EP3101733B1

Movatterモバイル変換

Info

Publication number: EP3101733B1
Application number: EP14879590.9A
Authority: EP
Inventors: Masanori Kaihatsu; Yuji Katada; Hisashi Kobayashi; Akifumi KITAMURA
Original assignee: Central Glass Co Ltd
Current assignee: Central Glass Co Ltd
Priority date: 2014-01-27
Filing date: 2014-11-27
Publication date: 2018-10-31
Anticipated expiration: 2034-11-27
Also published as: WO2015111300A1; JP6221773B2; EP3101733A4; EP3101733A1; JP2015142162A

Description

BACKGROUND OF THE INVENTION

This invention relates to a glass antenna arranged on a surface of a glass sheet, and more particularly, to an antenna configured to receive broadcast waves having a plurality of frequencies.
In countries all over the world, radio and television broadcasting frequencies and a frequency used for a remote keyless entry system differ among countries and regions, and hence it is necessary to develop an antenna having elements that differ in length for each delivery destination. However, in order to develop various kinds of antennas, a large number of work man-hours are required, and hence an antenna configured to support a plurality of bands is desired. For example, the frequency of an FM radio broadcast is from 76 MHz to 90 MHz in Japan, and is from 88 MHz to 108 MHz in most countries other than Japan. Therefore, when a satisfactory sensitivity cannot be obtained in a plurality of bands, it is necessary to adjust the lengths of the elements for each delivery destination.
Further, with digital audio broadcasting (DAB) becoming common in Europe, there are cases where only FM and AM radio broadcast bands are covered and where the FM and AM radio broadcast bands and a DAB band are covered depending on the delivery destination. Therefore, with one antenna supporting a plurality of bands, it is possible to reduce the number of kinds of antennas to be developed and the number of development man-hours.
As an antenna for obtaining a satisfactory sensitivity with such a plurality of frequencies, inJP 2010-81567 A, there is disclosed an antenna capable of satisfactorily receiving two kinds of DAB bands (Band III: from 174 MHz to 245 MHz and L-Band: from 1,452 MHz to 1,492 MHz).
Further, inJP H06-291530 A, there is disclosed an antenna of a typical two-frequency switching type. In order to receive two radio waves in an 800 MHz band and a 1,500 MHz band, the antenna disclosed inJP H06-291530 A includes two elements having lengths suitable for the respective frequencies, and has the two elements connected to each other in a bifurcated shape or a V shape.
However, the antenna disclosed inJP 2010-81567 A cannot satisfactorily receive the FM radio broadcast and a DAB broadcast band. Further, with the antenna disclosed inJP H06-291530 A, it is difficult to obtain a satisfactory sensitivity in two wide bands such as an FM radio broadcast band and DAB Band III.
Moreover,US 6, 243, 043 B1 discloses a glass antenna device for an automobile. A first resonance is generated by the inductance of a first coil connected between a first antenna conductor in a window glass sheet and a receiver and the impedance of the antenna conductor, and a second resonance is generated by the inductance of a second coil connected between a second antenna conductor and an automobile body as the earth. The antenna conductor and the antenna conductor are in a capacitive coupling relation, whereby signals in different broadcast band; a low frequency band and a high frequency band, are well received.
JP S61 189611 U also discloses a glass antenna device used for diversity reception in automobiles.
US 2011/032163 A1 discloses a glass antenna that is formed on a rear window glass of vehicles such as an automobile, and that includes separate antennas of an AM radio broadcast wave receiving antenna and an FM radio broadcast wave receiving antenna, particularly a glass antenna that is suitable for receiving radio waves of FM broadcast waves.

SUMMARY OF THE INVENTION

This invention has an object to provide an antenna capable of satisfactorily receiving both frequencies of an FM radio broadcast band and a DAB band.
That is, according to one embodiment of this invention, there is provided a glass antenna according toclaim 1.
According to a further embodiment of this invention, there is provided a glass antenna according to claim 3.
According to the representative embodiments of this invention, it is possible to obtain a satisfactory sensitivity in both frequencies of an FM radio broadcast band and a DAB band.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view for illustrating an antenna pattern according to an example 1 of this invention.
FIG. 2 is a front view for illustrating an antenna pattern according to an example 2 of this invention.
FIG. 3 is a front view for illustrating an antenna pattern according to an example 3 of this invention.
FIG. 4 is a front view for illustrating an antenna pattern according to an example 4 of this invention.
FIG. 5 is a front view for illustrating an antenna pattern according to an example 5 of this invention.
FIG. 6 is a front view for illustrating an antenna pattern according to an example 6 of this invention.
FIG. 7 is a front view for illustrating an antenna pattern according to an example 7 of this invention.
FIG. 8 is a front view for illustrating an antenna pattern according to an example 8 of this invention.
FIG. 9 is a front view for illustrating an antenna pattern according to an example 9 of this invention.
FIG. 10 is a front view for illustrating an antenna pattern according to an example 10 of this invention.
FIG. 11 is a front view for illustrating an antenna pattern according to an example 11 of this invention.
FIG. 12 is a front view for illustrating an antenna pattern according to an example 12 of this invention.
FIG. 13 is a front view for illustrating an antenna pattern according to an example 13 of this invention.
FIG. 14 is a front view for illustrating an antenna pattern according to an example 14 of this invention.
FIG. 15 is a front view for illustrating an antenna pattern according to an example 15 of this invention.
FIG. 16 is a front view for illustrating an antenna pattern according to an example 16 of this invention.
FIG. 17 is a front view for illustrating an antenna pattern according to an example 17 of this invention.
FIG. 18 is a front view for illustrating an antenna pattern according to an example 18 of this invention.
FIG. 19 is a front view for illustrating an antenna pattern according to an example 19 of this invention.
FIG. 20 is a front view for illustrating an antenna pattern according to an example 20 of this invention.
FIG. 21 is a front view for illustrating an antenna pattern according to an example 21 of this invention.
FIGs. 22 to 24 are drawings for illustrating frequency characteristics of the antenna according to the example 21.

