate vibrations that may be in synch with, for example, audio signals such as speech or music.

In operation, control and/or data information, which may comprise the programmable parameters, may be transferred from other portions of thewireless device150, not shown inFIG. 1, to theprocessor156. Similarly, theprocessor156 may be enabled to transfer control and/or data information, which may include the programmable parameters, to other portions of thewireless device150, not shown inFIG. 1, which may be part of thewireless device150.

TheCODEC172 in thewireless device150 may communicate with theprocessor156 in order to transfer audio data and control signals. Control registers for theCODEC172 may reside within theprocessor156. Theprocessor156 may exchange audio signals and control information via thesystem memory158. TheCODEC172 may up-convert and/or down-convert the frequencies of multiple audio sources for processing at a desired sampling rate.

Theleaky wave antennas164 may be operable to transmit and/or receive wireless signals. Received RF signals may be converted to one or more DC voltages by the RF-to-DC module169. In this manner, power may be supplied by devices external to thewireless device150. Resonant cavities may be configured between reflective surfaces in and/or on thepackage167 so that signals may be transmitted and/or received from any location on thepackage167 without requiring large areas needed for conventional antennas and associated circuitry.

The frequency of the transmission and/or reception may be determined by the cavity height of theleaky wave antennas164. Accordingly, the reflective surfaces may be integrated at different heights or lateral spacing in thepackage167, thereby configuring leaky wave antennas with different resonant frequencies.

In an exemplary embodiment of the invention, the resonant cavity frequency of theleaky wave antennas164 may be configured by tuning the cavity height using MEMS actuation. Accordingly, a bias voltage may be applied such that one or both of the reflective surfaces of theleaky wave antennas164 may be deflected by the applied potential. In this manner, the cavity height, and thus the resonant frequency of the cavity, may be configured. Similarly, the patterns of slots and/or patches in the partially reflected surface may be configured by theswitches165.

Different frequency signals may be transmitted and/or received by theleaky wave antennas164 by selectively coupling thetransceiver152 to leaky wave antennas with different cavity heights. For example, leaky wave antennas with reflective surfaces on the top and the bottom of thepackage167 may have the largest cavity height, and thus provide the lowest resonant frequency. Conversely, leaky wave antennas with a reflective surface on the surface of thepackage167 and another reflective surface just below the surface of thepackage167, may provide a higher resonant frequency. The selective coupling may be enabled by theswitches165 and/or CMOS devices in thechip162.

FIG. 2 is a block diagram illustrating an exemplary leaky wave antenna, in accordance with an embodiment of the invention. Referring toFIG. 2, there is shown theleaky wave antennas164 comprising a partiallyreflective surface201A, areflective surface201B, and afeed point203. The space between the partiallyreflective surface201A and thereflective surface201B may be filled with dielectric material, for example, and the height, h, between the partiallyreflective surface201A and thereflective surface201B may be utilized to configure the frequency of transmission of theleaky wave antennas164. In another embodiment of the invention, an air gap may be integrated in the space between the partiallyreflective surface201A and thereflective surface201B to enable MEMS actuation. There is also shown (micro-electromechanical systems) MEMS bias voltages, +V_MEMSand −V_MEMS.

Thefeed point203 may comprise an input terminal for applying an input voltage to theleaky wave antennas164. The invention is not limited to asingle feed point203, as there may be any amount of feed points for different phases of signal or a plurality of signal sources, for example, to be applied to theleaky wave antennas164.

In an embodiment of the invention, the height, h, may be one-half the wavelength of the desired transmitted mode from theleaky wave antennas164. In this manner, the phase of an electromagnetic mode that traverses the cavity twice may be coherent with the input signal at thefeed point203, thereby configuring a resonant cavity known as a Fabry-Perot cavity. The magnitude of the resonant mode may decay exponentially in the lateral direction from thefeed point203, thereby reducing or eliminating the need for confinement structures to the sides of theleaky wave antennas164. The input impedance of theleaky wave antennas164 may be configured by the vertical placement of thefeed point203, as described further inFIG. 6.

