JP2008060762A - Feeding structure of antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a feeding structure of an antenna which, while a feedable frequency bandwidth is a wide band, does not largely project outward from a dielectric material board. <P>SOLUTION: A back side signaling electrode plate 16 and a back side grounding electrode plate 18 are closely arranged without being short-circuited on a back face of the dielectric material board 10, a front side signaling electrode plate 12 and a front side grounding electrode plate 14 are closely arranged without being short-circuited in the front side, and the dielectric material board 10 is interposed between the rear side signaling electrode plate 16 and the front side signaling electrode plate 12, and the rear side grounding electrode plate 18 and the front side grounding electrode plate 14 and are arranged in face to face with each other. The rear side signaling electrode plate 16 is electrically connected to a center conductor of a transmission route, and the rear side grounding electrode plate 18 is electrically connected to an outer conductor of the transmission route respectively. The front side signaling plate 12 is composed to be connected to the antenna, and the front side grounding electrode plate 14 is composed to function as an ground of the antenna. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an antenna feeding structure in which a high-frequency signal is fed to an antenna via a dielectric material plate.

As an example of a technique for feeding a high-frequency signal from a communication device installed in a vehicle to an antenna arranged and fixed outside the vehicle without drilling holes or the like in the body of a car, Japanese Utility Model Publication No. 6-31863 There is what was shown in the gazette (patent document 1). The prior art described in Patent Document 1 is a power feeding structure based on electromagnetic coupling in which two helical conductors are coaxially disposed so as to sandwich a window glass of an automobile, which is a dielectric material plate, from outside and inside the vehicle. Another conventional technique is disclosed in US Pat. No. 5,212,492 (Patent Document 2). In the prior art described in Patent Document 2, a pair of electrode plates are disposed so as to sandwich a window glass of an automobile, which is a dielectric material plate, and a power feeding structure based on capacitive coupling by a capacitance between the pair of electrode plates. is there.
Japanese Utility Model Publication No. 6-31763 USP 5212492

  In the prior art described in Patent Document 1, there is a problem that the frequency band that can be fed is narrow, and the axial dimension of the helical conductor greatly protrudes outward from the window glass. Further, the conventional technique described in Patent Document 2 does not protrude greatly from the window glass, but has a problem that the frequency band that can be fed is still a narrow band.

  The present invention has been made in view of the circumstances of the prior art as described above, and provides a feeding structure for an antenna that has a wide frequency band that can be fed and does not protrude significantly from a dielectric material plate. With the goal.

  In order to achieve such an object, the antenna power feeding structure of the present invention is arranged such that the back side signal electrode plate and the back side ground electrode plate are placed close to the back surface of the dielectric material plate without short-circuiting the dielectric material plate. The front side signal electrode plate and the front side ground electrode plate are arranged close to the surface of the material plate without short-circuiting, and the back side signal electrode plate and the front side signal electrode plate or the back side ground electrode plate The front-side ground electrode plates are opposed to each other with the dielectric material plates sandwiched therebetween, and a center conductor of a transmission line is electrically connected to the back-side signal electrode plate and the transmission line is connected to the back-side ground electrode plate. These external conductors are electrically connected, an antenna is connected to the front signal electrode plate, and the front ground electrode plate operates as the ground of the antenna.

  Further, a matching element may be interposed between the front signal electrode plate and the front ground electrode plate.

  2. The antenna feeding structure according to claim 1, wherein a line of electric force is generated between a back-side signal electrode plate and a back-side ground electrode plate disposed on the back surface of the dielectric material plate by a signal fed from the transmission line. Occurs. Due to the lines of magnetic force generated by the electric lines of force, similar electric lines of force are generated between the front-side signal electrode plate and the front-side ground electrode plate disposed on the surface of the dielectric material plate. Accordingly, the electrode plates disposed on the back surface and the front surface are electromagnetically coupled. In addition, the back side signal electrode plate, the front side signal electrode plate, the back side ground electrode plate, and the front side ground electrode plate disposed with the dielectric material plate interposed therebetween are capacitively coupled as capacitors. By these electromagnetic coupling and capacitive coupling, the frequency band that can be fed becomes wide. Further, since the front-side signal electrode plate and the front-side ground electrode plate are provided on the surface of the dielectric material plate, power can be supplied to an antenna that requires grounding. In addition, the feeding structure itself does not protrude greatly from the surface of the dielectric material plate.