DETAILED DESCRIPTION

FIG. 1 to FIG. 20 are diagrams of a glass antenna when viewed from the inside of a vehicle. As illustrated inFIG. 1, the glass antenna is provided to a rear glass of an automobile, and includes a firstpower feeding point 15, afirst element 11 connected to the firstpower feeding point 15 and extending in a substantially horizontal direction, and a second element connected to the firstpower feeding point 15 and extending in a direction opposite to the extending direction of thefirst element 11. The second element is formed of amain body portion 21 extending from the firstpower feeding point 15 and a foldedportion 22 that is folded back at an end portion of themain body portion 21 and extends along themain body portion 21 in a direction approaching the firstpower feeding point 15. The foldedportion 22 is arranged in proximity to and in substantially parallel with themain body portion 21.
The firstpower feeding point 15 is connected to a reception amplifier 6 through a connecting line (for example, low voltage cable for automobile) 5, and the reception amplifier 6 is connected to a receiver (not shown) by a high-frequency cable (for example, coaxial cable). Further, the reception amplifier 6 is connected to the ground (vehicle body).
It should be noted that in the example ofFIG. 1, the foldedportion 22 extends from the end portion of themain body portion 21, but may extend from a position (midpoint) of themain body portion 21 other than the end portion.
Further, as illustrated inFIG. 2, thefirst element 11 and the second element may extend in the same direction.
Further, as illustrated inFIG. 3, athird element 31 extending from the firstpower feeding point 15 may be provided. Thethird element 31 may extend in a direction different from the extending direction of thefirst element 11 or the extending direction of the second element.
Further, as illustrated inFIG. 4 andFIG. 5,auxiliary elements 12 and 13 extending from thefirst element 11 along (for example, in parallel with) thefirst element 11 may be provided. The number of auxiliary elements may be one as illustrated inFIG. 4, may be two as illustrated inFIG. 5, or may be a plurality larger than two. Further, the auxiliary element may be provided above or below thefirst element 11. For example, one auxiliary element may be provided above thefirst element 11. Theauxiliary elements 12 and 13 may extend from the firstpower feeding point 15, or may extend from thefirst element 11, or another auxiliary element may extend from a given auxiliary element.
Afirst antenna 10 is formed in the above-mentioned manner. Elements of thefirst antenna 10 are adjusted to have lengths suitable to receive an FM radio broadcast band (from 76 MHz to 108 MHz) and Band III (from 174 MHz to 245 MHz) of digital audio broadcasting (DAB).
Further, as illustrated inFIG. 5 andFIG. 6, theauxiliary element 12 may be arranged in proximity to adefogger 90, and may be capacitively coupled to aheating wire 91 on an outermost side of thedefogger 90. It should be noted that an illustration of the right half of thedefogger 90 is omitted inFIG. 5 andFIG. 6.
It should be noted that elements of a first antenna may be arranged in proximity to a conductor (for example, another antenna) that is not connected to the ground instead of thedefogger 90, and may be capacitively coupled to the conductor. In other words, the conductor in proximity to the elements of the first antenna may be theheating wire 91 of thedefogger 90 as illustrated inFIG. 5 andFIG. 6, may be anon-feed element 40 as illustrated inFIG. 6, or may be asecond antenna 50 as illustrated inFIG. 7 and FIG. 8. Thesecond antenna 50 has respective wires arranged so as to secure a reception effective area for enabling an AM radio frequency band (from 526.5 kHz to 1,606.5 kHz) to be received in a preferred manner. In addition, the elements of the first antenna in proximity to the conductor that is not connected to the ground may be any one of thefirst element 11, theauxiliary elements 12 and 13, and the second element (21 and 22).
Further, as illustrated inFIG. 9 and FIG. 10, a foldedportion 56 may be included at an end portion of ahorizontal wire 52D. Further, the foldedportion 56 may be folded back in a downward direction as illustrated inFIG. 9, or may be folded back in an upward direction as illustrated inFIG. 10.
Further, as illustrated inFIG. 11, the foldedportion 56 may extend from an end portion of an uppermosthorizontal wire 52F, may be folded back in the upward direction, and may extend along (for example, in parallel with) thehorizontal wire 52F. The foldedportion 56 is arranged in proximity to abody flange 2 of the vehicle body on which arear glass 1 is mounted, and is capacitively coupled to thebody flange 2.
Further, as illustrated inFIG. 12, two foldedportions 56 and 57 may be capacitively coupled to thebody flange 2.
Further, as illustrated inFIG. 13, anauxiliary wire 58 extending from a secondpower feeding point 54 outward (in a direction opposite to the extending direction of a horizontal wire 52) may be provided. Theauxiliary wire 58 may be bent downward and may extend downward (along the third element 31) as illustrated inFIG. 13, or may extend outward linearly.
Further, as illustrated inFIG. 14, athird antenna 60 may be provided on therear glass 1 in a position spaced apart from the first antenna 10 (for example, below the defogger 90). Thethird antenna 60 is formed of twohorizontal elements 61 and 62 and a thirdpower feeding point 63, which are adjusted to have lengths suitable to receive the FM radio broadcast band (from 76 MHz to 108 MHz) and a TV broadcast band (from 470 MHz to 770 MHz). In this case, thefirst antenna 10 and thethird antenna 60 may form a diversity antenna to diversity-receive an FM radio broadcast.
Thedefogger 90 includes a pair of bus bars 93 provided on the left and right of therear glass 1 and a plurality ofheating wires 91 connecting the twobus bars 93 to each other. Further, thedefogger 90 may include avertical wire 92 connecting the plurality ofheating wires 91 to one another. The number ofvertical wires 92 may be one or a plurality.
Further, as illustrated inFIG. 15, thedefogger 90 may be used as thethird antenna 60. Theheating wire 91 and thevertical wire 92 that form thedefogger 90 function as a horizontal wire and a vertical wire, respectively, in thethird antenna 60.
In this case, one of the bus bars 93 of thedefogger 90 is connected to a power supply via adefogger coil 94, and theother bus bar 93 is connected to the ground via thedefogger coil 94, to thereby suppress noise in a received frequency band flowing into thethird antenna 60 from the power supply and the ground. Further, a thirdpower feeding point 95 is provided to onebus bar 93. Further, also in this case, thefirst antenna 10 and thethird antenna 60 form a diversity antenna.
Further, as illustrated inFIG. 16, thethird antenna 60 includes a plurality of parallelauxiliary wires 96, 97, and 98 that extend downward from a lowermosthorizontal wire 91 and are arranged along thehorizontal wire 91. End portions the parallelauxiliary wires 96, 97, and 98 are in positions spaced apart from one another. Further, a part of the parallelauxiliary wire 96 and a part of the parallelauxiliary wire 97 are arranged along, in proximity to, and in substantially parallel with each other. In addition, a part of the parallelauxiliary wire 97 and a part of the parallelauxiliary wire 98 are arranged along, in proximity to, and in substantially parallel with each other. It should be noted that not parts of but almost all of parallel auxiliary wires may be arranged along and in proximity to each other.
Further, the number of auxiliary wires extending along thehorizontal wire 91 may be three as illustrated inFIG. 16, may be two as illustrated inFIG. 17, or may be equal to or larger than four. In addition, the auxiliary wires extending along thehorizontal wire 91 may extend downward from thehorizontal wire 91 as illustrated inFIG. 16, or may extend downward from thebus bar 93 as illustrated inFIG. 17. Further, also in the case illustrated inFIG. 17, a part of the parallelauxiliary wire 96 and at least a part of the parallelauxiliary wire 98 are arranged along, in proximity to, and in substantially parallel with each other.
Further, as illustrated inFIG. 18, anauxiliary wire 89 extending upward from the bus bar 93 (orhorizontal wire 91 on the outermost side) may be provided. In addition, afourth antenna 70 may be provided in proximity to theauxiliary wire 89. Thefourth antenna 70 is formed of a fourthpower feeding point 71 and ahorizontal element 72, which are adjusted to have lengths suitable to receive the TV broadcast band (from 470 MHz to 770 MHz). In this case, thethird antenna 60 and thefourth antenna 70 may form a diversity antenna to diversity-receive a TV broadcast.
Further, as illustrated inFIG. 19, theheating wires 91 of thedefogger 90 may be connected to one another by a plurality ofvertical wires 92. It should be noted that the number ofvertical wires 92 may be three as illustrated inFIG. 19, or may be one, two, or equal to or larger than four.
Further, as illustrated inFIG. 20, there may be provided a horizontalauxiliary wire 99 extending downward from the lowermosthorizontal wire 91 and extending both leftward and rightward from the center of a defogger along thehorizontal wire 91.
The antenna is formed by printing a pattern of the antenna with conductive ceramic paste in a predetermined position on an indoor surface side of a window glass sheet with each wire having a width of approximately 0.7 millimeter, drying the pattern, and then baking the pattern in a heating furnace. Further, the antenna may be formed of a conductive pattern formed on a resin film that transmits light, and may be bonded to a glass sheet.
An example is described above by taking a mode of providing the antenna on therear glass 1 of the automobile, but the antenna may be provided on another part (for example, windshield or side glass).
Next, an action of the glass antenna according to the embodiment of this invention is described.
The antenna according to this embodiment includes thefirst element 11, themain body portion 21 of the second element, and the foldedportion 22 of the second element, and therefore can obtain a satisfactory sensitivity in a plurality of frequency bands. In particular, the length of the foldedportion 22 is set to approximately αλ₂/4, the length of themain body portion 21 is set to approximatelyαλ₁/5, the length of thefirst element 11 is set to approximatelyαλ₁/6, and hence a satisfactory sensitivity can be obtained in both the FM radio broadcast band having a low frequency ((wavelength of center frequency)=λ₁) and a DAB broadcast band ((wavelength of center frequency)=λ₂). A satisfactory sensitivity can also be obtained in DAB L-Band (from 1,452 MHz to 1,492 MHz).
The foldedportion 22 is folded back from the end portion of themain body portion 21, and arranged along and in proximity to themain body portion 21, and hence the foldedportion 22 and themain body portion 21 are connected to each other electrically strongly. Therefore, it is possible to obtain a satisfactory sensitivity in both the FM radio broadcast band having a low frequency and the DAB broadcast band.
Further, two elements (first element 11 andmain body portion 21 of second element) having different lengths for FM radio broadcast reception are provided, and hence it is possible to improve the sensitivity in the FM radio broadcast band over a wide bandwidth. In addition, the foldedportion 22 is formed by folding back the second element, to thereby be able to improve the sensitivity also in DAB Band III having a high frequency.
Further, thefirst element 11 and themain body portion 21 of the second element extend in the same direction, to thereby arrange thefirst element 11 and the second element (21 and 22) on one side of the firstpower feeding point 15 and allow downsizing of the antenna. Therefore, the firstpower feeding point 15 can be arranged in a position close to a side of aglass sheet 1.
Further, thethird element 31 extending from the firstpower feeding point 15 is provided in the direction opposite to the extending direction of thefirst element 11 and the extending direction of themain body portion 21 of the second element, and the length and a relative positional relationship of thethird element 31 are adjusted, to thereby be able to improve the sensitivity on a high band side of the FM radio broadcast band. It is also possible to improve the sensitivity in DAB Band III as a whole.
Further, theauxiliary element 12 extending from the firstpower feeding point 15 is provided as illustrated inFIG. 4, and theauxiliary elements 12 and 13 extending from thefirst element 11 are provided as illustrated inFIG. 5. Therefore, it is possible to improve the sensitivity in DAB Band III having a high frequency.
Further, theauxiliary element 12 is arranged in proximate to theheating wire 91 of thedefogger 90, and thefirst antenna 10 is capacitively coupled to thedefogger 90. Therefore, a broadcast wave received by theheating wire 91 of thedefogger 90 can be guided to thefirst antenna 10, and it is possible to improve the sensitivity of thefirst antenna 10. In particular, it is possible to improve the sensitivity in DAB Band III having a high frequency.
Further, the first antenna 10 (auxiliary element 12 and second element) is arranged in proximate tolinear conductors 91, 42, and 52, and thefirst antenna 10 is capacitively coupled to theconductors 91, 42, and 52. Therefore, the broadcast wave received by theconductors 91, 42, and 52 can be guided to thefirst antenna 10, and it is possible to improve the sensitivity of the antenna. Further, the lengths and the relative positional relationship of the elements on sides of theconductors 91, 42, and 52 are adjusted, to thereby be able to improve the sensitivity in the FM radio broadcast band having a low frequency.
Further, the second element (21 and 22) is arranged in proximate to thehorizontal wire 52, and thefirst antenna 10 is capacitively coupled to thesecond antenna 50. Therefore, the broadcast wave received by thesecond antenna 50 can be guided to thefirst antenna 10, and it is possible to improve the sensitivity of thefirst antenna 10. Further, the lengths and the relative positional relationship ofelements 52 and 53 of thesecond antenna 50 are adjusted, to thereby be able to improve the sensitivity in the FM radio broadcast band.
Further, thesecond antenna 50 is formed of a plurality ofhorizontal wires 52, avertical wire 53 connecting thehorizontal wires 52 to one another, and the secondpower feeding point 54, and hence it is possible to form an antenna for another frequency (for example, for AM radio broadcast reception) with a simple structure.
Further, a plurality ofvertical wires 53 are provided, and intervals between thevertical wires 53 are adjusted, to thereby be able to easily improve the sensitivity in the FM radio broadcast band.
Further, the second element (21 and 22) is arranged in proximity to thehorizontal wire 52, to thereby be able to capacitively couple thefirst antenna 10 and thesecond antenna 50 to each other.
Further, thehorizontal wires 52 are arranged between thefirst element 11 and the second element (21 and 22), and hence thefirst antenna 10 and thesecond antenna 50 are connected to each other strongly, and are likely to be affected by each other. Therefore, thefirst antenna 10 is susceptible to a change in characteristics of thesecond antenna 50 due to the adjustment of the lengths of elements thereof and the relative positional relationship of the elements, and it is possible to easily improve the characteristics of thefirst antenna 10.
Further, the foldedportions 56 and 57 folded back upward or downward are provided, and hence it is possible to adjust the sensitivity of thefirst antenna 10 without greatly changing the characteristics of thesecond antenna 50. Further, the foldedportions 56 and 57 are formed to be folded back upward from thehorizontal wire 52, to thereby be able to improve the sensitivity of thefirst antenna 10 in the FM radio broadcast band (in particular, middle band).
Further, the foldedportions 56 and 57 are capacitively coupled to thebody flange 2 as illustrated inFIG. 11 to FIG. 15. Therefore, it is possible to improve the sensitivity of thefirst antenna 10 in the FM radio broadcast band (in particular, middle band) by adjusting the lengths of the foldedportions 56 and 57 and a spacing from a body flange.
Further, theauxiliary wire 58 extending from the secondpower feeding point 54 in the direction opposite to the extending direction of thehorizontal wire 52 is provided, and hence by adjusting the length and the extending direction of theauxiliary wire 58, it is possible change the characteristics of thesecond antenna 50 and to improve the sensitivity of thefirst antenna 10 in the FM radio broadcast band (in particular, middle band).
Further, thethird antenna 60 is arranged in the position spaced apart from thefirst antenna 10, and diversity reception is effected by thefirst antenna 10 and thethird antenna 60. Therefore, it becomes easy to receive an arrival wave, and it is possible to improve reception performance.
Further, thethird antenna 60 is formed of thewires 91 and 92 of thedefogger 90. Therefore, an antenna element does not need to be provided separately, and it is possible to suppress deterioration in an outer appearance. Further, the thirdpower feeding point 95 is provided to thebus bar 93, and hence a power feeding point for the radio-frequency signal and a power feeding point for the heating wire can be shared. Further, thebus bar 93 is connected to the power supply and the ground via thedefogger coil 94, and hence thebus bar 93 can be connected to the power supply and the ground in terms of a direct current, and can be floated from the power supply and the ground in terms of a high frequency.
Further, the horizontal wires (heating wires) 91 and the parallelauxiliary wires 96, 97, and 98 extending from thebus bar 93 or thehorizontal wire 91 on the outermost side are provided, end portions of the parallelauxiliary wires 96, 97, and 98 are isolated from one another, and two of the parallelauxiliary wires 96, 97, and 98 are arranged along and in proximity to each other. Therefore, by adjusting a width and a length of an overlap between the parallel auxiliary wires, it is possible to improve the sensitivity of thethird antenna 60 and to improve the sensitivity of another antenna with which a diversity is formed.
Further, the parallelauxiliary wires 96, 97, and 98 extend from thebus bar 93. Therefore, by increasing the lengths of the parallel auxiliary wires and increasing the length of the overlap between the parallel auxiliary wires, it is possible to widen an adjustment range.
Further, theauxiliary wire 89 is provided to thethird antenna 60, and hence it is possible to improve the sensitivity of thethird antenna 60, and to improve the sensitivity of the antenna provided around thethird antenna 60.
Further, thevertical wire 92 connecting thehorizontal wires 91 to one another is provided, and hence it is possible to improve the sensitivity of thethird antenna 60.
Further, the horizontalauxiliary wire 99 extending from an end portion of thevertical wire 92 along thehorizontal wire 91 is provided, and an end portion of the horizontalauxiliary wire 99 is not connected to thedefogger 90. Therefore, it is possible to increase a degree of freedom for adjusting antenna characteristics.

