Radio antenna

The present invention relates to a wireless antenna, and more particularly to a wireless antenna having a dielectric waveguide structure.

Conventionally, as a wireless antenna for transmitting and receiving radio waves from a wireless module, for example, a wireless antenna substrate 1 having a waveguide structure inside as shown in FIG. 1 has been used. A typical wireless antenna substrate 1 is provided with a planar antenna 2 on either the upper surface or the lower surface of the planar substrate. Inside the flat substrate, a waveguide 4 is formed in a region surrounded by the wall structure 3, and the flat antenna 2 is arranged in the region of the waveguide 4. With such a configuration, for example, the radio wave received by the planar antenna 2 is transmitted only in the waveguide 4. Therefore, when the wireless module 5 is mounted on the wireless antenna board 1 and the wireless module 5 and the waveguide 4 are connected by a transmission path such as a coaxial cable, the wireless antenna board 1 is not only used as a transmitting / receiving antenna for the wireless module. , Can also function as a fixed board for the wireless module 5.

Further, at present, as shown in FIG. 1 (b), for example, the same wireless module 5 may be used in a plurality of arrays in a radar system or the like. At this time, if the wireless antenna substrate 1 as shown in FIG. 1A is used, it is possible to regularly construct a stable array structure having the same shape.

<p> However, when the conventional wireless antenna board 1 as shown in FIG. 1A is arrayed, an arrangement area for the wireless module 5 is also required on the antenna surface side where the planar antenna 2 is provided. However, there was a problem that the degree of integration was lowered. Further, as a method for improving the decrease in the degree of integration as shown in FIG. 1 (b), it is conceivable to provide the wireless module 5 on the back surface of the surface on which the flat antenna 2 is provided. Since the wireless module 5 is arranged on the mounting surface side in order to face the outside of the antenna, there is a problem that it becomes difficult to remove or adjust the wireless module 5.</p><p> Therefore, in view of the above problems, an object of the present invention is to provide a wireless antenna capable of reducing the total area even if a wireless module is mounted.</p>

<p> In order to achieve such an object, the present invention has a plate-shaped substrate made of a dielectric and a waveguide provided in the front surface, the back surface and the thickness direction of the substrate and together with the substrate, as described in claim 1. It is a radio antenna characterized by having a peripheral conductor constituting a mode transmission path and a radiation portion lacking the peripheral conductor in the thickness direction of the substrate. According to such a configuration, since the radiation portion having the end surface of the plate-shaped substrate as the radiation surface is provided, radio waves can be transmitted and received in the direction perpendicular to the main surface of the plate-shaped substrate, and the main surface can be transmitted and received. A component such as a radio module can be mounted on the top so as to be located above the radiation section.</p><p> In the radio antenna according to claim 1, as described in claim 2, the peripheral conductors in the thickness direction of the substrate are arranged at a pitch shorter than the wavelength of the radio wave transmitted in the substrate. It can be configured to be a plurality of conductors.</p><p> The wireless antenna according to claim 1 has a configuration in which the peripheral conductors in the thickness direction of the substrate are arranged in a rectangular shape when viewed from a direction perpendicular to the plane of the substrate, as described in claim 3. Can be done.</p><p> In the radio antenna according to claim 1, as described in claim 4, the peripheral conductor in the thickness direction of the substrate becomes wider toward the radiation portion when viewed from a direction perpendicular to the plane of the substrate. It can be configured to be arranged in such a manner.</p><p> In the radio antenna according to claim 1, as described in claim 5, the peripheral conductor in the thickness direction of the substrate faces a rectangular region and the radiation portion when viewed from a direction perpendicular to the plane of the substrate. It can be configured to have a region having a large width.</p><p> As described in claim 6, the wireless antenna according to claim 1 may have a configuration in which a component mounting surface is included on the front surface or the back surface of the substrate.</p><p> The wireless antenna according to claim 6 can be configured such that components are mounted on the front surface or the back surface of the substrate as described in claim 7. This component is, for example, a wireless module.</p>

