JP3586915B2 - Vehicle antenna device - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to an antenna device for quasi-microwave communication used for, for example, a mobile phone, and more particularly to a single-band and multi-band vehicle antenna device which is effectively mounted on an automobile.
[0002]
[Prior art]
With the spread of automobile telephones and the like, various antennas for these quasi-microwaves have been developed, but especially when used for in-vehicle use, downsizing is required due to the necessity of housing in a limited space, Further, it is required to reduce the attitude, and in a state where these requirements are satisfied, it is required to have high gain and omnidirectionality in terms of performance.
[0003]
In response to such demands for in-vehicle use, for example, a low-profile in-vehicle antenna as disclosed in Japanese Patent Application Laid-Open No. 4-369902 has been proposed. According to the low-profile vehicle-mounted antenna proposed here, the height can be reduced to, for example, about 52 mm in height, but it is difficult to achieve a sufficiently low profile.
[0004]
Also, for example, in the document “Modified transmission line antenna for mobile communication” (IEICE AP91-82: September 10, 1991), a double-structure loop antenna is introduced, and according to this loop antenna, the height is increased. It is as low as 30 mm and downsized. However, since the loop antenna introduced here is made of wire, it is difficult to easily process it because of its structure, leading to a significant cost increase, leading to practical use. Not in.
[0005]
On the other hand, in recent years, there have been many media such as a car phone (800 MHz, 1500 MHz), GPS, VICS, PHS, etc. as in-vehicle communication systems. Antenna is required.
[0006]
The problem here is that various problems occur due to the increase in the number of mounted antennas.
In other words, simply as many media as required, multiple antennas are installed in one vehicle, which causes problems in appearance or interior design (aesthetics), mounting space, and cost. It is.
[0007]
On the other hand, as a conventional dual-frequency antenna device, Japanese Utility Model Laid-Open No. 5-41211 discloses a dual-frequency antenna.
That is, the dual-frequency antenna includes a first linear portion provided on a surface of the first and second dielectric layers opposite to a surface of the first dielectric layer which is in contact with the second dielectric layer. A ring-shaped patch antenna loaded, and between the first dielectric layer and the second dielectric layer, so that a linear portion is orthogonal to the linear portion of the first linear portion-loaded ring-shaped patch antenna. A second linear portion-loaded ring-shaped patch antenna provided, a ground conductor provided on a surface of the second dielectric layer opposite to a surface in contact with the first dielectric layer; And a feed line connected to each of the ring patch antennas loaded with the linear portion.
[0008]
However, this conventional technique (Japanese Utility Model Laid-Open No. 5-41211) has a problem that the directivity of radio waves is not suitable for an antenna device for a vehicle-mounted telephone and the cost is high because a high-frequency dielectric is used.
[0009]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described points, and has been downsized so as to be capable of being sufficiently lowered to be particularly suitable for a single band and to be able to be stored in a limited space. In addition, the present invention provides a single-band compatible vehicle antenna apparatus which can satisfy the requirements of high gain and omnidirectionality in terms of performance, and can be effectively applied to, for example, an automobile telephone. It is assumed that.
[0010]
In addition, the present invention has been made in view of the above points, and is particularly small in size so that it can be sufficiently lowered to be suitable for multi-band use and can be stored in a limited space. And a multi-band vehicular antenna device that can be effectively applied to, for example, a car telephone so as to satisfy the requirement of high gain and omnidirectionality in terms of performance. It is what we are going to offer.
[0011]
[Means for Solving the Problems]
The vehicle antenna device according to one aspect of the present invention has a first and a second configuration in which a predetermined interval is set above a ground conductor plate, and a conductive plate material is formed in a loop shape in parallel with the ground conductor plate. Two parallel loop portions are arranged, and a vertical feed portion is provided so as to be commonly connected to each of the first and second parallel loop portions. An insulating part is arranged on the ground conductor plate, and the vertical power supply part is fixed to the insulating part. Further, first and second vertical short-circuit portions connected to the ground conductor plate are provided at positions symmetrical to the positions of the vertical power supply portions with respect to the first and second parallel loop portions, respectively. The first parallel loop portion, the vertical feed portion, the first vertical short-circuit portion, and the ground conductor plate constitute a first loop antenna, and the second parallel loop portion, the vertical feed portion, and the second vertical short-circuit portion And a ground conductor plate to constitute a second loop antenna.