Examples

Various examples of this invention are described below.

FIG. 1 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 1 of this invention.
A glass antenna according to the example 1 is formed of thefirst antenna 10. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11 connected to the firstpower feeding point 15 and extending in a substantially horizontal direction (leftward direction inFIG. 1), and the second element connected to the firstpower feeding point 15 and extending in a direction (rightward direction inFIG. 1) opposite to the extending direction of thefirst element 11.
The second element is formed of themain body portion 21 extending from the firstpower feeding point 15 and the foldedportion 22 that is folded back at the end portion of themain body portion 21 in the downward direction (or, upward direction) and extends along and in substantially parallel with themain body portion 21 in the direction approaching the firstpower feeding point 15. It should be noted that the foldedportion 22 may extend from the midpoint of themain body portion 21.
By making the length of each of elements according to the example 1 the same as the length of each of elements according to an example 2 described later, it is possible to realize the antenna suitable to receive the FM radio broadcast band and DAB Band III.
A third element (not shown) extending from the firstpower feeding point 15 may be provided to the antenna according to the example 1. The third element may extend in the direction (for example, downward direction) different from the extending direction of thefirst element 11 or the extending direction of the second element.

FIG. 2 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 2 of this invention.
A glass antenna according to the example 2 is different from the glass antenna according to the example 1 in the extending direction of thefirst element 11.
The glass antenna according to the example 2 is formed of thefirst antenna 10. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11 connected to the firstpower feeding point 15 and extending in a substantially horizontal direction (rightward direction inFIG. 2), and the second element connected to the firstpower feeding point 15 and extending along and in substantially parallel with thefirst element 11 in the same direction (rightward direction inFIG. 2) as the extending direction of thefirst element 11.
The second element is formed of themain body portion 21 extending from the firstpower feeding point 15 and the foldedportion 22 that is folded back at the end portion of themain body portion 21 in the downward direction (or, upward direction) and extends along and in substantially parallel with themain body portion 21 in the direction approaching the firstpower feeding point 15. It should be noted that the foldedportion 22 may extend from the midpoint of themain body portion 21.
Each of the elements of thefirst antenna 10 according to the example 2 has a length adjusted to have the length suitable to receive the FM radio broadcast band and DAB Band III such that a vertical portion of thefirst element 11 extending from the firstpower feeding point 15 has a length of 20 millimeters, a horizontal portion extending from an end portion of the vertical portion of thefirst element 11 has a length of 400 millimeters, themain body portion 21 of the second element has a length of 460 millimeters, the foldedportion 22 of the second element has a length of 300 millimeters, and a spacing between themain body portion 21 and the foldedportion 22 is 7 millimeters.
In other words, when a wavelength shortening rateα of therear glass 1 is 0.7 and the center frequency (wavelength=λ₁) of the FM radio broadcast band is 92 MHz, the length of thefirst element 11 is approximatelyαλ₁/6, and the length of themain body portion 21 is approximatelyαλ₁/5. Further, when the center frequency (wavelength=λ₂) of DAB Band III is 210 MHz, the length of the foldedportion 22 is approximatelyαλ₂/4.
At this time, the length of thefirst element 11 may be only the length of the horizontal portion, or may include the length of the vertical portion in addition to the length of the horizontal portion.
In the examples 1 and 2, two elements having different lengths, that is, thefirst element 11 and themain body portion 21 of the second element, are provided in order to receive the FM radio broadcast band having a low frequency, and hence it is possible to improve the sensitivity in a wide bandwidth of the FM radio broadcast band having a low frequency. In addition, the foldedportion 22 is formed by folding back the second element, and is arranged in proximity to the main body portion 21 (in parallel with themain body portion 21 with a spacing of 7 millimeters), to thereby be able to improve the sensitivity in DAB Band III having a high frequency without impairing the sensitivity in the FM radio broadcast band having a low frequency.
Further, in the example 2, thefirst element 11 and themain body portion 21 of the second element extend in the same direction, to thereby arrange thefirst element 11 and the second element (21 and 22) on one side of the firstpower feeding point 15 and allow the downsizing of the antenna. Therefore, the firstpower feeding point 15 can be arranged in the position close to the side of theglass sheet 1.

FIG. 3 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 3 of this invention.
A glass antenna according to the example 3 is different from the glass antenna according to the example 2 in that thethird element 31 is provided.
The glass antenna according to the example 3 is formed of thefirst antenna 10. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, and thethird element 31. The second element is formed of themain body portion 21 and the foldedportion 22.
Thethird element 31 extends from the firstpower feeding point 15 in the direction different from the extending direction of thefirst element 11 or the extending direction of the second element. Specifically, thethird element 31 includes: a horizontal portion extending from the firstpower feeding point 15 in a direction (leftward direction inFIG. 3) opposite to the extending direction of themain body portion 21 of the second element; and a vertical portion extending from an end portion of the horizontal portion in the downward direction (direction different from the rightward direction in which thefirst element 11 and the second element extend). The horizontal portion of thethird element 31 has a length of 5 millimeters, and the vertical portion has a length of 150 millimeters. InFIG. 3, the number ofthird elements 31 is one, but a plurality ofthird elements 31 may be provided.
Components of the example 3 other than the above-mentioned components are the same as those of the example 2, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 3, thethird element 31 extending from the firstpower feeding point 15 is provided. Therefore, by adjusting the lengths and the relative positional relationship of thethird element 31, it is possible to improve the sensitivity on the high band side of the FM radio broadcast band. It is also possible to improve the sensitivity in DAB Band III as a whole.

FIG. 4 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 4 of this invention.
A glass antenna according to the example 4 is different from the glass antenna according to the example 3 in that theauxiliary element 12 is provided.
The glass antenna according to the example 4 is formed of thefirst antenna 10. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary element 12. The second element is formed of themain body portion 21 and the foldedportion 22.
Theauxiliary element 12 is arranged so as to extend downward from the firstpower feeding point 15 and then extend along and in substantially parallel with thefirst element 11. Theauxiliary element 12 may have a length shorter than the length of thefirst element 11, or may have almost the same length as the length of thefirst element 11. Specifically, a vertical portion of theauxiliary element 12 has a length of 33 millimeters, and a horizontal portion of theauxiliary element 12 has a length of 125 millimeters. Theauxiliary element 12 may extend from the firstpower feeding point 15, or may extend from thefirst element 11.
Components of the example 4 other than the above-mentioned components are the same as those of the example 3, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 4, theauxiliary element 12 extending from the firstpower feeding point 15 is provided, and hence it is possible to improve the sensitivity in DAB Band III having a high frequency.