<p> According to the present invention, since the antenna surface is located on the side end surface of the substrate, the surface of the substrate can be freely used. For example, even if the wireless module is mounted on the surface of the substrate, the total area can be reduced.</p>

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

First, Example 1 of the present invention will be described in detail with reference to the drawings. FIG. 2 shows the wireless antenna substrate 10 according to the first embodiment, FIG. 2 (a) is a front view, and FIG. 2 (b) is a cross-sectional view. The wireless antenna substrate 10 according to the first embodiment has a plate shape, and includes a peripheral conductor 10b that surrounds the periphery of the substrate and a dielectric 10c that fills the inside thereof. The dielectric 10c is, for example, a dielectric such as polytetrafluoroethylene. A waveguide 12 formed by the wall member 11 is provided in a part of the dielectric 10c. The wall member 11 is a conductor electrically connected to the surrounding conductor 10b, and as shown in FIG. 2 (a), the conductors are intermittently formed at intervals smaller than the wavelength of the continuously formed structure or the transmitted signal. The structure may be arranged in. The waveguide 12 is a closed space surrounded by the wall member 11 and the peripheral conductor 10b, and has an open surface in which the peripheral conductor 10b is not formed only on the right end surface in the drawing. With such a structure, the radio wave or signal input into the inside is configured so as not to leak to the outside from a portion other than the open surface.

The main surface of the wireless antenna board 10 is a component mounting surface, on which the wireless module 13 is mounted. The power feeding unit 14 provided on the lower surface of the wireless module 13 is connected so as to project inside the waveguide 12. The waveguide 12 acts as a resonator by receiving an input from the feeding unit 14, and serves as an antenna that emits radio waves from an open surface. With such a configuration, the antenna surface for transmitting and receiving radio waves is provided on the end surface side and is in the direction orthogonal to the mounting surface of the wireless module 13, so that the occupied area of the wireless antenna board 10 can be reduced. It becomes.

Next, a modification of the wireless antenna substrate 10 according to the first embodiment will be described. FIG. 3 shows a modification of the wireless antenna substrate 10 according to the first embodiment, FIG. 3 (a) is a first modification, and FIG. 3 (b) is a second modification. In the first modification, the wall member 11 forms a substantially trapezoidal waveguide 12b provided in a substantially trapezoidal cross section in which the width increases toward the open surface side. In the second modification, the wall member 11 forms a so-called horn antenna-shaped waveguide 12c which is provided in a substantially rectangular cross section up to the middle portion and then in a substantially trapezoidal cross section. By forming in this way, the substantially trapezoidal waveguide 12b according to the first embodiment and the horn antenna-shaped waveguide 12c according to the second embodiment both radiate radio waves transmitted from the radio module 13 at a wider angle. It becomes possible to do.

Next, a third modification of the first embodiment will be described. FIG. 4 shows a third modification according to the first embodiment. In the third modification, a plurality of through holes 15 are provided at equal intervals instead of the wall member forming the waveguide 12. As shown in FIG. 4B, the through holes 15 have a diameter d and are provided for each distance D. The through hole 15 is formed by covering the inner surface with the conductor 15b or inserting a cylinder of the conductor 15d, and is electrically connected to the peripheral conductor 10b of the wireless antenna substrate 10. The distance D between the two through holes is sufficiently smaller than the wavelength λ of the radio wave to be transmitted, and the diameter d of the through holes 15 is smaller than the distance D. With such a configuration, the transmitted radio wave cannot pass between the two through holes 15. That is, the plurality of through holes 15 can be regarded as a pseudo wall surface. Since the structure provided with the plurality of through holes 15 can be processed after the wireless antenna substrate 10 is manufactured, the manufacturing process can be simplified and the manufacturing cost can be reduced.

With the above configuration, according to the wireless antenna substrate 10 according to the first embodiment, the waveguide antenna structure having the end surface of the wireless antenna substrate 10 as the radiation surface is formed inside the wireless antenna substrate 10. Even if the wireless module 13 is mounted on the upper surface of the wireless antenna substrate 10, the overall area can be reduced.