  In the antenna feeding structure according to claim 2, electromagnetic coupling is achieved by interposing a matching element between the front signal electrode plate and the front ground electrode plate disposed on the surface of the dielectric material plate. The balance of capacitive coupling can be adjusted, transmission loss can be reduced, and the frequency bandwidth that can be fed can be further widened.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a basic configuration of an antenna feeding structure according to the present invention. FIG. 2 is a diagram for explaining electromagnetic coupling of electrode plates provided on the front and back surfaces of the dielectric material plate in the configuration of FIG. FIG. 3 is a diagram illustrating capacitive coupling of electrode plates provided on the front and back surfaces of the dielectric material plate in the configuration of FIG. FIG. 4 is a perspective view showing the structure of the first embodiment in which the antenna feeding structure of the present invention is applied to the VHF band. FIG. 5 is an enlarged view of a main part of the AA cross section of FIG. 6 is a plan dimension view of FIG. FIG. 7 is an equivalent circuit diagram of the first embodiment. FIG. 8 is a graph showing transmission loss in the first embodiment in which a matching element is interposed.

  First, as shown in FIG. 1, the basic structure of the antenna power feeding structure of the present invention is such that a front signal electrode plate 12 made of a conductor and a front ground are formed on the surface of a dielectric material plate 10 such as an automobile window glass. The electrode plates 14 are arranged so that their edges are parallel to each other and close to each other without being short-circuited. Further, a back-side signal electrode plate 16 and a back-side ground electrode plate 18 made of a conductor are arranged on the back surface of the dielectric material plate 10 so that the edges thereof are parallel to each other and close to each other without being short-circuited. Is done. Moreover, the front-side signal electrode plate 12 and the back-side signal electrode plate 16 are disposed so as to face each other with the dielectric material plate 10 in between, and the front-side ground electrode plate 14 and the back-side ground electrode plate 18 are also dielectric. It arrange | positions so that the body material board 10 may be pinched | interposed.

  In such a configuration, a central conductor of a transmission line such as a coaxial cable is connected to the back side signal electrode plate 16 and an external conductor is connected to the back side ground electrode plate 18 so that a signal in an appropriate frequency band is transmitted via the transmission line. 2, as shown in FIG. 2, electric lines of force 20 are generated between the edges of the back-side signal electrode plate 16 and the back-side ground electrode plate 18, thereby passing through the dielectric material plate 10. Magnetic field lines 22 are generated. Therefore, the magnetic lines of force 20 are also generated between the edge portions of the front-side signal electrode plate 12 and the front-side ground electrode plate 14 by the magnetic force lines 22. Accordingly, the signals applied to the back signal electrode plate 16 and the back ground electrode plate 18 are fed to the front signal electrode plate 12 and the front ground electrode plate 14 by such electromagnetic coupling. Further, the back-side signal electrode plate 16 and the front-side signal electrode plate 12 or the back-side ground electrode plate 18 and the front-side ground electrode plate 14 form a capacitor with the dielectric material plate 10 interposed therebetween, and the back-side signal electrode As shown in FIG. 3, the signals applied to the plate 16 and the back side ground electrode plate 18 are fed to the front side signal electrode plate 12 and the front side ground electrode plate 14 by capacitive coupling. Therefore, according to the basic structure of the antenna feeding structure of the present invention, the signals applied to the back-side signal electrode plate 16 and the back-side ground electrode plate 18 provided on the back surface of the dielectric material plate 10 are converted into the front-side signals provided on the surface. Electric power is supplied to the electrode plate 12 and the front ground electrode plate 14 by electromagnetic coupling and capacitive coupling. The signals applied to the front signal electrode plate 12 and the front ground electrode plate 14 provided on the surface of the dielectric material plate 10 are transferred to the back signal electrode plate 16 and the back ground electrode plate 18 provided on the back surface. Of course, power is supplied by electromagnetic coupling and capacitive coupling. Here, the power supply by electromagnetic coupling is transmission by TEM mode, and there is little loss due to dielectric transmission loss and characteristic impedance change due to foreign substance incidence.

