Composite planar antenna device

Abstract

To provide a composite planar antenna device that is adaptable to a plurality of frequency bands with little deterioration of antenna characteristics even in a limited space.SOLUTION: A composite planar antenna device includes a first feeder 10, a second feeder 20, a first planar element 30, a second planar element 40, and a filter unit 50. The first planar element 30 is disposed on a ground conductor surface 1 so as to face the ground conductor surface 1, and is adaptable to a first frequency band. The second planar element 40 is disposed on a same plane as the first planar element 30 so as to face the ground conductor surface 1, is disposed with a gap G of a predetermined width from an edge portion in a longitudinal direction of the first planar element 30, and is adaptable to a second frequency band when used together with the first planar element 30. The filter section 50 is connected to the gap G between the first planar element 30 and the second planar element 40, attenuates signals in the first frequency band, and passes signals in the second frequency band.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a composite planar antenna device, and more particularly to a composite planar antenna device that is arranged on a ground conductor plane and is compatible with a plurality of frequency bands. [Background technology]

[0002] There are various types of antenna devices that are compatible with multiple frequency bands and are mounted on vehicles, for example, antenna devices compatible with the AM / FM band, such as pillar antennas, roof-mounted antennas, glass antennas, etc. However, pillar antennas that protrude a lot are likely to bend due to contact, etc. In addition, roof-mounted antennas are high above the ground and therefore need to be folded down or removed when in a multi-storey parking lot or automatic car wash. In addition, glass antennas require unique development for each vehicle model, which increases the development costs, etc.

[0003] In recent years, the design of vehicles has become important, and antenna devices mounted on vehicles are required to not spoil the aesthetic appearance of the vehicle as much as possible. For this reason, spoiler-mounted antenna devices and vehicle body-embedded antenna devices have been developed.

[0004] For example, Patent Document 1 discloses a vehicle body embedded antenna device by the same applicant as the present applicant. The vehicle body embedded antenna device disclosed in Patent Document 1 has a plate antenna element disposed inside a bathtub-shaped portion provided in the metal body of the vehicle. By disposing the plate antenna element at the highest position possible inside the bathtub-shaped portion, it is possible to suppress deterioration of the signal reception performance of the plate antenna element. Furthermore, since it is disposed inside the bathtub-shaped portion, noise radiated from electrical equipment inside the vehicle is also shielded, so there is no need to take any additional noise countermeasures. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-031519 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the conventional vehicle body embedded antenna device disposed inside the bathtub-shaped part, the bottom of the bathtub-shaped part is also a metal body, so the proportion of antenna current flowing to the pillar via a grounding bracket or the like is reduced. For this reason, in a harsh environment where antenna sensitivity is reduced in a limited space, it was difficult to realize a composite antenna device capable of supporting multiple frequency bands using multiple plate-shaped antenna elements, due to problems with element size and isolation between elements. When multiple elements are used in a limited space, if the elements are placed close to each other, coupling occurs between the elements, causing degradation of both. For example, in the case of elements of close frequency bands such as the FM frequency band and the DAB frequency band, there is a contradictory relationship in which improving the antenna characteristics of the DAB frequency band will deteriorate the antenna characteristics of the FM frequency band. These antenna characteristics depend on the efficiency of the elements due to wavelength shortening and the size of the elements. On the other hand, in the case of a configuration in which a common element is used and separated by a distributor to support multiple frequency bands, loss due to the distributor may occur. Therefore, in any of the conventional methods, the deterioration of antenna characteristics was unavoidable compared to a single element of the same size.

[0007] In view of the above circumstances, the present invention aims to provide a composite planar antenna device that is compatible with a plurality of frequency bands and has little degradation of antenna characteristics even in a limited space. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object of the present invention, the composite planar antenna device according to the present invention includes a first feed section for a first frequency band, a second feed section for a second frequency band lower than the first frequency band, a first planar element arranged opposite to the ground conductor surface and connected to the first feed section, and capable of supporting the first frequency band, a second planar element arranged opposite to the ground conductor surface on the same plane as the first planar element and connected to the second feed section, the second planar element being arranged with a gap of a predetermined width between the longitudinal edge of the second planar element and the longitudinal edge of the first planar element, and being capable of supporting the second frequency band when used together with the first planar element, and a filter section connected to the gap between the first planar element and the second planar element, which attenuates signals in the first frequency band and passes signals in the second frequency band.

[0009] Here, the filter section may be connected to the gap between the vicinity of a position of the first planar element far from the first feeding portion and the vicinity of a position of the second planar element far from the second feeding portion.

[0010] In addition, the filter section may be connected to a gap near a position of the first planar element and the second planar element far from the ground conductor surface when the distance between the first planar element and the second planar element and the ground conductor surface changes.

[0011] The second planar element may be connected to the second power supply portion via a resonant coil.

[0012] Moreover, the filter section is made up of a trap coil, and the resonant coil may have an inductance lower than that of the trap coil.

[0013] The filter section may be made up of a trap coil or a low-pass filter circuit. Effect of the Invention

[0014] The composite planar antenna device of the present invention that is compatible with a plurality of frequency bands has the advantage that the deterioration of antenna characteristics is small even in a limited space, for example. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic plan view for explaining a complex planar antenna device of the present invention. [Diagram 2] FIG. 2 is a circuit diagram for explaining a filter portion of the composite planar antenna device of the present invention. [Diagram 3] FIG. 3 is a schematic side cross-sectional view for explaining a specific example of the complex planar antenna device of the present invention. [Figure 4] FIG. 4 is a schematic side cross-sectional view for explaining a modified example of the complex planar antenna device of the present invention. [Diagram 5] FIG. 5 is a schematic plan view for explaining another example of the complex planar antenna device of the present invention. [Figure 6] FIG. 6 is a schematic plan view for explaining still another example of the complex planar antenna device of the present invention. [Figure 7] FIG. 7 is a schematic plan view for explaining another example of the first planar element of the complex planar antenna device of the present invention. [Figure 8] FIG. 8 is a schematic plan view for explaining another example of the second planar element of the complex planar antenna device of the present invention. [Figure 9] FIG. 9 is a schematic plan view for explaining another example of the arrangement positions of the first and second feeding portions of the complex planar antenna device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the embodiment of the present invention will be described with reference to the illustrated examples. FIG. 1 is a schematic plan view for explaining the composite planar antenna device of the present invention. The composite planar antenna device of the present invention is compatible with a plurality of frequency bands. Specifically, it may be compatible with, for example, the FM frequency band and the DAB frequency band of radio. However, the present invention is not limited to this, and may be combined with other frequency bands such as UHF frequency bands as long as it is a plurality of frequency bands. In particular, when the frequency bands are close to each other, such as the FM frequency band and the DAB (Band-III) frequency band, a problem of coupling between elements may occur. However, according to the present invention, since the isolation is high and the deterioration of the antenna characteristics is small, it is suitable even in such a case. As shown in the figure, the composite planar antenna device of the present invention is mainly composed of a first power supply section 10, a second power supply section 20, a first planar element 30, a second planar element 40, and a filter section 50. The composite planar antenna device of the present invention is disposed on a ground conductor surface 1. More specifically, it may be disposed inside a bathtub-shaped portion in which, for example, the metal body of a vehicle is recessed from the metal body surface. That is, the composite planar antenna device of the present invention can also be provided as an antenna device embedded in a vehicle body.

[0017] The first power supply unit 10 is a power supply unit for a first frequency band. Specifically, the first frequency band may be, for example, the DAB frequency band, that is, a band of 174 MHz to 240 MHz. The first power supply unit 10 may be provided on a substrate 12, for example.

[0018] The second power supply unit 20 is a power supply unit for a second frequency band that is lower than the first frequency band. Specifically, the second frequency band may be, for example, an FM frequency band, that is, a 76 MHz to 95 MHz band or a 88 MHz to 108 MHz band. The second power supply unit 20 may also be provided on the substrate 12, for example.

[0019] The first planar element 30 is an element capable of handling a first frequency band. The first planar element 30 is connected to the first power supply unit 10. The first planar element 30 is disposed on the ground conductor surface 1 facing each other. The first planar element 30 may be, for example, a conductor plate having a planar plate-shaped portion. The first planar element 30 is a grounded antenna, and functions, for example, like a monopole antenna. It may also be configured to function as an inverted F-type antenna or an inverted L-type antenna. The first planar element 30 may have an antenna capacity that functions as a capacitive antenna capable of handling, for example, the DAB frequency band. The first planar element 30 is formed, for example, by processing a metal plate. That is, it is sufficient that a rectangular planar plate-shaped portion is formed by cutting the metal plate. However, the present invention is not limited thereto, and the first planar element 30 may be formed, for example, by processing a conductor foil of a printed circuit board or a flexible printed circuit board. Furthermore, the planar plate-shaped portion of the first planar element 30 may have an antenna capacity that functions as a capacitive antenna, and may be a meander-shaped element configured to have an antenna capacity substantially equivalent to that of the planar plate-shaped portion. The first planar element 30 is provided with a first feeder 31. The first feeder 31 may be a lead wire, but may be formed into a pin shape by bending the end of the planar plate-shaped portion of the first planar element 30, for example. That is, the first planar element 30 may be configured as an inverted L antenna. The first planar element 30 may be designed based on, for example, λ / 4 of the wavelength of the first frequency band.

[0020] The second planar element 40 is connected to the second power supply unit 20. The second planar element 40 is disposed on the same plane as the first planar element 30, facing the ground conductor surface 1. Furthermore, the second planar element 40 is disposed such that the longitudinal edge of the second planar element 40 is disposed with respect to the longitudinal edge of the first planar element 30 via a gap G of a predetermined width. That is, in the illustrated example, the second planar element 40 is disposed so as to be parallel to the first planar element 30 in the longitudinal direction. The second planar element 40 is an element that can correspond to the second frequency band when used together with the first planar element 30. The second planar element 40 may be, for example, a conductor plate having a planar plate-shaped portion. The second planar element 40 functions like a loop antenna together with the first planar element 30 via the filter unit 50 described later. The element length of the second planar element 40 may be such that the total element length of the second planar element 40 and the element length of the first planar element 30 is an element length that can correspond to the FM frequency band or the like. The second planar element 40 may be formed by processing a metal plate, for example. That is, a rectangular planar plate-shaped portion may be formed by cutting the metal plate. However, the present invention is not limited to this, and the second planar element 40 may be formed by processing a conductor foil of a printed circuit board or a flexible printed circuit board, for example. In this case, the first planar element 30 and the second planar element 40 may be arranged on the same board. In addition, the second planar element 40 is provided with a second feeder 41. The second feeder 41 may be a lead wire, but may be formed into a pin shape by bending the end of the planar plate-shaped portion of the second planar element 40, for example. That is, the second planar element 40 may be configured like an inverted L antenna while being configured like a loop antenna.

[0021] The filter section 50 attenuates signals in the first frequency band and passes signals in the second frequency band. The filter section 50 is connected to the gap G between the first planar element 30 and the second planar element 40. As shown in the figure, the filter section 50 is connected to the gap G between the vicinity of a position far from the first power supply section 10 of the first planar element 30 and the vicinity of a position far from the second power supply section 20 of the second planar element 40. This maximizes the loop of the element compatible with the second frequency band. However, the present invention is not limited to this, and the filter section 50 may be connected to the gap G between the vicinity of a position close to the first power supply section 10 or the second power supply section 20 as long as the antenna characteristics are within an acceptable range.

[0022] FIG. 2 shows an example of the filter section 50. FIG. 2 is a circuit diagram for explaining the filter section of the composite planar antenna device of the present invention. FIG. 2(a) shows an example in which the filter section 50 is composed of a trap coil 51. The trap coil may be, for example, an air-core coil. FIG. 2(b) shows an example in which the filter section 50 is composed of an LC filter composed of a coil 52 and a capacitor 53. Such a low-pass filter circuit may be used. In the illustrated example, the coil 52 and the capacitor 53 are shown, but it is not necessarily necessary to provide electronic circuit components, and the filter section 50 may be configured to be an LC filter in terms of an equivalent circuit using coupling capacitance or the like. The filter section 50 configured in this manner attenuates signals in the first frequency band and passes signals in the second frequency band. The present invention is not limited to this, and any existing or future configurations of the filter section 50 can be applied as long as the filter section 50 is configured to attenuate signals in the first frequency band and pass signals in the second frequency band.

[0023] The composite planar antenna device of the present invention configured in this way operates as follows. That is, for the first frequency band, the first planar element 30 connected to the first feeding section 10 is used to resonate in the first frequency band. The filter section 50 is connected between the first planar element 30 and the second planar element 40, but in order to attenuate the signal in the first frequency band, the signal does not propagate to the second planar element 40 side, and only the first planar element 30 functions as an antenna element. The filter section 50 makes the second planar element 40 invisible from the first planar element 30. Therefore, the filter section 50 plays a role in increasing the isolation between the first planar element 30 and the second planar element 40.

[0024] On the other hand, for the second frequency band, the second planar element 40 connected to the second power supply 20, the filter unit 50, and the first planar element 30 are used to resonate at λ / 2 of the wavelength of the second frequency band. The filter unit 50 functions as an antenna element from the second planar element 40 to the first planar element 30 via the filter unit 50 to pass signals of the second frequency band. That is, for the second frequency band, the second planar element 40, the filter unit 50, and the first planar element 30 function as a loop antenna. Here, it can be seen that the tip of the element configured like a loop antenna is configured to terminate at the first power supply 10.

[0025] In this way, the filter section 50 acts as a trap coil for the first frequency band, attenuating signals in the first frequency band, and acts as a resonant coil that forms part of an element with a wavelength of λ / 2 of the second frequency band, for the second frequency band.

[0026] In the composite planar antenna device of the present invention, the filter section 50 makes it easy to ensure isolation between elements. Therefore, the longitudinal edges of the first planar element 30 and the second planar element 40, which have a large area, can be arranged close to each other. Therefore, the elements can be arranged in a minimum range even in a limited space. Furthermore, since the first planar element 30 and the second planar element 40 can be arranged via a gap G of a predetermined width that allows capacitive coupling, the first planar element 30 can be capacitively loaded onto the second planar element 40, improving the antenna characteristics of the second planar element 40. That is, even if the first planar element 30 and the second planar element 40 are arranged close to each other, the deterioration of the antenna characteristics as a whole can be reduced.

[0027] Here, the width of the gap G may be such that the first planar element 30 and the second planar element 40 are capacitively coupled. The width of the gap G that is sufficient for capacitive coupling also varies depending on the length of the longitudinal edges of the first planar element 30 and the second planar element 40 facing each other. To give a specific example, when the length of the longitudinal edges is 200 mm, the width of the gap G may be, for example, 15 mm or less. The narrower the width of the gap G is, for example, when it is set to 5 mm, the larger the capacity loading is, and therefore the antenna characteristics of the second frequency band are further improved. In addition, the longer the length of the longitudinal edges of the first planar element 30 and the second planar element 40 facing each other, the larger the capacity loading is, and therefore the antenna characteristics of the second frequency band are further improved. At this time, as described above, the second planar element 40 is not visible from the first planar element 30, and therefore isolation is high, and therefore the deterioration of the antenna characteristics of the first planar element 30 is small.

[0028] For example, when the first frequency band is the DAB frequency band and the second frequency band is the FM frequency band, when the required level of the antenna characteristics of the DAB frequency band is high, it is possible to make the element shape and size significant for the antenna characteristics of the DAB frequency band, such as making the area of ​​the second planar element 40 small and the area of ​​the first planar element 30 large. This increases the design freedom of the first planar element 30. In addition, the area ratio of the first planar element 30 and the second planar element 40 may be appropriately distributed within the same area of ​​limited space. That is, it is also possible to appropriately design by changing the area ratio by moving the arrangement position of the gap G up and down on FIG. 1. In this way, even within the range of the same area, it is possible to appropriately design the area ratio of the first planar element 30 and the second planar element 40 so as to obtain optimal antenna characteristics by looking at the antenna characteristics of the first frequency band and the second frequency band.

[0029] FIG. 3 is a schematic side cross-sectional view for explaining a specific example of the composite planar antenna device of the present invention. In the figure, the parts with the same reference numerals as those in FIG. 1 represent the same objects. In this example, the first planar element 30 and the second planar element 40 are configured as an inverted L antenna. However, as described above, the second planar element 40 is also configured as a loop antenna. In the illustrated example, the ground conductor surface 1 is a bathtub-shaped portion. That is, this is an example in which the composite planar antenna device of the present invention is embedded inside the bathtub-shaped portion. The first planar element 30 and the second planar element 40 are arranged in parallel on the ground conductor surface 1 at the highest position that can be arranged inside the bathtub-shaped portion. Then, the first planar element 30 and the second planar element 40 are covered with a cover 3 such as a blind cover or a glass cover. Therefore, the filter section 50 is arranged on the surface side of the first planar element 30 and the second planar element 40 facing the ground conductor surface 1.

[0030] FIG. 4 is a schematic side cross-sectional view for explaining a modified example of the concrete example of the composite planar antenna device of the present invention. In the figure, the parts with the same reference numerals as those in FIG. 3 represent the same objects. In the illustrated example, for example, the composite planar antenna device of the present invention is embedded inside a bathtub-shaped part provided at the rear of the vehicle roof where the vehicle height is low. The difference from the one shown in FIG. 3 is that since the vehicle roof is curved, the cover 3 is also curved accordingly, and the height to the ground conductor surface 1 is gradually lowered. In such a case, the first planar element 30 and the second planar element 40 may be curved according to the appearance of the vehicle roof. In this way, when the distance from the first planar element 30 and the second planar element 40 to the ground conductor surface 1 changes, the filter unit 50 may be connected to the first planar element 30 and the second planar element 40 near the position far from the power supply unit, but near the position far from the ground conductor surface 1. That is, as shown in the figure, the filter unit 50 may be disposed near the area before the surface facing the ground conductor surface 1 curves and hangs down from the parallel position and approaches the ground conductor surface 1. This is because, for example, when a coil is used in the filter section 50, the Q value decreases when a conductor comes close, so it is better to place the coil as far away from the ground conductor surface 1 as possible.

[0031] Next, FIG. 5 shows another example of the composite planar antenna device of the present invention. FIG. 5 is a schematic plan view for explaining another example of the composite planar antenna device of the present invention. In the figure, the parts with the same reference numerals as in FIG. 1 represent the same objects. In this example, the second planar element 40 and the second power supply section 20 are connected via a resonant coil 54. That is, for the second frequency band, the resonant coil 54, the second planar element 40, the filter section 50, and the first planar element 30 are used to resonate at λ / 2 of the wavelength of the second frequency band. By using the resonant coil 54, finer adjustments can be made to accommodate the second frequency band. Here, if the resonant coil 54 has a high Q value, it will have narrowband characteristics. Therefore, for example, a chip inductor with a lower Q value than an air-core coil may be used as the resonant coil 54. Since the resonant coil 54 is arranged on the substrate 12, if it is a chip inductor, the cost of the component itself can be reduced, and the assembly man-hours can be reduced by automatic mounting.

[0032] 5, when the second planar element 40 is connected to the second power supply unit 20 via a resonant coil 54, the inductance of the resonant coil 54 may be set as follows. That is, when the filter unit 50 is a trap coil, the resonant coil 54 may have a lower inductance than the trap coil of the filter unit 50.

[0033] For example, the dimensions and inductance of each element will be specifically described for the case where the first frequency band is the DAB frequency band and the second frequency band is the FM frequency band. The dimensions of the first planar element 30 are, for example, 200 mm in the longitudinal direction and 55 mm in the short side direction. The dimensions of the second planar element 40 are, for example, 200 mm in the longitudinal direction and 20 mm in the short side direction. The gap G is 5 mm. In the case of such dimensions, the resonant coil 54 may have an inductance of 410 nH, and the trap coil of the filter section 50 may have an inductance of 870 nH. Note that these specific values ​​are merely examples, and the present invention is not limited to these.

[0034] Next, FIG. 6 shows yet another example of the composite planar antenna device of the present invention. FIG. 6 is a schematic plan view for explaining yet another example of the composite planar antenna device of the present invention. In the figure, the parts with the same reference numerals as in FIG. 1 represent the same objects. In this example, the first planar element 30 is configured as an inverted-F antenna. Specifically, in the illustrated example, the first planar element 30 is connected to the ground via a short-circuit coil 55. If it can be configured as an inverted-F antenna, it may be connected to the ground by a load resistance without using the short-circuit coil 55, or it may be connected to the ground directly. When the short-circuit coil 55 is used, the impedance adjustment for the first frequency band is possible by this inductance. More specifically, while adjusting to the first frequency band by the area of ​​the first planar element 30, the entire first frequency band is adjusted by the length in the longitudinal direction of the first planar element 30 and the line length of the first feeder 31, and the impedance adjustment is performed by the short-circuit coil 55. The short-circuit coil 55 may be, for example, a chip inductor. In cases where the space in which the composite planar antenna device of the present invention is arranged is narrow and the size of the first planar element 30 cannot be increased, and the band can be narrowed by shortening the wavelength, the band can be broadened by adjusting the short-circuit coil 55.

[0035] For the first frequency band, the inverted-F antenna has better antenna characteristics than the monopole antenna. On the other hand, for the second frequency band, there is almost no difference in antenna characteristics between the first feeding point 10 and the short-circuit coil 55.

[0036] Although the resonant coil 54 described with reference to FIG. 5 is not shown in FIG. 6, it is of course possible to provide the resonant coil 54 on the second planar element 40 side.

[0037] In the above-mentioned illustrated examples, the second planar element 40 is arranged so as to be parallel to the first planar element 30 in the longitudinal direction. However, the present invention is not limited to this. FIG. 7 is a schematic plan view for explaining another example of the first planar element of the composite planar antenna device of the present invention. In the figure, the parts with the same reference numerals as in FIG. 1 represent the same objects. Note that only the first planar element 30, the second planar element 40, and the filter section 50 are shown, and the other parts are omitted from the illustration. As shown in the figure, in this example, the first planar element 30 is configured to be L-shaped in a plan view. The first planar element 30 is configured to wrap around the tip of the second planar element 40. The filter section 50 may be connected to the gap G between the tip of the second planar element 40 and the wrapped-around part of the first planar element 30. In view of the antenna characteristics of the first frequency band and the second frequency band, the shape of the first planar element 30 may be appropriately modified as shown in the figure.

[0038] FIG. 8 is a schematic plan view for explaining another example of the second planar element of the composite planar antenna device of the present invention. In the figure, the parts with the same reference numerals as those in FIG. 1 represent the same objects. Note that only the first planar element 30, the second planar element 40, and the filter section 50 are shown, and the other parts are omitted from the illustration. As shown in the figure, in this example, the second planar element 40 is configured to be L-shaped in a plan view. The second planar element 40 is configured to wrap around the tip of the first planar element 30. The filter section 50 may be connected to the gap G between the tip of the first planar element 30 and the wrapped-around part of the second planar element 40. The shape of the second planar element 40 may be appropriately modified as shown in the figure, taking into account the antenna characteristics of the first frequency band and the second frequency band.

[0039] As shown in FIG. 7 and FIG. 8, if the longitudinal edge of the first planar element and a part of the longitudinal edge of the second planar element are arranged with a gap of a predetermined width therebetween, the antenna characteristics are less degraded by the coupling due to the filter section 50 for the first frequency band, and the antenna characteristics are improved by the capacitance loading for the second frequency band, as described above.

[0040] Furthermore, in the illustrated examples so far, the first power feed section 10 and the second power feed section 20 are arranged on the same substrate 12. However, the present invention is not limited to this. FIG. 9 is a schematic plan view for explaining another example of the arrangement position of the first power feed section and the second power feed section of the composite planar antenna device of the present invention. In the figure, the parts with the same reference numerals as in FIG. 1 represent the same objects. Note that only the first power feed section 10, the second power feed section 20, the first planar element 30, the second planar element 40, and the filter section 50 are shown, and the other parts are omitted from the illustration. As shown in the figure, in this example, the first planar element 30 and the second planar element 40 are arranged parallel to the longitudinal direction, as in FIG. 1, but the first power feed section 10 and the second power feed section 20 are arranged separately on the left and right, not at the same end. And, in the illustrated example, the filter section 50 is connected to the gap G between the longitudinal center vicinity.

[0041] Even with such a configuration, as in the above-described illustrated example, it is possible to make the first planar element 30 function as a capacitive antenna, while making the second planar element 40, the filter section 50, and the first planar element 30 function as a loop antenna.

[0042] In this way, the composite planar antenna device of the present invention can be modified in various ways depending on the space in which it is arranged, and even in such cases, it is possible to realize a device with little deterioration in antenna characteristics.

[0043] The composite planar antenna device of the present invention is not limited to the above-mentioned illustrated examples, and it is needless to say that various modifications can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0044] 1. Ground conductor surface 3 Cover 10 First power supply section 12 Substrate 20 Second power supply section 30 First Planar Element 31 1st feeder line 40 Second Planar Element 41 2nd feeder line 50 Filter section 51 Trap coil 52 Coil 53 Capacitor 54 Resonant coil 55 Shorted coil G Gap

Claims

1. A composite planar antenna device that is disposed on a ground conductor surface and is compatible with a plurality of frequency bands, the composite planar antenna device comprising: a first feeding section for a first frequency band; a second feeding section for a second frequency band lower than the first frequency band; a first planar element disposed on a ground conductor plane so as to face each other, connected to a first feeding portion, and compatible with a first frequency band; A second planar element is disposed on the same plane as the first planar element, facing the ground conductor surface, and connected to a second power supply portion, and a longitudinal edge of the second planar element is disposed with a gap of a predetermined width from a longitudinal edge of the first planar element, and is compatible with a second frequency band when used together with the first planar element; a filter section connected to a gap between the first and second planar elements, the filter section attenuating signals in a first frequency band and passing signals in a second frequency band; A composite planar antenna device comprising:

2. 2. The composite planar antenna device according to claim 1, wherein the filter section is connected to a gap between a position near a first feed section of the first planar element and a position near a second feed section of the second planar element.

3. 2. The composite planar antenna device according to claim 1, wherein the filter section is connected to a gap near a position far from the ground conductor surface of the first planar element and the second planar element when the distance between the first planar element and the second planar element and the ground conductor surface changes.

4. 2. The complex planar antenna device according to claim 1, wherein the second planar element is connected to a second feeding portion via a resonant coil.

5. 5. The composite planar antenna device according to claim 4, The filter unit includes a trap coil. The resonant coil has a lower inductance than the trap coil. A composite planar antenna device comprising:

6. 5. The composite planar antenna device according to claim 1, wherein the filter section comprises a trap coil or a low-pass filter circuit.

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