Next, Example 2 of the present invention will be described with reference to the drawings. FIG. 5 is a plan view showing the wireless antenna module 20 according to the second embodiment. The wireless antenna module 20 according to the second embodiment includes a peripheral conductor that surrounds the periphery and serves as a housing, a wireless module 23, a dielectric that fills the periphery of the wireless module 23, and a connector 25 that is connected to an external electronic device. including. The dielectric is, for example, polytetrafluoroethylene or the like. The dielectric is provided with a waveguide 22 formed by the wall member 21. The wall member 21 is a conductor electrically connected to the surrounding conductor, and has a structure formed continuously or a plurality of penetrations at intervals D smaller than the wavelength of the transmitted signal as shown in FIG. 4 (b). A structure in which holes are arranged may also be used. The waveguide 22 is a closed space surrounded by the wall member 21 and the peripheral conductor, and has an open surface in which the peripheral conductor is not formed only on the right end surface in the drawing. With such a structure, the radio wave or signal input into the inside is configured so as not to leak to the outside from a portion other than the open surface.

The wireless module 23 is provided inside the peripheral conductor, and the power feeding unit 24 provided in the wireless module 23 is connected so as to project inside the waveguide 22. The waveguide 22 acts as a resonator by receiving an input from the feeding unit 24, and serves as an antenna that emits radio waves from an open surface. The wireless module 23 can also be arranged so that its upper surface coincides with the upper surface of the surrounding conductor. The connector 25 is provided so that the connector terminal is arranged on the surface of the wireless antenna module 20, and is electrically connected to the wireless module 23 inside the wireless antenna module 20. With such a configuration, since the antenna surface for transmitting and receiving radio waves is provided on the end surface side, it is possible to reduce the occupied area of the wireless antenna module 20.

Further, as shown in FIG. 5B, the wireless antenna module 20 shown in FIG. 5 is formed as a card-type module in which the radiation surface of the waveguide and the connector are provided on opposite surfaces, for example, a personal computer. It is also possible to make the attachment portion 31 to a device such as 30 into a slot shape. That is, by housing the wireless module and the antenna inside the card-type housing, it is possible to simplify the configuration of the connection portion on the device side to be attached.

With the above configuration, according to the wireless antenna module 20 according to the second embodiment, a waveguide antenna structure having the end surface of the wireless antenna module 20 as a radiation surface is formed inside the wireless antenna module 20 to be wireless. By providing the module 23 and the connector 25 inside the peripheral conductor serving as the housing, it is possible to reduce the area of the entire wireless antenna module 20. Further, according to the wireless antenna module 20 according to the second embodiment, it is possible to simplify the configuration of the connection portion on the device side to be attached.

From the above examples, according to the present invention, since the antenna surface is located on the side end surface of the substrate, the surface of the substrate can be freely used. For example, even if the wireless module is mounted on the surface of the substrate, the total area can be reduced.

The examples described above are only one of the best modes for carrying out the present invention, and the present invention can be implemented in various changes and modifications as long as the gist of the present invention is not deviated.

<figref num="1">It is a top view which shows the structure and application example of the wireless antenna substrate 1 which has a waveguide structure inside in the prior art.</figref><figref num="2">The configuration of the wireless antenna substrate 10 according to the first embodiment is shown, FIG. 2 (a) is a front view, and FIG. 2 (b) is a cross-sectional view.</figref><figref num="3">A first modification and a second modification of the wireless antenna substrate 10 according to the first embodiment are shown.</figref><figref num="4">A third modification of the wireless antenna substrate 10 according to the first embodiment is shown.</figref><figref num="5">It is a figure which shows the structure and application example of the wireless antenna module 20 by this Example 2.</figref>

Code description

10 Radio antenna board 10b Peripheral conductor 10c Dielectric 11, 21 Wall member 12, 12b, 12c, 22 Wavelength path 13, 23 Radio module 14, 24 Feeding part 15 Through hole d Through hole 15 Diameter D Two through holes 15 Distance between λ Wavelength of transmitted radio waves