  In the first embodiment in which this basic configuration is specifically adapted to the VHF band of the television broadcast frequency, as shown in FIGS. 4 to 6, the relative permittivity is around 7 and the thickness is 3 mm and 300 mm × 300 mm. The front-side signal electrode plate 12 and the back-side signal electrode plate 16 face the dielectric material plate 10 which is a glass plate in the same shape of 15 mm × 70 mm, and the front-side ground electrode plate 14 and the back-side ground electrode plate 18. Are opposite in the same shape of 40 mm × 70 mm, and the clearance between the front signal electrode plate 12 and the front ground electrode plate 16 and the clearance between the back signal electrode plate 16 and the back ground electrode plate 18 are each 1 mm. Is done. A matching element 24 is interposed between the front signal electrode plate 12 and the front ground electrode plate 14. As an example, the matching element 24 is a 56 nH inductance element. Further, as shown in FIG. 5, a central conductor 26a of a transmission line 26 such as a coaxial cable is electrically connected to the back side signal electrode plate 16 by solder or the like, and an external conductor 26b is soldered to the back side electrode plate 18 or the like. Is electrically connected. An equivalent circuit having such a configuration is as shown in FIG. In FIG. 7, Zr is the input / output impedance of the connected antenna, and Zc is the output impedance of the transmission line 26. The size of the front signal electrode plate 12, the front ground electrode plate 14, the back signal electrode plate 16, and the back ground electrode plate 18, the gap between them, the constant of the matching element 24, etc. Since the capacitive coupling depends on the frequency band of the signal to be fed, the dielectric material plate 10 should be appropriately set and adjusted in consideration of the relative dielectric constant, thickness, and the like.

  As shown in FIG. 8, the transmission loss of the first embodiment is −1.01 dBi at 170 MHz in the VHF band, −0.83 dBi at 200 MHz, −0.49 dBi at 220 MHz, and is the entire VHF band. There is very little transmission loss in the band.

  Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a perspective view showing the structure of a second embodiment in which the antenna feeding structure of the present invention is applied to the UHF band. FIG. 10 is a plan dimension view of FIG. FIG. 11 is a graph showing transmission loss in the second embodiment in which a matching element is interposed. FIG. 12 is a graph showing transmission loss in the second embodiment with the matching element omitted. 9 and 10, the same or equivalent members as those shown in FIGS. 1 to 7 are denoted by the same reference numerals, and redundant description is omitted.

  In the second embodiment of the antenna feeding structure of the present invention, as shown in FIGS. 9 and 10, the front side signal electrode plate 12 and the back side signal electrode plate 16 have the same shape of 15 mm × 30 mm so as to be applied to the UHF band. The front side ground electrode plate 14 and the back side ground electrode plate 18 are also arranged to face each other in the same shape of 40 mm × 30 mm. The gap between the front-side signal electrode plate 12 and the front-side ground electrode plate 16 and the gap between the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are 1 mm, respectively, as in the first embodiment. No. 10 is the same as the first embodiment with a relative dielectric constant of around 7 and a thickness of 3 mm. The matching element 24 interposed between the front-side signal electrode plate 12 and the front-side ground electrode plate 14 is, for example, a 22 nH inductance element.

  With the matching element 24 interposed in the second embodiment, the transmission loss is −0.60 dBi at 400 MHz in the UHF band, −0.40 dBi at 470 MHz, and −500 MHz at −500 MHz as shown in FIG. It is 0.43 dBi, −0.78 dBi at 600 MHz, and −1.29 dBi at 700 MHz, and the transmission loss is extremely small in the entire UHF band. Further, when the transmission loss is measured with the structure of the second embodiment without the matching element 24, as shown in FIG. 12, it is −1.18 dBi at 400 MHz, −1.49 dBi at 470 MHz, and 500 MHz. -1.65 dBi, -2.10 dBi at 600 MHz, -2.36 dBi at 700 MHz, which is a fully usable range, but compared to the state where the matching element 24 is provided, the entire band of the UHF band The transmission loss is slightly increased over time.

  Furthermore, a third embodiment of the present invention will be described with reference to FIGS. FIG. 13 is a perspective view showing the structure of a third embodiment in which the antenna feeding structure of the present invention is applied to a quasi-microwave band. 14A and 14B show the dimensions of the electrode of FIG. 13, where FIG. 14A is a front surface dimension diagram and FIG. 14B is a back surface dimension diagram. FIG. 15 is a graph showing transmission loss in the third embodiment in which a matching element is interposed. 13 and FIG. 14, the same or equivalent members as those shown in FIG. 1 to FIG. 7, FIG. 9 and FIG.

  In the third embodiment of the antenna feeding structure of the present invention, the front-side signal electrode plate 12 and the back-side signal electrode plate 16 have a size of 10 mm × 13 mm as shown in FIGS. The front side ground electrode plate 14 is 35 mm × 30 mm, and the back side ground electrode plate 18 is 20 mm × 20 mm so as to face each other in the same shape. The gap between the front-side signal electrode plate 12 and the front-side ground electrode plate 16 and the gap between the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are 1 mm, respectively, as in the first embodiment. No. 10 is the same as the first embodiment with a relative dielectric constant of around 7 and a thickness of 3 mm. The matching element 24 interposed between the front-side signal electrode plate 12 and the front-side ground electrode plate 14 is, for example, an inductance element of 4.7 nH.