In operation, a signal to be transmitted via a power amplifier in thetransceiver152 may be communicated to thefeed point203 of theleaky wave antennas164 with a frequency f, or a signal to be received by theleaky wave antennas164 may be directed at the antenna. The cavity height, h, may be configured to correlate to one half the wavelength of a harmonic of the signal of frequency f. The signal may traverse the height of the cavity and may be reflected by the partiallyreflective surface201A, and then traverse the height back to thereflective surface201B. Since the wave will have traveled a distance corresponding to a full wavelength, constructive interference may result and a resonant mode may thereby be established.

Leaky wave antennas may enable the configuration of high gain antennas without the need for a large array of antennas which require a complex feed network and suffer from loss due to feed lines. Theleaky wave antennas164 may be operable to transmit and/or receive wireless signals via conductive layers in and/or on thepackage167. In this manner, the resonant frequency of the cavity may cover a wider range due to the larger size of thepackage167, compared to thechip162, without requiring large areas needed for conventional antennas and associated circuitry. In addition, by integrating leaky wave antennas in a plurality of packages on one or more printed circuit boards, wireless communication between packages may be enabled.

In an exemplary embodiment of the invention, the frequency of transmission and/or reception of theleaky wave antennas164 may be configured by selecting one of theleaky wave antennas164 with the appropriate cavity height for the desired frequency.

In another embodiment of the invention, the cavity height, h, may be configured by MEMS actuation. For example, the bias voltages +V_MEMSand −V_MEMSmay deflect one or both of the

reflective surfaces

201A and201B compared to zero bias, thereby configuring the resonant frequency of the cavity.

Theleaky wave antennas164 may receive RF signals that may be utilized to generate one or more DC voltages that may be used to power circuitry in thewireless device150. In this manner, thewireless device150 may operate without a batter or with reduced power storage capabilities.

FIG. 3 is a block diagram illustrating a plan view of exemplary partially reflective surfaces, in accordance with an embodiment of the invention. Referring toFIG. 3, there is shown a partiallyreflective surface300 comprising periodic slots in a metal surface, and a partiallyreflective surface320 comprising periodic metal patches. The partiallyreflective surfaces300/320 may comprise different embodiments of the partiallyreflective surface201A described with respect toFIG. 2.

The spacing, dimensions, shape, and orientation of the slots and/or patches in the partiallyreflective surfaces300/320 may be utilized to configure the bandwidth, and thus Q-factor, of the resonant cavity defined by the partiallyreflective surfaces300/320 and a reflective surface, such as thereflective surface201B, described with respect toFIG. 2. The partiallyreflective surfaces300/320 may thus comprise frequency selective surfaces due to the narrow bandwidth of signals that may leak out of the structure as configured by the slots and/or patches.

The spacing between the patches and/or slots may be related to wavelength of the signal transmitted and/or received, which may be somewhat similar to beamforming with multiple antennas. The length of the slots and/or patches may be several times larger than the wavelength of the transmitted and/or received signal or less, for example, since the leakage from the slots and/or regions surround the patches may add up, similar to beamforming with multiple antennas.

In an embodiment of the invention, the slots/patches may be configured via CMOS and/or micro-electromechanical system (MEMS) switches, such as theswitches165 described with respect toFIG. 1, to tune the Q of the resonant cavity. The slots and/or patches may be configured in conductive layers in and/or on thepackage167 and may be shorted together or switched open utilizing theswitches165. In this manner, RF signals, such as 60 GHz signals, for example, may be transmitted from various locations without the need for additional circuitry and conventional antennas with their associated circuitry that require valuable chip space.

In another embodiment of the invention, the slots or patches may be configured in conductive layers in a vertical plane of thechip162, thepackage167, and/or the printedcircuit board171, thereby enabling the communication of wireless signals in a horizontal direction in the structure.

