JP2018050240A - Planar antenna and antenna device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a planar antenna and an antenna device capable of suppressing antenna loss.SOLUTION: The planar antenna 100 includes: at least one antenna conductor 13; a ground conductor 16; and at least one support portion 15. The antenna conductor 13 transmits and receives electromagnetic waves and constitutes a reflection wall of the electromagnetic wave. The ground conductor 16 faces the antenna conductor 13 and constitutes a reflection wall of the electromagnetic wave. The support portion 15 forms a gap between the at least one antenna conductor 13 and the ground conductor 16.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a planar antenna and an antenna device.

  Patent Document 1 discloses a planar antenna in which a conductor layer is disposed on both sides with a dielectric layer in between. In this planar antenna, a material obtained by laminating a polyolefin resin and glass fiber is used as the dielectric instead of the foamed polyethylene used as a conventional dielectric material. Thereby, the flat antenna of patent document 1 can acquire a high antenna characteristic.

JP 2013-89995 A

  However, although the planar antenna of Patent Document 1 obtains high antenna characteristics by changing the material and configuration of the dielectric from conventional materials, the influence of the presence of the dielectric on the antenna characteristics is not a little. That is, in the antenna of Patent Document 1, electromagnetic waves are transmitted and received by traveling through the dielectric body while reflecting the electromagnetic waves between both conductors sandwiching the dielectric. Therefore, there is a problem that the intensity of the electromagnetic wave is lost due to the presence of the dielectric, and as a result, the transmission / reception characteristics of the antenna are lost. Therefore, a configuration capable of further suppressing antenna loss has been demanded.

  Accordingly, an object of the present invention is to provide a planar antenna and an antenna device that can suppress antenna loss.

  A planar antenna according to an aspect of the present invention includes at least one antenna conductor, a counter conductor, and at least one support portion. The antenna conductor transmits and receives electromagnetic waves and constitutes a reflection wall of the electromagnetic waves. The counter conductor opposes the antenna conductor and constitutes a reflection wall of the electromagnetic wave. The support portion forms a gap between the at least one antenna conductor and the opposing conductor.

  According to the above configuration, since the antenna conductor and the opposing conductor, which are electromagnetic wave reflection walls, are supported by the support portion so that there is a gap between them, there is no ratio between the antenna conductor and the opposing conductor. Air with a dielectric constant of about 1.0 is present. Since air has a relative dielectric constant smaller than that in the case where a dielectric material is interposed between the antenna conductor and the opposing conductor, it is possible to suppress power loss of electromagnetic waves propagating between the antenna conductor and the opposing conductor.

  Further, since the support portion only needs to support the antenna conductor with respect to the opposing conductor, air can be interposed between the antenna conductor and the opposing conductor with a simple configuration. Furthermore, since it is not necessary to support the antenna conductor with a separate substrate, the planar antenna can be reduced in size, weight, and cost.

  In the planar antenna, the at least one support portion is provided on a straight line that passes through the vicinity of the center of the antenna conductor in a plan view of the planar antenna and extends in an orthogonal direction orthogonal to the resonance direction of the electromagnetic wave. be able to.

  An electromagnetic wave having the antenna conductor as a reflection wall is in a resonance state, and a standing wave is generated. At this time, the node of the standing wave is located at the center of the resonance direction of the antenna element. A straight line passing through the vicinity of the center of the antenna conductor and orthogonal to the resonance direction extends corresponding to the position of the node of the standing wave. Therefore, the electric field strength of the electromagnetic wave is smaller on the straight line passing through the vicinity of the center than in other regions other than the vicinity of the center. Therefore, by connecting the support portion and the antenna conductor on this straight line, the influence on the electromagnetic wave propagating between the antenna conductor and the opposing conductor caused by providing the support portion can be suppressed, and the antenna loss can be suppressed. .

  The “near the center” may be a region having a low electric field strength in the antenna conductor, and includes not only the central portion of the antenna conductor but also the central portion and the vicinity thereof. Further, “orthogonal” includes substantially orthogonal, and includes, for example, a case where a resonance direction and a straight line intersect at an angle of about 80 ° to about 100 °. Moreover, the support part should just be located on a straight line at least the connection part with an antenna conductor, and the whole support part does not necessarily need to be located on a straight line.

  In the planar antenna, in the plan view of the planar antenna, the at least one support portion may be disposed in a region excluding a side of an outer peripheral edge of the antenna conductor in a vicinity of a center of the antenna conductor. .

  In the vicinity of the center of the antenna conductor, the electric field strength of the electromagnetic wave is smaller than the area other than the vicinity of the center. However, the side of the antenna conductor tends to have a stronger electromagnetic wave strength than the central portion. This is considered to be due to the fact that the antenna conductor is in contact with air at the side of the antenna conductor, so that the effective dielectric constant of the antenna conductor changes, and this change makes it easier for electromagnetic waves to concentrate. In the above configuration, unlike the antenna conductor side, the support portion is arranged in a region excluding the antenna conductor side where the electromagnetic wave strength is low. Thereby, the influence to the electromagnetic waves in an antenna conductor produced by providing a support part can be suppressed, and antenna loss can be suppressed.

  In the planar antenna, the antenna conductor may include a pair of first sides that extend along the resonance direction and face each other in plan view. At this time, the support portion is provided near the center of each of the pair of first sides and extends toward the counter conductor.

  As described above, the vicinity of the center of the antenna conductor in the resonance direction corresponds to the position of the node of the standing wave, and the electric field strength of the electromagnetic wave is small compared to other regions other than the vicinity of the center. In the above configuration, each support portion extends from each of the pair of first sides toward the opposing conductor in the vicinity of the center of the resonance direction of the antenna conductor. Therefore, it is possible to suppress the influence on the electromagnetic wave in the antenna conductor, which is caused by providing the support portion, and to suppress the antenna loss.

  In the planar antenna, the antenna conductor may include a pair of first sides that extend along the resonance direction and face each other in plan view. At this time, the support portion is connected to each of the pair of first sides. Each of the support portions has a horizontal portion extending from the vicinity of the center of the first side toward the end separated from the antenna conductor along the planar direction of the antenna conductor, and from the end of the horizontal portion. And a vertical portion extending toward the opposing conductor.

  As described above, the vicinity of the center of the antenna conductor in the resonance direction corresponds to the position of the node of the standing wave, and the electric field strength of the electromagnetic wave is small compared to other regions other than the vicinity of the center. However, the first side of the antenna conductor tends to have a higher electromagnetic wave strength than the central portion of the antenna conductor. This is presumably because, on the first side, the antenna conductor is in contact with air, so that the effective dielectric constant of the antenna conductor changes, and this change makes it easier for electromagnetic waves to concentrate.

  In the above configuration, first, the horizontal portion of the support portion extends along a plane from the first side near the center in the resonance direction of the antenna conductor toward the end away from the antenna conductor. That is, in the support portion, the horizontal portion first extends along the plane of the antenna conductor so as to be away from the first side of the antenna conductor having a high electromagnetic wave intensity. Thereby, it can suppress that electromagnetic waves with a large electric field strength concentrate in a horizontal part. The vertical portion of the support portion extends from the end of the horizontal portion of the support portion toward the opposing conductor. Thereby, the influence to the electromagnetic waves in an antenna conductor produced by providing a support part can be suppressed, and antenna loss can be suppressed.

  In the planar antenna, in the plan view, each of the pair of first sides and the connecting portion of each support portion are symmetric with respect to a straight line passing through the center of the antenna conductor and along the resonance direction of the electromagnetic wave. be able to.

  In the above configuration, the connection portion between the antenna conductor and each support portion is positioned symmetrically with respect to a straight line along the resonance direction. Therefore, the influence which each support part which mutually opposes on the electromagnetic wave in an antenna conductor becomes symmetrical. Thereby, the resonance state of the electromagnetic wave in the antenna conductor can be maintained symmetrically with respect to the vicinity of the center. Therefore, antenna loss due to non-uniform resonance can be suppressed.

  In the planar antenna, a connection portion between the at least one support portion and the antenna conductor may be located in a region of the antenna conductor having a low electric field strength.

  In the above configuration, the support portion is connected to a region of the antenna conductor where the electric field strength is low. Therefore, it is possible to suppress the influence on the electromagnetic wave in the antenna conductor, which is caused by providing the support portion, and to suppress the antenna loss.

  In the planar antenna, the antenna conductor may include at least one pair of second sides parallel to each other orthogonal to the resonance direction of the electromagnetic wave in plan view.

  In the above configuration, the electromagnetic wave is in a resonance state and a standing wave is formed with the pair of parallel second sides in the antenna conductor as the edge. The antinodes of the standing waves are located at the edges of the pair of second sides, and the nodes of the standing waves are located at the center of the pair of second sides. At this time, the electromagnetic wave in the antenna conductor resonates at a certain resonance frequency, and power loss can be minimized.

  In the planar antenna, when the in-tube wavelength of the electromagnetic wave in the antenna conductor is λg, the distance between the pair of second sides can be λg / 2.

  According to the above configuration, a standing wave having a pair of second sides as a belly and a node at the center of the pair of second sides is generated. At this time, the electromagnetic wave in the antenna conductor resonates at a certain resonance frequency, and power loss can be minimized.

  In the planar antenna, the at least one support portion may be connected in the vicinity of the center of the antenna conductor and in the vicinity of λg / 4 from the pair of second sides.

The vicinity of λg / 4 from the set of second sides is a central portion between the set of second sides. A node of a standing wave is located in the vicinity of λg / 4 from the second side of the set, and the electric field strength of the electromagnetic wave is smaller than that in other regions. By providing the support portion at this position, the influence on the electromagnetic wave in the antenna conductor by providing the support portion can be suppressed, and the antenna loss can be suppressed.
Note that the vicinity of λg / 4 from the set of second sides may be within a range of ± λg / 8 with λg / 4 as the center from the set of second sides, for example.