  With the matching element 24 interposed in the third embodiment, the transmission loss is -1.98 dBi at 1.25 GHz in the quasi-microwave band and -0.87 dBi at 1.4 GHz as shown in FIG. It is -0.50 dBi at 1.5 GHz, -0.49 dBi at 1.6 GHz, and -0.63 dBi at 1.7 GHz, and transmission loss is extremely small over the entire band of the quasi-microwave band.

  As shown in the first to third embodiments, good transmission characteristics with little transmission loss can be obtained in any of the VHF band, UHF band, and quasi-microwave band of the television broadcasting frequency. However, in the first to third embodiments, the front-side signal electrode plate 12, the front-side ground electrode plate 14, the back-side signal electrode plate 16, and the back-side ground electrode plate 18 are all rectangular and are used for the front-side signal. The electrode plate 12 and the front-side ground electrode plate 14 and the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are arranged to face each other so that the approaching edges are straight and parallel. Therefore, the transmission loss was measured when the front-side signal electrode plate 12, the front-side ground electrode plate 14, the back-side signal electrode plate 16 and the back-side ground electrode plate 18 were other than rectangular, for example, circular.

  A fourth embodiment of the present invention having a circular electrode plate will be described with reference to FIGS. FIG. 16 is a plan view showing the structure of the fourth embodiment of the antenna feeding structure of the present invention. FIG. 17 is a graph showing transmission loss in the fourth embodiment of FIG. In FIG. 16, the same or equivalent members as those shown in FIG. 1 to FIG.

  In the fourth embodiment of the antenna feeding structure according to the present invention, as shown in FIG. 16, the front-side signal electrode plate 12 and the back-side signal electrode plate 16 have a circular shape with a diameter of 40 mm and are opposed to each other as shown in FIG. The front-side ground electrode plate 14 and the back-side ground electrode plate 18 are arranged to face each other in the same circular shape having a diameter of 90 mm. The gap between the front-side signal electrode plate 12 and the front-side ground electrode plate 16 and the gap between the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are 1 mm, respectively, as in the first embodiment. No. 10 is the same as the first embodiment with a relative dielectric constant of around 7 and a thickness of 3 mm. The matching element 24 interposed between the front-side signal electrode plate 12 and the front-side ground electrode plate 14 is, for example, a 22 nH inductance element.

  With the matching element 24 interposed in the fourth embodiment, the transmission loss is −1.12 dBi at 300 MHz in the UHF band, −0.75 dBi at 350 MHz, and −450 MHz as shown in FIG. 17. It is 0.62 dBi, −0.94 dBi at 550 MHz, and −1.13 dBi at 600 MHz, and has a low transmission loss in the entire UHF band and can be used sufficiently.

  Furthermore, as in the structure of the fourth embodiment of the antenna feeding structure of the present invention, a modification in which the electrode plate is other than a rectangle will be described with reference to FIGS. FIG. 18 is a plan view showing a first modification of the structure of the fourth embodiment of the power feeding structure of the antenna of the present invention. FIG. 19 is a plan view showing a second modification of the structure of the fourth embodiment of the antenna feeding structure of the present invention. FIG. 20 is a plan view showing a third modification of the structure of the fourth embodiment of the antenna feeding structure of the present invention. 18 to 20, the same or equivalent members as those shown in FIGS. 1 to 7 and the like are denoted by the same reference numerals, and redundant description is omitted.

  In the first modification of the structure of the fourth embodiment of the antenna feeding structure of the present invention shown in FIG. 18, the front-side signal electrode plate 12 and the back-side signal electrode plate 16 are arranged in the same shape of small triangles facing each other. The front-side ground electrode plate 14 and the back-side ground electrode plate 18 are arranged to face each other in the same shape of a large triangle. The gap between the front-side signal electrode plate 12 and the front-side ground electrode plate 16 and the gap between the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are arranged so that the triangle sides are parallel to each other. The matching element 24 is interposed between the front signal electrode plate 12 and the front ground electrode plate 14.

  In the second modification of the structure of the fourth embodiment of the antenna feeding structure of the present invention shown in FIG. 19, the front-side signal electrode plate 12 and the back-side signal electrode plate 16 face each other with the same shape of a small eight-stroke shape. The front-side ground electrode plate 14 and the back-side ground electrode plate 18 are arranged to face each other in the same large octagonal shape. The gap between the front-side signal electrode plate 12 and the front-side ground electrode plate 16 and the gap between the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are parallel to each other with the eight stroke sides facing each other. The matching element 24 is interposed between the front signal electrode plate 12 and the front ground electrode plate 14.

  In the third modification of the structure of the fourth embodiment of the antenna feeding structure of the present invention shown in FIG. 20, the front-side signal electrode plate 12 and the back-side signal electrode plate 16 face each other in the same shape of a small crescent. The front-side ground electrode plate 14 and the back-side ground electrode plate 18 are arranged to face each other in the same large crescent shape. The front-side signal electrode plate 12 and the front-side ground electrode plate 16 and the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are arranged so that a large crescent-shaped arc approaches each other so that a gap is formed between them. The matching element 24 is interposed between the front signal electrode plate 12 and the front ground electrode plate 14.

  Even in the first to third modifications of the structure of the fourth embodiment shown in FIGS. 18 to 20, substantially the same characteristics as in the case of the fourth embodiment can be obtained.

  Next, an embodiment in which an antenna is disposed in the antenna feeding structure of the present invention will be described with reference to FIGS. FIG. 21 is an external perspective view of an embodiment in which a J-type antenna is provided in the antenna feeding structure of the present invention. 22 is a plan dimension view of FIG. FIG. 23 is a Smith chart of the J-type antenna of FIG. FIG. 24 is a VSWR characteristic diagram of the J-type antenna of FIG. FIG. 25 is a graph showing the dipole antenna ratio of the J-type antenna of FIG. FIG. 26 is a horizontal plane directivity characteristic diagram of the J-type antenna of FIG. 21, where (a) is measured at 530 MHz, (b) is 590 MHz, (c) is 650 MHz, and (d) is measured at 710 MHz. 21 and FIG. 22, the same or equivalent members as those shown in FIG. 1 to FIG.

    21 and 22, a front signal electrode plate 12 and a front ground electrode plate 14 are disposed on the surface of a dielectric material plate 10, and a matching element 24 is interposed therebetween. In addition, a back signal electrode plate 16 and a back ground electrode plate 18 are disposed on the back surface. The front-side signal electrode plate 12 and the back-side signal electrode plate 16 face each other in the same shape of 15 mm × 30 mm, and the front-side ground electrode plate 14 and the back-side ground electrode plate 18 face each other in the same shape of 40 mm × 30 mm. The gap between the front-side signal electrode plate 12 and the front-side ground electrode plate 16 and the gap between the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are 1 mm, respectively, as in the first embodiment. The dielectric material plate 10 is a 400 mm × 400 mm plate glass having a relative dielectric constant of about 6.5 and a thickness of 6 mm. The matching element 24 interposed between the front-side signal electrode plate 12 and the front-side ground electrode plate 14 is, for example, a 22 nH inductance element. Further, the base end of the main radiating element 28 a of the J-type antenna 28 is disposed on the front side signal electrode plate 12, and the base end of the sub-radiating element 28 b is disposed on the front side ground electrode plate 14. In order to operate in the UHF band, the main radiating element 28a is 200 mm which resonates at a frequency near 530 MHz, and the sub-radiating element 28b is 120 mm which resonates at a frequency near 700 MHz. 10 mm.

  In such a configuration, the antenna input impedance is as shown in the Smith chart shown in FIG. 23. As shown in FIG. 24, the VSWR suddenly deteriorates in characteristics at 720 MHz or higher, but the lower frequency band of 710 MHz or lower. Excellent characteristics have been obtained. Further, as shown in FIG. 25, the J-type antenna 28 disposed in the antenna feeding structure of the present invention has a very good dipole antenna ratio, and a gain equivalent to that of a half-wave dipole antenna is obtained. . Further, as shown in FIGS. 26 (a), (b), (c), and (d), the horizontal directivity characteristics can be obtained at any frequency of 530 MHz, 590 MHz, 650 MHz, and 710 MHz. Yes. Therefore, it has excellent characteristics as an antenna operating in the UHF band.

  Furthermore, another embodiment in which an antenna is disposed in the antenna feeding structure of the present invention will be described with reference to FIGS. FIG. 27 is an external perspective view of another embodiment in which a loop antenna is provided in the antenna feeding structure of the present invention. FIG. 28 is a plan view of FIG. FIG. 29 is a Smith chart of the loop antenna of FIG. FIG. 30 is a VSWR characteristic diagram of the loop antenna of FIG. 27 and 28, the same or equivalent members as those shown in FIGS. 1 to 7 and the like are denoted by the same reference numerals, and redundant description is omitted.