In another exemplary embodiment of the invention, the partiallyreflective surfaces300/320 may be integrated in and/or on thepackage167. In this manner, different frequency signals may be transmitted and/or received. Accordingly, a partiallyreflective surface300/320 integrated within thepackage167 and areflective surface201B may transmit and/or receive signals at a higher frequency signal than from a resonant cavity defined by a partiallyreflective surface300/320 on surface of thepackage167 and areflective surface201B on the other surface of thepackage167.

FIG. 4 is a block diagram illustrating an exemplary phase dependence of a leaky wave antenna, in accordance with an embodiment of the invention. Referring toFIG. 4, there is shown a leaky wave antenna comprising the partiallyreflective surface201A, thereflective surface201B, and thefeed point203. In-phase condition400 illustrates the relative beam shape transmitted by theleaky wave antennas164 when the frequency of the signal communicated to thefeed point203 matches that of the resonant cavity as defined by the cavity height, h, and the dielectric constant of the material between the reflective surfaces.

By configuring the leaky wave antennas for in-phase and out-of-phase conditions, signals possessing different characteristics may be directed out of and/or into thepackage167 in desired directions, thereby enabling wireless communication between a plurality of packages or devices. In an exemplary embodiment of the invention, the angle at which signals may be transmitted by a leaky wave antenna may be dynamically controlled so that signal may be directed to desired receiving leaky wave antennas. In another embodiment of the invention, theleaky wave antennas164 may be operable to receive RF signals, such as 60 GHz signals, for example. The direction in which the signals are received may be configured by the in-phase and out-of-phase conditions.

In an exemplary embodiment of the invention, by configuring the leaky wave antennas to receive RF signals from any desired direction, thewireless device150 may then be operable to generate DC voltages from other RF transmitting devices in any direction from thewireless device150.

FIG. 5 is a block diagram illustrating exemplary in-phase and out-of-phase beam shapes for a leaky wave antenna, in accordance with an embodiment of the invention. Referring toFIG. 5, there is shown aplot500 of transmitted signal beam shape versus angle, Θ, for the in-phase and out-of-phase conditions for a leaky wave antenna.

The In-phase curve in theplot500 may correlate to the case where the frequency of the signal communicated to a leaky wave antenna matches the resonant frequency of the cavity. In this manner, a single vertical main node may result. In instances where the frequency of the signal at the feed point is not at the resonant frequency, a double, or conical-shaped node may be generated as shown by the Out-of-phase curve in theplot500. By configuring the leaky wave antennas for in-phase and out-of-phase conditions, signals may be directed out of thechip162,package167, and/or the printedcircuit board171 in desired directions.

In another embodiment of the invention, theleaky wave antennas164 may be operable to receive wireless signals, and may be configured to receive from a desired direction via the in-phase and out-of-phase configurations. In this manner, DC voltages may be generated by RF signals received from a plurality of directions from theleaky wave antennas164.

FIG. 6 is a block diagram illustrating a leaky wave antenna with variable input impedance feed points, in accordance with an embodiment of the invention. Referring toFIG. 6, there is shown aleaky wave antenna600 comprising the partiallyreflective surface201A and thereflective surface201B. There is also shown feed points601A-601C. The feed points601A-601C may be located at different positions along the height, h, of the cavity thereby configuring different impedance points for the leaky wave antenna.

In this manner, a leaky wave antenna may be utilized to couple to a plurality of power amplifiers, low-noise amplifiers, and/or other circuitry with varying output or input impedances. Similarly, by integrating leaky wave antennas in conductive layers in thepackage167, the impedance of the leaky wave antenna may be matched to the power amplifier or low-noise amplifier without impedance variations that may result with conventional antennas and their proximity or distance to associated driver electronics. In addition, by integrating reflective and partially reflective surfaces with varying cavity heights and varying feed points, leaky wave antennas with different impedances and resonant frequencies may be enabled. In an embodiment of the invention, the heights of the feed points601A-601C may be configured by MEMS actuation.

