Antenna device

Abstract

A post wall waveguide antenna of an antenna device according to the present invention is provided with: a first conductor foil and a second conductor foil which are laminated on a substrate; and two via walls which extend in the lamination direction, which include a plurality of vias that are disposed at a prescribed interval in the first direction, and which electrically connect the first conductor foil and the second conductor foil. First polarized waves are emitted from an end part of a region surrounded by the first conductor foil, the second conductor foil, and the two via walls. A horizontal polarization antenna of the antenna device has an antenna element which emits second polarized waves that are orthogonal to the first polarized waves and a power supply line which is connected to the antenna element, which extends in the first direction, and which supplies power to the antenna element from a feeding point. The post wall waveguide antenna and the horizontal polarization antenna are disposed alternately along a second direction which is perpendicular to the lamination direction and the first direction. The antenna element is provided at a position further away from the feeding point than the end part in the first direction.

Description

Antenna device

[0001] The present disclosure relates to an antenna device.

[0002] One of the transmission lines for transmitting high-frequency signals such as microwaves, millimeter waves, and terahertz waves is a post-wall waveguide. The post-wall waveguide has a dielectric layer, a pair of conductor foils disposed above and below the dielectric layer, and vias (which may also be referred to as via holes) that electrically connect between the two conductor foils. The post-wall waveguide is also used as an antenna structure that radiates radio waves from its end. A post-wall waveguide having an antenna structure that radiates radio waves may be referred to as a post-wall waveguide antenna.

[0003] A polarization-sharing antenna configured by combining a post-wall waveguide antenna and another antenna and capable of transmitting and receiving vertical polarization waves and horizontal polarization waves orthogonal to each other has been studied.

[0004] In Patent Document 1, a structure is disclosed in which a feeding line of a horizontal polarization antenna is disposed inside a post-wall waveguide, and horizontal polarization waves are radiated from an antenna disposed in front of the open end of the post-wall waveguide.

[0005] Japanese Unexamined Patent Application Publication No. 2023-131711, Patent No. 7013586

[0006] Yosuke Suga et al., ”Cost-Effective 60-GHz Antenna-Package with End-Fire Radiation from Open-Ended Post-Wall Waveguide for Wireless File-Transfer System”, IMS2010, p.449-452

[0007] However, in the structure of Patent Document 1, since the feeding line of the horizontal polarization antenna is disposed inside the post-wall waveguide, there is a possibility that transmission loss may occur in the feeding line when radio waves are transmitted inside the post-wall waveguide.

[0008] The non-limiting embodiments of the present disclosure contribute to providing an antenna device capable of suppressing transmission loss inside a post-wall waveguide.

[0009] An antenna device according to one embodiment of the present disclosure comprises a plurality of post-wall waveguide antennas and a plurality of horizontally polarized antennas, wherein the post-wall waveguide antenna comprises a first conductor foil and a second conductor foil laminated on a substrate, and two via walls that electrically connect the first conductor foil and the second conductor foil, and include a plurality of vias extending in the lamination direction and arranged at predetermined intervals in a first direction, and the end of the region enclosed by the first conductor foil, the second conductor foil and the two via walls The horizontal polarization antenna radiates a first polarization, and the horizontal polarization antenna has an antenna element that radiates a second polarization perpendicular to the first polarization, and a feed line connected to the antenna element, extending in the first direction, and supplying power from a feed point to the antenna element. The post-wall waveguide antenna and the horizontal polarization antenna are arranged alternately along a second direction perpendicular to the stacking direction and the first direction, and the antenna element is provided in the first direction at a position further from the feed point than the end.

[0010] According to one embodiment of the present disclosure, transmission loss inside the post-wall waveguide can be suppressed.

[0011] Further advantages and effects of one embodiment of this disclosure will be made apparent from the specification and drawings. Such advantages and / or effects are provided by several embodiments and features described in the specification and drawings, but not all of them are necessarily provided in order to obtain one or more identical features.

[0012] A perspective view showing an example of an antenna device according to Embodiment 1 of this disclosure. A diagram showing an example of the X-Y plane of an antenna device according to Embodiment 1 of this disclosure. A diagram showing an example of the Y-Z plane of an antenna device according to Embodiment 1 of this disclosure. A diagram showing an example of the Y-Z plane of an antenna device according to Variation 1 of Embodiment 1 of this disclosure. A diagram showing an example of the X-Y plane of an antenna device according to Variation 2 of Embodiment 1 of this disclosure. A diagram showing an example of the Y-Z plane of a post-wall waveguide antenna. A diagram showing the X-Y plane of a modified horizontal polarization antenna. A diagram showing the X-Y plane of a modified horizontal polarization antenna. Figure showing the X-Y plane of an example Figure showing the X-Y plane of a modified example of a horizontally polarized antenna Figure showing the X-Y plane of a modified example of a horizontally polarized antenna Perspective view showing an example of an antenna device according to Embodiment 2 of the present disclosure Figure showing an example of the X-Y plane of an antenna device according to Embodiment 2 of the present disclosure Figure showing an example of the Y-Z plane of an antenna device according to Embodiment 2 of the present disclosure Figure showing an example of the Y-Z plane of an antenna device according to Variation 1 of Embodiment 2 of the present disclosure Figure showing an example of the Y-Z plane of a post-wall waveguide antenna Figure showing an example of the Y-Z plane of an antenna device according to Variation 2 of Embodiment 2 of the present disclosure

[0013] The embodiments of this disclosure will be described in detail below, with reference to the drawings as appropriate. However, some unnecessarily detailed explanations may be omitted. For example, detailed explanations of already well-known matters and redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art.

[0014] The attached drawings and the following description are provided to enable a person skilled in the art to fully understand this disclosure, and are not intended to limit the subject matter described in the claims.

[0015] In various drawings, some elements are omitted for clarity, and some elements may not be drawn to scale.

[0016] (Knowledge leading to this disclosure) Post-wall waveguides are one type of transmission line for transmitting high-frequency signals such as microwaves, millimeter waves, and terahertz waves. A post-wall waveguide has a dielectric layer, a pair of conductive foils arranged above and below it, and vias (which may also be called via holes) that electrically connect the two conductive foils. For example, the vias are arranged at λ / 2 intervals along the transmission direction of the signal transmitted through the waveguide. In a post-wall waveguide, the pair of conductive foils are used as the wide wall of the waveguide, and the multiple via holes are used as the narrow wall of the waveguide.

[0017] Post-wall waveguides are also used as antenna structures that radiate radio waves from their ends.

[0018] Non-patent document 1 describes an antenna structure in which the end of a post-wall waveguide is left open, two matching posts are placed inside the waveguide to adjust the impedance, and vertical polarization is radiated from the open end toward the edge of the substrate.

[0019] In Patent Document 1, a structure is disclosed in which a post-wall waveguide antenna is combined with another antenna to form a polarization-sharing antenna, in which the feed line of a horizontal polarization antenna is placed inside the post-wall waveguide, and horizontal polarization is radiated from an antenna placed in front of the open end of the post-wall waveguide.

[0020] However, in the structure of Patent Document 1, the feed line for the horizontally polarized antenna is located inside the post-wall waveguide, so there is a possibility that transmission loss may occur in the feed line when radio waves are transmitted inside the post-wall waveguide.

[0021] Therefore, the following embodiments describe antenna devices that can suppress transmission loss inside the post-wall waveguide.

[0022] In the following description, the antenna structure of a post-wall waveguide will be referred to as a post-wall waveguide antenna or waveguide antenna. Also, in the following description, λ or wavelength may be the effective wavelength of the radio wave propagating through the post-wall waveguide antenna, taking into account the dielectric constant of the dielectric layer containing the post-wall waveguide antenna.

[0023] (Embodiment 1) Figure 1 is a perspective view showing an example of an antenna device 10 according to Embodiment 1. Figure 2 is a diagram showing an example of the X-Y plane of the antenna device 10 according to Embodiment 1. Figure 3 is a diagram showing an example of the Y-Z plane of the antenna device 10 according to Embodiment 1.

[0024] Figures 1 to 3 show the antenna device 10 and the X, Y, and Z axes defined for the antenna device 10. Note that while Figure 3 shows the dielectric 30, Figures 1 and 2 show the antenna device 10 with the dielectric 30 transparent for illustrative purposes.

[0025] Figure 2 shows an example of the X-Y plane as viewed from the positive Z-axis direction of the antenna device 10 shown in Figure 1, and Figure 3 shows an example of the Y-Z plane as viewed from the positive X-axis direction of the antenna device 10 shown in Figure 1. For convenience of illustration, some of the reference numerals assigned to the same components may be omitted in Figures 1 to 3.

[0026] The antenna device 10 is formed on a laminated substrate that includes one or more dielectric layers (dielectric 30 in Figure 3) and one or more conductive foil layers (conductive foil 12-1, conductive foil 13-1, etc. in Figures 1 to 3). The plane along the dielectric layers and conductive foil layers is defined as the X-Y plane. The X-Y plane is a plane defined by the X axis and the Y axis. In this case, the multiple dielectric layers and conductive foil layers are arranged along the X-Y plane. The conductive foil layers may also be called conductive layers or conductive foils.

[0027] The antenna device 10 includes a post-wall waveguide antenna 11 and a horizontal polarization antenna 16. The direction indicated by the Z-axis in Figures 1 to 3 (hereinafter referred to as the Z-axis direction) corresponds to the thickness direction of the antenna device 10 and the stacking direction of the substrate on which the antenna device 10 is stacked. The direction indicated by the X-axis in Figures 1 to 3 (hereinafter referred to as the X-axis direction) is perpendicular to the Z-axis direction and corresponds to the direction in which the post-wall waveguide antenna 11 extends. The Y-axis direction in Figures 1 to 3 is perpendicular to the X-axis and the Z-axis.

[0028] Below, the positive direction of the Z-axis corresponds to "up" or "upward," and the negative direction of the Z-axis corresponds to "down" or "downward." The positive direction of the X-axis corresponds to "forward" or "forward," and the negative direction of the X-axis corresponds to "backward" or "backward." The positive direction of the Y-axis corresponds to "left" or "leftward," and the negative direction of the Y-axis corresponds to "right" or "rightward."

[0029] In the antenna device 10, three post-wall waveguide antennas 11 and three horizontal polarization antennas 16 are arranged alternately in the Y-axis direction. Hereafter, when the three post-wall waveguide antennas 11 are distinguished, they will be referred to as post-wall waveguide antennas 11-1 to 11-3, respectively. Similarly, when the three horizontal polarization antennas 16 are distinguished, they will be referred to as horizontal polarization antennas 16-1 to 16-3, respectively.

[0030] The configurations of the post-wall waveguide antenna 11 and the horizontal polarization antenna 16 will be explained below, using the post-wall waveguide antenna 11-1 and the horizontal polarization antenna 16-1 as examples.

[0031] The post-wall waveguide antenna 11-1 includes a conductor foil 12-1, a via wall 13-1, a conductor foil 14-1, and a via wall 15-1.

[0032] Conductive foil 12-1 and conductive foil 14-1 are layers of conductive foil laminated on a substrate. In the examples shown in Figures 1-3, conductive foil 12-1 is provided on the upper surface layer of the substrate, and conductive foil 14-1 is provided on the lower surface layer of the substrate.

[0033] In Figures 1 to 3, the conductor foils 12-1 to 12-3 are shown as separate, but they may also be provided as a single conductor foil without being separated. Similarly, in Figures 1 to 3, the conductor foils 14-1 to 14-3 are shown as separate, but they may also be provided as a single conductor foil without being separated.

[0034] Via wall 13-1 and via wall 15-1 electrically connect conductor foil 12-1 and conductor foil 14-1, respectively.

[0035] The via wall 13-1 is formed by vias 13a that extend along the Z-axis and are periodically arranged at specific intervals in the X-axis direction. Conductor foil 12-1 and conductor foil 14-1 are electrically connected by the vias 13a.

[0036] The via wall 13-1 may be configured with two or more vias arranged in the Z-axis direction. For example, the via wall 13-1 may have two or more vias arranged in the Z-axis direction and a conductive foil placed between the vias. In this case, the conductive foil 12-1 and the conductive foil 14-1 are electrically connected by the two or more vias arranged in the Z-axis direction and the conductive foil placed between the vias.

[0037] The via wall 15-1 is formed by vias 15a that extend along the Z-axis and are periodically arranged at specific intervals in the X-axis direction. Conductor foil 12-1 and conductor foil 14-1 are electrically connected by the vias 15a.

[0038] The via wall 15-1 may be configured with two or more vias arranged in the Z-axis direction. For example, the via wall 15-1 may have two or more vias arranged in the Z-axis direction and a conductive foil placed between the vias. In this case, the conductive foil 12-1 and the conductive foil 14-1 are electrically connected by the two or more vias arranged in the Z-axis direction and the conductive foil placed between the vias.

[0039] Radio waves propagate through the region enclosed by the conductor foil 12-1, via wall 13-1, conductor foil 14-1, and via wall 15-1, and are radiated from end E. The radio waves radiated from end E are vertically polarized. Vertical polarization is polarization that oscillates in the Z-axis direction. The direction of propagation (or transmission direction) of radio waves transmitted through the post-wall waveguide antenna 11-1 corresponds to the direction along the X-axis. In the following, as an example, in the post-wall waveguide antenna 11-1, radio waves are transmitted in the positive direction of the X-axis. In addition, in the post-wall waveguide antenna 11-1, radio waves may be transmitted in the negative direction of the X-axis.

[0040] The intervals between the conductor foils 12-1 and 14-1, the intervals between the via walls 13-1 and 15-1, the intervals between the aligned vias 13a, the intervals between the aligned vias 15a, etc. may be determined based on the wavelength of the propagating radio waves.

[0041] Since the post-wall waveguide antennas 11-2 and 11-3 each have the same configuration as the post-wall waveguide antenna 11-1, the description thereof is omitted. In the post-wall waveguide antenna 11-2, radio waves propagate in the region surrounded by the conductor foil 12-2, the via wall 13-2, the conductor foil 14-2, and the via wall 15-2, and radio waves are radiated from the end portion F. In the post-wall waveguide antenna 11-3, radio waves propagate in the region surrounded by the conductor foil 12-3, the via wall 13-3, the conductor foil 14-3, and the via wall 15-3, and radio waves are radiated from the end portion G. Note that the end portions of the post-wall waveguide antennas 11-1 to 11-3 may be at the same position in the X-axis direction.

[0042] The horizontally polarized antenna 16-1 includes a horizontally polarized element 18-1 and a feeding line 17-1.

[0043] The horizontally polarized element 18-1 is a conductor line along the Y-axis. The horizontally polarized element 18-1 includes an element 18a-1 extending in the negative direction of the Y-axis from the connection portion with the feeding line 17-1 and an element 18b-1 extending in the negative direction of the Y-axis from the connection portion with the feeding line 17-1. The element 18a-1 is located in front of the end portion E of the post-wall waveguide antenna 11-1, that is, on the positive side of the X-axis. The element 18b-1 is located in front of the end portion F of the post-wall waveguide antenna 11-2. In other words, the horizontally polarized element 18-1 is provided at a position farther from the feeding point than the end portion E of the post-wall waveguide antenna 11-1 and the end portion F of the post-wall waveguide antenna 11-2 in the X-axis direction.

[0044] The power supply line 17-1 connects a power supply point (omitted in FIGS. 1 to 3) and the horizontally polarized element 18-1. The power supply line 17-1 is disposed between the post-wall waveguide antennas 11-1 and 11-2. In other words, the power supply line 17-1 is not disposed inside any of the post-wall waveguide antennas 11-1 to 11-3. The power supply line 17-1 supplies power to the horizontally polarized element 18-1.

[0045] The radio wave radiated from the horizontally polarized element 18-1 is horizontally polarized. The horizontal polarization is a polarization that vibrates in the Y-axis direction.

[0046] As described above, the antenna device 10 includes a plurality of post-wall waveguide antennas 11 and a plurality of horizontally polarized antennas 16. The post-wall waveguide antenna 11-1 includes conductor foils 12-1 and 14-1 laminated on a substrate, and a plurality of vias 13a and 15a extending in the Z-axis direction and arranged at a predetermined interval in the X-axis direction, and via walls 13-1 and 15-1 that electrically connect between the conductor foil 12-1 and the conductor foil 14-1. The post-wall waveguide antenna 11-1 radiates vertical polarization from an end of a region surrounded by the conductor foils 12-1 and 14-1 and the via walls 13-1 and 15-1. The horizontally polarized antenna 16-1 has a horizontally polarized element 18-1 that radiates horizontally polarized waves, and a power supply line 17-1 that is connected to the horizontally polarized element 18-1, extends in the X-axis direction, and supplies power from a power supply point to the horizontally polarized element 18-1. The post-wall waveguide antennas 11 and the horizontally polarized antennas 16 are alternately arranged along the Y-axis direction. The horizontally polarized element 18-1 is provided at a position farther from the power supply point than the end of the post-wall waveguide antenna 11-1 in the X-axis direction.

[0047] In the examples of FIGS. 1 to 3, in the Z-axis direction, the position of the post-wall waveguide antenna 11 is at the center of the substrate. By having the position of the post-wall waveguide antenna 11 at the center of the substrate in the Z-axis direction, it is possible to avoid the radio wave radiated from the end of the post-wall waveguide antenna 11 from being deflected in the positive or negative direction of the Z-axis due to the action of the dielectric.

[0048] Furthermore, in the examples shown in Figures 1 to 3, the horizontal polarization antenna 16 is located in the center of the substrate in the Z-axis direction. In other words, the thickness of the dielectric 30 stacked above the horizontal polarization antenna 16 and the thickness of the dielectric stacked below the horizontal polarization antenna 16 may be equal. By positioning the horizontal polarization antenna 16 in the center of the substrate in the Z-axis direction, it is possible to avoid the radio waves radiated from the horizontal polarization antenna 16 being biased in the positive or negative direction of the Z-axis due to the action of the dielectric.

[0049] Note that the position of the post-wall waveguide antenna 11 and / or the horizontal polarization antenna 16 in the Z-axis direction does not have to be in the center of the substrate.

[0050] Figures 1 to 3 show an example in which three post-wall waveguide antennas 11 and three horizontal polarization antennas 16 are arranged. However, the number of post-wall waveguide antennas 11 and horizontal polarization antennas 16 may be two or less, or four or more. Furthermore, the number of post-wall waveguide antennas 11 and horizontal polarization antennas 16 may be different as long as they are arranged alternately in the Y-axis direction.

[0051] Furthermore, the multiple post-wall waveguide antennas 11 of the antenna device 10 may be operated as an array antenna, with each post-wall waveguide antenna 11 serving as an antenna element. Also, the multiple horizontal polarization antennas 16 of the antenna device 10 may be operated as an array antenna, with each horizontal polarization antenna 16 serving as an antenna element.