  27 and 28, a front-side signal electrode plate 12 and a front-side ground electrode plate 14 are disposed on the surface of the dielectric material plate 10, and a matching element 24 is interposed therebetween. In addition, a back signal electrode plate 16 and a back ground electrode plate 18 are disposed on the back surface. The front side signal electrode plate 12 and the back side signal electrode plate 16 face each other in the same shape of 15 mm × 30 mm, and the front side ground electrode plate 14 and the back side ground electrode plate 18 face each other in the same shape of 30 mm × 30 mm. The gap between the front-side signal electrode plate 12 and the front-side ground electrode plate 16 and the gap between the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are 1 mm, respectively, as in the first embodiment. The dielectric material plate 10 is a 400 mm × 400 mm plate glass having a relative dielectric constant of about 6.5 and a thickness of 6 mm. The matching element 24 interposed between the front-side signal electrode plate 12 and the front-side ground electrode plate 14 is, for example, a 1.8 pF capacitance element. Further, both ends of the front-side signal electrode plate 12 and the front-side ground electrode plate 14 are provided, and a loop antenna 30 having a circumferential length of about 550 mm, which is one wavelength of 534 MHz, is provided.

  In such a configuration, the antenna input impedance is as shown in the Smith chart shown in FIG. 29, and an excellent VSWR characteristic of 2 or less is obtained at 534 MHz as shown in FIG. Therefore, it has excellent characteristics as an antenna operated at 534 MHz.

  Further, another embodiment in which an antenna is disposed in the antenna feeding structure of the present invention will be described with reference to FIGS. FIG. 31 is an external perspective view of another embodiment in which an inverted F-type antenna is provided in the antenna feeding structure of the present invention. 32A and 32B show dimensions of the electrodes and the like of FIG. 31, wherein FIG. 32A is a front surface dimension diagram, FIG. 32B is a rear surface dimension diagram, and FIG. 32C is a dimension diagram of an inverted F-type antenna. FIG. 33 is a Smith chart of the inverted F-type antenna of FIG. FIG. 34 is a VSWR characteristic diagram of the inverted-F antenna of FIG. 31 and 32, the same or equivalent members as those shown in FIGS. 1 to 7 and the like are denoted by the same reference numerals, and redundant description is omitted.

  31 and 32, a front-side signal electrode plate 12 and a front-side ground electrode plate 14 are disposed on the surface of a dielectric material plate 10, and a matching element 24 is interposed therebetween. In addition, a back signal electrode plate 16 and a back ground electrode plate 18 are disposed on the back surface. The front-side signal electrode plate 12 and the back-side signal electrode plate 16 face each other in the same shape of 15 mm × 30 mm, the front-side ground electrode plate 14 is 90 mm × 40 mm, and the back-side ground electrode plate 18 is 40 mm × 30 mm with different dimensions. The gap between the front-side signal electrode plate 12 and the front-side ground electrode plate 16 and the gap between the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are each 1 mm, which is the same as in the first embodiment. It is. The dielectric material plate 10 is a 400 mm × 400 mm plate glass having a relative dielectric constant of about 6.5 and a thickness of 6 mm. The matching element 24 interposed between the front-side signal electrode plate 12 and the front-side ground electrode plate 14 is, for example, a 22 nH inductance element. Further, the base end of the radiating element 32 a of the inverted F-type antenna 32 is disposed on the front side signal electrode plate 12, and the base end of the short stub 32 b is disposed on the front side ground electrode plate 14. The inverted F-type antenna 32 is set to a length of a quarter wavelength of the use frequency so as to resonate at a frequency near 500 MHz to be used, and is about 160 mm long. It is arranged in parallel with a height of 30 mm from the surface. The inverted F-type antenna 32 requires a sufficiently large ground plane with respect to the wavelength. In this alternative embodiment, the front-side ground electrode plate 14 is a diagonal line of a rectangular electrode plate within the practical range. Is set to be about ¼ wavelength of the operating frequency.

  In such a configuration, the antenna input impedance is as shown in the Smith chart shown in FIG. 33, and the VSWR has an excellent VSWR characteristic of about 1.5 at 500 MHz as shown in FIG. Therefore, it has excellent characteristics as an antenna operated at 500 MHz.

  In the antenna power feeding structure of the present invention, as described in the above embodiment, the front-side signal electrode plate 12 and the back-side signal electrode plate 16 are dimensioned in any of the VHF band, the UHF band, and the quasi-microwave band. Even if it exists, the short side of a rectangular electrode plate can be 15 mm. Therefore, as shown in FIG. 35, the front-side signal electrode plate 12 and the back side are not sandwiched between the defoggers 34, 34,... A signal electrode plate 16 can be provided. The front-side ground electrode plate 14 and the back-side ground electrode plate 18 are disposed with the defoggers 34, 34.

  In such a configuration, the front-side signal electrode plate 12 and the back-side signal electrode plate 16 are closely related to the radiation characteristics, and if a conductive wire such as the defogger 34, 34,. Influence. However, as shown in FIG. 35, such an influence can be avoided by disposing within the interval between the defoggers 34, 34. The front-side ground electrode plate 14 and the back-side ground electrode plate 18 are disposed with the defoggers 34, 34,... Between them, and the electromagnetic coupling TEMmode is short-circuited. The electric lines of force between the back side ground electrode plate 18 are slight, and the influence on radiation is sufficiently ignored except for the edge portion facing the front side signal electrode plate 12 and the back side signal electrode plate 16 necessary for electromagnetic coupling. obtain. In addition, by sandwiching or contacting conductive wires such as the defoggers 34, 34..., The area as the ground of the front-side ground electrode plate 14 and the back-side ground electrode plate 18 acts to increase the radiation. Does not affect. The same applies to conductive wires such as an antenna pattern provided on the window glass instead of the defogger 34.

  As long as the antenna is disposed in the antenna feeding structure of the present invention, any member as long as it is the dielectric material plate 10 can be disposed. As shown in FIG. 36, the antenna is disposed on the Freon glass 34 or the rear glass 36 of the automobile. Not only can it be installed on the glass 38 of the headlamp. Moreover, if it shape | molds with dielectric materials, such as a resin material, it can install also in the part of the roof 40 or the fender 42. FIG.

  In the above embodiments, the antenna power feeding structure of the present invention has been described with reference to the embodiments provided in an automobile. You may arrange | position in what performs wireless communication. For example, it may be disposed in a housing of a wireless LAN server. In such a case, the front-side signal electrode plate 12 and the front-side ground electrode plate 14 are arranged on the surface of the printed circuit board as the dielectric material plate 10, and the back-side signal electrode plate 16 and the back-side ground electrode plate 18 are arranged on the back surface. May be unitized.

It is a perspective view which shows the fundamental structure of the electric power feeding structure of the antenna of this invention. It is a figure explaining the electromagnetic coupling of the electrode plate provided in the surface and back surface of the dielectric material board by the structure of FIG. It is a figure explaining the capacitive coupling of the electrode plate provided in the surface of a dielectric material board by the structure of FIG. 1, and a back surface. It is a perspective view which shows the structure of 1st Example which applied the electric power feeding structure of the antenna of this invention to the VHF band. It is a principal part enlarged view of the AA cross section of FIG. FIG. 5 is a plan dimension view of FIG. 4. FIG. 3 is an equivalent circuit diagram of the first embodiment. It is a graph which shows the transmission loss in 1st Example in which the matching element was interposed. It is a perspective view which shows the structure of 2nd Example which applied the electric power feeding structure of the antenna of this invention to the UHF band. FIG. 10 is a plan dimension view of FIG. 9. It is a graph which shows the transmission loss in 2nd Example which interposed the matching element. It is a graph which shows the transmission loss in 2nd Example in the state which excluded the matching element. It is a perspective view which shows the structure of 3rd Example which applied the electric power feeding structure of the antenna of this invention to the quasi-microwave band. The dimension of the electrode of FIG. 13 is shown, (a) is a surface dimension figure, (b) is a back surface dimension figure. It is a graph which shows the transmission loss in 3rd Example which interposed the matching element. It is a top view which shows the structure of 4th Example of the electric power feeding structure of the antenna of this invention. It is a graph which shows the transmission loss in 4th Example of FIG. It is a top view which shows the 1st modification of the structure of 4th Example of the electric power feeding structure of the antenna of this invention. It is a top view which shows the 2nd modification of the structure of 4th Example of the electric power feeding structure of the antenna of this invention. It is a top view which shows the 3rd modification of the structure of 4th Example of the electric power feeding structure of the antenna of this invention. It is an external appearance perspective view of the Example which has arrange | positioned the J-type antenna in the electric power feeding structure of the antenna of this invention. FIG. 22 is a plan dimension view of FIG. 21. It is a Smith chart of the J-type antenna of FIG. FIG. 22 is a VSWR characteristic diagram of the J-type antenna of FIG. 21. It is a graph which shows the dipole antenna ratio of the J-type antenna of FIG. It is a horizontal plane directivity characteristic figure of J type antenna of Drawing 21, (a) is 530MHz, (b) is 590MHz, (c) is 650MHz, (d) is measured at 710MHz, respectively. It is an external appearance perspective view of the other Example which has arrange | positioned the loop antenna in the electric power feeding structure of the antenna of this invention. It is a top view of FIG. It is a Smith chart of the loop antenna of FIG. It is a VSWR characteristic view of the loop antenna of FIG. It is an external appearance perspective view of another Example which has arrange | positioned the inverted F type antenna to the electric power feeding structure of the antenna of this invention. 31 shows the dimensions of the electrodes and the like in FIG. 31, where (a) is a front surface dimension diagram, (b) is a rear surface dimension diagram, and (c) is a dimension diagram of an inverted F-type antenna. FIG. 32 is a Smith chart of the inverted F-type antenna of FIG. 31. FIG. 32 is a VSWR characteristic diagram of the inverted F-type antenna of FIG. 31. It is a figure which shows that the electric power feeding structure of the antenna of this invention can arrange | position a front side signal electrode plate and a back side signal electrode plate without pinching | pinching the defogger provided in the window glass of the motor vehicle. It is a figure which shows that the structure which has arrange | positioned the antenna to the electric power feeding structure of the antenna of this invention can be arrange | positioned in various parts of a motor vehicle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dielectric material plate 12 Front-side signal electrode plate 14 Front-side ground electrode plate 16 Back-side signal electrode plate 18 Back-side ground electrode plate 20 Electric field line 22 Magnetic field line 24 Matching element 26 Transmission path 26a Central conductor 26b External conductor 28 J type Antenna 28a Main radiating element 28b Sub-radiating element 30 Loop antenna 32 Inverted F type antenna 32a Radiating element 32b Short stub 34 Defoger 36 Front glass 38 Rear glass 40 Headlight glass 42 Roof 44 Fender

Claims (9)

  A backside signal electrode plate and a backside ground electrode plate are placed close to each other without being short-circuited on the back surface of the dielectric material plate, and a front side signal electrode plate and a front side ground electrode plate are placed on the surface of the dielectric material plate. Closely arranged without short-circuiting, and the dielectric material plate is sandwiched between the back-side signal electrode plate and the front-side signal electrode plate or the back-side ground electrode plate and the front-side ground electrode plate. The center conductor of the transmission line is electrically connected to the back-side signal electrode plate, the external conductor of the transmission line is electrically connected to the back-side ground electrode plate, and an antenna is connected to the front-side signal electrode plate. And the front-side ground electrode plate is configured to operate as the ground of the antenna.   2. The antenna feeding structure according to claim 1, wherein a matching element is interposed between the front-side signal electrode plate and the front-side ground electrode plate.   3. The antenna feeding structure according to claim 1 or 2, wherein an edge of the front signal electrode plate and an edge of the front ground electrode plate are arranged to face each other in parallel, and the back signal electrode An antenna feeding structure, wherein an edge portion of a plate and an edge portion of the back side ground electrode plate are arranged to face each other in parallel.   3. The antenna feeding structure according to claim 1, wherein the antenna is a J-type antenna, the main radiating element is connected to the front-side signal electrode plate, and the sub-radiating element is connected to the front-side ground electrode plate. An antenna feeding structure characterized by comprising   3. The antenna feeding structure according to claim 1, wherein the antenna is a one-wavelength loop antenna, one end of which is connected to the front signal electrode plate, and the other end is connected to the front ground electrode plate. An antenna feeding structure characterized by that.   3. The antenna feeding structure according to claim 1, wherein the antenna is an inverted F-type antenna, the radiating element is connected to the front signal electrode plate, and a short stub is connected to the front ground electrode plate. An antenna feeding structure characterized by comprising.   3. The antenna feeding structure according to claim 1 or 2, wherein the antenna feeding structure is arranged in a portion formed of window glass or resin of an automobile as the dielectric material plate.   8. The antenna feeding structure according to claim 7, wherein the dielectric material plate is disposed on a window glass of an automobile, and the front-side signal electrode plate and the back-side signal electrode plate are provided on the window glass. An antenna feeding structure, characterized in that a conductor wire such as a defogger or a glass antenna pattern is disposed so as not to be sandwiched.   9. The antenna feeding structure according to claim 8, wherein the front-side ground electrode plate and the back-side ground electrode plate are arranged so as to sandwich a conductor wire such as the defogger or a glass antenna pattern. Antenna feed structure.