FIG. 7 is a block diagram illustrating a cross-sectional view of coplanar and microstrip waveguides, in accordance with an embodiment of the invention. Referring toFIG. 7, there is shown amicrostrip waveguide720 and acoplanar waveguide730 and asupport structure701. Themicrostrip waveguide720 may comprise signalconductive lines723, aground plane725, aresonant cavity711A, and an insulatinglayer727. Thecoplanar waveguide730 may comprise signal

conductive lines

731 and733, aresonant cavity711B, the insulatinglayer727, and amulti-layer support structure701. Thesupport structure701 may comprise thechip162, thepackage167, and/or the printedcircuit board171, for example.

The signal

conductive lines

723,731, and733 may comprise metal traces or layers deposited in and/or on the insulatinglayer727. In another embodiment of the invention, the signal

conductive lines

723,731, and733 may comprise poly-silicon or other conductive material. The separation and the voltage potential between the signalconductive line723 and theground plane725 may determine the electric field generated therein. In addition, the dielectric constant of the insulatinglayer727 may also determine the electric field between the signalconductive line723 and theground plane725.

The

resonant cavities

711A and711B may comprise the insulatinglayer727, an air gap, or a combination of an air gap and the insulatinglayer727, thereby enabling MEMS actuation and thus frequency tuning.

The insulatinglayer727 may comprise SiO₂or other insulating material that may provide a high resistance layer between the signalconductive line723 and theground plane725, and the signal

conductive lines

731 and733. In addition, the electric field between the signalconductive line723 and theground plane725 may be dependent on the dielectric constant of the insulatinglayer727.

The thickness and the dielectric constant of the insulatinglayer727 may determine the electric field strength generated by the applied signal. The resonant cavity thickness of a leaky wave antenna may be dependent on the spacing between the signalconductive line723 and theground plane725, or the signal

conductive lines

731 and733, for example.

The signal

conductive lines

731 and733, and the signalconductive line723 and theground plane725 may define resonant cavities for leaky wave antennas. Each layer may comprise a reflective surface or a partially reflective surface depending on the pattern of conductive material. For example, a partially reflective surface may be configured by alternating conductive and insulating material in a desired pattern. In this manner, signals may be directed out of, or received into, a surface of thechip162, thepackage167, and/or the printedcircuit board171, as illustrated with themicrostrip waveguide720. In another embodiment of the invention, signals may be communicated in the horizontal plane of thechip162, thepackage167, and/or the printedcircuit board171 utilizing thecoplanar waveguide730.

Thesupport structure701 may provide mechanical support for themicrostrip waveguide720, thecoplanar waveguide730, and other devices that may be integrated within. In another embodiment of the invention, thechip162, thepackage167, and/or the printedcircuit board171 may comprise Si, GaAs, sapphire, InP, GaO, ZnO, CdTe, CdZnTe, ceramics, polytetrafluoroethylene, and/or Al₂O₃, for example, or any other substrate material that may be suitable for integrating microstrip structures.

In operation, a bias and/or a signal voltage may be applied across the signalconductive line723 and theground plane725, and/or the signal

conductive lines

731 and733. The thickness of a leaky wave antenna resonant cavity may be dependent on the distance between the conductive lines in themicrostrip waveguide720 and/or thecoplanar transmission waveguide730.

By alternating patches of conductive material with insulating material, or slots of conductive material in dielectric material, a partially reflective surface may result, which may allow a signal to “leak out” in that direction, as shown by the Leaky Wave arrows inFIG. 7. In this manner, wireless signals may be directed in to or out of the surface plane of the support structure710, or parallel to the surface of the support structure710.

Similarly, by sequentially placing the

conductive signal lines

731 and733 with different spacing, different cavity heights may result, and thus different resonant frequencies, thereby forming a distributed leaky wave antenna. In this manner, a plurality of signals at different frequencies may be transmitted from, or received by, the distributed leaky wave antenna.