[0052] (Variation 1 of Embodiment 1: Change in dielectric thickness) Figures 1 to 3 show an example in which the conductive foil 12 is provided on the upper surface layer and the conductive foil 14 is provided on the lower surface layer, but the disclosure is not limited thereto. An example in which the conductive foil 12 and the conductive foil 14 are provided on the inner layer of the substrate will be described.

[0053] Figure 4 shows an example of the Y-Z plane of the antenna device 10a according to variation 1 of this embodiment 1. In Figure 4, components similar to those in Figures 1 to 3 are given the same reference numerals and their descriptions may be omitted.

[0054] As shown in the comparison between Figure 4 and Figure 3, the thickness of the dielectric 30 in the antenna device 10a is greater than the thickness of the dielectric 30 in the antenna device 10 in Figure 3. Except for the difference in the thickness of the dielectric 30, the antenna device 10a shown in Figure 4 has the same configuration as the antenna devices 10 shown in Figures 1 to 3.

[0055] In the example shown in Figure 4, conductive foils 12-1 to 12-3 and conductive foils 14-1 to 14-3 are provided in the inner layers of the substrate. In other words, in the example shown in Figure 4, a layer of dielectric 30 is laminated above conductive foils 12-1 to 12-3, and a layer of dielectric 30 is laminated below conductive foils 14-1 to 14-3.

[0056] In the example shown in Figure 4, the position of the post-wall waveguide antenna 11 in the Z-axis direction may be at the center of the substrate. In other words, the thickness of the dielectric 30 laminated above the conductor foil 12 may be equal to the thickness of the dielectric laminated below the conductor foil 14. By positioning the post-wall waveguide antenna 11 at the center of the substrate in the Z-axis direction, it is possible to avoid bias of the radio waves radiated from the end of the post-wall waveguide antenna 11 in the positive or negative direction of the Z-axis due to the action of the dielectric.

[0057] Furthermore, in the example shown in Figure 4, the position of the horizontal polarization antenna 16 in the Z-axis direction may be at the center of the substrate. In other words, the thickness of the dielectric 30 stacked above the horizontal polarization antenna 16 may be equal to the thickness of the dielectric stacked below the horizontal polarization antenna 16. By positioning the horizontal polarization antenna 16 at the center of the substrate in the Z-axis direction, it is possible to avoid the radio waves radiated from the horizontal polarization antenna 16 being biased in the positive or negative direction of the Z-axis due to the action of the dielectric.

[0058] (Variation 2 of Embodiment 1: Addition of Matching Posts) Figure 5 shows an example of the X-Y plane of the antenna device 10b according to Variation 2 of Embodiment 1. Note that in Figure 5, the same reference numerals are used for components similar to those in Figures 1 to 4, and their descriptions may be omitted.

[0059] In the antenna device 10b, a matching post 51 is provided inside the post-wall waveguide antenna 11.

[0060] The matching post 51 adjusts the impedance of the post-wall waveguide antenna 11. For example, the matching post 51 included in the post-wall waveguide antenna 11-1 is located inside the via walls 13-1 and 15-1, and electrically connects the conductor foil 12-1 and the conductor foil 14-1.

[0061] In this embodiment 1, since the feed line 17 is not located inside the post-wall waveguide antenna 11, as shown in Figure 5, the matching post 51 can be placed inside the post-wall waveguide antenna 11 without interfering with the feed line 17, and the impedance of the post-wall waveguide antenna 11 can be easily adjusted.

[0062] Next, an example of the frequencies used in the antenna device 10 of this embodiment 1 will be described.

[0063] Figure 6 shows an example of the Y-Z plane of a post-wall waveguide antenna 11. As shown in Figure 6, the thickness of the post-wall waveguide antenna 11 is t, and the relative permittivity of the substrate is ε r Therefore, the cutoff wavelength λ of the TE01 mode of the post-wall waveguide antenna 11, which corresponds to horizontal polarization. c_te01 This is determined by the following equation (1). Furthermore, if the speed of light is c, then the cutoff frequency f of the TE01 mode. c_te01 This is determined by equation (2). In other words, the frequency used is the cutoff frequency f of the TE01 mode. c_te01 By lowering the value, the horizontal polarization radiated by the horizontal polarization antenna 16 cannot propagate inside the post-wall waveguide antenna 11, and the horizontal polarization is reflected. Because the horizontal polarization is reflected in the post-wall waveguide antenna 11, the horizontal polarization antenna 16 can increase the radiation efficiency of radio waves in the positive direction of the X axis. In addition, the isolation between the post-wall waveguide antenna 11 and the horizontal polarization antenna 16 can be increased.

[0064] (Variation 3 of Embodiment 1: Modification of Horizontal Polarization Antenna) In Embodiment 1 described above, an example was shown in which the horizontal polarization antenna 16 is a linear dipole antenna using a differential transmission line, but this disclosure is not limited to this. Variation 3 describes variations of the horizontal polarization antenna.

[0065] Figures 7A to 7E show the X-Y plane of a modified horizontal polarization antenna 16. For illustrative purposes, the boundary B between the feed line 17 and the antenna element is shown in Figures 7A to 7E.

[0066] In the horizontal polarization antenna 16a shown in Figure 7A, the antenna element 18a connected to the feed line 17 is a dipole antenna with a bowtie shape. In the horizontal polarization antenna 16b shown in Figure 7B, the antenna element 18b connected to the feed line 17 is a tapered slot antenna. Although not shown in the figures, a Vivaldi antenna may also be used as the horizontal polarization antenna 16.

[0067] Figure 7C shows via 15a included in via wall 15-1 of post-wall waveguide antenna 11-1, which is located to the left of horizontal polarization antenna 16c-1, and via 13a included in via wall 13-2 of post-wall waveguide antenna 11-2, which is located to the right of horizontal polarization antenna 16c-1. The horizontal polarization antenna 16c shown in Figure 7C is a monopole antenna using a single-ended feed line 17c. The horizontal polarization antenna 16c includes a single-ended feed line 17c and an antenna element 18c.

[0068] Figure 7D shows via 15a included in via wall 15-1 of post-wall waveguide antenna 11-1, which is located to the left of horizontal polarization antenna 16d-1, and via 13a included in via wall 13-2 of post-wall waveguide antenna 11-2, which is located to the right of horizontal polarization antenna 16d-1. The horizontal polarization antenna 16d-1 shown in Figure 7D includes a feed line 17d-1 and an antenna element 18d, and is an inverted F antenna in which one end of the antenna element 18d is shorted to via wall 13-2, which is the narrow wall surface of post-wall waveguide antenna 11-2.

[0069] Figure 7E shows via 15a included in via wall 15-1 of post-wall waveguide antenna 11-1, which is located to the left of horizontal polarization antenna 16e-1, and via 13a included in via wall 13-2 of post-wall waveguide antenna 11-2, which is located to the right of horizontal polarization antenna 16e-1. The horizontal polarization antenna 16e-1 shown in Figure 7E includes a feed line 17e-1 and an antenna element 18e, and is an unbalanced dipole antenna in which the antenna element 18e is extended from via 13-2, which is the narrow wall surface of post-wall waveguide antenna 11-2.

[0070] The horizontal polarization antenna 16 shown in Figures 1 to 3 may be replaced with any of the modified examples shown in Figures 7A to 7E.

[0071] As described above, according to this embodiment 1, the feed line 17 of the horizontal polarization antenna 16 is arranged between the post-wall waveguide antennas 11 and not inside the post-wall waveguide antennas 11. Therefore, it is possible to avoid transmission loss in the feed line when radio waves are transmitted inside the post-wall waveguide, and transmission loss inside the post-wall waveguide can be suppressed.

[0072] (Embodiment 2) Figure 8 is a perspective view showing an example of an antenna device 80 according to Embodiment 2. Figure 9 is a diagram showing an example of the X-Y plane of the antenna device 80 according to Embodiment 2. Figure 10 is a cross-sectional view taken along line A-A' in Figure 9. Note that in Figures 8 to 10, components similar to those in Figures 1 to 3, etc., are given the same numbering and their descriptions may be omitted.

[0073] Figures 8 to 10 show the antenna device 80 and the X, Y, and Z axes defined for the antenna device 80. In Figure 10, the dielectric 30 is shown, but in Figures 8 and 9, for illustrative purposes, the antenna device 80 is shown with the dielectric 30 transparent. Also, for illustrative purposes, in Figure 8, the conductive foils 82 and 84 are shown transparent.

[0074] Figure 9 shows an example of the X-Y plane as viewed from the positive Z-axis direction of the antenna device 80 shown in Figure 8. For convenience of illustration, some of the reference numerals assigned to the same components may be omitted in Figures 8 to 10.

[0075] The antenna device 80 is formed on a laminated substrate that includes one or more dielectric layers (dielectric 30 in Figure 10) and one or more conductive foil layers (conductive foil 82, conductive foil 83, etc. in Figures 8 to 10). The plane along the dielectric layers and conductive foil layers is defined as the X-Y plane. The X-Y plane is a plane defined by the X axis and the Y axis. In this case, the multiple dielectric layers and conductive layers are arranged along the X-Y plane.

[0076] The antenna device 80 includes a post-wall waveguide antenna 81 and a horizontal polarization antenna 16. The Z-axis direction shown in Figures 8 to 10 corresponds to the thickness direction of the antenna device 80 and the stacking direction of the substrate on which the antenna device 80 is stacked. The X-axis direction shown in Figures 8 to 10 is perpendicular to the Z-axis direction and corresponds to the direction in which the post-wall waveguide antenna 81 extends. The Y-axis direction shown in Figures 8 to 10 is perpendicular to the X-axis and Z-axis.

[0077] In the antenna device 80, three post-wall waveguide antennas 81 and three horizontally polarized antennas 16 are arranged alternately in the Y-axis direction. Hereafter, when the three post-wall waveguide antennas 81 are distinguished, they will be referred to as post-wall waveguide antennas 81-1 to 81-3, respectively. Similarly, when the three horizontally polarized antennas 16 are distinguished, they will be referred to as horizontally polarized antennas 16-1 to 16-3, respectively.

[0078] The configuration of the post-wall waveguide antenna 81 will be explained below, using the post-wall waveguide antenna 81-1 as an example.

[0079] The post-wall waveguide antenna 81-1 includes a conductor foil 82, a via wall 83-1, a conductor foil 84, and a via wall 85-1.

[0080] Conductive foil 82 and conductive foil 84 are layers of conductive foil laminated on the substrate. In the examples shown in Figures 8 to 10, conductive foil 82 is provided on the upper surface layer of the substrate, and conductive foil 84 is provided on the lower surface layer of the substrate.

[0081] In Figures 8 to 10, the conductor foil 82 is provided without division, but similar to the conductor foils 12-1 to 12-3 of Embodiment 1, the conductor foil 82 may be divided for each post-wall waveguide antenna 81. Also, in Figures 8 to 10, the conductor foil 84 is provided without division, but similar to the conductor foils 14-1 to 14-3 of Embodiment 1, the conductor foil 84 may be divided for each post-wall waveguide antenna 81.

[0082] Via wall 83-1 and via wall 85-1 electrically connect conductor foil 82 and conductor foil 84, respectively.

[0083] The via wall 83-1 has a conductive foil 86-1, a conductive foil 87-1, a via 88-1, a via 89-1, and a via 90-1.

[0084] Conductor foils 86-1 and 87-1 are conductor foils located between conductor foil 82 and conductor foil 84, as shown in Figures 8 and 10. Conductor foil 86-1 is located between conductor foil 82 and conductor foil 87-1 and extends along the X-axis direction. Conductor foil 87-1 is located between conductor foil 84 and conductor foil 86-1 and extends along the X-axis direction. The width (length in the Y-axis direction) of conductor foils 86-1 and 87-1 may be about twice the diameter of the via.

[0085] Vias 88-1, 89-1, and 90-1 are positioned at different heights in the Z-axis direction.

[0086] Vias 88-1 extend along the Z-axis and are arranged periodically at specific intervals along the X-axis. Vias 88-1 electrically connect conductor foil 82 and conductor foil 86-1.

[0087] Vias 89-1 extend along the Z-axis and are arranged periodically at specific intervals along the X-axis. Vias 89-1 electrically connect conductor foil 86-1 and conductor foil 87-1.

[0088] Vias 90-1 extend along the Z-axis and are arranged periodically at specific intervals in the X-axis direction. Vias 90-1 electrically connect conductor foil 84 and conductor foil 87-1.

[0089] As illustrated in Figures 8 and 10, vias 88-1 and 90-1 are positioned on the negative side of the Y-axis compared to via 89-1. In other words, vias 88-1 and 90-1 are positioned offset outward from the post-wall waveguide antenna 81-1.

[0090] The via wall 85-1 has a conductive foil 91-1, a conductive foil 92-1, a via 93-1, a via 94-1, and a via 95-1.

[0091] Conductor foils 91-1 and 92-1 are conductor foils located between conductor foil 82 and conductor foil 84, as shown in Figures 8 and 10. Conductor foil 91-1 is located between conductor foil 82 and conductor foil 92-1 and extends along the X-axis direction. Conductor foil 92-1 is located between conductor foil 84 and conductor foil 91-1 and extends along the X-axis direction. The width (length in the Y-axis direction) of conductor foils 91-1 and 92-1 may be about twice the diameter of the via.

[0092] Vias 93-1, 94-1, and 95-1 are arranged at different heights in the Z-axis direction. Via 93-1 extends along the Z-axis direction and is periodically arranged at specific intervals in the X-axis direction. Via 93-1 electrically connects conductor foil 82 and conductor foil 91-1.

[0093] Vias 94-1 extend along the Z-axis and are arranged periodically at specific intervals in the X-axis direction. Vias 94-1 electrically connect conductor foil 91-1 and conductor foil 92-1.

[0094] Vias 95-1 extend along the Z-axis and are arranged periodically at specific intervals in the X-axis direction. Vias 95-1 electrically connect conductor foil 84 and conductor foil 92-1.

[0095] As illustrated in Figures 8 and 10, vias 93-1 and 95-1 are positioned on the positive Y-axis side of via 94-1. In other words, vias 93-1 and 95-1 are positioned offset outwards from the post-wall waveguide antenna 81-1.

[0096] Radio waves propagate within the area enclosed by the conductor foil 82, via wall 83-1, conductor foil 84, and via wall 85-1, and are radiated from end E. The radio waves radiated from end E are vertically polarized. Vertical polarization is polarization that oscillates in the Z-axis direction. The direction of propagation (or transmission direction) of radio waves transmitted through the post-wall waveguide antenna 81-1 corresponds to the direction along the X-axis. In the following, as an example, in the post-wall waveguide antenna 81-1, radio waves are transmitted in the positive direction of the X-axis. In addition, in the post-wall waveguide antenna 81-1, radio waves may be transmitted in the negative direction of the X-axis.

[0097] The spacing between the conductive foil 82 and the conductive foil 84, the spacing between the via wall 83-1 and the via wall 85-1, the spacing between the vias, etc., may be determined based on the wavelength of the propagating radio waves.

[0098] Post-wall waveguide antennas 81-2 and 81-3 have the same configuration as post-wall waveguide antenna 81-1, so their description is omitted. In post-wall waveguide antenna 81-2, radio waves propagate through the region enclosed by conductor foil 82, via wall 83-2, conductor foil 84, and via wall 85-2, and radio waves are radiated from end F. In post-wall waveguide antenna 81-3, radio waves propagate through the region enclosed by conductor foil 82, via wall 83-3, conductor foil 84, and via wall 85-3, and radio waves are radiated from end G. Note that the ends of post-wall waveguide antennas 81-1 to 81-3 may be in the same position in the X-axis direction.

[0099] As described above, the antenna device 80 comprises a plurality of post-wall waveguide antennas 81 and a plurality of horizontal polarization antennas 16. The post-wall waveguide antenna 81-1 comprises conductive foils 82 and 84 laminated on a substrate, and via walls 83-1 and 85-1 that electrically connect conductive foils 82 and 84, and include a plurality of vias (vias 88-1 to 90-1, vias 93-1 to 95-1, etc.) that extend in the Z-axis direction and are arranged at predetermined intervals in the X-axis direction. The post-wall waveguide antenna 81-1 radiates vertical polarization from the end of the region enclosed by conductive foils 82 and 84 and via walls 83-1 and 85-1. The horizontal polarization antenna 16-1 includes a horizontal polarization element 18-1 that radiates horizontal polarization, and a feed line 17-1 connected to the horizontal polarization element 18-1, extending in the X-axis direction, and supplying power from the feed point to the horizontal polarization element 18-1. The post-wall waveguide antenna 81 and the horizontal polarization antenna 16 are arranged alternately along the Y-axis direction. The horizontal polarization element 18-1 is positioned in the X-axis direction at a location further from the feed point than the end of the post-wall waveguide antenna 81-1.

[0100] In the examples shown in Figures 8 to 10, the post-wall waveguide antenna 81 is located at the center of the substrate in the Z-axis direction. By positioning the post-wall waveguide antenna 81 at the center of the substrate in the Z-axis direction, it is possible to avoid the radio waves radiated from the ends of the post-wall waveguide antenna 81 being biased in the positive or negative direction of the Z-axis due to the effect of the dielectric.

[0101] Furthermore, in the examples shown in Figures 8 to 10, the horizontal polarization antenna 16 is located in the center of the substrate in the Z-axis direction. In other words, the thickness of the dielectric 30 stacked above the horizontal polarization antenna 16 and the thickness of the dielectric stacked below the horizontal polarization antenna 16 may be equal. By having the horizontal polarization antenna 16 located in the center of the substrate in the Z-axis direction, it is possible to avoid the radio waves radiated from the horizontal polarization antenna 16 being biased in the positive or negative direction of the Z-axis due to the action of the dielectric.

[0102] Note that the position of the post-wall waveguide antenna 81 and / or the position of the horizontal polarization antenna 16 in the Z-axis direction do not have to be in the center of the substrate.

[0103] Figures 8 to 10 show an example in which three post-wall waveguide antennas 81 and three horizontally polarized antennas 16 are arranged. However, the number of post-wall waveguide antennas 81 and horizontally polarized antennas 16 may be two or less, or four or more. Furthermore, the number of post-wall waveguide antennas 81 and horizontally polarized antennas 16 may be different, as long as the post-wall waveguide antennas 81 and horizontally polarized antennas 16 are arranged alternately in the Y-axis direction.

[0104] Furthermore, the multiple post-wall waveguide antennas 81 of the antenna device 80 may be operated as an array antenna, with each post-wall waveguide antenna 81 serving as an antenna element. Also, the multiple horizontal polarization antennas 16 of the antenna device 80 may be operated as an array antenna, with each horizontal polarization antenna 16 serving as an antenna element.

[0105] (Variation 1 of Embodiment 2: Change in Dielectric Thickness) Figures 8 to 10 show an example in which conductive foil 82 is provided on the upper surface layer and conductive foil 84 is provided on the lower surface layer, but the disclosure is not limited thereto. An example in which conductive foil 82 and conductive foil 84 are provided on the inner layer of the substrate will be described.

[0106] Figure 11 shows an example of the Y-Z plane of the antenna device 80a according to variation 1 of this embodiment 2. In Figure 11, components similar to those in Figures 8 to 10 are given the same reference numerals and their descriptions may be omitted. Figure 11 corresponds to a cross-sectional view at the same position as in Figure 10.

[0107] As shown in the comparison between Figure 11 and Figure 10, the thickness of the dielectric 30 in the antenna device 80a is greater than the thickness of the dielectric 30 in the antenna device 80 shown in Figure 10. Except for the difference in the thickness of the dielectric 30, the antenna device 80a shown in Figure 11 has the same configuration as the antenna devices 80 shown in Figures 8 to 10.

[0108] In the example shown in Figure 11, the conductive foil 82 and the conductive foil 84 are provided in the inner layer of the substrate. In other words, in the example shown in Figure 11, a layer of dielectric 30 is laminated above the conductive foil 82, and a layer of dielectric 30 is laminated below the conductive foil 84.

[0109] In the example shown in Figure 11, the position of the post-wall waveguide antenna 81 in the Z-axis direction may be at the center of the substrate. In other words, the thickness of the dielectric 30 laminated above the conductor foil 82 may be equal to the thickness of the dielectric laminated below the conductor foil 84. By positioning the post-wall waveguide antenna 81 at the center of the substrate in the Z-axis direction, it is possible to avoid bias of the radio waves radiated from the end of the post-wall waveguide antenna 81 in the positive or negative direction of the Z-axis due to the action of the dielectric.

[0110] Furthermore, in the example shown in Figure 11, the position of the horizontal polarization antenna 16 in the Z-axis direction may be at the center of the substrate. In other words, the thickness of the dielectric 30 stacked above the horizontal polarization antenna 16 may be equal to the thickness of the dielectric stacked below the horizontal polarization antenna 16. By positioning the horizontal polarization antenna 16 at the center of the substrate in the Z-axis direction, it is possible to avoid the radio waves radiated from the horizontal polarization antenna 16 being biased in the positive or negative direction of the Z-axis due to the action of the dielectric.

[0111] In addition, as in the example shown in Figure 5, the matching post may be provided inside the post-wall waveguide antenna 81.

[0112] Next, an example of the frequencies used in the antenna device 80 of this second embodiment will be described.

[0113] Figure 12 shows an example of the Y-Z plane of the post-wall waveguide antenna 81. As shown in Figure 12, the cutoff frequencies of the TE10 mode are compared under the condition that the distance between vias in the Y-Z plane of the comparative example and the distance between vias in the Y-Z plane of the post-wall waveguide antenna 81 are equal to each other (d).

[0114] In this case, since vias 88-1, 90-1, 93-1, and 95-1 are shifted to the outside of the post-wall waveguide antenna 81, the cutoff frequency can be lowered compared to the comparative example. In other words, the frequency range in which the antenna can operate can be shifted to the lower frequency side.

[0115] For example, in a conventional post-wall waveguide antenna used as a comparative example, lowering the frequency used requires increasing the size of the post-wall waveguide antenna in the Y-axis direction, which necessitates widening the spacing between the antenna arrays in the Y-axis direction. According to this embodiment 2, it is possible to lower the frequency used without widening the spacing between the antenna arrays in the Y-axis direction.

[0116] (Variation 2 of Embodiment 2: Commonization of vias) Figure 13 shows an example of the Y-Z plane of the antenna device 80b according to variation 2 of Embodiment 2. In Figure 13, components similar to those in Figures 8 to 11 are given the same reference numerals and their descriptions may be omitted. Figure 13 corresponds to a cross-sectional view at the same position as in Figures 10 and 11.

[0117] In antenna device 80b, some vias of adjacent post-wall waveguide antennas 81 are used in common.

[0118] For example, in the antenna device 80 shown in Figure 10, via 93-1 of via wall 85-1 of post-wall waveguide antenna 81-1 and via 88-2 of via wall 83-2 of post-wall waveguide antenna 81-2 are provided separately. Also, in the antenna device 80 shown in Figure 10, via 95-1 of via wall 85-1 of post-wall waveguide antenna 81-1 and via 90-2 of via wall 83-2 of post-wall waveguide antenna 81-2 are provided separately.

[0119] On the other hand, in the antenna device 80b shown in Figure 13, vias 93-1 and 88-2 shown in Figure 10 are replaced by via 131-1. In other words, vias 93-1 and 88-2 shown in Figure 10 are common as via 131-1 in Figure 13. Also, in the antenna device 80b shown in Figure 13, vias 95-1 and 90-2 shown in Figure 10 are replaced by via 132-1. In other words, vias 93-1 and 88-2 shown in Figure 10 are common as via 132-1 in Figure 13.

[0120] In this embodiment 2, the horizontal polarization antenna 16 is not limited to a straight-shaped dipole antenna using a differential transmission line. For example, it may be replaced with another configuration as shown in Figures 7A to 7E of Embodiment 1.

[0121] As described above, according to this second embodiment, the feed line 17 of the horizontal polarization antenna 16 is arranged between the post-wall waveguide antennas 81 and not inside the post-wall waveguide antennas 81. Therefore, it is possible to avoid transmission loss in the feed line when radio waves are transmitted inside the post-wall waveguide, and transmission loss inside the post-wall waveguide can be suppressed.

[0122] Furthermore, according to this second embodiment, as illustrated in Figure 12, it is possible to lower the frequency used without widening the spacing of the antenna array in the Y-axis direction.

[0123] Furthermore, a post-wall waveguide antenna may simply be called a waveguide antenna or a waveguide line antenna. Alternatively, a post-wall waveguide antenna may also be called a stacked waveguide antenna or a stacked waveguide line antenna. In these descriptions, the term "antenna" may be omitted.

[0124] In each of the above embodiments, "radio waves" may be replaced with terms such as "electromagnetic waves," "signals," or "beams." Furthermore, although the above embodiments show an example where the post-wall waveguide antenna is a transmitting antenna that radiates radio waves, the post-wall waveguide antenna in each embodiment may also be applied to a receiving antenna that receives radio waves. Furthermore, although the above embodiments show an example where the horizontally polarized antenna is a transmitting antenna that radiates radio waves, the horizontally polarized antenna in each embodiment may also be applied to a receiving antenna that receives radio waves. One of the post-wall waveguide antenna and the horizontally polarized antenna may be a transmitting antenna and the other a receiving antenna, or at least one of the post-wall waveguide antenna and the horizontally polarized antenna may be switchable between transmitting and receiving.

[0125] <Summary of Embodiments> An antenna device according to one embodiment of the present disclosure comprises a plurality of post-wall waveguide antennas and a plurality of horizontally polarized antennas, wherein the post-wall waveguide antenna comprises a first conductor foil and a second conductor foil laminated on a substrate, and two via walls that electrically connect the first conductor foil and the second conductor foil, and include a plurality of vias extending in the lamination direction and arranged at predetermined intervals in a first direction, and the end of the region surrounded by the first conductor foil, the second conductor foil and the two via walls The horizontal polarization antenna radiates a first polarization, and the horizontal polarization antenna has an antenna element that radiates a second polarization perpendicular to the first polarization, and a feed line connected to the antenna element, extending in the first direction, and supplying power from a feed point to the antenna element. The post-wall waveguide antenna and the horizontal polarization antenna are arranged alternately along a second direction perpendicular to the stacking direction and the first direction, and the antenna element is provided in the first direction at a position further from the feed point than the end.

[0126] In this antenna device, the via wall has at least one third conductive foil, and the plurality of vias electrically connect the first conductive foil and the second conductive foil via the third conductive foil.

[0127] In this antenna device, the via wall includes a fourth conductor foil laminated between the first conductor foil and the second conductor foil, a fifth conductor foil laminated between the second conductor foil and the third conductor foil, a first via connecting the first conductor foil and the fourth conductor foil, a second via connecting the third conductor foil and the fifth conductor foil, and a third via connecting the fourth conductor foil and the second conductor foil, wherein the first via and the third via are provided outside the second via in the second direction of the post-wall waveguide antenna.

[0128] In this antenna device, the horizontal polarization antenna is provided between the second vias of the via wall of adjacent post-wall waveguide antennas.

[0129] In this antenna device, among the plurality of post-wall waveguide antennas, the first via and the third via of the first post-wall waveguide antenna are shared with the first via and the third via of the second post-wall waveguide antenna adjacent to the first post-wall waveguide antenna, respectively.

[0130] In this antenna device, the feed line is of the balanced type.

[0131] In this antenna device, the antenna element is a dipole antenna.

[0132] In this antenna device, the first conductor foils of adjacent post-wall waveguide antennas are laminated integrally.

[0133] In this antenna device, the post-wall waveguide antenna is located in the center of the substrate in the stacking direction.

[0134] In this antenna device, the horizontally polarized antenna is located in the center of the substrate in the stacking direction.

[0135] In this antenna device, the frequency of the second polarization is lower than the cutoff frequency of the TE01 mode of the post-wall waveguide antenna.

[0136] While embodiments have been described above with reference to the drawings, this disclosure is not limited to such examples. It will be apparent to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims. Such modifications or alterations are also understood to fall within the technical scope of this disclosure. Furthermore, the components in the embodiments may be combined in any way without departing from the spirit of this disclosure.

[0137] All disclosures in the specification, drawings, and abstract contained in the Japanese application 2025-009924, filed on January 23, 2025, are incorporated herein by reference.

[0138] One embodiment of the present disclosure is useful for an antenna device.

[0139] 10, 10a, 10b, 80, 80a, 80b Antenna equipment 11, 81 Post-wall waveguide antenna 12-1, 12-2, 12-3, 14-1, 14-2, 14-3, 82, 84, 86-1, 87-1, 91-1, 92-1 Conductor foil 13-1, 13-2, 13-3, 15-1, 15-2, 15-3, 83-1, 83-2, 83-3, 85-1, 85-2, 85-3 Via wall 13a, 15a, 88-1, 89-1, 90-1, 93-1, 94-1, 95-1, 131-1, 132-1 Via 16, 16a, 16b, 16c, 16d, 16e Horizontal polarization antenna 17-1, 17-2, 17-3 Power supply line 18-1, 18-2, 18-3 Antenna element 30 Dielectric 51 Matching post

Claims

1. The system comprises a plurality of post-wall waveguide antennas and a plurality of horizontally polarized antennas, wherein the post-wall waveguide antenna comprises a first conductor foil and a second conductor foil laminated on a substrate, and two via walls extending in the lamination direction and including a plurality of vias arranged at predetermined intervals in a first direction, electrically connecting the first conductor foil and the second conductor foil, the post-wall waveguide antenna radiates a first polarization from the end of the region enclosed by the first conductor foil, the second conductor foil and the two via walls, the horizontally polarized antenna comprises an antenna element radiating a second polarization perpendicular to the first polarization, and a feed line connected to the antenna element, extending in the first direction, and supplying power from a feed point to the antenna element, the post-wall waveguide antenna and the horizontally polarized antenna are arranged alternately along a second direction perpendicular to the lamination direction and the first direction, An antenna device wherein the antenna element is provided in the first direction at a position further from the feed point than the end.

2. The antenna device according to claim 1, wherein the via wall has at least one third conductive foil, and the plurality of vias electrically connect the first conductive foil and the second conductive foil via the third conductive foil.

3. The via wall includes: a fourth conductor foil laminated between the first conductor foil and the second conductor foil; a fifth conductor foil laminated between the second conductor foil and the third conductor foil; a first via connecting the first conductor foil and the fourth conductor foil; a second via connecting the third conductor foil and the fifth conductor foil; and a third via connecting the fourth conductor foil and the second conductor foil, wherein the first via and the third via are provided outside the second via in the second direction of the post-wall waveguide antenna, the antenna device according to claim 1.

4. The antenna device according to claim 3, wherein the horizontally polarized antenna is provided between the second vias of the via wall of adjacent post-wall waveguide antennas.

5. The antenna device according to claim 3, wherein, among the plurality of post-wall waveguide antennas, the first via and the third via of the first post-wall waveguide antenna are shared with the first via and the third via of a second post-wall waveguide antenna adjacent to the first post-wall waveguide antenna, respectively.

6. The antenna device according to claim 1, wherein the power supply line is of the balanced type.

7. The antenna device according to claim 1, wherein the antenna element is a dipole antenna.

8. The antenna device according to claim 1, wherein the first conductor foils of adjacent post-wall waveguide antennas are integrally laminated.

9. The antenna device according to claim 1, wherein the post-wall waveguide antenna is located in the center of the substrate in the stacking direction.

10. The antenna device according to claim 1, wherein the horizontally polarized antenna is located in the center of the substrate in the stacking direction.

11. The antenna device according to claim 1, wherein the frequency of the second polarization is lower than the cutoff frequency of the TE01 mode of the post-wall waveguide antenna.

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