FIG. 5 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 5 of this invention.
A glass antenna according to the example 5 is different from the glass antenna according to the example 3 in that theauxiliary elements 12 and 13 are provided.
The glass antenna according to the example 5 is formed of thefirst antenna 10. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22.
Theauxiliary element 12 is arranged so as to extend downward from an intersection point of the vertical portion and the horizontal portion of the first element and then extend along and in substantially parallel with thefirst element 11. Theauxiliary element 12 may have a length shorter than the length of thefirst element 11, or may have almost the same length as the length of thefirst element 11. Specifically, the vertical portion of theauxiliary element 12 has a length of 33 millimeters, and the horizontal portion of theauxiliary element 12 has a length of 125 millimeters.
Theauxiliary element 13 is arranged so as to extend rightward from the vertical portion of the first element and then extend along and in substantially parallel with thefirst element 11. Theauxiliary element 13 may have a length shorter than the length of thefirst element 11, or may have almost the same length as the length of thefirst element 11. Specifically, theauxiliary element 13 has a length of 175 millimeters.
Theauxiliary elements 12 and 13 may extend from thefirst element 11, or may extend from the firstpower feeding point 15.
Components of the example 5 other than the above-mentioned components are the same as those of the example 3, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 4, theauxiliary element 12 is provided on the lower side of thefirst element 11. Further, in the example 5, theauxiliary element 12 is provided on the lower side of thefirst element 11, and theauxiliary element 13 is provided on the upper side of thefirst element 11. That is, the number of auxiliary elements is not limited to the numbers exemplified. Further, the auxiliary elements may be each provided on any one of the upper side and the lower side of thefirst element 11. For example, in the example 5, only theauxiliary element 13 may be provided on the upper side of thefirst element 11.
Further, when a plurality of auxiliary elements are provided, one auxiliary element may extend from another auxiliary element.
Further, in the example 5, theauxiliary element 12 is arranged along and in proximity to the defogger 90 (for example, in parallel with thedefogger 90 with a spacing of 5 millimeters) so as to be capacitively coupled to theuppermost heating wire 91 of thedefogger 90.
Thedefogger 90 includes the pair of bus bars 93 provided on the left and right of therear glass 1 and the plurality ofheating wires 91 connecting the twobus bars 93 to each other. It should be noted that inFIG. 5, only the left half of thedefogger 90 is illustrated.
In the example 5, theauxiliary elements 12 and 13 extending from thefirst element 11 are provided, and hence it is possible to improve the sensitivity in DAB Band III having a high frequency. In addition, the first antenna 10 (auxiliary element 12) and the defogger 90 (heating wire 91) are arranged in proximity to each other, and thefirst antenna 10 is capacitively coupled to thedefogger 90. Therefore, the broadcast wave received by theheating wire 91 of the defogger can be guided to thefirst antenna 10, and it is possible to improve the sensitivity of thefirst antenna 10. In particular, it is possible to improve the sensitivity in DAB Band III having a high frequency.

FIG. 6 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 6 of this invention.
A glass antenna according to the example 6 includes thefirst antenna 10 and thenon-feed element 40, and is different from the glass antenna according to the example 5 in that the second element (21 and 22) and thenon-feed element 40 are capacitively coupled to each other.
The glass antenna according to the example 6 is formed of thefirst antenna 10 and thenon-feed element 40. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22.
Thenon-feed element 40 is formed of a plurality ofhorizontal wires 42 and at least onevertical wire 43 connecting thehorizontal wires 42 to one another, and the power feeding point is not provided thereto. In other words, thenon-feed element 40 is a conductor that is not connected to the ground. It suffices that the number ofhorizontal wires 42 is at least one, and a plurality ofvertical wires 43 may be provided as long as at least onevertical wire 43 is provided.
Theauxiliary element 12 is arranged along, in proximity to, and in substantially parallel with thedefogger 90 so as to be capacitively coupled to theuppermost heating wire 91 of thedefogger 90.
Thedefogger 90 includes the pair of bus bars 93 provided on the left and right of therear glass 1, the plurality ofheating wires 91 connecting the twobus bars 93 to each other, and thevertical wire 92 connecting the plurality ofheating wires 91 to one another. It should be noted that inFIG. 6, only the left half of thedefogger 90 is illustrated.
Themain body portion 21 of the second element is arranged along and in proximity to the non-feed element 40 (for example, in parallel with thenon-feed element 40 with a spacing of 10 millimeters) so as to be capacitively coupled to a lowermosthorizontal wire 42A of thenon-feed element 40.
Components of the example 6 other than the above-mentioned components are the same as those of the example 5, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 6, themain body portion 21 of the second element and thehorizontal wire 42 of thenon-feed element 40 are arranged in proximity to each other, and thefirst antenna 10 and thenon-feed element 40 are capacitively coupled to each other. Therefore, the broadcast wave received by thenon-feed element 40 can be guided to thefirst antenna 10, and it is possible to improve the sensitivity of the antenna. Further, the length and a relative positional relationship of thenon-feed element 40 are adjusted, to thereby be able to improve the sensitivity in the FM radio broadcast band having a low frequency.

FIG. 7 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 7 of this invention.
A glass antenna according to the example 7 includes thefirst antenna 10 and thesecond antenna 50, and is different from the glass antenna according to the example 5 in that the second element (21 and 22) and thesecond antenna 50 are capacitively coupled to each other.
The glass antenna according to the example 7 is formed of thefirst antenna 10 and thesecond antenna 50. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22.
Thesecond antenna 50 includes a plurality ofhorizontal wires 52, a plurality ofvertical wires 53 connecting thehorizontal wires 52 to one another, and the secondpower feeding point 54. Further, the intervals between thevertical wires 53 may be regular intervals, or may be different intervals. The intervals between thevertical wires 53 are adjusted, to thereby be able to improve the sensitivity in the FM radio broadcast band. It suffices that the number ofhorizontal wires 52 is at least one, and the number ofvertical wires 53 is at least one. Thesecond antenna 50 has the respective wires arranged so as to secure a reception effective area for enabling an AM radio broadcast band (from 526.5 kHz to 1,606.5 kHz) to be received in a preferred manner.
The secondpower feeding point 54 may be provided at an end portion of thehorizontal wire 52, may be provided in a central portion (for example, intersection point of ahorizontal wire 52B and the vertical wire 53) of thehorizontal wire 52, or may be provided to another part. The secondpower feeding point 54 is connected to a reception amplifier through the connecting line (for example, low voltage cable for automobile), and the reception amplifier is connected to the receiver by the high-frequency cable (for example, coaxial cable). Further, the reception amplifier is connected to the ground (vehicle body).
The second element (21 and 22) is arranged in proximity to ahorizontal wire 52A of thesecond antenna 50, and thefirst antenna 10 and thesecond antenna 50 are capacitively coupled to each other.
It should be noted that the defogger is not illustrated inFIG. 7, but thedefogger 90 may be provided so as to be capacitively coupled to theauxiliary element 12 or may not be provided.
Themain body portion 21 of the second element is arranged along and in proximity to the second antenna 50 (for example, in parallel with thesecond antenna 50 with a spacing of 10 millimeters) so as to be capacitively coupled to thehorizontal wire 52A provided at a lower portion of thesecond antenna 50.
Components of the example 7 other than the above-mentioned components are the same as those of the example 5, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 7, themain body portion 21 of the second element and thehorizontal wire 52 of thesecond antenna 50 are arranged in proximity to each other, and thefirst antenna 10 and thesecond antenna 50 are capacitively coupled to each other. Therefore, the broadcast wave received by thesecond antenna 50 can be guided to thefirst antenna 10, and it is possible to improve the sensitivity of thefirst antenna 10. Further, the length and the relative positional relationship of thehorizontal wire 52 and thevertical wire 53 of thesecond antenna 50 are adjusted, to thereby be able to improve the sensitivity in the FM radio broadcast band having a low frequency.
Further, it is possible to form thesecond antenna 50 for another frequency (for example, for AM radio broadcast reception) with a simple structure.

FIG. 8 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 8 of this invention.
A glass antenna according to the example 8 is different from the glass antenna according to the example 7 in that thehorizontal wire 52B of thesecond antenna 50 is arranged between theauxiliary element 13 and the foldedportion 22 of thefirst antenna 10.
The glass antenna according to the example 8 is formed of thefirst antenna 10 and thesecond antenna 50. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22. Thesecond antenna 50 includes the plurality ofhorizontal wires 52, a plurality ofvertical wires 53, and the secondpower feeding point 54.
In the example 8, the left part of the lowermosthorizontal wire 52B extends into a region in which thefirst antenna 10 is provided. In other words, the left part of thehorizontal wire 52B is arranged between theauxiliary element 13 and the foldedportion 22 of thefirst antenna 10 along, in proximity to, and in substantially parallel with theauxiliary element 13 and along, in proximity to, and in substantially parallel with the foldedportion 22. In short, the left part of thehorizontal wire 52B is arranged between thefirst element 11 and the second element (21 and 22) of thefirst antenna 10. The plurality of horizontal wires 52 (for example, two horizontal wires 52) may be arranged between thefirst element 11 and the second element (21 and 22).
Further, the secondpower feeding point 54 is connected to thesecond antenna 50 via a connectingwire 55 extending from ahorizontal wire 52C.
It should be noted that the defogger is not illustrated inFIG. 8, but thedefogger 90 may be provided so as to be capacitively coupled to theauxiliary element 12 or may not be provided.
Components of the example 8 other than the above-mentioned components are the same as those of the example 7, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 8, thehorizontal wires 52 are arranged between thefirst element 11 and the second element (21 and 22), and hence thefirst antenna 10 and thesecond antenna 50 are connected to each other strongly, and are likely to be affected by each other. Therefore, thefirst antenna 10 is susceptible to a change in characteristics of thesecond antenna 50 due to the adjustment of the lengths and the relative positional relationship of the elements, and it is possible to easily adjust the characteristics of thefirst antenna 10.

FIG. 9 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 9 of this invention.
A glass antenna according to the example 9 is different from the glass antenna according to the example 8 in that thehorizontal wire 52D of thesecond antenna 50 includes the foldedportion 56 and that the secondpower feeding point 54 is arranged at the end portion of ahorizontal wire 52E provided therebelow.
The glass antenna according to the example 9 is formed of thefirst antenna 10 and thesecond antenna 50. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22. Thesecond antenna 50 includes the plurality ofhorizontal wires 52, the plurality ofvertical wires 53, the secondpower feeding point 54, and the foldedportion 56.
In thesecond antenna 50 according to the example 9, the secondpower feeding point 54 is arranged at a left end portion of thehorizontal wire 52E provided in the lower part. Therefore, the firstpower feeding point 15 of thefirst antenna 10 and the secondpower feeding point 54 of thesecond antenna 50 are arranged so as to be adjacent to each other, which facilitates the work of connecting a connecting line to the power feeding point of each antenna.
Further, the foldedportion 56 is provided at a right end of thehorizontal wire 52D of thesecond antenna 50. The foldedportion 56 extends in the downward direction from the right end of thehorizontal wire 52D, is folded back in the leftward direction, and extends in the leftward direction along and in proximity to thehorizontal wire 52D (for example, in parallel with thehorizontal wire 52D with a spacing of 5 millimeters).
It should be noted that the defogger is not illustrated inFIG. 9, but thedefogger 90 may be provided so as to be capacitively coupled to theauxiliary element 12 or may not be provided.
Components of the example 9 other than the above-mentioned components are the same as those of the example 7, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 9, the foldedportion 56 is provided, and hence it is possible to improve the sensitivity of thefirst antenna 10 without greatly changing the characteristics of thesecond antenna 50.

FIG. 10 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 10 of this invention.
A glass antenna according to the example 10 is different from the glass antenna according to the example 9 in the direction in which the foldedportion 56 is folded back from thehorizontal wire 52D.
The glass antenna according to the example 10 is formed of thefirst antenna 10 and thesecond antenna 50. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22. Thesecond antenna 50 includes the plurality ofhorizontal wires 52, the plurality ofvertical wires 53, the secondpower feeding point 54, and the foldedportion 56.
The foldedportion 56 is provided at the right end of thehorizontal wire 52D of thesecond antenna 50. The foldedportion 56 extends in the upward direction from the right end of thehorizontal wire 52D, is folded back in the leftward direction, and extends in the leftward direction along and in proximity to thehorizontal wire 52D (for example, in parallel with thehorizontal wire 52D with a spacing of 5 millimeters).
It should be noted that the defogger is not illustrated inFIG. 10, but thedefogger 90 may be provided so as to be capacitively coupled to theauxiliary element 12 or may not be provided.
Components of the example 10 other than the above-mentioned components are the same as those of the example 9, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 10, the foldedportion 56 is formed by upwardly folding back thehorizontal wire 52. Therefore, it is possible to improve the sensitivity of thefirst antenna 10 in the FM radio broadcast band (in particular, middle band).

FIG. 11 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 11 of this invention.
A glass antenna according to the example 11 is different from the glass antenna according to the example 10 in that the foldedportion 56 is capacitively coupled to thebody flange 2.
The glass antenna according to the example 11 is formed of thefirst antenna 10 and thesecond antenna 50. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22. Thesecond antenna 50 includes the plurality ofhorizontal wires 52, the plurality ofvertical wires 53, the secondpower feeding point 54, and the foldedportion 56.
The foldedportion 56 is provided at a right end of the uppermosthorizontal wire 52F of thesecond antenna 50. The foldedportion 56 extends in the upward direction from the right end of thehorizontal wire 52F, is folded back in the leftward direction, and extends in the leftward direction along and in proximity to thehorizontal wire 52F (for example, in parallel with thehorizontal wire 52F with a spacing of 5 millimeters). The foldedportion 56 is arranged in proximity to thebody flange 2 of the vehicle body (for example, in parallel with thebody flange 2 with a spacing of 5 millimeters), and is capacitively coupled to the body flange (that is, ground).
It should be noted that the defogger is not illustrated inFIG. 11, but thedefogger 90 may be provided so as to be capacitively coupled to theauxiliary element 12 or may not be provided.
Components of the example 11 other than the above-mentioned components are the same as those of the example 9, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 11, the foldedportion 56 is capacitively coupled to thebody flange 2. Therefore, it is possible to improve the sensitivity of thefirst antenna 10 in the FM radio broadcast band (in particular, middle band) by adjusting the length of the foldedportion 56 and a spacing from thebody flange 2.

FIG. 12 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 12 of this invention.
A glass antenna according to the example 12 is different from the glass antenna according to the example 11 in that the glass antenna according to the example 12 includes the two foldedportions 56 and 57.
The glass antenna according to the example 12 is formed of thefirst antenna 10 and thesecond antenna 50. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22. Thesecond antenna 50 includes the plurality ofhorizontal wires 52, the plurality ofvertical wires 53, the secondpower feeding point 54, and the foldedportions 56 and 57.
The foldedportion 56 is provided at the right end of the uppermosthorizontal wire 52F of thesecond antenna 50. The foldedportion 56 extends in the upward direction from the right end of thehorizontal wire 52F, is folded back in the leftward direction, and extends in the leftward direction along and in proximity to thehorizontal wire 52F (for example, in parallel with thehorizontal wire 52F with a spacing of 5 millimeters). Further, the foldedportion 57 is provided at a midpoint of thehorizontal wire 52F. The foldedportion 57 extends in the upward direction from thehorizontal wire 52F, is folded back in the leftward direction, and extends along and in proximity to thehorizontal wire 52F (for example, in parallel with thehorizontal wire 52F with a spacing of 5 millimeters). The foldedportions 56 and 57 are arranged in proximity to thebody flange 2 of the vehicle body (for example, in parallel with thebody flange 2 with a spacing of 5 millimeters), and are capacitively coupled to the body flange 2 (that is, ground).
It should be noted that the number of folded portions may be one as illustrated inFIG. 11, may be two as illustrated inFIG. 12, or may be equal to or larger than three.
It should be noted that the defogger is not illustrated inFIG. 12, but thedefogger 90 may be provided so as to be capacitively coupled to theauxiliary element 12 or may not be provided.
Components of the example 12 other than the above-mentioned components are the same as those of the example 9, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 12, the two foldedportions 56 and 57 are capacitively coupled to thebody flange 2, and hence it is possible to widen an adjustment range of the antenna characteristics.

FIG. 13 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 13 of this invention.
A glass antenna according to the example 13 is different from the glass antenna according to the example 12 in that the glass antenna according to the example 13 includes theauxiliary wire 58.
The glass antenna according to the example 13 is formed of thefirst antenna 10 and thesecond antenna 50. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22. Thesecond antenna 50 includes the plurality ofhorizontal wires 52, the plurality ofvertical wires 53, the secondpower feeding point 54, the foldedportions 56 and 57, and theauxiliary wire 58.
Theauxiliary wire 58 extends from the secondpower feeding point 54 outward (in the direction opposite to the extending direction of the horizontal wire 52), is bent downward, and extends along thethird element 31. Theauxiliary wire 58 may extend outward (in the direction opposite to the extending direction of the horizontal wire 52) linearly.
Further, the foldedportion 57 according to the example 13 extends in the upward direction from an intersection point of thehorizontal wire 52F and thevertical wire 53, is folded back in the leftward direction, and extends along and in proximity to thehorizontal wire 52F (for example, in parallel with thehorizontal wire 52F with a spacing of 5 millimeters).
It should be noted that a position of thehorizontal wire 52F from which the folded portion extends may be the intersection point of thehorizontal wire 52F and thevertical wire 53 as illustrated inFIG. 13, or may be another position as illustrated inFIG. 12, as long as the position falls on thehorizontal wire 52F.
It should be noted that the defogger is not illustrated inFIG. 13, but thedefogger 90 may be provided so as to be capacitively coupled to theauxiliary element 12 or may not be provided.
Components of the example 13 other than the above-mentioned components are the same as those of the example 9, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 13, theauxiliary wire 58 extending from the secondpower feeding point 54 in the direction opposite to the extending direction of thehorizontal wire 52 is provided. Therefore, by adjusting the length and the extending direction of theauxiliary wire 58, it is possible to change the characteristics of thesecond antenna 50, and to improve the sensitivity of thefirst antenna 10 in the FM radio broadcast band (in particular, middle band).

FIG. 14 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 14 of this invention.
A glass antenna according to the example 14 is different from the glass antenna according to the example 13 in that the glass antenna according to the example 14 includes thethird antenna 60.
The glass antenna according to the example 14 is formed of thefirst antenna 10, thesecond antenna 50, and thethird antenna 60. Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22. Thesecond antenna 50 includes the plurality ofhorizontal wires 52, the plurality ofvertical wires 53, the secondpower feeding point 54, the foldedportions 56 and 57, and theauxiliary wire 58. Thethird antenna 60 includes the twohorizontal elements 61 and 62 arranged along each other and the thirdpower feeding point 63, and is adjusted to have a length suitable to receive at least one broadcast wave of the FM radio broadcast band, the TV broadcast band, and DAB Band III.
Thethird antenna 60 is arranged in a position spaced apart from thefirst antenna 10, and forms the diversity antenna with thefirst antenna 10 to diversity-receive the FM radio broadcast.
It should be noted that thedefogger 90 is illustrated inFIG. 14, but thedefogger 90 may not be provided. Thedefogger 90 includes the pair of bus bars 93 provided on the left and right of therear glass 1, the plurality ofheating wires 91 connecting the twobus bars 93 to each other, and thevertical wire 92 connecting the plurality ofheating wires 91 to one another. The number ofvertical wires 92 may be one or a plurality.
Theauxiliary element 12 is arranged along and in proximity to thedefogger 90 so as to be capacitively coupled to theuppermost heating wire 91 of thedefogger 90. Therefore, the broadcast wave received by theheating wire 91 can be guided to thefirst antenna 10, and it is possible to improve the sensitivity of the antenna.
Components of the example 14 other than the above-mentioned components are the same as those of the example 13, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 14, the diversity reception is effected by thefirst antenna 10 and thethird antenna 60. Therefore, it becomes easy to receive the arrival wave, and it is possible to improve the reception performance.

FIG. 15 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 15 of this invention.
A glass antenna according to the example 15 is different from the glass antenna according to the example 14 in that thedefogger 90 functions as a third antenna.
The glass antenna according to the example 15 is formed of thefirst antenna 10, thesecond antenna 50, and thethird antenna 60. Thedefogger 90 functions as thethird antenna 60 as described later.
Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22. Thesecond antenna 50 includes the plurality ofhorizontal wires 52, the plurality ofvertical wires 53, the secondpower feeding point 54, the foldedportions 56 and 57, and theauxiliary wire 58.
Thedefogger 90 functioning as thethird antenna 60 includes the pair of bus bars 93 provided on the left and right of therear glass 1, the plurality ofheating wires 91 connecting the twobus bars 93 to each other, and thevertical wire 92 connecting the plurality ofheating wires 91 to one another. The number ofvertical wires 92 may be one or a plurality. Thedefogger 90 according to the example 15 functions as the third antenna, and hence theheating wire 91 and thevertical wire 92 that form thedefogger 90 function as the horizontal wire and the vertical wire, respectively, in thethird antenna 60.
The defogger coils 94 and the thirdpower feeding point 95 are provided to the bus bars 93. In other words, onebus bar 93 is connected to the power supply via thedefogger coil 94, and theother bus bar 93 is connected to the ground via thedefogger coil 94. By the defogger coils 94, noise in a received frequency band flowing into thethird antenna 60 from the power supply and the ground is suppressed. Further, the thirdpower feeding point 95 is provided to one of the bus bars 93 (for example, on a power supply side). The thirdpower feeding point 95 is connected to the reception amplifier through the connecting line (for example, low voltage cable for automobile), and the reception amplifier is connected to the receiver by the high-frequency cable (for example, coaxial cable). Further, the reception amplifier is connected to the ground (vehicle body).
Thedefogger coil 94 and the thirdpower feeding point 95 are arranged in a central portion of thebus bar 93 so that thedefogger coil 94 is positioned on the upper side and the thirdpower feeding point 95 is positioned on the lower side, but thedefogger coil 94 and the thirdpower feeding point 95 may be arranged in any positions on thebus bar 93. In addition, an arrangement order (vertical positional relationship) of thedefogger coil 94 and the thirdpower feeding point 95 is not limited to the order illustrated inFIG. 15.
When the third antenna 60 (defogger 90) receives the broadcast wave of DAB Band III, a power feeding point may be provided separately from the power feeding point for extracting a received FM radio broadcast wave. In this case, the power feeding point for an FM radio broadcast wave and the power feeding point for a DAB broadcast wave may be provided to the bus bars 93 different from (opposed to) each other.
Thethird antenna 60 forms a diversity antenna with thefirst antenna 10 to diversity-receive at least one broadcast wave of the FM radio broadcast and DAB Band III broadcast.
Theauxiliary element 12 is arranged along and in proximity to thedefogger 90 so as to be capacitively coupled to theuppermost heating wire 91 of thedefogger 90.
Components of the example 15 other than the above-mentioned components are the same as those of the example 14, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 15, thethird antenna 60 is formed of thewires 91 and 92 of thedefogger 90. Therefore, an antenna element does not need to be provided separately, and it is possible to suppress deterioration in an appearance. Further, the thirdpower feeding point 95 is provided to thebus bar 93, and hence the power feeding point for the radio-frequency signal and the power feeding point for the heating wire can be shared. Further, thebus bar 93 is connected to the power supply and the ground via thedefogger coil 94, and hence thebus bar 93 can be connected to the power supply and the ground in terms of a direct current, and can be floated from the power supply and the ground in terms of a high frequency.

FIG. 16 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 16 of this invention.
A glass antenna according to the example 16 is different from the glass antenna according to the example 15 in that theauxiliary wires 96, 97, and 98 extending from the lowermosthorizontal wire 91 of thethird antenna 60 are provided. Further, the glass antenna according to the example 16 is different from the glass antenna according to the example 15 in that the configuration of the example 2 is employed for thefirst antenna 10.
The glass antenna according to the example 16 is formed of thefirst antenna 10 and thethird antenna 60. It should be noted that inFIG. 16, only thefirst antenna 10 and the third antenna 60 (defogger 90) are illustrated, but thesecond antenna 50 according to another example described above may be provided, and thesecond antenna 50 and thebody flange 2 may be capacitively coupled to each other.
Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, and the second element. The second element is formed of themain body portion 21 and the foldedportion 22. It should be noted that the configuration of the first antenna is not limited to the configuration illustrated inFIG. 16, and the configuration of any one of the examples described above may be employed. For example, thefirst antenna 10 may include theauxiliary element 12 that is capacitively coupled to the uppermosthorizontal wire 91 of thethird antenna 60.
Thedefogger 90 functioning as thethird antenna 60 includes the pair of bus bars 93 provided on the left and right of therear glass 1, the plurality ofheating wires 91 connecting the twobus bars 93 to each other, and the parallelauxiliary wires 96, 97, and 98 extending from thelowermost heating wire 91. Thedefogger 90 may include at least onevertical wire 92 connecting the plurality ofheating wires 91 to one another. Thedefogger 90 according to the example 16 functions as the third antenna, and hence theheating wire 91 that forms thedefogger 90 functions as the horizontal wire of thethird antenna 60. The defogger coils 94 and the thirdpower feeding point 95 are provided to the bus bars 93.
The parallelauxiliary wire 96 is arranged so as to extend downward from the lowermosthorizontal wire 91, and extend along thehorizontal wire 91 in the leftward direction. The parallelauxiliary wire 97 is arranged so as to extend from the midpoint of the parallelauxiliary wire 96 substantially horizontally in the leftward direction, be then bent downward, and further extend along thehorizontal wire 91 in the leftward direction. The parallelauxiliary wire 98 is arranged so as to extend downward from the lowermosthorizontal wire 91, and extend along thehorizontal wire 91 in the rightward direction.
The end portions of the respective parallelauxiliary wires 96, 97, and 98 are in positions spaced apart from one another. Further, a part of the parallelauxiliary wire 96 and a part of the parallelauxiliary wire 97 are arranged along, in proximity to, and in substantially parallel with each other. In addition, a part of the parallelauxiliary wire 97 and a part of the parallelauxiliary wire 98 are arranged along, in proximity to, and in substantially parallel with each other. In this manner, two of the respective parallelauxiliary wires 96, 97, and 98 are arranged with an overlap (part indicated by the broken line), and the respective parallel auxiliary wires are thus capacitively coupled to each other at the end portions. It should be noted that not parts of but almost all of the parallel auxiliary wires may be arranged along and in proximity to each other.
It should be noted that the number of auxiliary wires extending along thehorizontal wire 91 may be two as illustrated inFIG. 17, may be three as illustrated inFIG. 16 andFIG. 18, or may be equal to or larger than four. The position of thedefogger 90 from which each of the parallelauxiliary wires 96, 97, and 98 extends may be a position in thebus bar 93 as illustrated inFIG. 17, or may be a position in thehorizontal wire 91 as illustrated inFIG. 16 andFIG. 18.
Components of the example 16 other than the above-mentioned components are the same as those of the example 15, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 16, the parallelauxiliary wires 96, 97, and 98 two of which are arranged along and in proximity to each other are provided. Therefore, by adjusting the width and the length of the overlap between the parallel auxiliary wires, it is possible to improve the sensitivity of thethird antenna 60 and to improve the sensitivity of another antenna with which a diversity is formed.

FIG. 17 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 17 of this invention.
A glass antenna according to the example 17 is different from the glass antenna according to the example 15 in that theauxiliary wires 96 and 98 extending from bus bars are provided.
The glass antenna according to the example 17 is formed of thefirst antenna 10 and thethird antenna 60. It should be noted that inFIG. 17, only thefirst antenna 10 and the third antenna 60 (defogger 90) are illustrated, but thesecond antenna 50 according to another example described above may be provided, and thesecond antenna 50 and thebody flange 2 may be capacitively coupled to each other.
Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, and the second element. The second element is formed of themain body portion 21 and the foldedportion 22. It should be noted that the configuration of the first antenna is not limited to the configuration illustrated inFIG. 17, and the configuration of any one of the examples described above may be employed.
Thedefogger 90 functioning as thethird antenna 60 includes the pair of bus bars 93 provided on the left and right of therear glass 1, the plurality ofheating wires 91 connecting the twobus bars 93 to each other, and the parallelauxiliary wires 96 and 98 extending from the bus bars 93. The defogger coils 94 and the thirdpower feeding point 95 are provided to the bus bars 93.
The parallelauxiliary wire 96 is arranged so as to extend downward from thebus bar 93 on the right side, and extend along thehorizontal wire 91 in the leftward direction. The parallelauxiliary wire 98 is arranged so as to extend downward from thebus bar 93 on the left side, and extend along thehorizontal wire 91 in the rightward direction. The end portions of the respective parallelauxiliary wires 96 and 98 are in positions spaced apart from each other. Further, a part of the parallelauxiliary wire 96 and a part of the parallelauxiliary wire 98 are arranged along, in proximity to, and in substantially parallel with each other. In this manner, two of the respective parallelauxiliary wires 96 and 98 are arranged with an overlap (part indicated by the broken line), and the respective parallel auxiliary wires are thus capacitively coupled to each other at the end portions. It should be noted that not parts of but almost all of the parallel auxiliary wires may be arranged along and in proximity to each other.
Components of the example 17 other than the above-mentioned components are the same as those of the example 16, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 17, the parallelauxiliary wires 96 and 98 extend from the bus bars 93. Therefore, by increasing the lengths of the parallel auxiliary wires and increasing the length of the overlap between the parallel auxiliary wires, it is possible to widen the adjustment range.

FIG. 18 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 18 of this invention.
A glass antenna according to the example 18 is different from the glass antenna according to the example 15 in that theauxiliary wires 96, 97, 98 and 89 extending from a bus bar are provided, and that thefourth antenna 70 is provided.
The glass antenna according to the example 18 is formed of thefirst antenna 10, thethird antenna 60, and thefourth antenna 70. It should be noted that inFIG. 18, only thefirst antenna 10, the third antenna 60 (defogger 90), and thefourth antenna 70 are illustrated, but thesecond antenna 50 according to another example described above may be provided, and thesecond antenna 50 and thebody flange 2 may be capacitively coupled to each other.
Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, and the second element. The second element is formed of themain body portion 21 and the foldedportion 22. It should be noted that the configuration of the first antenna is not limited to the configuration illustrated inFIG. 18, and the configuration of any one of the examples described above may be employed. For example, thefirst antenna 10 may include theauxiliary element 12 that is capacitively coupled to the uppermosthorizontal wire 91 of thethird antenna 60.
Thedefogger 90 functioning as thethird antenna 60 includes the pair of bus bars 93 provided on the left and right of therear glass 1, the plurality ofheating wires 91 connecting the twobus bars 93 to each other, and the parallelauxiliary wires 96, 97, and 98 and theauxiliary wire 89 extending from the bus bars 93. The defogger coils 94 and the thirdpower feeding point 95 are provided to the bus bars 93.
The parallelauxiliary wire 96 is arranged so as to extend downward from the bus bars 93, and extend along thehorizontal wire 91 in the leftward direction. The parallelauxiliary wire 97 is arranged so as to extend from the midpoint of the parallelauxiliary wire 96 substantially horizontally in the leftward direction, be then bent downward, and further extend along thehorizontal wire 91 in the leftward direction. The parallelauxiliary wire 98 is arranged so as to extend downward from the bus bars 93, and extend along thehorizontal wire 91 in the rightward direction.
The end portions of the respective parallelauxiliary wires 96, 97, and 98 are in positions spaced apart from one another. Further, a part of the parallelauxiliary wire 96 and a part of the parallelauxiliary wire 97 are arranged along, in proximity to, and in substantially parallel with each other. In addition, a part of the parallelauxiliary wire 97 and a part of the parallelauxiliary wire 98 are arranged along, in proximity to, and in substantially parallel with each other. In this manner, two of the respective parallelauxiliary wires 96, 97, and 98 are arranged with an overlap (part indicated by the broken line), and the respective parallel auxiliary wires are thus capacitively coupled to each other at the end portions. It should be noted that not parts of but almost all of the parallel auxiliary wires may be arranged along and in proximity to each other.
Theauxiliary wire 89 extends upward from thebus bar 93 on the right side (to which the thirdpower feeding point 95 is provided), and is bent in the leftward direction to further extend. Theauxiliary wire 89 may extend from thehorizontal wire 91 on the outermost side. Theauxiliary wire 89 may be bent in the rightward direction instead of being bent in the leftward direction, or may merely extend in the upward direction without being bent.
In addition, theauxiliary wire 89 may extend in the downward direction from the defogger 90 (bus bar 93 and lowermost horizontal wire 91), and may extend along thehorizontal wire 91. In this case, theauxiliary wire 89 functions as the parallel auxiliary wire.
Theauxiliary wire 89 may extend downward from thebus bar 93 on the right side, or may extend upward or downward from thebus bar 93 on the left side. In particular, when theauxiliary wire 89 is connected to a lower edge of thebus bar 93 to which the thirdpower feeding point 95 is provided, it is possible to improve the sensitivity in DAB Band III having a high frequency. When theauxiliary wire 89 is connected to an upper edge of thebus bar 93, on the other hand, it is possible to improve the sensitivity of the antenna for television broadcast reception provided separately (in particular, VHF-Highband of from 170 MHz to 230 MHz).
Thefourth antenna 70 is formed of the fourthpower feeding point 71 and thehorizontal element 72, and is adjusted to have a length suitable to receive the TV broadcast band (from 470 MHz to 770 MHz). In this case, thethird antenna 60 and thefourth antenna 70 may form a diversity antenna to diversity-receive the TV broadcast. The fourthpower feeding point 71 is connected to the reception amplifier through the connecting line (for example, low voltage cable for automobile), and the reception amplifier is connected to the receiver by the high-frequency cable (for example, coaxial cable). Further, the reception amplifier is connected to the ground (vehicle body).
When theauxiliary wire 89 is bent in the leftward direction or the rightward direction, the end portion of theauxiliary wire 89 may be arranged in proximity to thefourth antenna 70.
Components of the example 18 other than the above-mentioned components are the same as those of the example 16, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 18, theauxiliary wire 89 is provided to thethird antenna 60, and hence it is possible to improve the sensitivity of thethird antenna 60. Further, theauxiliary wire 89 is arranged in proximity to thefourth antenna 70, and hence it is possible to improve the sensitivity of the antenna (for example, fourth antenna 70) provided around thethird antenna 60.

FIG. 19 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 19 of this invention.
A glass antenna according to the example 19 is different from the glass antenna according to the example 18 in that the third antenna 60 (defogger 90) includes thevertical wire 92.
The glass antenna according to the example 19 is formed of thefirst antenna 10, thethird antenna 60, and thefourth antenna 70. It should be noted that inFIG. 19, only thefirst antenna 10, the third antenna 60 (defogger 90), and thefourth antenna 70 are illustrated, but thesecond antenna 50 according to another example described above may be provided, and thesecond antenna 50 and thebody flange 2 may be capacitively coupled to each other.
Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, and the second element. The second element is formed of themain body portion 21 and the foldedportion 22. It should be noted that the configuration of the first antenna is not limited to the configuration illustrated inFIG. 19, and the configuration of any one of the examples described above may be employed. For example, thefirst antenna 10 may include theauxiliary element 12 that is capacitively coupled to the uppermosthorizontal wire 91 of thethird antenna 60.
Thedefogger 90 functioning as thethird antenna 60 includes the bus bars 93, theheating wires 91, thevertical wires 92, the parallelauxiliary wires 96, 97, and 98, and theauxiliary wire 89. Thedefogger 90 according to the example 19 functions as the third antenna, and hence theheating wire 91 and thevertical wire 92 that form thedefogger 90 function as the horizontal wire and the vertical wire of thethird antenna 60, respectively. The number ofvertical wires 92 is not limited to three as illustrated inFIG. 19, and may be one, two, or equal to or larger than four. The defogger coils 94 and the thirdpower feeding point 95 are provided to the bus bars 93.
Thefourth antenna 70 is formed of the fourthpower feeding point 71 and thehorizontal element 72, and is adjusted to have a length suitable to receive the TV broadcast band (from 470 MHz to 770 MHz).
Components of the example 19 other than the above-mentioned components are the same as those of the example 18, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 19, thevertical wire 92 connecting thehorizontal wires 91 to each other is provided, and hence it is possible to improve the sensitivity of thethird antenna 60.

FIG. 20 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 20 of this invention.
A glass antenna according to the example 20 is different from the glass antenna according to the example 19 in that the third antenna 60 (defogger 90) includes the horizontalauxiliary wire 99.
The glass antenna according to the example 20 is formed of thefirst antenna 10, thethird antenna 60, and thefourth antenna 70. It should be noted that inFIG. 20, only thefirst antenna 10, the third antenna 60 (defogger 90), and thefourth antenna 70 are illustrated, but thesecond antenna 50 according to another example described above may be provided, and thesecond antenna 50 and thebody flange 2 may be capacitively coupled to each other.
Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, and the second element. The second element is formed of themain body portion 21 and the foldedportion 22. It should be noted that the configuration of the first antenna is not limited to the configuration illustrated inFIG. 20, and the configuration of any one of the examples described above may be employed. For example, thefirst antenna 10 may include theauxiliary element 12 that is capacitively coupled to the uppermosthorizontal wire 91 of thethird antenna 60.
Thedefogger 90 functioning as thethird antenna 60 includes the bus bars 93, theheating wires 91, thevertical wires 92, the parallelauxiliary wires 96, 97, and 98, theauxiliary wire 89, and the horizontalauxiliary wire 99. The defogger coils 94 and the thirdpower feeding point 95 are provided to the bus bars 93.
The horizontalauxiliary wire 99 is formed of a horizontal portion extending downward from the lowermosthorizontal wire 91, and extending both leftward and rightward from the center of the defogger along thehorizontal wire 91.
Thefourth antenna 70 is formed of the fourthpower feeding point 71 and thehorizontal element 72, and is adjusted to have a length suitable to receive the TV broadcast band (from 470 MHz to 770 MHz).
Components of the example 20 other than the above-mentioned components are the same as those of the example 19, and are therefore denoted by like reference symbols, and descriptions thereof are omitted.
In the example 20, the horizontalauxiliary wire 99 extending from the end portion of thevertical wire 92 along thehorizontal wire 91 is provided, and hence the end portion of the horizontalauxiliary wire 99 is not connected to thedefogger 90. Therefore, it is possible to increase the degree of freedom for adjusting the antenna characteristics.

FIG. 21 is a front view of the glass antenna to be provided to therear glass 1 of the automobile, for illustrating an antenna pattern according to an example 21 of this invention.
The glass antenna according to the example 21 is formed of thefirst antenna 10, thesecond antenna 50, thethird antenna 60, thefourth antenna 70, and thefifth antenna 100.
Thefirst antenna 10 includes the firstpower feeding point 15, thefirst element 11, the second element, thethird element 31, and theauxiliary elements 12 and 13. The second element is formed of themain body portion 21 and the foldedportion 22. Thefirst antenna 10 according to the example 21 has the same configuration as the configuration of thefirst antenna 10 according to the example 5 illustrated inFIG. 5, and hence a detailed description thereof is omitted.
Thesecond antenna 50 includes the plurality ofhorizontal wires 52, the plurality ofvertical wires 53, the secondpower feeding point 54, and the foldedportions 56 and 57. Thesecond antenna 50 according to the example 21 has the same configuration as the configuration of thesecond antenna 50 according to the example 12 illustrated inFIG. 12, and hence a detailed description thereof is omitted.
The left part of thehorizontal wire 52B is arranged between theauxiliary element 13 of thefirst antenna 10 and the foldedportion 22 along, in proximity to, and in substantially parallel with theauxiliary element 13 and along, in proximity to, and in substantially parallel with the foldedportion 22. Therefore, thefirst antenna 10 and thesecond antenna 50 are capacitively coupled to each other. Further, the foldedportions 56 and 57 are arranged in proximity to thebody flange 2 of the vehicle body (for example, in parallel with thebody flange 2 with a spacing of 5 millimeters), and thesecond antenna 50 and the body flange 2 (that is, ground) are capacitively coupled to each other.
Thedefogger 90 functioning as thethird antenna 60 includes the bus bars 93, theheating wires 91, thevertical wires 92, the parallelauxiliary wires 96, 97, and 98, theauxiliary wire 89, and the horizontalauxiliary wire 99. The defogger coils 94 and the thirdpower feeding point 95 are provided to the bus bars 93. Thethird antenna 60 according to the example 21 has the same configuration as the configuration of thethird antenna 60 according to the example 20 illustrated inFIG. 20, and hence a detailed description thereof is omitted.
Thefourth antenna 70 is formed of the fourthpower feeding point 71, a plurality ofhorizontal elements 72, and a plurality ofvertical elements 73, and is adjusted to have a length suitable to receive the TV broadcast band (from 470 MHz to 770 MHz).
Thehorizontal element 72 is arranged in proximity to thehorizontal wires 52 of thesecond antenna 50, and thefourth antenna 70 and thesecond antenna 50 are capacitively coupled to each other. Further, thehorizontal element 72 is arranged in proximity to theauxiliary wire 89 of thethird antenna 60, and thefourth antenna 70 and thethird antenna 60 are capacitively coupled to each other.
Thefifth antenna 100 includes a fifth power feeding point, a plurality of vertical wires, and one horizontal wire. The fifth power feeding point is connected to the reception amplifier through the connecting line (for example, low voltage cable for automobile), and the reception amplifier is connected to the receiver by the high-frequency cable (for example, coaxial cable). Further, the reception amplifier 6 is connected to the ground (vehicle body).
The descriptions made below with reference toFIG. 22 to FIG. 24 each relate to a sensitivity of an antenna exhibited when the arrangement or the length of an element described below is changed without changing the configuration of other elements. Further, the sensitivity of the antenna has a value obtained by measuring omnidirectional (360-degree) sensitivities of the antenna within a horizontal plane and calculating an average thereof.
FIG. 22 is an illustration of a gain (sensitivity) of the antenna in DAB Band III exhibited when the length of the foldedportion 22 is changed in the antenna according to the example 21. The length of themain body portion 21 is fixed at 460 millimeters, and the spacing between themain body portion 21 and the foldedportion 22 is fixed at 7 millimeters. InFIG. 22, a characteristic exhibited when the length of the foldedportion 22 is set to 300 millimeters is indicated by the solid line, a characteristic exhibited when the length is set to 400 millimeters is indicated by the broken line, and a characteristic exhibited when the length is set to 200 millimeters is indicated by the one-dot chain line. According toFIG. 22, when the length of the foldedportion 22 is set to 300 millimeters, the gain drops by a small amount on the high band side, and the antenna exhibits the highest average gain within the band. Therefore, it may be preferred that the length of the foldedportion 22 be approximatelyαλ₂/4. Here,λ₂ represents a wavelength (1.5 meters) of the center frequency of DAB Band III being 210 MHz.
FIG. 23 is an illustration of a gain (sensitivity) of the antenna in the FM radio broadcast band exhibited when the length of themain body portion 21 is changed in the antenna according to the example 21. The length of the foldedportion 22 is fixed at 300 millimeters, and the spacing between themain body portion 21 and the foldedportion 22 is fixed at 7 millimeters. InFIG. 23, a characteristic exhibited when the length of themain body portion 21 is set to 460 millimeters is indicated by the solid line, a characteristic exhibited when the length is set to 410 millimeters is indicated by the broken line, and a characteristic exhibited when the length is set to 510 millimeters is indicated by the one-dot chain line. According toFIG. 23, when the length of themain body portion 21 is set to 460 millimeters, the antenna has a flat characteristic within the band, and exhibits the highest average gain within the band. Therefore, it may be preferred that the length of themain body portion 21 be approximatelyαλ₁/5. Here,λ₁ represents a wavelength (3.3 meters) of the center frequency of the FM radio broadcast band being 92 MHz.
FIG. 24 is an illustration of a gain (sensitivity) of the antenna in the FM radio broadcast band exhibited when the length of thefirst element 11 is changed in the antenna according to the example 21. The length of the vertical portion of thefirst element 11 is fixed at 20 millimeters. InFIG. 24, a characteristic exhibited when the length of the horizontal portion of thefirst element 11 is set to 400 millimeters is indicated by the solid line, a characteristic exhibited when the length is set to 350 millimeters is indicated by the broken line, and a characteristic exhibited when the length is set to 450 millimeters is indicated by the one-dot chain line. According toFIG. 24, when the length of themain body portion 21 is set to 400 millimeters, the antenna has a flat characteristic within the band. Therefore, it may be preferred that the length of thefirst element 11 be approximatelyαλ₁/6.
While the present invention has been described in detail and pictorially in the accompanying drawings, the present invention is not limited to such detail but covers various obvious modifications and equivalent arrangements, which fall within the purview of the appended claims.

Claims

A glass antenna arranged on a window glass (1) for a vehicle, comprising a first antenna (10) and a defogger (90) configured to function as a third antenna (60), wherein the third antenna is further configured to form a diversity with the first antenna, wherein:
the first antenna includes:
a first power feeding point (15) connected to a receiver;
a first element (11) connected to the first power feeding point; and
a second element (21, 22) connected to the first power feeding point,
the first power feeding point is arranged in proximity to a side of the window glass,
the second element includes:
a main body portion (21) extending from the first power feeding point;
a folded portion (22) connected to the main body portion, and
the folded portion is folded back from the main body portion and is arranged along the main body portion,
an element (12) of the first antenna is arranged in proximity to the defogger (90) arranged on the window glass so as to be capacitively coupled to a heating wire (91) of the defogger;
the third antenna is composed by using the heating wire (91) of the defogger as an antenna; and
the third antenna includes a third power feeding point (95), the third power feeding point being connected to the receiver; and
characterized in that:
the glass antenna is configured to receive signals on a first frequency band having a wavelength of a center frequency set as λ₁ and a second frequency band having a wavelength of a center frequency set as λ₂; and
the folded portion has a length of approximatelyαλ₂/4, the main body portion has a length of approximatelyαλ₁/5, and the first element has a length of approximatelyαλ₁/6, whereα represents a wavelength shortening rate of the window glass.
The glass antenna according to claim 1, wherein the folded portion (22) is folded back from an end portion of the main body portion (21), and is arranged along and in proximity to the main body portion.
A glass antenna configured to receive signals on a first frequency band and a second frequency band and arranged on a window glass (1) for a vehicle, comprising a first antenna (10), a second antenna (50) and a defogger configured to function as a third antenna (60), wherein the third antenna is further configured to form a diversity with the first antenna, wherein:
the first antenna includes:
a first power feeding point (15) connected to a receiver;
a first element (11) connected to the first power feeding point; and
a second element (21, 22) connected to the first power feeding point,
the first power feeding point is arranged in proximity to a side of the window glass,
the second element includes:
a main body portion (21) extending from the first power feeding point;
a folded portion (22) connected to the main body portion, and
the folded portion is folded back from the main body portion and is arranged along the main body portion,
an element of the first antenna is arranged in proximity to the defogger arranged on the window glass so as to be capacitively coupled to a heating wire (91) of the defogger;
the second antenna includes:
a plurality of horizontal wires (52); and
at least one vertical wire (53) connecting the plurality of horizontal wires to one another; and
the second antenna is configured to receive a signal on a third frequency band.
wherein the second antenna further includes:
a second power feeding point (54) provided to an end portion of any one of the plurality of horizontal wires;
a wire (56, 57) for capacitive coupling that extends from an uppermost wire of the plurality of horizontal wires, and is arranged in a position capacitively coupled to a body flange (2); and
an auxiliary wire (58) extending in a direction opposite to a direction in which the one of the plurality of horizontal wires extends from the second power feeding point,
wherein, the first antenna is arranged in proximity to the plurality of horizontal wires arranged on the window glass, and is capacitively coupled to the second antenna;
the third antenna is composed by using the heating wire (91) of the defogger as an antenna; and
the third antenna includes a third power feeding point (95), the third power feeding point being connected to the receiver.
The glass antenna according to claim 3, wherein the at least one vertical wire (53) includes a plurality of vertical wires.
The glass antenna according to claim 3, wherein at least one of the plurality of horizontal wires (52) is arranged in proximity to the second element (21, 22), and is capacitively coupled to the second element.
The glass antenna according to claim 3, wherein at least one of the plurality of horizontal wires (52) is arranged between the first element (11) and the second element (21, 22).
The glass antenna according to claim 3, wherein the wire (56, 57) for capacitive coupling includes a folded portion (56, 57) having an end portion folded back toward one of an upper side and a lower side.
The glass antenna according to claim 1, wherein:
the defogger (90) includes:
a pair of bus bars (93) provided on left and right of the window glass (1); and
a plurality of heating wires (91) connecting the pair of bus bars to each other;
the third antenna (60) includes:
a plurality of horizontal wires (91) used for the plurality of heating wires; and
at least two parallel auxiliary wires (96, 97, 98) that extend from one of: one of the bus bars; and one of the plurality of horizontal wires on an outermost side, and are arranged so that end portions of the at least two parallel auxiliary wires are spaced apart from each other; and
the at least two parallel auxiliary wires are arranged along and in proximity to each other.
The glass antenna according to claim 8, wherein the third antenna (60) further includes at least one auxiliary wire (96, 97, 98).
The glass antenna according to claim 8, wherein the third antenna (60) further includes at least one vertical wire (92) connecting the plurality of horizontal wires of the third antenna to one another.
The glass antenna according to claim 10, further comprising a horizontal auxiliary wire (99) extending from an end portion of the at least one vertical wire along one of the plurality of horizontal wires.