By integrating the

conductive signal lines

731 and733 and theground plane725 in thepackage167, wireless signals may be received by thepackage167. Wireless signals may be communicated packages in the horizontal or vertical planes depending on which type of leaky wave antenna is enabled, such as a coplanar or microstrip structure. Received RF signals may be communicated to RF-to-DC circuitry that may be operable to generate one or more DC voltages from the received RF signals, as described further with respect toFIG. 9.

FIG. 8 is a diagram illustrating a cross-sectional view of an integrated circuit package with integrated leaky wave antennas for receiving RF signals, in accordance with an embodiment of the invention. Referring toFIG. 8, there is shown thepackage167,metal layers801A-801G,solder balls803, an interconnect layer805,thermal epoxy807,leaky wave antennas811A-811C, and anRF signal source820. Thechip162 and the printedcircuit board171 may be as described previously.

Thechip162, or integrated circuit, may comprise one or more components and/or systems within thewireless system150. Thechip162 may be bump-bonded or flip-chip bonded to thepackage167 utilizing thesolder balls803. In this manner, wire bonds connecting thechip162 to thepackage167 may be eliminated, thereby reducing and/or eliminating uncontrollable stray inductances due to wire bonds, for example. In addition, the thermal conductance out of thechip162 may be greatly improved utilizing thesolder balls803 and thethermal epoxy807. Thethermal epoxy807 may be electrically insulating but thermally conductive to allow for thermal energy to be conducted out of thechip162 to the much larger thermal mass of thepackage167.

The metal layers801A-801G may comprise deposited metal layers utilized to delineate leaky wave antennas and interconnects in and/or on thepackage167. The metal layers801A-801G may be utilized to define leaky wave antennas on thepackage167. In an embodiment of the invention, the spacing between pairs of metal layers, for example801A and801B,801C and801D, and801E and801F, may define a resonant cavity of a leaky wave antenna with cavity heights determined by the spacing between the metal layers. In this regard, a partially reflective surface, as shown inFIGS. 2 and 3, for example, may enable the resonant electromagnetic mode in the cavity to leak out from that surface.

In an exemplary embodiment of the invention the metal layers801C and801D may both comprise partially reflective surfaces, thereby enabling bi-directional reception and/or transmission. For example, theleaky wave antenna811B may be operable to receive RF signals from external devices such as theRF signal source820 and may also transmit RF signals to theleaky wave antenna811C. In another embodiment of the invention, theleaky wave antenna811B may comprise stacked leaky wave antennas with a common conductive surface, with thereby enabling bi-directional transmission/reception.

The metal layers801A-801G may comprise a coplanar and/or a microstrip structure as described with respect toFIG. 7. Themetal layer801G may comprise conductive material that may provide electrical contact to theleaky wave antenna811A and other layers and/or devices in thepackage167.

The number of metal layers are not limited to the number ofmetal layers801A-801G shown inFIG. 8. Accordingly, there may be any number of layers embedded within and/or on thepackage167, depending on the number of leaky wave antennas, traces, waveguides and other devices fabricated within and/or on thepackage167.

Thesolder balls803 may comprise spherical balls of metal to provide electrical, thermal and physical contact between thechip162, thepackage167, and/or the printedcircuit board171. In making the contact with thesolder balls803, thechip162 and/or thepackage167 may be pressed with enough force to squash the metal spheres somewhat, and may be performed at an elevated temperature to provide suitable electrical resistance and physical bond strength. Thethermal epoxy807 may fill the volume between thesolder balls803 and may provide a high thermal conductance path for heat transfer out of thechip162.

TheRF signal source820 may comprise a wireless device with one or more leaky wave antennas that may be operable to communicate RF signals to theleaky wave antennas811A-811C. For example, theRF signal source820 may comprise an access point.