[0012]
Further, a vehicle antenna device according to another aspect of the present invention is configured such that a predetermined interval is set above a ground conductor plate, and a conductive plate material is formed in a loop shape in parallel with the ground conductor plate. The second and third parallel loop portions are arranged, and a vertical power supply portion is provided so as to be commonly connected to each of the first, second, and third parallel loop portions. An insulating part is arranged on the ground conductor plate, and the vertical power supply part is fixed to the insulating part. Furthermore, first, second, and third vertical short-circuits connected to the ground conductor plate at positions symmetrical with respect to the first, second, and third parallel loop portions with respect to the position of the vertical feed portion. A first loop antenna is formed by the first parallel loop portion, the vertical feed portion, the first vertical short-circuit portion, and the ground conductor plate, and the second parallel loop portion, the vertical feed portion, and the second A second loop antenna is constituted by the vertical short-circuit portion and the ground conductor plate, and a third loop antenna is constituted by the third parallel loop portion, the vertical feed portion, the third vertical short-circuit portion and the ground conductor plate. Like that.
[0013]
[Action]
In the vehicle antenna device according to one aspect configured as described above, the vehicle antenna device has a double structure in which the second loop antenna is inserted into the first loop antenna formed into a plate shape. Yes, manufacturing is simplified as well as miniaturization. At this time, since each loop antenna is supported on the ground conductor plate by the vertical feeding section (via the insulating section) and the short-circuit section located on the opposite side (symmetric position) to the vertical feeding section, The antenna is supported at two points, and the antenna can be firmly supported. In addition, since the insulating part is arranged on the ground conductor plate and the lower end of the vertical feeding part is fixed to the insulating part, short circuit between the vertical feeding part and the short-circuit part can be prevented, and it can function as an antenna. Can be. In such a plate-shaped antenna device, different current paths are generated in the first and second loop antennas, the standing wave ratio is suppressed, and the bandwidth can be sufficiently widened. . Therefore, it is miniaturized so as to be able to be stored in a limited space with a low attitude, omnidirectional and high gain is obtained in terms of performance, and is sufficient for a single-band compatible mobile phone, for example. Function is exhibited.
[0014]
Further, in the vehicle antenna device according to another aspect configured as described above, the second loop antenna is inserted into the first loop antenna formed into a plate shape, and the second loop antenna is inserted into the first loop antenna. Has a triple structure in which the third loop antenna can be inserted, thereby simplifying manufacturing as well as miniaturization. At this time, since each loop antenna is supported on the ground conductor plate by the vertical feeding section (via the insulating section) and the short-circuit section located on the opposite side (symmetric position) to the vertical feeding section, The antenna is supported at two points, and the antenna can be firmly supported. In addition, since the insulating part is arranged on the ground conductor plate and the lower end of the vertical feeding part is fixed to the insulating part, short circuit between the vertical feeding part and the short-circuit part can be prevented, and it can function as an antenna. Can be. In such a plate-shaped antenna device, different current paths are generated in the first, second, and third loop antennas, the standing wave ratio is raised, and the bandwidth is sufficiently widened. Can be. Therefore, it is miniaturized so as to be able to be stored in a limited space together with a low attitude, omnidirectional and high gain is obtained in terms of performance, and is sufficient for, for example, a multi-band compatible mobile phone. Function is exhibited.
[0015]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows the configuration of the first embodiment. The antenna device according to the first embodiment is used for a single band, for example, an 800 MHz band automobile telephone, and is an electric device determined by a plate-shaped first resonance frequency. It has a double structure in which a first loop antenna 11 having a length and a second loop antenna 12 having an electrical length determined by a second resonance frequency also formed in a plate shape are inserted.
[0016]
The first and second loop antennas 11 and 12 are provided with a common ground conductor plate 13. The first loop antenna 11 includes a first parallel loop flat plate 111 which is disposed above the ground conductor plate 13 at a predetermined interval. It is constituted by cutting out. At the center of one side of the first parallel loop flat plate 111, a vertical feed flat plate 14 is provided so as to extend in a direction perpendicular to the plane of the parallel loop flat plate 111. A first vertical short-circuited flat plate 112 is provided at a position symmetrical with the ground conductor plate 13 so as to be connected to the ground conductive plate 13.
[0017]
Here, the end of the vertical power supply plate 14 is fixed to, for example, an insulating plate 18 integrally attached to the ground conductor plate 13 so that the vertical power supply plate 14 and the ground conductor plate 13 are insulated. I have.
[0018]
Further, the second loop antenna 12 includes a second parallel loop flat plate 121 similarly formed by cutting a plate material into a rectangular loop, and the parallel loop flat plate 121 is located at the center of one side thereof, The vertical feeder plate 14 which is shared with the one parallel loop flat plate 111 is connected, and a second vertical feeder plate 14 is connected to the ground conductor plate 13 at a position symmetrical to the mounting position of the vertical feeder plate 14. A short-circuit plate 122 is provided.
[0019]
The radiating element of the first loop antenna 11 includes a ground conductor plate 13, a vertical short-circuiting plate 112 and a vertical feeding plate 14, which are disposed on the ground conductor plate 13 at a predetermined interval L1 in plane parallel, and a first parallel loop plate. 111. Similarly, the radiating element of the second loop antenna includes a ground conductor plate 13, a vertical short-circuiting plate 122 and a vertical feeding plate 14, which are disposed on the grounding conductor plate 13 at a predetermined interval L2 in a plane-parallel manner, and a second parallel loop. It is constituted by a flat plate 121. The first and second loop antennas 11 and 12 have the same feed point 16 to which the coaxial cable 15 is connected, and share the same vertical feed plate 14.
[0020]
Here, the configuration of the power supply unit is such that the coaxial cable 15 is disposed on the grounding conductor plate 13 for lowering the posture, the outer conductor of the coaxial cable 15 is connected to the grounding conductor plate 14, and the center conductor is connected to the vertical power supply plate. The lower end 14 is electrically connected to a feeding point 16. Are formed in the ground conductor plate 13. The through holes 171, 172,... Are positioned when the antenna device is housed in an antenna case (not shown). The position is selected so as not to affect the current path flowing between the radiating elements.
[0021]
Currently, the frequency of use of a mobile phone in Japan is divided into two frequency bands of 810 to 885 [MHz] for reception and 898 to 956 [MHz] for transmission. For this reason, the antenna apparatus shown in this embodiment is divided into first and second loop antennas 11 and 12 having individual resonance frequencies for transmission and reception. The loop antennas 11 and 12 are connected in parallel to form a low-profile dual-structure loop antenna shared by two frequencies and integrated as one antenna.
[0022]
This double-structured loop antenna device is constituted by a plate-shaped structure, and a coaxial cable 15 is connected to a vertical feed plate 14 common to the first loop antenna 11 and the second loop antenna 12. The high frequency current I is supplied. This high-frequency current I flows to the vertical short-circuiting plates 112 and 122 together with the first and second parallel loop plates 111 and 121.
[0023]
Here, the antenna element in this antenna device is divided into an element part contributing to radiation and an element part contributing to impedance. In the element part contributing to radiation, first and second loop antennas 11 and 12 are used. Vertically polarized waves are radiated by the vertical feeding flat plate 14 which is the same feeding portion and the vertical short-circuiting plates 112 and 122 which are short-circuit portions of the antennas 11 and 12, respectively. At this time, the high-frequency current I supplied to the common vertical feeder plate 14 of the first and second loop antennas 11 and 12 has the same phase, and the gain increases compared to the open-ended antenna, and furthermore, The high-frequency current I flowing through the vertical short-circuiting plates 112 and 122 of the first and second loop antennas 11 and 12 respectively increases and decreases according to the distances L1 and L2 between the vertical feeding plate 14 and the vertical short-circuiting plates 112 and 122, respectively. .
[0024]
On the other hand, as elements that contribute to impedance, there are first and second parallel loop flat plates 111 and 121. Since the transmission line is formed together with the image line formed on the ground conductor plate 13, the impedance is controlled by the heights H1 and H2 according to the transmission path theory. When the height is small, the impedance becomes low and the height becomes low. Is large, the impedance is high.
[0025]
In the double-structured loop antenna configured as described above, the gain is increased by the three radiating elements, ie, the vertical feeding plate 14 and the vertical short-circuiting plates 112 and 122. The impedance matching is facilitated and its resonance frequency f ₀ The desired characteristics can be obtained by changing the antenna length and the shape parameters, and the design is facilitated.
[0026]
Further, since each element is formed into a plate shape by the flat plate structure, various current paths different from each other are generated in each of the plate-shaped elements, and a voltage standing wave ratio (VSWR) is suppressed. 2A and 2B show the effect of the plate element. FIG. 2A shows a case where a loop antenna is formed by a linear body, and FIG. 2B shows a case where a loop antenna is formed by a plate body as in the embodiment. The vertical axis indicates the voltage standing wave ratio (VSWR), and the horizontal axis indicates the frequency (MHz).
[0027]
In general, the voltage standing wave ratio (VSWR) is required to be 1.9 or less, the range is a use frequency bandwidth ΔW [MHz], and the line having a diameter of 4 mm shown in FIG. In the case of the configuration using the shape, “ΔW = ΔW1 + ΔW2”, and the bandwidth ΔW is approximately 90 MHz. On the other hand, in the case of FIG. 6B constituted by a plate-like body having a width of 6 mm and a thickness of 0.6 mm, the voltage standing wave ratio (VSWR) is suppressed and the used frequency bandwidth ΔW is approximately 200 MHz. The band is widened.
[0028]
In the antenna device configured as described above, since the antenna device is configured by a plate material, one plate material can be manufactured by press working, which is sufficiently compared with a case where the antenna device is configured by a wire material. In addition, the processing can be simplified, and a great effect can be exerted on cost reduction. In addition, since the loop antenna made of the plate material can be configured with a small number of connection portions, the mechanical strength can be reliably improved, and further, there are few connection portions using solder or the like. Therefore, good electrical conductivity can be maintained. More importantly, since various current paths can be set in the plate-like body, the voltage standing wave ratio (VSWR) can be effectively suppressed, and the ratio band “ΔW / f” ₀ (%) ”Can be ensured widely.
[0029]
In the above embodiment, the first and second parallel loop flat plates 111 and 121 are formed by processing a plate-like body. However, as shown in FIG. 3, the first and second parallel loop flat plates 111 and 121 have the same shape as the loop flat plate. The first and second parallel loop flat plates 111 and 121 may be constituted by loops 212 and 222 formed by printing a conductive thin film on the surfaces of the first and second parallel plates 221 and 221, respectively. By using the printed boards 211 and 221, the mechanical strength of the parallel loop flat plates 111 and 121 is further improved.
[0030]
Further, in each of the embodiments described above, each of the loops of the first and second parallel loop flat plates 111 and 121 is formed by a quadrilateral. However, as shown in FIG. And 121 may both be configured in a circular shape. In this case, the vertical feeding plate 14 and the vertical short-circuiting plates 112 and 122 are attached at positions where the circle is divided into two. The shape of the parallel loop flat plates 111 and 121 can be arbitrarily designed in consideration of a design surface such as an ellipse. By changing the shape of the parallel loop flat plates, an antenna having a high degree of freedom can be obtained. The design of the device is made possible.
[0031]
In the case where an antenna element including a parallel loop flat plate is cut out from a plate-like body, as shown in FIG. 5B, the first and second parallel loop flat plates 111 and 121 are vertically separated from one metal plate. The shape of the ground conductor plate 13 is cut out together with the feed plate 14 and the vertical short-circuit plates 112 and 122 so as to be integrally continuous, and then bent to be assembled as shown in FIG. , A predetermined double-structured loop antenna can be formed.
[0032]
Here, in FIG. 3B, the first parallel loop flat plate 111 and the ground conductor plate 13 are connected by the vertical feed plate 14, but this metal plate is cut out and bent. After the antenna device is assembled as described above, the connecting piece 141 is cut off so that the vertical feed plate 14 and the ground conductor plate 13 are not electrically connected.
[0033]
In order to further reduce the size of the antenna device having such a structure, it is conceivable to use first and second dielectric substrates 25 and 26 as shown in FIG. That is, the first dielectric substrate 25 having a thickness corresponding to the distance between the first and second parallel loops 111 and 121 corresponds to the distance between the ground conductor plate 13 and the second parallel loop flat plate 121. A laminated structure is formed in which the second dielectric substrate 26 is stacked on the second dielectric substrate 26 having a thickness, and the second dielectric substrate 26 is disposed on the ground conductor plate 13. Then, by forming and etching a conductive thin film on the surfaces of the first and second dielectric substrates 25 and 26, respectively, the first and second loops 251 and 261 are formed. And the second parallel loop flat plates 111 and 121 are configured.
[0034]
Here, the first and second dielectric substrates 25 and 26 superimposed on the ground conductor plate 13 are fixed by fixing pieces 271 and 272 so that the superposed state is maintained. Although not shown in detail, the grounding conductor plate 13 and the loops 251 and 261 are not electrically connected to each other by the fixing pieces 271 and 272, respectively. Are provided so as to be connected to the loops 251 and 261.
[0035]
That is, the first loop 251 constituting the first parallel loop flat plate 111 is formed on the surface of the dielectric substrate 25 having a high frequency characteristic and a good dielectric constant ε, A dielectric substrate 26 having a dielectric constant is provided, and a second loop 261 is formed on the surface of the dielectric substrate 26, thereby reducing the electrical length 1 / ε of each element including the first and second loops 251 and 262. Therefore, the size can be effectively reduced, and the mechanical structure can be surely strengthened.
[0036]
In the above description, the description of the configuration and the operation and operation is intended especially for the 800 MHz band, but this is merely an example, and for example, not only the 1.5 GHz band, but also all other frequencies. It is also applicable to belts.
[0037]
Next, with reference to FIG. 7, as a second embodiment according to the present invention, an antenna device which is compatible with a multi-band and handles two frequency bands (800 MHz band mobile phone and 1500 MHz band mobile phone) with three loop antennas will be described.
[0038]
As shown in FIG. 7 where the same reference numerals are given to the same components as those in FIG. 1 described above, the antenna device according to the second embodiment includes a ground conductor plate 13 and a ground conductor plate 13. And a first parallel loop flat plate 111 formed by forming a conductive plate material provided in parallel with the ground conductor plate 13 at a predetermined interval.
[0039]
Further, the antenna device is connected to the first parallel loop plate 111, and a vertical feed plate 14 set perpendicular to the parallel loop plate 111, and the vertical feed plate with respect to the first parallel loop plate 111. A first vertical short-circuiting plate 112 which is connected to a position symmetrical to the position 14 and is set perpendicular to the parallel loop plate 111 and connects the parallel loop plate 111 to the ground conductor 13; On the grounding conductor plate 13, provided between the grounding conductor plate 13 and the parallel loop flat plate 111 and in parallel with the grounding conductor plate 13, the conductive plate material is formed into a loop shape and the vertical The power supply plate 14 has a second parallel loop plate 121 that is commonly connected to the first parallel loop plate 111.
[0040]
Further, this antenna device is connected to a position symmetrical to the position of the vertical feed plate 14 with respect to the second parallel loop plate 121, and is set to be perpendicular to the second parallel loop plate 121. A second vertical short-circuit flat plate 122 connecting the second parallel loop flat plate 121 and the ground conductor plate 13, the first parallel loop flat plate 111 on the ground conductive plate 13, and the second parallel loop The vertical feeding plate 14 is provided between the flat plate 121 and the ground conductor plate 13 in parallel with the ground conductor plate 13. , And a third parallel loop flat plate 131.
[0041]
Further, this antenna device is connected to a position symmetrical to the position of the vertical feed plate 14 with respect to the third parallel loop plate 131, and is set perpendicular to the third parallel loop plate 131. There is provided a third vertical short-circuiting plate 132 for connecting the third parallel loop plate 131 to the ground conductor plate 13.
[0042]
In this antenna device, the first loop antenna 11 is constituted by the parallel loop flat plate 111, the vertical feeding flat plate 14, the ground conductor plate 13, and the first vertical short-circuit flat plate 112, and the second parallel loop flat plate 121, the vertical The second loop antenna 12 is constituted by the short-circuiting plate 14, the ground conductor plate 13, and the second vertical short-circuiting plate 122. The third parallel loop plate 131, the vertical feeding plate 14, the grounding conductor plate 13, and the third vertical antenna plate 13. The third loop antenna 10 is configured by the short-circuiting plate 132.
[0043]
Here, the third loop antenna 10 is for the 1500 MHz band.
Further, the two loop antennas composed of the first loop antenna 11 and the second loop antenna 12 are for the 800 MHz band, and the loop antenna for the 800 MHz band is completely the same as that described in the first embodiment. They are the same.
[0044]
The operation principle of the third loop antenna 10 of the 1500 MHz band is the same as that of the 800 MHz band antenna described in the first embodiment, and therefore description thereof will be omitted. However, the antenna characteristics are as shown in FIG. In the 800 MHz band, a bandwidth: ΔW1 = 170 MHz is obtained, and in the 1500 MHz band, a bandwidth: ΔW2 = 90 MHz is obtained, thereby realizing a multi-band compatible vehicle antenna apparatus usable in any of these two frequency bands. It becomes possible.
[0045]
The antenna element used in this embodiment may be made of a flat plate-shaped material as shown in FIG.
In the description of FIG. 7, the 800 MHz band is widened using two of the three loop antennas, and the relatively narrow 1500 MHz band is used using one. In the case where two bands are supported, multi-banding may be performed using two loop antennas as shown in FIG.
[0046]
That is, FIG. 9 is exactly the same as FIG. 7 except that the second loop antenna 12 and its related components are removed from FIG. 7, and the two loop antennas of the first loop antenna 11 and the third loop antenna 10 are used. This is an example in which a multi-band is achieved with one loop antenna.
[0047]
As described above, according to the antenna apparatus of the second embodiment, for example, a multi-band can be achieved for an 800 MHz band that requires a relatively wide fractional band and a 1500 MHz band having a high frequency. It is a posture type antenna and has high productivity due to a flat antenna element.
[0048]
In the description of the second embodiment, the antenna element is formed of a flat plate. However, other shapes such as a round bar may be used, and the configurations of FIGS. 3 to 6 showing modifications of the first embodiment may be used. The second embodiment may be adopted as appropriate.
[0049]
【The invention's effect】
Therefore, according to the vehicle antenna device according to the present invention as described in detail above, Ten It can be configured to be small enough to be able to be housed in a limited space by making it possible to lower the position, and it is also high gain and omnidirectional in terms of performance. When the requirements are satisfied, for example, for single-band and multi-band mobile phones To Can be applied effectively.
[Brief description of the drawings]
FIG. 1A is a perspective view showing a vehicle antenna device according to a first embodiment of the present invention, and FIG. 1B is a side view thereof.
FIGS. 2A and 2B are diagrams showing standing wave ratio characteristics, in which FIG. 2A shows a case using a wire, and FIG. 2B shows a case using a plate as shown in the first embodiment. Show.
FIG. 3 is a perspective view showing an antenna device according to a modification of the first embodiment of the present invention.
FIG. 4 is a perspective view showing an antenna device according to a modification of the first embodiment of the present invention.
FIG. 5A is a perspective view showing an antenna device according to a modification of the first embodiment, and FIG. 5B is a diagram showing the antenna device in an unfolded state.
FIG. 6 is a perspective view showing an antenna device according to a modification of the first embodiment.
FIG. 7A is a perspective view showing an antenna device according to a second embodiment of the present invention, and FIG. 7B is a side view thereof.
FIG. 8 is a diagram showing antenna characteristics of the first embodiment.
FIG. 9A is a perspective view showing an antenna device according to a modification of the second embodiment, and FIG. 9B is a side view of the same.
[Explanation of symbols]
11, 12: first and second loop antennas, 111, 121: first and second parallel loop plates, 112, 122: vertical short-circuit plate, 13: ground conductor plate, 14: vertical feed plate, 15: coaxial Cable, 16: feeding point, 211, 221: printed circuit board, 212, 222, 251, 261: loop, 25, 26: first and second dielectric substrates, 10: third loop antenna, 131: third Parallel loop plate, 132 ... vertical short circuit plate

Claims (6)

A ground conductor plate made of a plate-shaped conductive member,
A first parallel loop portion provided in parallel with the ground conductor plate with a predetermined gap therebetween and made of a loop-shaped conductive member;
An insulating portion disposed on the ground conductor plate,
This is fixed to the insulating portion, one end connected to the first parallel loop portion, and the vertical feeding portion to which the other end made of a conductive member which is insulated from the ground conductor plate via the insulating section,
A first short-circuit portion made of a conductive member having one end connected to a position symmetrical to the position of the vertical power supply portion with respect to the first parallel loop portion and the other end connected to the ground conductor plate ; ,
At a position between the ground conductor plate and the first parallel loop portion, a part is connected to the vertical power supply portion and is provided in parallel with the ground conductor plate, and is formed of a loop-shaped conductive member. Two parallel loops,
A second short-circuit portion made of a conductive member having one end connected to a position symmetrical to the position of the vertical power supply portion and the other end connected to the ground conductor plate with respect to the second parallel loop portion; A first loop antenna is formed by the first parallel loop portion, the vertical feed portion, the ground conductor plate, and the first short-circuit portion, and the second parallel loop portion, the vertical feed portion, and the ground conductor plate are provided. A second loop antenna is constituted by the second short-circuit portion and the second short-circuit portion, and the first loop antenna and the second loop antenna resonate at two different frequencies. At least one, the ground conductor vehicular antenna apparatus 請 Motomeko 1, wherein configured integrally by a single conductive plate with plate of said first and second loop antennas. The ground conductor plate further includes a coaxial cable disposed along the ground conductor plate, a center conductor of the coaxial cable is electrically connected to a lower end of the vertical power supply unit, and an external conductor is electrically connected to the ground conductor plate. The vehicle antenna device according to claim 1, wherein the vehicle antenna device is connected to a vehicle. A ground conductor plate,
A first parallel loop portion provided in parallel with the ground conductor plate at a predetermined interval above the ground conductor plate and formed of a conductive material in a loop shape;
An insulating portion disposed on the ground conductor plate,
A vertical power supply unit fixed to the insulation unit, one end of which is connected to the first parallel loop unit, and the other end of which is a conductive member insulated from the ground conductor plate via the insulation unit;
The first parallel loop portion is connected to a position symmetrical with respect to the position of the vertical power supply portion with respect to the first parallel loop portion, and is set perpendicular to the first parallel loop portion so that the first parallel loop portion and the ground conductor A first vertical short circuit connecting the plate,
Above the ground conductor plate, provided between the ground conductor plate and the first parallel loop portion and in parallel with the ground conductor plate, the conductive member is formed into a loop shape, and the vertical power supply portion is provided. A second parallel loop portion commonly connected to the first parallel loop portion;
The second parallel loop portion is connected to a position symmetrical to the position of the vertical feeding portion, and is set to be perpendicular to the parallel loop portion and connects the parallel loop portion to the ground conductor plate. 2 vertical shorts,
On the ground conductor plate, the first parallel loop portion, located between the second parallel loop portion, provided in parallel with the ground conductor plate, the conductive material into a loop shape, A third parallel loop portion in which the vertical power supply portion is commonly connected to the first and second parallel loop portions; and a position and symmetry of the vertical power supply portion with respect to the third parallel loop portion. A third vertical short-circuit portion which is connected to a position where the third parallel loop portion is set perpendicular to the third parallel loop portion and connects the third parallel loop portion to the ground conductor plate.
The first parallel loop section, the vertical feed section, the ground conductor plate, and the first vertical short-circuit section A second loop antenna is formed by the second parallel loop portion, the vertical feed portion, the ground conductor plate, and the second vertical short-circuit portion, and the third parallel loop portion, the vertical feed portion A third loop antenna configured by the first portion, the ground conductor plate, and the third vertical short-circuit portion. The vehicle antenna device according to claim 4, wherein at least one of the first, second, and third loop antennas is formed integrally with the ground conductor plate by one conductive plate material. The ground conductor plate further includes a coaxial cable disposed along the ground conductor plate, a center conductor of the coaxial cable is electrically connected to a lower end of the vertical power supply unit, and an external conductor is electrically connected to the ground conductor plate. The vehicle antenna device according to claim 4, wherein the vehicle antenna device is connected to a vehicle.

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