  In the planar antenna, the planar shape of the antenna conductor may be rectangular.

  The antenna conductor has, for example, a rectangular shape such as a rectangle, a square, and a trapezoid. With such a rectangular shape, for example, standing waves having edges that are parallel to each other as edges are formed, and electromagnetic waves are in a resonance state. Thereby, antenna loss can be suppressed.

  The planar antenna is provided with a plurality of antenna conductors, and can further include a connection conductor for connecting adjacent antenna conductors.

  The sensitivity of electromagnetic wave transmission / reception can be improved by arranging a plurality of antenna conductors connected by connecting conductors.

  An antenna device according to an aspect of the present invention includes any one of the planar antennas described above and a power converter that performs power conversion of electromagnetic waves transmitted and received in the planar antenna.

  The antenna device may further include a high frequency circuit connected to the power converter.

  ADVANTAGE OF THE INVENTION According to this invention, the planar antenna and antenna apparatus which can suppress antenna loss can be provided.

The perspective view of the antenna apparatus containing the planar antenna which concerns on 1st Embodiment. The enlarged view of the area | region containing a 1st antenna conductor and a 2nd antenna conductor among the planar antennas of FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. The analysis figure which shows electric field strength distribution in the case of planarly viewing a planar antenna. The perspective view which shows the structure 1 with which the planar antenna 100 was connected to the power converter 200. FIG. Sectional drawing in the straight line (alpha) of FIG. The exploded perspective view which shows the structure 2 with which the planar antenna 100 was connected to the power converter 200. FIG. The perspective view which shows the structure by which the coaxial cable is connected to the planar antenna. The top view which shows the arrangement | positioning relationship with respect to the antenna conductor 13 of the left support part 15L and the right support part 15R. The top view which shows the arrangement | positioning relationship with respect to the antenna conductor 13 of the left support part 15L and the right support part 15R. The perspective view of the antenna apparatus containing the planar antenna which concerns on 2nd Embodiment. The enlarged view of the area | region containing a 1st antenna conductor and a 2nd antenna conductor among the planar antennas of FIG. AA line sectional view of Drawing 12. The analysis figure which shows electric field strength distribution in the case of planarly viewing a planar antenna. The perspective view of the antenna apparatus containing the planar antenna which concerns on 3rd Embodiment. The enlarged view of the area | region containing a 1st antenna conductor and a 2nd antenna conductor among the planar antennas of FIG. FIG. 17 is a sectional view taken along line AA in FIG. 16. The analysis figure which shows electric field strength distribution in the case of planarly viewing a planar antenna. The perspective view of the antenna apparatus at the time of providing the support part of 1st Embodiment in the connection conductor. The perspective view of the antenna apparatus at the time of providing the support part of 2nd Embodiment in the connection conductor. The perspective view of the antenna apparatus at the time of providing the support part of 3rd Embodiment in the connection conductor. The top view which shows another shape of an antenna conductor. The top view which shows another shape of an antenna conductor. An explanatory view at the time of arranging a plurality of antenna conductors in a plurality of rows. An explanatory view at the time of arranging a plurality of antenna conductors in a plurality of rows. An explanatory view at the time of arranging a plurality of antenna conductors in a plurality of rows. The perspective view of the antenna apparatus containing an ideal planar antenna. The enlarged view of the area | region containing a 1st antenna conductor and a 2nd antenna conductor among the ideal planar antennas of FIG. AA line sectional view of Drawing 25. Electric field intensity distribution of the ideal planar antenna 195. The directivity of the planar antenna of Example 1-1. The directivity of the planar antenna of Example 1-2. The directivity of the planar antenna of Example 1-3. Directivity of an ideal planar antenna. The perspective view of the antenna apparatus containing the planar antenna of the comparative example 1. FIG. AA line sectional view of Drawing 33. The electric field strength distribution in the flat antenna 5000 of Comparative Example 1. Directivity of the planar antenna 5000 of Comparative Example 1 Explanatory drawing which shows electric field strength distribution of the planar antenna 1001 of Example 2-1. Explanatory drawing which shows electric field strength distribution of the planar antenna 1002 of Example 2-2.

  Hereinafter, a planar antenna and an antenna apparatus including the planar antenna according to a first embodiment of the present invention will be described with reference to the drawings.

<1. First Embodiment>
(1) Schematic Configuration of Antenna Device FIG. 1 is a perspective view of an antenna device including a planar antenna according to the first embodiment. FIG. 2 is an enlarged view of a region including the first antenna conductor and the second antenna conductor in the planar antenna of FIG. FIG. 3 is a cross-sectional view taken along line AA in FIG.

  As shown in FIG. 1, the antenna device 1000 according to this embodiment includes a planar antenna 100 that receives and transmits electromagnetic waves, a high-frequency circuit 300 that transmits and receives high frequencies such as millimeter waves and microwaves, and the planar antenna 100 and the high-frequency circuit 300. And a power converter 200 that performs power conversion with the power converter. The high-frequency circuit 300 is, for example, an MMIC (monolithic microwave integrated circuit), and transmits and receives high-frequency waves such as millimeter waves and microwaves as described above. The planar antenna 100 radiates an electromagnetic wave transmitted from the high frequency circuit 300 and subjected to power conversion in the power converter 200. On the other hand, when the planar antenna 100 receives an electromagnetic wave, the planar antenna 100 transmits the received electromagnetic wave to the high-frequency circuit 300 via the power converter 200. Hereinafter, each member will be described in detail.

(2) Overall Configuration of Planar Antenna First, the overall configuration of the planar antenna 100 according to the first embodiment will be described. In the following, description will be given in the direction shown in FIG. 1, that is, up, down, front, back, right, left. However, although the present invention is not limited by this orientation, the “front-rear direction” of the present embodiment corresponds to the resonance direction of the present invention, and the “left-right direction” is the direction orthogonal to the resonance direction of the present invention. Equivalent to.

  Further, in the following description, the term “in-tube wavelength of a certain part” means the wavelength of an electromagnetic wave in a certain part that is affected by any configuration adjacent to the certain part. For example, as described later, the in-tube wavelength of the electromagnetic wave in the antenna conductor 13 means the wavelength of the electromagnetic wave in the antenna conductor 13 that is affected by any configuration around the antenna conductor 13 such as air adjacent to the antenna conductor 13. It shall be.

  As shown in FIG. 1, the planar antenna 100 includes four antenna conductors 13 (13 a to 13 d) that transmit and receive electromagnetic waves, a grounded ground conductor (opposing conductor) 16, and each antenna conductor 13 as a ground conductor 16. The support part 15 supported with respect to it is included. Further, the four antenna conductors 13a to 13d are arranged in a straight line and are connected to each other by connection conductors 11b to 11d. And the antenna conductor 13a arrange | positioned at the tail is connected to the power converter 200 via the connection conductor 11a. Each antenna conductor 13 and the ground conductor 16 are formed of flat conductors, and are arranged to face each other in the vertical direction. Therefore, the electromagnetic wave propagates while being reflected between the antenna conductor 13 and the ground conductor 16. In the following, for convenience of explanation, the antenna conductors arranged from the rear to the front are referred to as a first antenna conductor 13a, a second antenna conductor 13b, a third antenna conductor 13c, and a fourth antenna conductor 14d, respectively. I will do it. The connection conductors 11 arranged from the rear to the front are referred to as a first connection conductor 11a, a second connection conductor 11b, a third connection conductor 11c, and a fourth connection conductor 11d, respectively. Thus, the transmission / reception sensitivity of electromagnetic waves can be improved by alternately connecting the plurality of antenna conductors 13 and the connection conductors 11 in a line.

  Each antenna conductor 13 is supported by the above-described support portion 15 (15a to 15d) so as to have a gap between the antenna conductor 13 and the ground conductor 16. For example, the first antenna conductor 13a is supported with respect to the ground conductor 16 by a left first support portion 15La connected to the left side and a right first support portion 15Ra connected to the right side. The left first support portion 15La and the right first support portion 15Ra are formed integrally with the first antenna conductor 13a, and the left and right sides of the first antenna conductor 13a with respect to the ground conductor 16 are substantially uniformly and stably. I support it.

  Similarly, the second antenna conductor 13b is supported by a second support portion 15b having a left second support portion 15Lb and a right second support portion 15Rb. The other third antenna conductor 13c is similarly supported by the third support portion 15c (15Lc, 15Rc), and the fourth antenna conductor 13d is similarly supported by the fourth support portion 15d (15Ld, 15Rd).

(3) Configuration of Each Part of Planar Antenna Next, the antenna conductor 13, the connection conductor 11, the support part 15, and the ground conductor 16 that are each part of the planar antenna 100 will be further described. The first to fourth antenna conductors 13a to 13d, the connection conductors 11a to 11d, and the support portions 15a to 15d have substantially the same configuration. Therefore, the first antenna conductor 13a, the first connection conductor 11a, the second connection conductor 11b, and the first support portion 15a will be described, and the other second to fourth antenna conductors 13b to 13d and the third to fourth connection conductors 11c. Description of ˜11d and the second to fourth support portions 15b to 15d will be omitted.

(3-1) First antenna conductor 13a
As shown in FIG. 2, the first antenna conductor 13a is a rectangular plate having four sides, that is, a set of first sides 19a extending in the front-rear direction and a set of second sides 17a extending in the left-right direction. It is formed by the shape. The pair of first sides 19a has a left first side 19La and a right first side 19Ra that face each other in the left-right direction and are parallel to each other. The pair of second sides 17a includes a front second side 17Fa and a rear second side 17Ba that face each other in the front-rear direction and are parallel to each other.

  The distance L1 between the front second side 17Fa and the rear second side 17Ba can be set to 1 / 2λg, where λg is the in-tube wavelength of the electromagnetic wave in the first antenna conductor 13a. In other words, the length L1 in the front-rear direction of each of the left first side 19La and the right first side 19Ra can be ½λg. The length L1 can be set to, for example, 1.5 mm to 1.9 mm. When the length L1 is 1 / 2λg, the electromagnetic wave in the first antenna conductor 13a enters a resonance state with the front-rear direction as the resonance direction, and a standing wave is generated. Specifically, the electromagnetic wave that has traveled forward from the rear of the first connection conductor 11a and entered the first antenna conductor 13a becomes a standing wave that repeatedly reflects in the front-rear direction of the first antenna conductor 13a. At this time, antinodes of standing waves are located on the front second side 17Fa and the rear second side 17Ba facing in the front-rear direction. On the other hand, when a straight line γ that passes through the center point β that is the center of the first antenna conductor 13a in the front-rear direction and the left-right direction and extends in the left-right direction is defined, a node of a standing wave is located on the straight line γ. Thus, the antenna conductor 13 resonates at a certain resonance frequency to form a standing wave, thereby minimizing power loss. The straight line γ is orthogonal to the straight line α that passes through the center point β and extends along the resonance direction. Here, “orthogonal” includes substantially orthogonal, and includes, for example, the case where the straight line α and the straight line γ intersect at an angle of about 80 ° to about 100 °.

  Further, the length L2 of the interval between the left first side 19La and the right first side 19Ra is not particularly limited as long as it is longer than the length L3 in the left-right direction of a first connection conductor 11a and a second connection conductor 11b described later. The length L2 can be, for example, longer than the length L3 and shorter than the length L1, for example, 1 mm.

  The first antenna conductor 13a has a substantially uniform thickness W2. The thickness W2 is not particularly limited. However, as W2 is smaller, the first antenna conductor 13a can be formed in a thin plate shape, and the planar antenna 100 can be made thinner. The thickness W2 can be set to, for example, 0.012 mm to 0.300 mm.

(3-2) First connection conductor 11a and second connection conductor 11b
The 1st connection conductor 11a is a rectangular parallelepiped rod-shaped member extended in the front-back direction. The first connection conductor 11 a connects the power converter 200 and the planar antenna 100. Therefore, the first connection conductor 11a outputs the electromagnetic wave output from the power converter 200 to the planar antenna 100. Further, on the contrary, the first connection conductor 11 a outputs the electromagnetic wave output from the planar antenna 100 to the power converter 200.

  The first connection conductor 11a is connected so as to protrude rearward from the center of the rear second side 17Ba of the first antenna conductor 13a. Specifically, the first connection conductor 11a extends along a straight line α that passes through the center point β of the first antenna conductor 13a and extends in the front-rear direction.

  The length L3 in the left-right direction of the first connection conductor 11a is determined by the size of impedance required for the first connection conductor 11a. For example, the length L3 is a distance at which the impedance is about 100Ω, and can be 0.2 mm to 0.25 mm. However, the length L3 in the left-right direction of the first connection conductor 11a is smaller than the length L2 in the left-right direction of the front second side 17Fa and the rear second side 17Ba. In particular, the length L3 is preferably sufficiently smaller than the length L2. Thereby, the electromagnetic wave is propagated between the first connection conductor 11a and the first antenna conductor 13a, and the electromagnetic wave is reflected with the front second side 17Fa and the rear second side 17Ba of the first antenna conductor 13a as end faces. it can. Therefore, in the first antenna conductor 13a, the electromagnetic wave can be brought into a resonance state in which the front-rear direction is the resonance direction, and a standing wave can be generated. On the other hand, when the length L3 is equal to or longer than the length L2, there is no wall surface for reflecting the electromagnetic wave in the front-rear direction in the first antenna conductor 13a. Therefore, it is impossible to generate a standing wave with the electromagnetic wave as a resonance state in the first antenna conductor 13a.

  The vertical thickness W3 of the first connecting conductor 11a is substantially the same as the thickness W2 of the first antenna conductor 13a. For example, the thickness W3 may be determined by the size of impedance required for the first connection conductor 11a.

  The length L4 in the front-rear direction of the first connection conductor 11a is determined by the distance between the first antenna conductor 13a and the power converter 200, and the like. However, the length L4 may be the same as the length L5 in the front-rear direction of the second connection conductor 11b described later.

  The 2nd connection conductor 11b is a rectangular parallelepiped rod-shaped member extended in the front-back direction similarly to the 1st connection conductor 11a. The second connection conductor 11b connects the adjacent first antenna conductor 13a and the second antenna conductor 13b, and propagates electromagnetic waves between the first antenna conductor 13a and the second antenna conductor 13b. The second connection conductor 11b is connected to the center in the left-right direction of the first antenna conductor 13a and the second antenna conductor 13b, and extends along the straight line α, like the first connection conductor 11a. The dimension of the second connection conductor 11b is substantially the same as that of the first connection conductor 11a.

(3-3) First support portion 15a
The left first support portion 15La and the right first support portion 15Ra constituting the first support portion 15a support the antenna conductor 13a so that the first antenna conductor 13a has a gap between the first conductor portion 13a and the ground conductor 16. Since the left first support portion 15La and the right first support portion 15Ra are symmetric about the straight line α, only the right first support portion 15Ra will be described.

  The right first support portion 15Ra is formed in an L shape having a right first horizontal portion 15HRa and a right first vertical portion 15VRa. The right first horizontal portion 15HRa is a rectangular parallelepiped rod-like member extending in the left-right direction, connected to the center of the right first side 19Ra of the first antenna conductor 13a, and extends along the straight line γ. The right first vertical portion 15VRa is connected to the right end portion of the right first horizontal portion 15HRa. The right first vertical portion 15VRa extends in the vertical direction, and the lower end thereof is connected to the ground conductor 16. For example, the lower end of the right first vertical portion 15VRa can be inserted into an opening provided in the ground conductor 16 and fixed.

  Here, the reason why the right first horizontal portion 15HRa is connected along the straight line γ will be described below. FIG. 4 is an analysis diagram showing the electric field strength distribution when the planar antenna is viewed in plan. In FIG. 4, for example, an electromagnetic wave having a power of 1 W and 76 GHz is supplied from the first connection conductor 11a. Referring to the electric field strength distribution obtained by enlarging the first antenna conductor 13a, the electric field strength is highest in the regions I, II, III, and IV including the four corners of the first antenna conductor 13a. On the other hand, the electric field strength was the smallest in the region V including the straight line γ. That is, the region V has a smaller electric field strength than the regions I, II, III, and IV. This is because the antinode of the standing wave of the electromagnetic wave in the first antenna conductor 13a is located on the front second side 17Fa and the rear second side 17Ba, and the node of the standing wave includes the straight line γ in the center of the first antenna conductor 13a. This is because it is located in the vicinity (region V). In the region where the node of the standing wave is located, the potential becomes zero and a short circuit occurs. As described above, by connecting the right first horizontal portion 15HRa and the first antenna conductor 13a on the straight line γ, the first antenna conductor 13a and the ground conductor generated by providing the right first support portion 15Ra. The influence on the electromagnetic wave propagating between 16 and 16 can be suppressed, and the antenna loss can be suppressed.

  The length L6 in the front-rear direction of the right first horizontal portion 15HRa is not particularly limited. However, the smaller the length L6, the smaller the influence of the right first support portion 15Ra on the electromagnetic waves in the first antenna conductor 13a, which is preferable. For example, the length L6 is preferably sufficiently smaller than the length L1 in the front-rear direction of the right first side 19Ra, and can be, for example, 0.100 mm to 0.400 mm.

  The thickness W4 in the vertical direction of the right first horizontal portion 15HRa can be substantially the same as the thickness W2 of the first antenna conductor 13a and the thickness W3 of the first connection conductor 11a. However, the thickness W4 may be different from the thickness W3 and the thickness W2.

  Here, the length L9 is the distance from the straight line α to the right end of the right first horizontal portion 15HRa, and the length L8 in the left-right direction of the right first horizontal portion 15HRa is from the length L9 to the length L2 / 2. It is the drawn length (L8 = L9−L2 / 2). The length L9 is approximately (1/4) λg × k (k is an integer of 1 or more). The length L9 can be set to, for example, 0.600 mm to 2 mm. Therefore, the length L10 in the left-right direction from the left end of the left first horizontal portion 15HLa to the right end of the right first horizontal portion 15HRa is 2 × L9 (L10 = 2 × L9).

  The length of the right first vertical portion 15VRa in the front-rear direction is substantially the same as the length L6 of the right first horizontal portion 15HRa in the front-rear direction. Further, the vertical length L7 of the right first vertical portion 15VRa is larger than the thickness W2 of the first antenna conductor 13a so that a gap can be formed between the first antenna conductor 13a and the ground conductor 16, It is larger than the thickness W4 in the vertical direction of the first horizontal portion 15HRa. The length L7 is preferably a length that can confine electromagnetic waves between the first antenna conductor 13a and the ground conductor 16. Specifically, the length L7 can be set to 0.080 mm to 0.250 mm, for example. On the other hand, the left-right length L11 of the right first vertical portion 15VRa shown in FIG. 3 is determined based on, for example, the strength that can support the first antenna conductor 13a and the right first horizontal portion 15HRa. Specifically, the length L11 can be set to 0.020 mm to 0.200 mm, for example.

(3-4) Ground conductor 16
The ground conductor 16 is opposed to the antenna conductors 13a to 13d, the connection conductors 11a to 11d, and the support portions 15a to 15d, and is formed from a single flat conductor larger than the overlapping area with the antenna conductors 13a to 13d. Yes. The thickness W1 in the vertical direction of the ground conductor 16 can be set to 0.012 mm to 1 mm, for example.

(3-5) Material and processing method of planar antenna 100 The antenna conductor 13, the ground conductor 16, the connection conductor 11, and the support portion 15 are formed of a conductor, such as gold, silver, copper, copper alloy, aluminum, and the like. A suitable material is selected from these metals. The antenna conductor 13, the connection conductor 11, and the support portion 15 can be integrally formed, for example, by punching or the like. In addition, the antenna conductor 13, the connection conductor 11, and the support portion 15 are obtained by forming a conductor integrally in a thin film on the base by plating, photoresist lithography, or the like, and then peeling the formed conductor from the base. May be. The ground conductor 16 may be formed similarly.

  Further, the antenna conductor 13, the connection conductor 11, the support portion 15, and the ground conductor 16 may be made of different materials. Furthermore, the support part 15 may be an insulating material instead of a conductor. When the support portion 15 is formed of an insulating material, even if the support portion 15 is provided on the antenna conductor 13, electromagnetic waves in the antenna conductor 13 are caused by the support portion 15 due to the difference in conductivity between the antenna conductor 13 and the support portion 15. It can suppress being affected.

(4) Power Converter Next, the configuration of the power converter 200 to which the planar antenna 100 is connected will be described. Hereinafter, configurations 1 and 2 will be described as examples of the power converter. That is, any one of configurations 1 and 2 can be used as the power converter, but power converters having other configurations can be used. However, the power converter 200 should just be able to convert electric power between the planar antenna 100 and the high frequency circuit 300, and is not limited to these structures. Hereinafter, the high-frequency circuit 300 connected to the power converter 200 is omitted. The high frequency circuit 300 is electrically connected to the power converter 200 by being mounted on the power converter 200 or connected to the power converter 200 via a wiring or the like, for example.

(4-1) Configuration 1
First, Configuration 1 of the power converter 200 will be described. FIG. 5 is a perspective view showing the configuration 1 in which the planar antenna 100 is connected to the power converter 200. FIG. 6 is a cross-sectional view taken along line α in FIG. 5 and 6, since the planar antenna 100 has the same configuration as that of the first embodiment, description thereof is omitted.

  As shown in FIGS. 5 and 6, the power converter 200 includes a plate-like first substrate unit 101, a plate-like second substrate unit 102 arranged to be opposed to the upper side of the first substrate unit 101, and these And a dielectric substrate 130 sandwiched between the substrate units 101 and 102.

  The first substrate unit 101 includes a rectangular first substrate 110. A first coupling surface 111, a first transmission pattern 112, and a first potential having a ground potential are formed on a first upper surface 110a of the first substrate 110. An upper surface ground 113 is disposed. The first transmission pattern 112 extends in the front-rear direction, and a high-frequency circuit 300 (not shown) can be connected to the first end 112a on the rear side. The first transmission pattern 112 is connected to the coupling element 111 at the second end 112b on the front side. On the other hand, on the first lower surface 110b of the first substrate 110, a first lower surface ground 114 having a ground potential is disposed almost entirely. The first substrate 110 is formed with a plurality of through holes 116 penetrating therethrough. The plurality of through holes 116 are arranged so as to surround the periphery of the coupling element 111 and the first transmission pattern 112.

  The second substrate unit 102 includes a second substrate 120, and a rectangular shield plate 127 and a second transmission pattern 128 are disposed on the second upper surface 120 a of the second substrate 120. A notch 127 a is formed at the front end of the shield plate 127, and the first end 128 a of the second transmission pattern 128 is inserted. The second transmission pattern 128 extends forward, and the second end portion 128 b is connected to the first connection conductor 11 a of the planar antenna 100. On the other hand, on the second lower surface 120b of the second substrate 120, a matching element 121 and a second transmission ground 123 having a ground potential and facing the second transmission pattern 128 are disposed. The matching element 121 and the coupling element 111 are opposed to each other with the dielectric substrate 130 interposed therebetween. In addition, a part of the first end portion 128 a of the second transmission pattern 128 faces the matching element 121.

  In the power converter 200 described above, an electromagnetic wave is input from the high-frequency circuit 300 to the first end 112a of the first transmission pattern 112. The input electromagnetic wave is transmitted to the second end 112b of the first transmission pattern 112 and is supplied to the coupling element 111 continuous thereto. Next, the coupling element 111 and the matching element 121 are electromagnetically coupled to each other via the dielectric substrate 130, and power conversion is performed between the coupling element 111 and the matching element 121. The electromagnetic wave that has passed through the matching element 121 is transmitted from the first end portion 128 a of the second transmission pattern 128 toward the second end portion 128 b and is supplied to the first connection conductor 11 a of the planar antenna 100. Note that the second transmission pattern 128 and the first connection conductor 11a may be integrally formed conductors. When an electromagnetic wave is supplied to the first connection conductor 11a, the electromagnetic wave is radiated from the antenna conductor 13 of the planar antenna 100. On the other hand, when the planar antenna 100 receives electromagnetic waves from the antenna conductor 13, the electromagnetic waves are transmitted to the high frequency circuit 300 through the power converter 200 in the reverse order as described above.

(4-2) Configuration 2
Next, configuration 2 of the power converter 200 to which the planar antenna 100 is connected will be described. FIG. 7 is an exploded perspective view showing the configuration 2 in which the planar antenna 100 is connected to the power converter 200. However, actually, each member shown in FIG. 7 has a laminated structure in contact. In FIG. 7, since the planar antenna 100 has the same configuration as that of the first embodiment, description thereof is omitted.

  As shown in FIG. 7, the power converter 200 includes a rectangular shield plate 141, a dielectric substrate 143 in contact with the lower surface of the shield plate 141, a ground substrate 145 in contact with the lower surface of the dielectric substrate 143, It has. Further, the power converter 200 includes a waveguide 149 disposed in contact with the lower portion of the ground substrate 145, a strip-shaped conductor pattern 165 disposed under the waveguide 149 and including the coupling element 160, It has. Specifically, the configuration is as follows.

  First, a notch 141a is formed at the front end of the shield plate 141, and the first connection conductor 11a of the planar antenna 100 is disposed in the notch 141a. A rectangular opening 146 is formed at a position corresponding to the notch 141 a of the shield plate 141 in the ground substrate 145 disposed below the dielectric substrate 143, and the matching element 147 is disposed in the opening 146. ing. The waveguide 149 disposed below the ground substrate 145 has a hollow portion 150 penetrating in the vertical direction. The upper opening of the hollow portion 150 coincides with the opening 146 of the ground substrate 145. So that they are aligned. Further, the coupling element 160 described above is disposed below the hollow portion 150. The coupling element 160 is connected to the second end 165 b of the conductor pattern 165 described above, and the first end 165 a of the conductor pattern 165 is connected to the high-frequency circuit 300.

  In the power converter 200 described above, an electromagnetic wave is input from the high-frequency circuit 300 to the first end 165a of the conductor pattern 165. The input electromagnetic wave is introduced into the hollow portion 150 of the waveguide 149 from the second end portion 165 b of the conductor pattern 165 through the coupling element 160. The electromagnetic wave transmitted through the hollow portion 150 is transmitted to the first connection conductor 11a through the matching element 147 and the dielectric substrate 143. When an electromagnetic wave is supplied to the first connection conductor 11a, the electromagnetic wave is radiated from the antenna conductor 13 of the planar antenna 100. On the other hand, when the planar antenna 100 receives electromagnetic waves from the antenna conductor 13, the electromagnetic waves are transmitted to the high frequency circuit 300 through the power converter 200 in the reverse order as described above.

(5) Other Antenna Devices In the above, the planar antenna 100 is connected to the power converter 200 as shown in FIGS. However, the planar antenna 100 may be connected to the high frequency circuit 300 without passing through the power converter 200. The planar antenna 100 may be connected to the high frequency circuit 300 via a cable such as the coaxial cable 400. FIG. 8 is a perspective view showing a configuration in which a coaxial cable is connected to the planar antenna. In FIG. 8, the first connection conductor 11 a of the planar antenna 100 is connected to the conductor in the coaxial cable 400. The coaxial cable 400 is connected to the high frequency circuit 300, and electromagnetic waves are transmitted and received between the planar antenna 100 and the high frequency circuit 300.

(6) Features (6-1)
In the planar antenna 100 of the first embodiment, a gap is formed between the antenna conductor 13 and the ground conductor 16, which serve as electromagnetic wave reflection walls, by the support portions 15 extending to the left and right. Therefore, air having a relative dielectric constant of about 1.0 is interposed between the antenna conductor 13 and the ground conductor 16. Since air has a relative permittivity smaller than that in the case where a dielectric material is interposed between the antenna conductor 13 and the ground conductor 16, it suppresses power loss of electromagnetic waves propagating between the antenna conductor 13 and the ground conductor 16. Can do.

  Moreover, since the support part 15 should just support the antenna conductor 13 with respect to the ground conductor 16, air can be interposed between the antenna conductor 13 and the ground conductor 16 by simple structure. Furthermore, since it is not necessary to support the antenna conductor 13 with a separate substrate, the planar antenna 100 can be reduced in size, weight, and cost.

(6-2)
In the planar antenna 100 of the first embodiment, the first support portion 15a is positioned on a straight line γ that passes through the center point β of the first antenna conductor 13a and extends in the left-right direction. Here, the electromagnetic wave in the first antenna conductor 13a is in a resonance state, and a node of a standing wave is located in the central portion in the resonance direction of the first antenna conductor 13a. The straight line γ extends corresponding to the position of the node of the standing wave. Therefore, on the straight line γ passing through the vicinity of the center of the first antenna conductor 13a, the electric field strength of the electromagnetic wave is smaller than in other areas other than the vicinity of the center. However, at the left first side 19La and the right first side 19Ra of the first antenna conductor 13a, the intensity of the electromagnetic wave tends to be larger than that at the center of the first antenna conductor 13a. This is considered to be due to the fact that the first antenna conductor 13a is in contact with air on the first side 19a, whereby the effective dielectric constant of the first antenna conductor 13a changes, and this change makes it easier for electromagnetic waves to concentrate.

  Therefore, in the planar antenna 100 described above, first, the right first horizontal portion 15HRa of the right first support portion 15Ra starts from the first first side 19Ra near the center in the resonance direction of the first antenna conductor 13a as the first antenna. It is formed to extend in the left-right direction on the plane of the conductor 13a. That is, in the first support portion 15a, the right first horizontal portion 15HRa extends along the plane of the first antenna conductor 13a so as to be away from the right first side 19Ra of the first antenna conductor 13a having a high electromagnetic wave strength. Yes. Thereby, it can suppress that electromagnetic waves with a large electric field strength concentrate in the right 1st horizontal part 15HRa. The right first vertical portion 15VRa is formed to extend from the end of the right first horizontal portion 15HRa toward the ground conductor 16. The left first support portion 15La is symmetrical to the right first support portion 15Ra. Thereby, the influence on the electromagnetic wave in the 1st antenna conductor 13a which arises by providing the 1st support part 15a can be suppressed, and antenna loss can be suppressed. Although the first antenna conductor 13a has been described above, the same can be said for the other antenna conductors 13b to 13d.

(6-3)
In the first antenna conductor 13a of the first embodiment, the left first support portion 15La and the right first support portion 15Ra are symmetrical with respect to the straight line α. Therefore, the effects of the left first support portion 15La and the right first support portion 15Ra facing each other on the electromagnetic waves in the first antenna conductor 13a are symmetric. Thereby, the resonance state of the electromagnetic wave in the first antenna conductor 13a can be maintained symmetrically with respect to the vicinity of the center. Therefore, antenna loss due to non-uniform resonance can be suppressed. Although the first antenna conductor 13a has been described above, the same can be said for the other antenna conductors 13b to 13d.

(7) Modification Examples of the planar antenna 100 according to the first embodiment will be described below. Note that modifications similar to those in the following second and third embodiments will be described later as common modifications.
(7-1)
In the first embodiment, in the support portion 15 (15a to 15d), the left support portion 15L (15La to 15Ld) and the right support portion 15R (15Ra to 15Rd) extend linearly along the left-right direction. However, the left support portion 15L and the right support portion 15R may be curved or bent.

(7-2)
It is only necessary that the support portion 15 has at least a connection portion with the antenna conductor 13 on the straight line γ, and the entire support portion 15 does not necessarily have to be positioned on the straight line γ.
(7-3)
In the first embodiment, the left support portion 15L (15La to 15Ld) and the right support portion 15R (15Ra to 15Rd) are symmetric with respect to the straight line α. However, at least the connection portion between the left support portion 15L and the antenna conductor 13 and the connection portion between the right support portion 15R and the antenna conductor 13 may be symmetrical. Such an example will be described with reference to FIG. FIG. 9 is a plan view showing the positional relationship of the left support portion 15L and the right support portion 15R with respect to the antenna conductor 13. As shown in FIG. In FIG. 9, the connection portion between the left support portion 15L and the antenna conductor 13 and the connection portion between the right support portion 15R and the antenna conductor 13 are symmetrical with respect to the straight line α. However, the left support portion 15L and the right support portion 15R are arranged in reverse symmetry. Since at least the connection portion between the support portion 15 and the antenna conductor 13 is bilaterally symmetric, it is possible to suppress antenna loss due to non-uniform resonance of the electromagnetic wave in the antenna conductor 13. Furthermore, as long as the resonance state of the electromagnetic wave in the antenna conductor 13 does not become uneven, the connecting portion between the support portion 15 and the antenna conductor 13 does not have to be completely symmetrical.

  Further, for example, the left support portion 15L and the right support portion 15R may be arranged asymmetrically with respect to the straight line α as shown in FIG. 10, for example. FIG. 10 is a plan view showing the positional relationship between the left support portion 15L and the right support portion 15R with respect to the antenna conductor 13. As shown in FIG. Similarly to FIG. 9, the connection portion between the left support portion 15L and the antenna conductor 13 and the connection portion between the right support portion 15R and the antenna conductor 13 are symmetrical with respect to the straight line α. However, unlike FIG. 9, the left support portion 15L and the right support portion 15R are arranged asymmetrically. Furthermore, in the said embodiment, although the right horizontal part 15HR (15HRa-15HRd) and the left horizontal part 15HL (15HLa-15HLd) are the same length, you may differ. However, when these lengths are the same on the left and right, the resonance state of the electromagnetic wave in the antenna conductor 13 is preferably substantially uniform.

(7-4)
In the first embodiment, the connection conductor 11 is a rectangular parallelepiped rod-shaped member. However, the shape of the connection conductor 11 is not limited as long as it is a member that connects the antenna conductor 13, and may be, for example, a cylindrical rod-shaped member. However, when the antenna conductor 13 and the connection conductor 11 are integrally formed by punching or the like, the connection conductor 11 is preferably a rectangular parallelepiped rod-like member for ease of processing.

(7-5)
In the first embodiment, the right vertical portion 15VR (15VRa to 15VRd) is a plate-like member extending in the vertical direction. However, the shape of the right vertical portion 15VR is not limited as long as it can support the antenna conductor 13 via the right horizontal portion 15HR (15HRa to 15HRd). For example, the right vertical portion 15VR may be a rod-shaped member such as a rod shape or a cylindrical shape. However, when the right vertical portion 15VR is bent with respect to the right horizontal portion 15HR, the right vertical portion 15VR is preferably a plate-like member for ease of processing.

<2. Second Embodiment>
Next, a planar antenna according to a second embodiment of the present invention and an antenna apparatus including the same will be described with reference to the drawings. The second embodiment differs from the first embodiment in the configuration of the support portion, and the other configurations are substantially the same as those in the first embodiment, and therefore the same components are denoted by the same reference numerals and description thereof is omitted. . FIG. 11 is a perspective view of an antenna device including a planar antenna according to the second embodiment. FIG. 12 is an enlarged view of a region including the first antenna conductor and the second antenna conductor in the planar antenna of FIG. 13 is a cross-sectional view taken along line AA in FIG.

(1) Configuration of Support Part Hereinafter, the support parts 151 that support the first to fourth antenna conductors 13a to 13d are referred to as first to fourth support parts 151a to 151d, respectively. As shown in FIGS. 11 to 13, the support portion 151 of the second embodiment is formed in a rod shape extending downward from the lower surface of the antenna conductor 13, and the lower end of the support portion 151 is connected to the ground conductor 16. . As a result, a gap is formed between the antenna conductor 13 and the ground conductor 16. For example, the first support portion 151a that supports the first antenna conductor 13a is formed in a quadrangular prism shape. As shown in FIG. 12 and the like, the first support portion 151a is arranged so that the center point β that is the center of the first antenna conductor 13a in the front-rear direction and the left-right direction coincides with the center of the first support portion 151a. Has been.

  Here, the reason why the first support portion 151a is disposed at the center point β will be described below. FIG. 14 is an analysis diagram showing the electric field strength distribution when the planar antenna is viewed in plan. In FIG. 14, for example, an electromagnetic wave having a power of 1 W and 76 GHz is supplied from the first connection conductor 11a. The electric field strength distribution in FIG. 14 is substantially the same as the electric field strength distribution in FIG. 4 of the first embodiment. That is, in FIG. 14, since the node of the standing wave of the electromagnetic wave in the first antenna conductor 13a is located in the region V, the electric field strength in the region V including the straight line γ is small. However, referring to FIG. 4 and FIG. 14, the electric field strength is also large at the left first side 19La and the right first side 19Ra. This is because, on the left first side 19La and the right first side 19Ra, the effective dielectric constant of the first antenna conductor 13a changes due to the first antenna conductor 13a being in contact with air, and electromagnetic waves are likely to concentrate due to this change. It is thought that.

  Therefore, in the region V where the electric field strength is low, the support portion 151 is disposed at the center point β away from the left first side 19La and the right first side 19Ra where the electric field strength is high. Thereby, the influence on the electromagnetic wave which propagates between the 1st antenna conductor 13a and the ground conductor 16 which arises by providing the 1st support part 151a can be suppressed, and antenna loss can be suppressed.

  The length L61 in the front-rear direction and the length L62 in the left-right direction of the first support portion 151a are not particularly limited as long as the antenna conductor 13a can be supported. However, the smaller the length L61 and the length L62, the smaller the influence of the first support 151a on the electromagnetic wave in the first antenna conductor 13a. For example, the length L61 is preferably sufficiently smaller than the length L1 in the front-rear direction of the first antenna conductor 13a, and can be, for example, 0.100 mm to 0.400 mm. For example, the length L62 is preferably sufficiently smaller than the length L2 in the left-right direction of the first antenna conductor 13a, and can be, for example, 0.100 mm to 0.400 mm.

  The length L71 of the first support portion 151a is not particularly limited, but is preferably a length that can confine electromagnetic waves between the first antenna conductor 13a and the ground conductor 16, for example. Specifically, the length L71 can be set to 0.080 mm to 0.250 mm, for example.

  The other second to fourth antenna conductors 13b to 13d have the same configuration and are supported with respect to the ground conductor 16 by the second to fourth support portions 151b to 151d.

(2) Features (2-1)
In the planar antenna 180 of the second embodiment, a rod-shaped support 151 is disposed between the antenna conductor 13 and the ground conductor 16 that serve as electromagnetic wave reflection walls. Therefore, air having a relative dielectric constant of about 1.0 is interposed between the antenna conductor 13 and the ground conductor 16. Since air has a relative dielectric constant smaller than that of the dielectric material, it is possible to suppress power loss of electromagnetic waves propagating between the antenna conductor 13 and the ground conductor 16.

  Further, air can be interposed between the antenna conductor 13 and the ground conductor 16 with a simple configuration in which the antenna conductor 13 is supported by the support portion 151. Furthermore, since it is not necessary to support the antenna conductor 13 with a separate substrate, the planar antenna 180 can be reduced in size, weight, and cost.

(2-2)
In the planar antenna 180 of the second embodiment, the first support portion 151a is located at the center point β of the first antenna conductor 13a. Since the center point β is far from the first side 19a of the first antenna conductor 13a where the node of the standing wave is located and the electric field strength is large, the electric field strength of the electromagnetic wave is larger than that in other regions other than the vicinity of the center. small. Therefore, by providing the first support portion 151a at the above-described position, it is possible to suppress the influence on the electromagnetic wave in the first antenna conductor 13a caused by providing the first support portion 15a, and to suppress the antenna loss. Although the first antenna conductor 13a has been described above, the same can be said for the other antenna conductors 13b to 13d.

(2-3)
Since the support portion 151 supports the center point β of the antenna conductor 13, the antenna conductor 13 can be stably supported with good balance.

(3) Modified Examples Hereinafter, modified examples of the planar antenna 180 of the second embodiment will be described. A modification similar to that of the first and third embodiments will be described later as a common modification.
(3-1)
In the second embodiment, the support portion 151 is disposed at the center point β. However, it may be arranged at any position on a straight line γ that passes through the center point β and extends in the left-right direction. Further, for example, the arrangement position of the support portion 151 on the straight line γ may be different depending on the antenna conductors 13a to 13d.

(3-2)
In the second embodiment, only one support portion 151 is provided for one antenna conductor 13. However, a plurality of support portions 151 may be provided for one antenna conductor 13. For example, support portions 151 may be provided at a plurality of locations on the straight line γ. In addition, it is sufficient that the four antenna conductors 13a to 13d are supported as a whole with respect to the ground conductor 16, and it is not necessary to provide the support portions 151 for all the antenna conductors 13. For example, the support 151 may be provided on any of the adjacent antenna conductors 13.

(3-3)
In the second embodiment, the support portion 151 has a quadrangular prism shape, but the shape of the support portion 151 is not limited as long as it can support the antenna conductor 13. For example, the support part 151 may be cylindrical, elliptical, polygonal, or the like.

<3. Third Embodiment>
Next, a planar antenna and an antenna apparatus including the same according to a third embodiment of the present invention will be described with reference to the drawings. The third embodiment is different from the first embodiment in the configuration of the support portion, and the other configurations are almost the same as those in the first embodiment. Therefore, the same reference numerals are given to the same configurations as those in the first embodiment. FIG. 15 is a perspective view of an antenna device including a planar antenna according to the third embodiment. FIG. 16 is an enlarged view of a region including the first antenna conductor and the second antenna conductor in the planar antenna of FIG. 17 is a cross-sectional view taken along line AA in FIG.

(1) Configuration of Support Part Hereinafter, the support parts 152 that support the first to fourth antenna conductors 13a to 13d are referred to as first to fourth support parts 152a to 152d, respectively. As shown in FIGS. 15-17, the support part 15 of 3rd Embodiment is the left support part 15L which has the left horizontal part 15HL and the left vertical part 15VL, and the right support which has the right horizontal part 15HR and the right vertical part 15VR. And 15R. However, the support portion 152 of the third embodiment is formed so as to extend from the side facing the left and right sides of the antenna conductor 13 to the ground conductor 16, so that there is a gap between the antenna conductor 13 and the ground conductor 16. It is formed.

  For example, the first antenna conductor 13a is supported with respect to the ground conductor 16 by a first support portion 152a including a flat left first support portion 152La and a right first support portion 152Ra. The left first support portion 152La is connected to the central portion where the left first side 19La of the first antenna conductor 13a intersects the straight line γ, and extends toward the ground conductor 16. Similarly, the right first support portion 152Ra is connected to the central portion where the right first side 19Ra and the straight line γ intersect and extends toward the ground conductor 16. A connection portion between the left first support portion 152La and the left first side 19La and a connection portion between the right first support portion 152Ra and the right first side 19Ra are symmetrical with respect to the straight line α.

  Here, the reason why the left first support portion 152La is connected to the center of the left first side 19La and the right first support portion 152Ra is connected to the center of the right first side 19Ra will be described below. FIG. 18 is an analysis diagram showing the electric field strength distribution when the planar antenna is viewed in plan. In FIG. 18, for example, an electromagnetic wave with a power of 1 W and 76 GHz is supplied from the first connection conductor 11a. The electric field strength distribution in FIG. 18 is substantially the same as the electric field strength distribution in FIG. 4 of the first embodiment. That is, in FIG. 18, since the node of the standing wave of the electromagnetic wave in the first antenna conductor 13a is located in the region V, the electric field strength in the region V including the straight line γ is small. Therefore, by providing the left first support portion 152La and the right first support portion 152Ra in the portion of the left first side 19La and the right first side 19Ra that intersect the straight line γ, by providing the first support portion 152a The effect on the electromagnetic wave which propagates between the 1st antenna conductor 13a and the ground conductor 16 which arises can be suppressed, and antenna loss can be suppressed.

  The length L65 in the front-rear direction and the length L66 in the left-right direction of the first support portion 152a are not particularly limited as long as the antenna conductor 13a can be supported. However, the smaller the length L65 and the length L66, the smaller the influence of the first support 152a on the electromagnetic wave in the first antenna conductor 13a. For example, the length L65 is preferably sufficiently smaller than the length L1 of the first antenna conductor 13a in the front-rear direction, and can be, for example, 0.100 mm to 0.400 mm. Further, the length L66 can be set to 0.020 mm to 0.200 mm, for example.

  The length L72 of the first support 152a is not particularly limited, but is preferably a length that can confine electromagnetic waves between the first antenna conductor 13a and the ground conductor 16, for example. Specifically, the length L72 can be set to 0.080 mm to 0.250 mm, for example.

The other second to fourth antenna conductors 13b to 13d have the same configuration and are supported with respect to the ground conductor 16 by the second to fourth support portions 151b to 151d.
(2) Features (2-1)
In the third embodiment, similarly to the second embodiment, a support portion 152 extending vertically is disposed between the antenna conductor 13 and the ground conductor 16. Therefore, since air having a relative dielectric constant of about 1.0 is interposed between the antenna conductor 13 and the ground conductor 16, power loss of electromagnetic waves propagating between the antenna conductor 13 and the ground conductor 16 is suppressed. be able to.

  As in the second embodiment, the planar antenna 190 can be reduced in size, weight, and cost by a simple configuration.

(2-2)
In the planar antenna 190 of the third embodiment, the support portion 152 is located at the intersection of the first side 19 of the antenna conductor 13 and the straight line γ. The straight line γ extends corresponding to the position of the node of the standing wave, and the electric field strength of the electromagnetic wave is smaller on the straight line γ than in other regions other than the vicinity of the center. Therefore, the influence on the electromagnetic wave in the antenna conductor 13 caused by providing the support portion 15 at the above-described position can be suppressed, and the antenna loss can be suppressed.

(2-3)
In the first antenna conductor 13a of the third embodiment, the left first support portion 152La and the right first support portion 152Ra are bilaterally symmetric with respect to the straight line α. Therefore, similarly to the case described in the first embodiment, it is possible to suppress the antenna loss due to the non-uniform resonance state of the electromagnetic wave in the first antenna conductor 13a. Although the first antenna conductor 13a has been described above, the same can be said for the other antenna conductors 13b to 13d.

(2-4)
Since each support portion 15 supports the vicinity of the center of the first side 19 of the antenna conductor 13 so as to face each other, the antenna conductor 13 can be stably supported in a balanced manner.

(3) Modified Examples Hereinafter, modified examples of the planar antenna 190 according to the third embodiment will be described. A modification similar to the first and second embodiments will be described later as a common modification.

(3-1)
In the third embodiment, the left first support portion 152La and the right first support portion 152Ra are symmetrical with respect to the straight line α. However, the left first support portion 152La and the right first support portion 152Ra do not have to be completely symmetrical with respect to the straight line α as long as the resonance state of the electromagnetic wave in the antenna conductor 13 is not uneven. .

(3-2)
In the third embodiment, the support portion 152 has a flat plate shape, but the shape is not limited as long as the antenna conductor 13 can be supported. For example, the support portion 152 may have a quadrangular prism shape, a cylindrical shape, an elliptical shape, a polygonal shape, or the like.

<4. Modification>
The first to third embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications as described below are possible without departing from the spirit of the present invention. . The gist of the following modifications can be combined as appropriate. In addition, although the modified example peculiar to each embodiment was described in each embodiment, here, a modified example common to the first to third embodiments will be described.

<4-1>
In the first to third embodiments, the support portions 15, 151, and 152 are located on the straight line γ, but are not necessarily located on the straight line γ. For example, the support portions 15, 151, and 152 may be located near the center of the antenna conductor 13 where the standing wave node formed by the electromagnetic wave is located. The “near the center” may be a region having a low electric field strength in the antenna conductor 13 and includes not only the center point β of the antenna conductor 13 but also the center point β and its vicinity. Furthermore, the support portions 15, 151, and 152 do not necessarily need to be positioned near the center of the antenna conductor 13 as long as the support portions 15, 151, and 152 are positioned on a straight line extending in the left-right direction through the node of the standing wave of the electromagnetic wave in the antenna conductor 13. .

<4-2>
In the above embodiment, the antenna conductor 13 is supported by the support portion 15 so as to have a gap between the antenna conductor 13 and the ground conductor 16. However, the antenna conductor 13 may be supported by the connection conductor 11. In this case, a support portion is provided in a region of the connection conductor 11 where the electric field strength is low. The area | region with a small electric field strength among the connection conductors 11 is area | region VI shown in FIG.4, FIG14 and FIG.18. The region VI is located in the central portion of the connection conductor 11 having a length L5 in the front-rear direction of 1 / 2λg. A configuration in which support portions 153 (153a to 153d), 154 (154a to 154d), and 155 (155a to 155d) are provided in the region VI is shown in FIGS. FIG. 19 is a perspective view of the antenna device when the support portion of the first embodiment is provided on a connection conductor. FIG. 20 is a perspective view of the antenna device when the support portion of the second embodiment is provided on the connection conductor. FIG. 21 is a perspective view of the antenna device when the support portion of the third embodiment is provided on the connection conductor.

  Thus, by providing the support portion 153 (FIG. 19), the support portion 154 (FIG. 20), and the support portion 155 (FIG. 21) in the region VI of the connection conductor 11, the support portions 153, 154, and 155 are connected to the connection conductor 11. Can suppress the influence on the electromagnetic wave. As a result, the influence which the connection conductor 11 has on the electromagnetic wave in the antenna conductor 13 can be suppressed, and the antenna loss can be suppressed. Moreover, since the support part 15 is not provided in the antenna conductor 13, it can further suppress that the electromagnetic wave in the antenna conductor 13 is influenced and antenna loss arises. Note that it is only necessary that the antenna conductor 13 can be supported by the support portions 153, 154, and 155, and it is not necessary to provide the support portions 15 in all the connection conductors 11 (11a to 11d).

<4-3>
In the above embodiment, the length L1 of the antenna conductor 13 in the front-rear direction is λg / 2. However, it is sufficient that the electromagnetic wave is in a resonance state in the front-rear direction of the antenna conductor 13, and the length L1 is not limited to λg / 2. For example, the length L1 of the antenna conductor 13 in the front-rear direction may be (λg / 2) × l (l is an integer of 2 or more). Similarly, in the above embodiment, the length L5 of the connecting conductor 11 in the front-rear direction is λg / 2. However, as described above, the length L5 is not limited to λg / 2, and may be (λg / 2) × m (m is an integer of 2 or more).

<4-4>
In the above embodiment, the antenna conductor 13 has a rectangular shape, but may have a rectangular shape such as a square shape or a trapezoidal shape other than the rectangular shape shown in FIGS. The antenna conductor 13 preferably has a pair of sides facing each other in the resonance direction that are parallel to each other. In addition, the antenna conductor 13 may have a shape including a polygonal shape and an arc rather than a quadrangle as long as a pair of sides facing each other in the resonance direction are parallel to each other.

<4-5>
In the above embodiment, the ground conductor 16 is illustrated as the opposing conductor that faces the antenna conductor 13. However, the opposing conductor does not need to be grounded, and may be a conductor having a predetermined potential, for example. However, it is preferable to use a grounded ground conductor 16 because the electric field of electromagnetic waves can be stabilized.

<4-6>
In the above embodiment, the planar antenna 100 includes the four antenna conductors 13. However, the number of antenna conductors 13 is not limited to this, and may be one or five or more. Similarly, the number of connection conductors 11 is not limited to four, and may be one or five or more.

<4-7>
In the above embodiment, the support portions 15, 151, and 152 are provided on all the antenna conductors 13. However, if a gap can be provided between the antenna conductor 13 and the ground conductor 16, it is not necessary to provide the support portions 15, 151, 152 on all the antenna conductors 13, and the number of the support portions 15, 151, 152 is not limited. Is not limited.

<4-8>
In the above embodiment, an example in which the plurality of antenna conductors 13 are arranged in one row has been described. However, a plurality of antenna conductors may be arranged in a plurality of rows. Such an example will be described with reference to FIGS. 24A to 24C are explanatory diagrams when a plurality of antenna conductors are arranged in a plurality of rows.

  The planar antenna 1011 shown in FIG. 24A includes three rows of sets 900a to 900c (900). The set 900 in one row includes four antenna conductors 13, four connection conductors 11, and four sets of left support 15L (15HL and 15VL) and right support 15R (15HR and 15VR) along the front-rear direction. Is disposed with respect to the ground conductor 16. Each antenna conductor 13 is supported by support portions 15 provided on the left and right. The support portions 15 of the antenna conductors 13 adjacent in the left-right direction are connected to each other. For example, the antenna conductor 13 of the set 900a is supported by the left horizontal portion 15HL and the right horizontal portion HR, and the left vertical portion 15VL and the right vertical portion 15VR. The right horizontal portion 15HR of the antenna conductor 13 of the set 900a and the left horizontal portion 15HL of the antenna conductor 13 of the set 900b are connected to each other.

  In the planar antenna 1012 shown in FIG. 24B, unlike the planar antenna 1011 shown in FIG. 24A, the support portions 15 (15HL, 15HR, 15VL, 15VR) of the antenna conductors 13 adjacent to the left and right are not connected to each other. Other configurations are the same as those of the planar antenna 1011.

  In the planar antenna 1013 shown in FIG. 24C, unlike the planar antenna 1011 shown in FIG. 24A, only the antenna conductor 13 in the left end set 900a and the right end set 900c in the left-right direction has the left vertical portion 15VL and the right vertical portion, respectively. 15VR. The left and right antenna conductors 13 are connected to the left horizontal portion 15HL and the right horizontal portion HR. No vertical portion is provided between the antenna conductors 13 adjacent to the left and right. Other configurations are the same as those of the planar antenna 1011.

<4-9>
In the antenna device, the planar antennas 100, 180, and 190 of the first to third embodiments may be combined.

  Examples of the present invention will be described below. However, the present invention is not limited to the following examples. And (1) electric field strength distribution and directivity were acquired by simulation. In addition, (2) the length L9 was evaluated. Below, (1) Evaluation about electric field intensity distribution and directivity is demonstrated first.

(1) Evaluation of electric field intensity distribution and directivity (1-1) Planar antenna and ideal planar antenna of Examples 1-1 to 1-3 (a) Configuration As a planar antenna of Examples 1-1 to 1-3 , Antennas having the same configuration as the planar antennas 100, 180, and 190 of the first to third embodiments described above were prepared. For comparison with these examples, an ideal planar antenna called an ideal planar antenna was prepared. This ideal planar antenna is shown in FIGS. FIG. 25 is a perspective view of an antenna device including an ideal planar antenna. FIG. 26 is an enlarged view of a region including the first antenna conductor and the second antenna conductor in the ideal planar antenna of FIG. 27 is a cross-sectional view taken along line AA in FIG.

  As shown in FIGS. 25 to 27, the ideal planar antenna 195 is a component of the antenna device 4000, and does not include the support portion 15 in the planar antenna 100 of the first embodiment. That is, the antenna conductor 13 and the connection conductor 11 are opposed to the ground conductor 16 via air without the support portion 15 being interposed. In addition, since it is thought that the structure which does not provide the support part 15 has the least influence on the electromagnetic waves in the antenna conductor 13, it is called an ideal planar antenna. Since other configurations are the same as those of the planar antenna 100 of the first embodiment, the description thereof is omitted.

In the planar antenna and the ideal planar antenna 195 of Examples 1-1 to 1-3, each dimension related to each antenna conductor 13 is as shown in Table 1 below.

  Subsequently, from the first connection conductor 11 to the planar antennas of Examples 1-1 to 1-3 (corresponding to the planar antennas 100, 180, and 190 of the first to third embodiments) and the ideal planar antenna 195, respectively. An electromagnetic wave having a power of 1 W and a frequency of 76 GHz was supplied. The electric field strength distribution and directivity in each planar antenna are as follows.

(B) Electric field strength distribution FIGS. 4, 14, and 18 are electric field strength distributions of the planar antennas of Examples 1-1 to 1-3, respectively. FIG. 28 shows the electric field intensity distribution of the ideal planar antenna 195. Examples 1-1 to 1-3 have already been described with reference to FIGS. 4, 14, and 18. Similar to these examples, the ideal planar antenna 195 has a standing wave as shown in FIG. 28. In the region V where the node is located, the electric field strength was the smallest. On the other hand, in each planar antenna, the electric field strength was highest in the regions I to IV where the antinodes of the standing waves were located.

(C) Directivity FIGS. 29 to 31 show the directivity (gain distribution for each angle) of the planar antennas of Examples 1-1 to 1-3. FIG. 32 shows the directivity of an ideal planar antenna. In each of FIG. 29 to FIG. 32, the solid lines indicate the directivity in the front-rear direction and the directivity in the left-right direction in the antenna conductor 13. The directivity in the front-rear direction is, for example, a gain in the front-rear direction when the antenna conductor 13 is viewed from the side in the left-right direction in FIG. On the other hand, the gain in the left-right direction is, for example, the gain in the left-right direction when the antenna conductor 13 is viewed from the front-rear direction in FIG.

  Specifically, in the solid line, in a plane passing through the straight line α and perpendicular to the antenna conductor, the center point β is set to 0 °, and the gain is obtained up to + 90 ° from the front side as a plus, and the rear side from the center point β is minus. The gain is acquired up to -90 °. On the other hand, in the broken line, on the plane perpendicular to the antenna conductor 13 through the straight line γ, the center point β is set to 0 °, and the gain is acquired up to + 90 ° with the left side as a plus, and the right side from the center point β is minus −90. Gain gain up to °.

29 to 32, the peak gains of the planar antennas and the ideal planar antennas 195 of Examples 1-1 to 1-3 were as shown in Table 2 below.

(1-2) Comparative Example 1
(A) Configuration As a comparative example, the planar antenna 5000 of the comparative example 1 has the configuration of FIG. FIG. 33 is a perspective view of an antenna device including the planar antenna of Comparative Example 1. 34 is a cross-sectional view taken along line AA in FIG. In the planar antenna 5000 of Comparative Example 1, in the planar antenna 100 of the first embodiment, the antenna conductor 13 and the connection conductor 11 are opposed to the ground conductor 16 via a dielectric. Therefore, the planar antenna 5000 of Comparative Example 1 does not include a support portion. Since other configurations are the same as those of the planar antennas 100, 180, and 190 of the first to third embodiments, the description thereof is omitted.

  Similarly to Examples 1-1 to 1-3, an electromagnetic wave having a power of 1 W and a frequency of 76 GHz was supplied from the first connection conductor 11 to the planar antenna 5000 of Comparative Example 1. The electric field strength distribution and directivity in the planar antenna 5000 of Comparative Example 1 are as follows.

(B) Electric field strength distribution FIG. 35 is an electric field strength distribution in the planar antenna 5000 of the first comparative example. Also in the flat antenna 5000 of Comparative Example 1, the electric field strength was the smallest in the region V which is the central portion of the antenna conductor 13, and the electric field strength was the largest in the regions I to IV.

(C) Directivity Directivity was obtained for the planar antenna 5000 of Comparative Example 1. FIG. 36 shows the directivity of the planar antenna 5000 of the first comparative example. As shown in FIG. 36, in the planar antenna 5000 of Comparative Example 1, the peak gain was 10.9 dB.

(1-3) Consideration The following points were found from the electric field intensity distribution and directivity. In each of Examples 1-1 to 1-3 (corresponding to the planar antennas 100, 180, and 190 of the first to third embodiments), as shown in FIGS. The support portions 15, 151, 152 are arranged in the vicinity of the center including the straight line γ. The region V is a region where the electric field strength is weak as described above. In this case, as described above, in Examples 1-1 to 1-3, the peak gain is higher than 10.9 dB of Comparative Example 1. In particular, in Example 1-1 (planar antenna 100 of the first embodiment), a peak gain comparable to that of the ideal planar antenna 195 shown in FIG. 32 can be secured. In Example 1-2 (planar antenna 180 of the second embodiment), the peak gain of the same level can be ensured although it is lower than the ideal planar antenna 195. Also in Example 1-3 (planar antenna 190 of the third embodiment), a planar antenna having a peak gain that is higher than the peak gain of Comparative Example 1 and somewhat high can be obtained. Therefore, in Examples 1-1 to 1-3, the influence on the electromagnetic wave propagating between the antenna conductor 13 and the ground conductor 16 caused by providing the support portions 15, 151, and 152 is suppressed. As a result, it can be seen that the antenna loss can be suppressed.

(2) Evaluation about length L9 Next, the optimal value of length L9 relevant to the length of the support part 15 was evaluated using Examples 2-1 and 2-2. The length L9 is a distance from the straight line α passing through the center point β of the antenna conductor 13 to the right end of the right horizontal portion 15HR (15HRa to 15HRd) as shown in FIG. 3 of the first embodiment, or The distance from the straight line α to the left end of the left horizontal portion 15HL (15HLa to 15HLd). Hereinafter, this point will be described with reference to FIGS. 37A and 37B. FIGS. 37A and 37B are explanatory diagrams showing electric field intensity distributions of the planar antennas 1001 and 1002 of Examples 2-1 and 2-2 shown below, respectively. In FIG. 37A and FIG. 37B, the electric field strength distribution in the cross section of the portion where the support portion 15 is provided in each of the planar antennas 1001 and 1002 is shown.

(2-1) Examples 2-1 and 2-2
(A) Configuration As shown in FIGS. 37A and 37B, the planar antennas 1001 and 1002 of Examples 2-1 and 2-2 of the present invention are the same as the length L9 in the planar antenna 100 of the first embodiment. L10 is as shown in Table 3 below. Since other configurations are the same as those of the planar antenna 100 of the first embodiment, description thereof is omitted.

  An electromagnetic wave having a power of 1 W and 76 GHz was supplied from the first connection conductor 11 to the planar antennas 1001 and 1002 of Examples 2-1 and 2-2. The electric field strength distribution and directivity in the planar antennas 1001 and 1002 of Examples 2-1 and 2-2 are as follows.

(B) Electric field strength distribution As shown in FIG. 37A, in the planar antenna 1001 of Example 2-1, the entire region VII from the right end portion to the left end portion of the support portion 15 (15L, 15R) has one electric field strength. It is a weak area.

  Further, in the planar antenna 1002 of Example 2-2, as shown in FIG. 37B, the region from the right end portion to the left end portion of the support portion 15 (15L, 15R) includes two regions VIII and Region VX. A region VIII is a region where the antenna conductor 13 is located. In each of the two regions VX, the right support portion 15R and the left support portion 15L are located. The lengths of the region VIII and the two regions VX in the left-right direction are substantially the same. That is, the length L102 in the left-right direction of the region VIII and the length L101 in the left-right direction of the two regions VX are substantially the same. The region VIII and the two regions VX are regions where the electric field strength is weak.

(C) Directivity The planar gain of the planar antenna 1001 of Example 2-1 was about 12.5 dB. Similarly, the planar gain of the planar antenna 1002 of Example 2-2 was about 12.5 dB.

(2-2) Consideration As shown in FIGS. 37A and 37B, in the planar antennas 1001 and 1002 of Examples 2-1 and 2-2, L10 is λg × 1/2 (about 1.8 mm) and λg ×, respectively. 3/2 (about 5.6 mm), and L10 = λg × (n / 2) (n is an odd number of 1 or more). Furthermore, in the planar antennas 1001 and 1002 of Examples 2-1 and 2-2, L9 is λg × 1/4 (about 0.9 mm) and λg × 3/4 (about 2.8 mm), respectively. = Λg × (o / 4) (o is an odd number of 1 or more). In this case, as shown in FIG. 33, regions VII, VIII, and VX from the right end portion to the left end portion of the support portion 15 have low electric field strength. The peak gains of the planar antennas 1001 and 1002 of Examples 2-1 and 2-2 were both excellent at about 12.5 dB. That is, it was found that the influence on the electromagnetic wave propagating between the antenna conductor 13 and the ground conductor 16 caused by providing the support portion 15 is suppressed. Therefore, the length L10 is preferably λg × (n / 2) (n is an odd number of 1 or more), and the length L9 is λg × (o / 4) (o is an odd number of 1 or more). I found it preferable.

11a to 11d: Connection conductors 13a to 13d: Antenna conductors 15a to 15d: Support portion 15HL: Left horizontal portion 15HR: Right horizontal portion 15VL: Left vertical portion 15VR: Right vertical portion 16: Ground conductor 100: Planar antenna 180: Planar antenna 190: Planar antenna 195: Ideal planar antenna 200: Power converter 300: High frequency circuit

Claims (14)

At least one antenna conductor that transmits and receives electromagnetic waves and constitutes a reflection wall of the electromagnetic waves;
Opposing conductor that faces the antenna conductor and constitutes a reflection wall of the electromagnetic wave,
At least one support that forms a gap between the at least one antenna conductor and the opposing conductor;
A planar antenna comprising:   2. The at least one support portion is provided on a straight line that passes in the vicinity of the center of the antenna conductor and extends in an orthogonal direction orthogonal to the resonance direction of the electromagnetic wave in a plan view of the planar antenna. Flat antenna.   3. The planar antenna according to claim 2, wherein, in a plan view of the planar antenna, the at least one support portion is disposed in a region excluding a side of an outer peripheral edge of the antenna conductor in a vicinity of a center of the antenna conductor. . In plan view, the antenna conductor includes a pair of first sides that extend along the resonance direction and face each other,
The planar antenna according to claim 2, wherein the support portion is provided in the vicinity of the center of each of the pair of first sides and extends toward the opposing conductor. In plan view, the antenna conductor includes a pair of first sides that extend along the resonance direction and face each other,
The support portion is connected to each of the set of first sides,
Each of the support portions includes a horizontal portion starting from the vicinity of the center of the first side and extending toward the end away from the antenna conductor along the planar direction of the antenna conductor, and the opposing conductor from the end of the horizontal portion The planar antenna according to claim 2, further comprising a vertical portion extending toward.   6. The plan view, wherein each of the pair of first sides and a connecting portion of each support portion is symmetrical with respect to a straight line passing through the center of the antenna conductor and along the resonance direction of the electromagnetic wave. A planar antenna according to claim 1.   The planar antenna according to claim 1, wherein a connection portion between the at least one support portion and the antenna conductor is located in a region of the antenna conductor having a low electric field strength.   The planar antenna according to any one of claims 1 to 7, wherein the antenna conductor includes at least one pair of second sides parallel to each other orthogonal to the resonance direction of the electromagnetic wave in a plan view. When the wavelength of the electromagnetic wave in the antenna conductor is λg,
The planar antenna according to claim 8, wherein an interval between the pair of second sides is λg / 2.   10. The planar antenna according to claim 9, wherein the at least one support portion is connected in the vicinity of the center of the antenna conductor and in the vicinity of λg / 4 from the pair of second sides.   The planar antenna according to claim 8, wherein a planar shape of the antenna conductor is a rectangular shape. Multiple antenna conductors are provided,
The planar antenna according to claim 1, further comprising a connection conductor connecting adjacent antenna conductors. A planar antenna according to any one of claims 1 to 12,
A power converter that performs power conversion of electromagnetic waves transmitted and received in the planar antenna;
An antenna device comprising:   The antenna device according to claim 13, further comprising a high-frequency circuit connected to the power converter.