In operation, thechip162 may comprise an RF front end, such as theRF transceiver152, described with respect toFIG. 1, and may be utilized to transmit and/or receive RF signals, at 60 GHz, for example. Thechip162 may be electrically coupled to thepackage167. Leaky wave antennas comprising the metal layers801A-801G integrated on or within thepackage167 may be enabled to receive RF signals that may be utilized to generate one or more DC voltages utilizing RF-to-DC circuitry, as described with respect toFIG. 9. Additionally, by utilizing a plurality of leaky wave antennas with configurable direction of reception, RF signals from any direction may be utilized to generate DC voltages.

Heat from thechip162 may be conducted to thepackage167 via thethermal epoxy807 and thesolder balls803. In an embodiment of the invention, the metal layers801A-801G may be configured at different heights in thepackage167 enabling the configuration of leaky wave antennas with different resonant frequencies.

Theleaky wave antennas811A-811C comprising the metal layers801A-801F may be configured by adjusting the spacing between the pairs of metal layers comprising a resonant cavity, and may be configurable via MEMS actuation, as described with respect toFIG. 2. Accordingly, the cavity height of a leaky wave antenna may be defined by a MEMS switch such that applying a bias may increase or decrease the spacing, thereby further configuring the resonant frequency of the leaky wave antenna. In addition, the slots and/or patches in the metal layer comprising a partially reflective surface for the leaky wave antenna, may be configured via one or more switches, which may alter the Q-factor of the cavity. In this manner, the communication parameters of leaky wave antennas integrated into thepackage167 may be configured for a plurality of applications.

The integration of leaky wave antennas in thepackage167, may result in the reduction of stray impedances when compared to wire-bonded connections to devices on printed circuit boards as in conventional systems, particularly for higher frequencies, such as 60 GHz. In this manner, volume requirements may be reduced and performance may be improved due to lower losses and accurate control of impedances via switches in thechip162 or on thepackage167, for example.

FIG. 9 is a block diagram illustrating an exemplary RF to DC module, in accordance with an embodiment of the invention. Referring toFIG. 9, there is shown an RF-to-DC converter900 comprising CMOS transistors M1a, M1b, M2a, M2b, MNa, and MNb, and capacitors C1a, C1b, C2a, C2b, CNa, and CNb. There is also shown an input RF signal and an output voltage DC. The element references MNc and MNd indicate that the RF-to-DC converter900 may comprise N stages, where N is an integer. The capacitors and CMOS transistors may comprise cascaded rectifier cells, such as the

rectifier cells

920,930, and940.

Each of the CMOS transistors M1a, M1b, M2a, M2b, MNa, and MNb may comprise diode-connected MOSFETs to enable rectification of AC signals. The capacitors C1a, C1b, C2a, C2b, CNa, and CNb may be operable to receive charge from forward-biased CMOS transistors due to the applied RF signal. The DC voltage, VDC, may be equal to 2*N*(VRF−Vdrop), where N is the number of stages, VRF is the magnitude of the applied RF signal, and Vdrop is the voltage drop across the forward-biased diode-connected CMOS transistors M1a, M1b, M2a, M2b, MNa, and MNb. Therefore, transistors with lower threshold voltage, and thus lower Vdrop, such as native MOSFETS, may result in increased efficiency.

In operation, an RF signal, RF, may be applied to the RF-to-DC converter900. In instances where the voltage of the applied signal, RF, is positive and the magnitude greater than the turn-on voltage for the CMOS transistors, the CMOS transistors M1b, M2b. . . MNb may be switched on and allow current to charge the capacitors. Similarly, when the voltage of the applied signal, RF, is negative with a magnitude greater than the turn-on voltage of the CMOS transistors, the CMOS transistors M1a, M2a. . . MNa may be switched on allowing the capacitors C1a, C2a, . . . , and CNa to be charged by current in the opposite direction. By cascading N rectifier cells, such asrectifier cell1920,

rectifier cell

2,930, . . . , andrectifier cell N940, large DC voltages may be generated at the output labeled VDC with a magnitude equal to 2*N*(VRF−Vdrop).

FIG. 10 is a block diagram illustrating exemplary steps for converting RF power received by leaky wave antennas to DC power, in accordance with an embodiment of the invention. Referring toFIG. 10, instep1003 afterstart step1001, one or more leaky wave antennas may be configured for a desired frequency via MEMS deflection or by selection of one or more leaky wave antennas with an appropriate cavity height in the package, for example. In addition, the Q of the cavity may be adjusted via shorting and/or opening slots or patches in the partially reflective surface, and/or may configure the direction of reception of the leaky wave antennas. Instep1005, high frequency RF signals may be received by the leaky wave antennas. Instep1007, the high frequency signals may be converted to one or more DC voltages for use in thewireless device150. Instep1009, in instances where thewireless device150 is to be powered down, the exemplary steps may proceed to endstep1011. Instep1009, in instances where thewireless device150 is not to be powered down, the exemplary steps may proceed to step1003 to configure the leaky wave antenna at a desired frequency/Q-factor/direction of reception.

In an embodiment of the invention, a method and system are disclosed for receiving RF wireless signals utilizing one or more

leaky wave antennas

164,400,420,600,720,730,801A-801C in awireless device150, and generating one or more DC voltages for use in thewireless device150 from the received RF signals, RF, utilizing cascaded

rectifier cells

920,930,940. A resonant frequency of the one or more

leaky wave antennas

164,400,420,600,720,730,801A-801C may be configured utilizing micro-electro-mechanical systems (MEMS) deflection. The one or more

leaky wave antennas

164,400,420,600,720,730,801A-801C may be configured to receive the RF signals from a desired direction. The one or more

leaky wave antennas

164,400,420,600,720,730,801A-801C may comprisemicrostrip waveguides720, wherein a cavity height of the one or more

leaky wave antennas

164,400,420,600,720,730,801A-801C is dependent on spacing between

conductive lines

723 and725 in themicrostrip waveguides720. The one or more

leaky wave antennas

164,400,420,600,720,730,801A-801C may comprisecoplanar waveguides730, wherein a cavity height of the one or more

leaky wave antennas

conductive lines

731 and733 in thecoplanar waveguides730. The received RF signals, RF, may be rectified via cascaded

rectifier cells

920,930,940 to generate the one or more DC voltages, VDC. The one or more

leaky wave antennas

164,400,420,600,720,730,801A-801C may be integrated in one or moreintegrated circuits162, integrated circuit packages167, and/or printedcircuit boards171. The one or moreintegrated circuit packages167 may be affixed, such as by flip-chip bonding, to one or more printedcircuit boards171 and the one or moreintegrated circuits162 may be flip-chip-bonded to the one or more integrated circuit packages167.

Other embodiments of the invention may provide a non-transitory computer readable medium and/or storage medium, and/or a non-transitory machine readable medium and/or storage medium, having stored thereon, a machine code and/or a computer program having at least one code section executable by a machine and/or a computer, thereby causing the machine and/or computer to perform the steps as described herein for converting RF power to DC power utilizing a leaky wave antenna.

Accordingly, aspects of the invention may be realized in hardware, software, firmware or a combination thereof. The invention may be realized in a centralized fashion in at least one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems, Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware, software and firmware may be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.

One embodiment of the present invention may be implemented as a board level product, as a single chip, application specific integrated circuit (ASIC), or with varying levels integrated on a single chip with other portions of the system as separate components. The degree of integration of the system will primarily be determined by speed and cost considerations. Because of the sophisticated nature of modern processors, it is possible to utilize a commercially available processor, which may be implemented external to an ASIC implementation of the present system. Alternatively, if the processor is available as an ASIC core or logic block, then the commercially available processor may be implemented as part of an ASIC device with various functions implemented as firmware.

The present invention may also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Computer program in the present context may mean, for example, any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form. However, other meanings of computer program within the understanding of those skilled in the art are also contemplated by the present invention.

While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from its scope. Therefore, it is intended that the present invention not be limited to the particular embodiments disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims.