Antenna device

Abstract

To provide an antenna device capable of suppressing a side lobe of a radio wave while suppressing an increase in size.SOLUTION: An antenna device includes a plurality of waveguide parts 20 and 30, a partition wall part that partitions the plurality of waveguide parts, a plurality of radiation opening parts 50 and 60 that radiate a radio wave, and a distribution part 40 that distributes and propagates the radio wave to a plurality of waveguide paths. Each of the plurality of waveguide parts extends in a first direction Dax, is formed side by side in a second direction Dcr, and overlaps a position in the first direction in connection parts 21 and 31 connected to an end part on the other side in the first direction of the distribution part. The plurality of radiation opening parts are disposed such that each position of the radiation opening parts of two waveguide parts adjacent to each other in the first direction are shifted from each other. The distribution part has a power supply opening in the second direction, and is formed by being folded back from one side to the other side in the first direction so that the radio waves can be propagated to the connection parts of the two waveguide parts adjacent to each other, and makes phases of the radio waves propagating to the connection parts of the two waveguide parts opposite to each other.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to antenna devices. [Background technology]

[0002] Conventionally, there is known an antenna apparatus including a plurality of antenna devices each having four radiation apertures that radiate radio waves (see, for example, Patent Document 1). The antenna devices arranged in this antenna apparatus have four radiation apertures arranged side by side at predetermined intervals in a predetermined direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022-122319 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, in the antenna device of Patent Document 1, four radiation apertures are arranged in a predetermined direction at predetermined intervals. When multiple radiation apertures are arranged in a predetermined direction like this, it is necessary to align the phases of the radio waves radiated from each of the multiple radiation apertures and combine these radio waves in order to improve the gain of the radio waves radiated from the antenna device. However, when aligning the phases of the radio waves radiated from each of the multiple radiation apertures arranged in a predetermined direction, the intervals between each of the multiple radiation apertures must be at least as large as the wavelength of the radio waves.

[0005] However, if the spacing between each of the multiple radiation apertures is set to the same size as the wavelength of the radio waves, the antenna device inevitably becomes larger in size in the direction in which the multiple radiation apertures are arranged. Also, if the multiple radiation apertures are arranged in a predetermined direction with spacing set to the same size as the wavelength of the radio waves, the side lobes of the radio waves radiated from the antenna device tend to become larger. The inventors have found the above as a result of detailed studies.

[0006] In view of the above, an object of the present disclosure is to provide an antenna device that can suppress side lobes of radio waves while preventing an increase in size. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, The antenna device a plurality of waveguide sections (20, 30, 70) each forming a waveguide path (20a, 30a, 70a) which is a propagation path of radio waves; a partition wall portion (13) disposed between the plurality of waveguide portions and separating the plurality of waveguide portions; a plurality of radiation openings (50, 60, 80) connected to the plurality of waveguide sections, respectively, for radiating radio waves; a distribution section (40) having a feed opening (411) into which radio waves are introduced and forming a distribution waveguide (40a) which is a propagation path through which the radio waves introduced from the feed opening are distributed to a plurality of waveguide paths and propagated; Each of the plurality of waveguide sections extends in a predetermined first direction (Dax), is formed side by side in a second direction (Dcr) perpendicular to the first direction, and has a connection section (21, 31, 71) on one side in the first direction that is connected to an end of the distribution section on the other side in the first direction, and the positions of the respective connection sections in the first direction overlap; the plurality of radiation openings are arranged such that positions of two radiation openings connected to two adjacent waveguide sections among the plurality of waveguide sections via a partition wall section are shifted in the first direction, The distribution section has a feed opening in the second direction and is formed by folding back from one side to the other side in the first direction so that radio waves can propagate to the connection portions of two adjacent waveguide sections via a partition wall portion among the plurality of waveguide sections, and causes the phases of the radio waves propagating to the connection portions of the two waveguide sections to be opposite to each other.

[0008] According to this, by bringing the phases of the radio waves radiated from the two radiation openings connected to two adjacent waveguide sections via the partition wall section closer to the same phase, it is possible to amplify the radio waves radiated from these two radiation openings while suppressing side lobes. Also, compared to a configuration in which a portion that radiates radio waves along the first direction is arranged in a single waveguide extending along the first direction, the dimension of each of the multiple waveguide sections in the first direction can be made smaller. Therefore, it is possible to prevent the antenna device from becoming large in size.

[0009] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0010] [Figure 1] 2. FIG. 3 is a cross-sectional view taken along line II in FIG. 2, schematically illustrating the general configuration of the antenna device according to the first embodiment. [Figure 2] 1 is a schematic diagram showing a state in which a first block and a second block constituting the antenna device according to the first embodiment are disassembled. FIG. [Figure 3] 3 is an explanatory diagram for explaining a power feeding section, a first waveguide section, a second waveguide section, a distribution section, a first radiation opening section, and a second radiation opening section according to the first embodiment. FIG. [Figure 4] 1 is a plan view schematically showing an antenna device according to a first embodiment as viewed in a direction perpendicular to the stacking direction. [Figure 5] FIG. 4 is a cross-sectional view of FIG. 3 . [Figure 6] 10 is a schematic diagram showing an illustrative hollow waveguide for explaining the phase of radio waves radiated by an antenna device. FIG. [Figure 7] 3A and 3B are explanatory diagrams for explaining electric and magnetic fields generated in a hollow waveguide. [Figure 8] FIG. 10 is a diagram showing a hollow waveguide in which a radiation port is arranged in a narrow wall portion. [Figure 9] FIG. 10 is a diagram showing a hollow waveguide in which a radiation port is arranged in a wide wall portion. [Figure 10] 1 is a schematic diagram showing a distribution waveguide that distributes radio waves propagating in a waveguide. FIG. [Figure 11] 10 is an explanatory diagram for explaining an electric field generated in a distribution hollow waveguide. FIG. [Figure 12] FIG. 1 is a schematic diagram showing a simplified antenna device according to a first embodiment. [Figure 13] FIG. 10 is a perspective view of a comparative waveguide of an antenna device of a comparative example. [Figure 14] FIG. 10 is a plan view of a comparative waveguide of an antenna device according to a comparative example. [Figure 15] FIG. 10 is a diagram illustrating the distribution of gain in an antenna device of a comparative example. [Figure 16] FIG. 3 is a diagram illustrating a distribution of gain in the antenna device of the first embodiment. [Figure 17] 10 is a view corresponding to FIG. 2 of an antenna device according to a first modified example of the first embodiment. FIG. [Figure 18] 4 is a diagram corresponding to FIG. 3 of an antenna device according to a first modified example of the first embodiment. FIG. [Figure 19] 6 is a view corresponding to FIG. 5 of an antenna device according to a second modified example of the first embodiment. FIG. [Figure 20] 6 is a view corresponding to FIG. 5 of an antenna device according to a second modified example of the first embodiment. FIG. [Figure 21] 6 is a view corresponding to FIG. 5 of an antenna device according to a second modified example of the first embodiment. FIG. [Figure 22] 10 is a view corresponding to FIG. 2 of an antenna device according to a third modified example of the first embodiment. FIG. [Figure 23] 10 is a view corresponding to FIG. 3 of an antenna device according to a third modified example of the first embodiment. FIG. [Figure 24] 10 is a view corresponding to FIG. 4 of an antenna device according to a third modified example of the first embodiment. FIG. [Figure 25] 10 is a view corresponding to FIG. 2 of an antenna device according to a fourth modified example of the first embodiment. FIG. [Figure 26] FIG. 10 is a view corresponding to FIG. 3 of an antenna device according to a fourth modified example of the first embodiment. [Figure 27] 10 is a view corresponding to FIG. 4 of an antenna device according to a fourth modified example of the first embodiment. FIG. [Figure 28] FIG. 10 is a view corresponding to FIG. 2 of an antenna device according to a fifth modified example of the first embodiment. [Figure 29] FIG. 10 is a view corresponding to FIG. 3 of an antenna device according to a fifth modified example of the first embodiment. [Figure 30] 13 is a diagram corresponding to FIG. 12 showing an antenna device according to a second embodiment. FIG. [Figure 31] 13 is a diagram corresponding to FIG. 12 showing an antenna device according to a third embodiment. FIG. [Figure 32] FIG. 10 is a diagram corresponding to FIG. 2 of an antenna device according to a fourth embodiment. [Figure 33] FIG. 10 is a view corresponding to FIG. 2 of an antenna device according to a first modified example of the fourth embodiment. [Figure 34] FIG. 10 is a diagram corresponding to FIG. 2 of an antenna device according to a fifth embodiment. [Figure 35] FIG. 10 is a plan view schematically showing the antenna device according to the fifth embodiment, as viewed in a direction perpendicular to the stacking direction. [Figure 36] 36 is a cross-sectional view taken along the line XXXVI-XXXVI of FIG. 35. [Figure 37] FIG. 13 is a plan view schematically showing the general configuration of an apparatus including a plurality of antenna devices in a sixth embodiment. [Figure 38] FIG. 13 is a cross-sectional view schematically showing the general configuration of an antenna device according to a seventh embodiment. [Figure 39] FIG. 13 is a cross-sectional view schematically showing the general configuration of an antenna device according to an eighth embodiment. [Figure 40] FIG. 13 is a cross-sectional view schematically showing the general configuration of an antenna device according to a ninth embodiment. [Figure 41] FIG. 22 is a cross-sectional view schematically showing the general configuration of an antenna device according to a tenth embodiment. [Figure 42] FIG. 22 is a cross-sectional view schematically showing the general configuration of an antenna device according to an eleventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, parts that are the same as or equivalent to those described in the preceding embodiments will be given the same reference numerals, and their description may be omitted. Furthermore, in the embodiments, when only some of the components are described, the components described in the preceding embodiments can be applied to the remaining components. The following embodiments can be partially combined with each other, even if not specifically stated, as long as there is no particular problem with the combination.

[0012] (First embodiment) This embodiment will be described with reference to FIGS. 1 to 16. In this embodiment, an example will be described in which an antenna device 1 of the present disclosure is applied to an apparatus including an MMIC 2, which is an electrical component. Note that "MMIC" is an abbreviation for Monolithic Microwave Integrated Circuit. The MMIC 2 shown in FIG. 1 is a semiconductor device including an input / output unit 3 that transmits and receives radio waves. The MMIC 2 is a transmitting / receiving apparatus provided in correspondence with the antenna device 1. In this embodiment, the operating frequency of the radio waves transmitted and received by the MMIC 2 is a frequency band corresponding to millimeter waves (e.g., 76.5 GHz). Note that the operating frequency of the radio waves transmitted and received by the MMIC 2 is not limited to a frequency corresponding to millimeter waves, and may be a frequency other than millimeter waves.

[0013] As shown in FIG. 1, the MMIC 2 is mounted on an electric substrate 4. The electric substrate 4 is a printed circuit board on which multiple wiring patterns are formed using a conductive material such as metal foil. The electric substrate 4 has one surface 4a on one side in the thickness direction of the substrate and another surface 4b on the other side in the thickness direction of the substrate. The MMIC 2 is mounted on the other surface 4b of the electric substrate 4. A substrate through-hole SH that penetrates the electric substrate 4 is formed in a position of the electric substrate 4 opposite the input / output unit 3 of the MMIC 2. Note that FIG. 1 also shows solder Sd that joins the MMIC 2 to the other surface 4b of the electric substrate 4.

[0014] A plurality of spacers 5 are arranged on one surface 4a of the electric substrate 4. The spacers 5 are made of, for example, a conductive material. The spacers 5 are fixed to the electric substrate 4. The antenna device 1 is arranged on one surface 4a of the electric substrate 4 with the plurality of spacers 5 sandwiched between them. The antenna device 1 is fixed to the electric substrate 4 by screws, adhesive, etc., while being in contact with the MMIC 2 and the plurality of spacers 5.

[0015] The antenna device 1 is an antenna that transmits radio waves transmitted and received by the MMIC 2. The antenna device 1 is composed of a structure ST having a laminated structure in which two conductive blocks BC1 and BC2 are stacked in a predetermined direction. The two blocks BC1 and BC2 are composed of metal blocks. Note that at least one of the two blocks BC1 and BC2 may not be a metal block, but may be, for example, a resin block with a conductive film such as a metal film formed on its surface by plating, or a block made of a conductive material other than metal.

[0016] The antenna device 1 has two blocks BC1 and BC2, which are joined to each other by screwing, adhesive, or the like. The antenna device 1 is fixed to the electric board 4 in an orientation in which the stacking direction Dst of the two blocks BC1 and BC2 coincides with the thickness direction of the electric board 4. In this embodiment, of the two blocks BC1 and BC2, the one closer to the electric board 4 is referred to as the first block BC1, and the one farther from the electric board 4 is referred to as the second block BC2. The antenna device 1 is stacked in the order of the first block BC1 and the second block BC2 from the other side to one side of the stacking direction Dst.

[0017] As shown in Figures 1 and 2, the two blocks BC1 and BC2 have the same rectangular shape in a plan view, which is a view taken along the stacking direction Dst. The two blocks BC1 and BC2 are also approximately the same size in a plan view so that they overlap each other in the stacking direction Dst. The first block BC1 and the second block BC2 have portions of their opposing surfaces in contact with each other. This electrically connects the two blocks BC1 and BC2.

[0018] The surface of the first block BC1 facing the electric substrate 4, i.e., the surface on the other side in the stacking direction Dst, faces one surface 4a of the electric substrate 4, with the MMIC 2 and a plurality of spacers 5 sandwiched between them. Although not shown, the first block BC1 is electrically connected to a ground pattern included in the wiring pattern formed on the one surface 4a of the electric substrate 4 via at least some of the plurality of spacers 5. The second block BC2 is electrically connected to the first block BC1, and is therefore electrically connected to the ground pattern of the electric substrate 4 via the first block BC1. The ground pattern of the electric substrate 4 is at ground potential.

[0019] An external port 6 is formed in the first block BC1 so that radio waves can propagate between it and the MMIC2. The external port 6 is formed in the first block BC1 as an opening that opens to the other side in the stacking direction Dst, and is provided so that radio waves can propagate between it and the MMIC2. The external port 6 is formed in the first block BC1 at a position facing the input / output unit 3 of the MMIC2, with a substrate through-hole SH sandwiched between it and the input / output unit 3. This allows radio waves to propagate between the external port 6 and the MMIC2.

[0020] 1 to 3, first block BC1 and second block BC2 are formed with a power feed section 10 that is provided to allow radio waves to propagate between them and MMIC 2, and a first waveguide section 20 and a second waveguide section 30 that form part of a waveguide that serves as a propagation path for the radio waves. Furthermore, first block BC1 and second block BC2 are formed with a distribution section 40 that distributes the radio waves introduced from power feed section 10 to first waveguide section 20 and second waveguide section 30. Furthermore, second block BC2 is formed with a first radiation opening 50 and a second radiation opening 60 that radiate the radio waves to external space.

[0021] The power supply unit 10, the first waveguide unit 20, the second waveguide unit 30, and the distribution unit 40 are formed by coupling a pair of grooves 121, 122 formed in portions of the first block BC1 and the second block BC2 that face each other in the stacking direction Dst. The first radiation opening 50 and the second radiation opening 60 are formed by penetrating the second block BC2 in the stacking direction Dst. The portions of the first block BC1 and the second block BC2 that form the power supply unit 10, the first waveguide unit 20, the second waveguide unit 30, and the distribution unit 40 form a "waveguide." In this embodiment, the power supply unit 10 is connected to the external port 6. Note that the surrounding area of ​​the external port 6 of the antenna device 1 is not shown in Figures 2, 3, and Figure 4 (described later).

[0022] A first groove 121 is formed in the first block BC1 at a location facing the second block BC2. The first groove 121 is configured as a bottomed groove recessed from one side to the other in the stacking direction Dst. An external port 6 is formed on the bottom surface of the first groove 121. A second groove 122 is formed in the second block BC2 at a location facing the first groove 121 of the first block BC1. The second groove 122 is configured as a bottomed groove recessed from the other side to one side in the stacking direction Dst.

[0023] The power feeding section 10 guides radio waves transmitted from the input / output section 3 of the MMIC 2 to the distribution section 40, and also guides radio waves received from the first radiation aperture 50 and the second radiation aperture 60 to the input / output section 3 of the MMIC 2. As shown in FIGS. 2 to 4, the power feeding section 10 has a substantially L-shaped cross section perpendicular to the stacking direction Dst. The power feeding section 10 is formed by connecting a first power feeding section 11 that communicates with the distribution section 40 and extends in a direction perpendicular to the stacking direction Dst, and a second power feeding section 12 that is perpendicular to the stacking direction Dst and the direction in which the first power feeding section 11 extends and communicates with the first power feeding section 11. That is, the power feeding section 10 is formed as a groove with a partially bent shape. In this embodiment, the power feeding section 10 is formed as a groove with a 90° bent shape.

[0024] Hereinafter, a direction perpendicular to the stacking direction Dst and in which the second power supply part 12 extends will be referred to as the tube axis direction Dax, and a direction perpendicular to the stacking direction Dst and the tube axis direction Dax and in which the first power supply part 11 extends will be referred to as the tube width direction Dcr. The tube axis direction Dax is a direction along the central axis of the second power supply part 12. The tube width direction Dcr is a direction along the central axis of the first power supply part 11. The tube axis direction Dax corresponds to the first direction. The tube width direction Dcr corresponds to the second direction. The stacking direction Dst corresponds to the third direction.

[0025] The first power supply part 11 and the second power supply part 12 have the same dimensions in the stacking direction Dst. The cross section of the first power supply part 11 perpendicular to the tube width direction Dcr has a rectangular shape extending in the stacking direction Dst. Specifically, the first power supply part 11 is formed in a rectangular shape whose dimension in the stacking direction Dst is larger than its dimension in the tube axis direction Dax.

[0026] The second power supply part 12 has a cross section perpendicular to the tube axis direction Dax that is rectangular and extends in the stacking direction Dst. Specifically, the second power supply part 12 is formed into a rectangular shape whose dimension in the stacking direction Dst is larger than its dimension in the tube width direction Dcr. The dimension of the first power supply part 11 in the tube axis direction Dax is equal to the dimension of the second power supply part 12 in the tube width direction Dcr.

[0027] One end of the first feeding unit 11 in the tube width direction Dcr is connected to the second feeding unit 12, and the other end of the first feeding unit 11 in the tube width direction Dcr is connected to the distribution unit 40. One end of the second feeding unit 12 in the tube axis direction Dax is connected to the MMIC 12 via the external port 6, and the other end of the second feeding unit 12 in the tube axis direction Dax is connected to the first feeding unit 11. This allows radio waves to propagate between the feeding unit 10 and the MMIC 2. A feeding path 10a that propagates radio waves is formed inside the feeding unit 10. The feeding path 10a is formed between the first block BC1 and the second block BC2 as a cavity formed by bending it 90 degrees.

[0028] The first waveguide section 20 is a propagation path constituting a "waveguide" that guides the radio waves introduced from the power feeding section 10 to the first radiation opening 50 and also guides the radio waves received from the first radiation opening 50 to the power feeding section 10. The second waveguide section 30 is a propagation path constituting a "waveguide" that guides the radio waves introduced from the power feeding section 10 to the second radiation opening 60 and also guides the radio waves received from the second radiation opening 60 to the power feeding section 10. As shown in FIGS. 2 to 4, the first waveguide section 20 and the second waveguide section 30 are formed to extend along the tube axis direction Dax.

[0029] The first waveguide section 20 and the second waveguide section 30 are formed side by side in the tube width direction Dcr, and their respective central axes extend along the tube axis direction Dax. As shown in Fig. 2, the first waveguide section 20 and the second waveguide section 30 are formed side by side in the tube width direction Dcr via the partition wall section 13. The first waveguide section 20 and the second waveguide section 30 each communicate with the distribution section 40 on one side in the tube axis direction Dax.

[0030] As shown in Fig. 4, the first waveguide section 20 has a first connection section 21 connected to the distribution section 40 on one side in the tube axis direction Dax, and a first end wall 22 forming the end section of the waveguide on the other side in the tube axis direction Dax. The first end wall 22 is formed of a planar wall extending in a direction perpendicular to the tube axis direction Dax. In Fig. 4, the first connection section 21, which is the boundary between the first waveguide section 20 and the distribution section 40, is indicated by a dashed line.

[0031] 3, the first waveguide section 20 has a one-side first wide wall surface 23 on one side in the tube width direction Dcr and a second-side first wide wall surface 24 on the other side in the tube width direction Dcr. Furthermore, the first waveguide section 20 has a one-side first narrow wall surface 25 on one side in the stacking direction Dst and a second-side first narrow wall surface 26 on the other side in the stacking direction Dst. The one-side first wide wall surface 23 and the second-side first wide wall surface 24 are planar and perpendicular to the tube width direction Dcr, and extend in the tube axis direction Dax and the stacking direction Dst. The one-side first narrow wall surface 25 and the second-side first narrow wall surface 26 are planar and perpendicular to the stacking direction Dst, and extend in the tube axis direction Dax and the tube width direction Dcr.

[0032] The size of the one-side first narrow wall surface 25 and the other-side first narrow wall surface 26 in the pipe width direction Dcr is smaller than the size of the one-side first wide wall surface 23 and the other-side first wide wall surface 24 in the stacking direction Dst. The first radiation opening portion 50 is connected to the one-side first narrow wall surface 25 side. That is, the first waveguide portion 20 does not have the first radiation opening portion 50 connected to the one-side first wide wall surface 23 side or the other-side first wide wall surface 24 side. The first waveguide portion 20 is configured as a waveguide that propagates radio waves between the power feeding portion 10 and the first radiation opening portion 50.

[0033] The second waveguide section 30 has a second connection section 31 connected to the distribution section 40 on one side in the tube axis direction Dax, and a second end wall 32 forming the end section of the waveguide on the other side in the tube axis direction Dax. The second end wall 32 is formed of a planar wall extending in a direction perpendicular to the tube axis direction Dax. In Fig. 4, the second connection section 31, which is the boundary between the second waveguide section 30 and the distribution section 40, is indicated by a dashed line.

[0034] The second waveguide section 30 has a one-side second wide wall surface 33 on one side in the tube width direction Dcr, a second-side second wide wall surface 34 on the other side in the tube width direction Dcr, a one-side second narrow wall surface 35 on one side in the stacking direction Dst, and a second-side second narrow wall surface 36 on the other side in the stacking direction Dst. The one-side second wide wall surface 33 and the other-side second wide wall surface 34 are planar and perpendicular to the tube width direction Dcr, and extend in the tube axis direction Dax and the stacking direction Dst. The one-side second narrow wall surface 35 and the other-side second narrow wall surface 36 are planar and perpendicular to the stacking direction Dst, and extend in the tube axis direction Dax and the tube width direction Dcr.

[0035] The size of the one-side second narrow wall surface 35 and the other-side second narrow wall surface 36 in the tube width direction Dcr is smaller than the size of the one-side second wide wall surface 33 and the other-side second wide wall surface 34 in the stacking direction Dst. The second radiation opening 60 is connected to the one-side second narrow wall surface 35 side. That is, the second waveguide section 30 does not have the second radiation opening 60 connected to the one-side second wide wall surface 33 side or the other-side second wide wall surface 34 side. The second waveguide section 30 is configured as a waveguide that propagates radio waves between the power feeding section 10 and the second radiation opening 60.

[0036] The first waveguide section 20 and the second waveguide section 30 have the first connecting section 21 and the second connecting section 31 overlapping in the tube axis direction Dax, and the first end wall 22 and the second end wall 32 overlapping in the tube axis direction Dax. That is, the first waveguide section 20 and the second waveguide section 30 have the same dimension in the tube axis direction Dax. The antenna device 1 has a partition wall section 13 that is disposed between the first waveguide section 20 and the second waveguide section 30 and separates the first waveguide section 20 and the second waveguide section 30.

[0037] A first waveguide 20a extending in the tube axis direction Dax and propagating radio waves is formed inside the first waveguide section 20. A second waveguide 30a extending in the tube axis direction Dax and propagating radio waves is formed inside the second waveguide section 30. The first waveguide 20a and the second waveguide 30a are formed between the first block BC1 and the second block BC2 as a cavity extending in the tube axis direction Dax. For example, in this embodiment, the boundary between the first block BC1 and the second block BC2 is located in the middle of the range occupied by the first waveguide 20a and the second waveguide 30a in the stacking direction Dst.

[0038] The first waveguide 20a is formed on one side of the center of the first block BC1 and the second block BC2 in the pipe width direction Dcr. In contrast, the second waveguide 30a is formed on the other side of the center of the first block BC1 and the second block BC2 in the pipe width direction Dcr. The first waveguide 20a and the second waveguide 30a are formed at positions equidistant from the center of the first block BC1 and the second block BC2 in the pipe width direction Dcr. A first radiation opening 50 is connected to the first waveguide section 20. A second radiation opening 60 is connected to the second waveguide section 30.

[0039] The distribution section 40 is a propagation path constituting a "waveguide" that distributes and propagates radio waves introduced from the power feed section 10 to the first waveguide section 20 and the second waveguide section 30. The groove that forms the distribution section 40 has a cross section perpendicular to the stacking direction Dst that is formed in a substantially U-shape. Specifically, the distribution section 40 is formed so that it can extend from the first connection section 21 of the first waveguide section 20 toward the other side in the tube axis direction Dax, turn back from the other side in the tube axis direction Dax to one side, and connect to the second connection section 31 of the second waveguide section 30. For this reason, the groove formed by the connection of the first waveguide section 20, the second waveguide section 30, and the distribution section 40 is formed in a substantially U-shape that is turned back.

[0040] As shown in FIGS. 3 and 4 , the distribution section 40 includes a first distribution section 41 extending along the tube axis direction Dax and connected to the first connection section 21 of the first waveguide section 20, and a second distribution section 42 extending along the tube axis direction Dax and connected to the second connection section 31 of the second waveguide section 30. Furthermore, the distribution section 40 includes a third distribution section 43 extending along the tube width direction Dcr and connected to the first distribution section 41 and the second distribution section 42. The first distribution section 41 and the second distribution section 42 are formed side by side in the tube width direction Dcr, with their respective central axes extending along the tube axis direction Dax. The first distribution section 41 and the second distribution section 42 are also arranged side by side in the tube width direction Dcr via the partition wall section 13.

[0041] The first distribution section 41 is a section that guides the radio waves introduced into the distribution section 40 to the first waveguide section 20. The other side of the first distribution section 41 in the tube axis direction Dax is connected to the first waveguide section 20, and one side of the first distribution section 41 in the tube axis direction Dax is connected to the third distribution section 43. The first distribution section 41 has a feed opening 411 to which the feed section 10 is connected on one side in the tube width direction Dcr, and radio waves are introduced from the feed opening 411.

[0042] The second distribution section 42 is a section that guides the radio waves introduced into the distribution section 40 to the second waveguide 30a. The other side of the second distribution section 42 in the tube axis direction Dax is connected to the second waveguide section 30, and one side in the tube axis direction Dax is connected to the third distribution section 43. The second distribution section 42 is connected to the power feeding section 10 via the first distribution section 41 and the third distribution section 43. The radio waves introduced from the power feeding opening 411 of the first distribution section 41 are introduced into the second distribution section 42 via the third distribution section 43. The first distribution section 41 and the second distribution section 42 have the same dimensions in the tube axis direction Dax. The third distribution section 43 extends along the tube width direction Dcr, and one side in the tube width direction Dcr is connected to the first distribution section 41, and the other side in the tube width direction Dcr is connected to the second distribution section 42. The third distribution unit 43 guides the radio waves introduced from the power supply opening 411 of the first distribution unit 41 to the second distribution unit .

[0043] The distribution section 40, which is composed of the first distribution section 41, the second distribution section 42, and the third distribution section 43 formed in this manner, is bent by 90°, i.e., a right angle, at a portion where the first distribution section 41 and the third distribution section 43 are connected. Also, the distribution section 40 is bent by 90°, i.e., a right angle, at a portion where the second distribution section 42 and the third distribution section 43 are connected. The distribution section 40 forms a folded section that is folded back by 180° from one side to the other side in the tube axis direction Dax so as to bypass the partition wall section 13.

[0044] The distribution section 40 is connected to the adjacent first and second waveguide sections 20 and 30 via the partition wall 13. A distribution waveguide 40a for propagating radio waves is formed inside the distribution section 40 by folding it back. The distribution waveguide 40a is formed between the first block BC1 and the second block BC2 as a cavity formed by bending it 180 degrees. The distribution section 40 has a distribution end wall 431 that forms part of the inner wall surface of the third distribution section 43 on one side in the tube axis direction Dax. The distribution end wall 431 faces the distribution waveguide 40a and is formed as a short-circuit section of the distribution waveguide 40a, and is composed of a planar wall that extends in a direction perpendicular to the tube axis direction Dax.

[0045] This allows radio waves to propagate between the first waveguide 20a, the second waveguide 30a, the distribution waveguide 40a, and the feed line 10a of the feed unit 10. Specifically, the radio waves introduced from the feed line 10a of the feed unit 10 to the distribution waveguide 40a of the distribution unit 40 are distributed within the distribution waveguide 40a and propagated to the first waveguide 20a of the first waveguide unit 20 and the second waveguide 30a of the second waveguide unit 30.

[0046] The first waveguide section 20, the second waveguide section 30, and the distribution section 40 have a rectangular cross section perpendicular to the direction of radio wave propagation that extends in the stacking direction Dst. Specifically, as shown in FIG. 5, the first waveguide section 20 and the second waveguide section 30 have a rectangular cross section perpendicular to the tube axis direction Dax, with the dimension in the stacking direction Dst being larger than the dimension in the tube width direction Dcr. The first distribution section 41 and the second distribution section 42 also have a rectangular cross section perpendicular to the tube axis direction Dax, with the dimension in the stacking direction Dst being larger than the dimension in the tube width direction Dcr. Furthermore, the third distribution section 43 has a rectangular cross section perpendicular to the tube width direction Dcr, with the dimension in the stacking direction Dst being larger than the dimension in the tube axis direction Dax. Note that in FIG. 5, the boundary between the first block BC1 and the second block BC2 is indicated by a dashed line.

[0047] The first waveguide section 20, the second waveguide section 30, and the distribution section 40 have the same cross-sectional shape perpendicular to the direction of radio wave propagation. Specifically, the first waveguide section 20, the second waveguide section 30, the first distribution section 41, the second distribution section 42, and the third distribution section 43 have the same dimensions in the stacking direction Dst. The first waveguide section 20, the second waveguide section 30, the first distribution section 41, and the second distribution section 42 have the same dimensions in the tube width direction Dcr. The first waveguide section 20, the second waveguide section 30, the first distribution section 41, and the second distribution section 42 have the same dimensions in the tube width direction Dcr and the dimension of the third distribution section 43 in the tube axis direction Dax.

[0048] The dimensions of the first waveguide section 20, the second waveguide section 30, the first distribution section 41, the second distribution section 42, and the third distribution section 43 in the stacking direction Dst are equal to the dimension of the power feeding section 10 in the stacking direction Dst. Furthermore, the dimension in the tube axis direction Dax from the distribution end wall 431 to the first connection section 21 of the first waveguide line 20a is equal to the dimension in the tube axis direction Dax from the distribution end wall 431 to the second connection section 31 of the second waveguide line 30a.

[0049] The first radiation opening 50 is a portion that radiates radio waves propagated from the power feed section 10 to the first waveguide section 20 into the external space of the antenna device 1 and also constitutes a slot portion that receives radio waves from the external space. The second radiation opening 60 is a portion that radiates radio waves propagated from the power feed section 10 to the second waveguide section 30 into the external space of the antenna device 1 and also constitutes a slot portion that receives radio waves from the external space.

[0050] The first radiation opening 50 is formed to penetrate the second block BC2 in the stacking direction Dst from one surface of the second block BC2 in the stacking direction Dst to the first waveguide section 20. The second radiation opening 60 is formed to penetrate the second block BC2 in the stacking direction Dst from one surface of the second block BC2 in the stacking direction Dst to the second waveguide section 30.

[0051] The first radiation opening 50 has a first radiation opening 51 on one side in the stacking direction Dst that opens toward the external space of the antenna device 1. Furthermore, the first radiation opening 50 has a first communication port 52 that communicates with the first waveguide section 20 on the other side in the stacking direction Dst. The first radiation opening 50 is formed as a through hole that penetrates the second block BC2 from the first radiation opening 51 to the first communication port 52. Furthermore, the first radiation opening 50 has a first peripheral wall surface 53 that is the wall surface of the first radiation opening 50 formed as a through hole. The first peripheral wall surface 53 is formed in an annular shape that surrounds the first radiation opening 50 when viewed in a direction perpendicular to the stacking direction Dst.

[0052] The second radiation opening 60 has a second radiation opening 61 on one side in the stacking direction Dst that opens toward the external space of the antenna device 1. Furthermore, the second radiation opening 60 has a second communication port 62 that communicates with the second waveguide section 30 on the other side in the stacking direction Dst. The second radiation opening 60 is formed as a through hole that penetrates the second block BC2 from the second radiation opening 61 to the second communication port 62. Furthermore, the second radiation opening 60 has a second peripheral wall surface 63 that is the wall surface of the second radiation opening 60 formed as a through hole. The second peripheral wall surface 63 is formed in an annular shape that surrounds the second radiation opening 60 when viewed in a direction perpendicular to the stacking direction Dst.

[0053] The first radiation opening 50 and the second radiation opening 60 have a cross section perpendicular to the stacking direction Dst that is formed into an oval shape extending in the tube axis direction Dax. That is, the first radiation opening 50 and the second radiation opening 60 have a smaller dimension in the tube width direction Dcr than the dimension in the tube axis direction Dax. The first radiation opening 50 and the second radiation opening 60 are formed into a tapered shape whose inner diameter increases from the other side to one side in the stacking direction Dst. Specifically, the first radiation opening 50 is formed as a through hole whose inner diameter widens from the first communication port 52 toward the first radiation opening 51. The second radiation opening 60 is formed as a through hole whose inner diameter widens from the second communication port 62 toward the second radiation opening 61.

[0054] In other words, the first radiation opening 50 and the second radiation opening 60 are formed as through holes whose inner diameters become wider toward one side in the stacking direction Dst. In the first radiation opening 50 of this embodiment, the dimension in the pipe width direction Dcr of the first communication port 52 is equal to the dimension in the pipe width direction Dcr of the first waveguide portion 20, and the dimension in the pipe width direction Dcr of the first radiation opening 51 is larger than the dimension in the pipe width direction Dcr of the first waveguide portion 20. In addition, in the second radiation opening 60 of this embodiment, the dimension in the pipe width direction Dcr of the second communication port 62 is equal to the dimension in the pipe width direction Dcr of the second waveguide portion 30, and the dimension in the pipe width direction Dcr of the second radiation opening 61 is larger than the dimension in the pipe width direction Dcr of the second waveguide portion 30.

[0055] For this reason, the first peripheral wall surface 53 surrounding the first radiation opening 50 is inclined with respect to the direction along the stacking direction Dst so that the distance from the axis of the first radiation opening 50 increases from the other side to one side of the stacking direction Dst. That is, the first peripheral wall surface 53 has an inclined surface in which the cross-sectional shape perpendicular to the tube axis direction Dax and the cross-sectional shape perpendicular to the tube width direction Dcr are both inclined with respect to the direction along the stacking direction Dst.

[0056] Furthermore, the second peripheral wall surface 63 surrounding the second radiation opening 60 is inclined relative to the direction along the stacking direction Dst so that the distance from the axis of the second radiation opening 60 increases from the other side to one side of the stacking direction Dst. That is, the second peripheral wall surface 63 is an inclined surface in which the cross-sectional shape perpendicular to the tube axis direction Dax and the cross-sectional shape perpendicular to the tube width direction Dcr are both inclined relative to the direction along the stacking direction Dst.

[0057] The first radiation opening 50 and the second radiation opening 60 are formed at different positions in the tube axis direction Dax, and are formed offset in the tube axis direction Dax. Specifically, in this embodiment, the first radiation opening 50 is formed offset to one side in the tube axis direction Dax from the second radiation opening 60.

[0058] As a result, the distance of the first radiation opening 50 from the feed opening 411 in the tube axis direction Dax is shorter than the distance in the tube axis direction Dax between the second radiation opening 60 and the feed opening 411. That is, the first radiation opening 50 is formed at a position closer to the feed opening 411 than the second radiation opening 60. In other words, the distance from the first connection portion 21 to the portion of the first waveguide 20a where the first communication port 52 communicates is shorter than the distance from the second connection portion 31 to the portion of the second waveguide 30a where the second communication port 62 communicates.

[0059] 4, the aperture pitch PT is the distance in the tube axis direction Dax between the center of a cross section perpendicular to the stacking direction Dst of the first radiation aperture 50 and the center of a cross section perpendicular to the stacking direction Dst of the second radiation aperture 60. The aperture pitch PT is the distance from the axis center of the first radiation aperture 50, whose cross section perpendicular to the stacking direction Dst is formed in an elliptical shape, to the axis center of the second radiation aperture 60, whose cross section perpendicular to the stacking direction Dst is also formed in an elliptical shape.

[0060] The opening pitch PT is set to a value that is smaller than the guide wavelength λ of the radio waves propagating through the first waveguide 20a and the second waveguide 30a. g For example, the aperture pitch PT is set based on the guide wavelength λ g In this embodiment, the opening pitch PT is set to a value obtained by multiplying half the length of the guide wavelength λ g ×0.5, i.e., the wavelength in the tube λ g The aperture pitch PT is set to half the wavelength λ in the strict sense. g ×0.5, it may be a size including manufacturing errors, for example, the wavelength in the tube λ g ×0.4~intra-tube wavelength λ g In the antenna device 1 of this embodiment, the guide wavelength λ g is 6.0 mm, the free space wavelength λ0 is 3.92 mm, and the aperture pitch PT is 3.0 mm.

[0061] As shown in FIG. 4 , the combined dimension of the first waveguide section 20 in the tube axis direction Dax and the distribution section 40 in the tube axis direction Dax is defined as the axial dimension Dx. The dimension from one end of the first waveguide section 20 in the tube width direction Dcr to the other end of the second waveguide section 30 in the tube width direction Dcr is defined as the width dimension Dr. In this embodiment, the axial dimension Dx is 8.75 mm, and the width dimension Dr is 1.3 mm. The width dimension Dr is a dimension that is less than half the free space wavelength λ0. The feeding section 10 has a tube width direction Dcr dimension of 0.85 mm. That is, the combined dimension of the width direction Dr and the feeding section 10 in the tube width direction Dcr is 2.15 mm.

[0062] Next, we will explain the operation of the antenna device 1. In the antenna device 1 of this embodiment, for example, when radio waves are output from the input / output unit 3 of the MMIC 2, the radio waves are input to the external port 6. Then, the radio waves input to the external port 6 propagate from the external port 6 to the power feed line 10a of the power feed unit 10, and are propagated to the distribution waveguide 40a of the distribution unit 40 via the power feed line 10a.

[0063] The radio waves input to the branching waveguide 40a are branched within the branching waveguide 40a, with one branch propagating to the other side in the tube axis direction Dax and the other branch propagating to one side in the tube axis direction Dax. The radio waves propagated to the other side in the tube axis direction Dax propagate to the first waveguide line 20a of the first waveguide section 20. The radio waves propagated to one side in the tube axis direction Dax propagate through the first branching section 41, the third branching section 43, and the second branching section 42, are folded back, and then propagate to the second waveguide line 30a of the second waveguide section 30. The radio waves propagating to the first waveguide line 20a are radiated from the first radiation opening 51 of the first radiation opening 50 to the external space of the antenna device 1. The radio waves propagating to the second waveguide line 30a are radiated from the second radiation opening 61 of the second radiation opening 60 to the external space of the antenna device 1.

[0064] For example, when the input / output unit 3 of the MMIC 2 receives radio waves from the space outside the antenna device 1, the antenna device 1 propagates the radio waves in the opposite direction to when the radio waves are output from the input / output unit 3 described above.

[0065] Next, we will explain why the antenna device 1 of this embodiment has a distribution section 40 and is configured to radiate the radio waves distributed within the distribution waveguide 40a from each of the first radiation opening 51 and the second radiation opening 61 into the space outside the antenna device 1. An antenna device having multiple openings for radiating radio waves, such as the antenna device 1 of this embodiment, can amplify the radio waves and improve the gain by making the phases of the radio waves radiated from each opening in the same phase. Therefore, when multiple openings are formed in a waveguide that propagates radio waves, it is necessary to arrange each of the multiple openings in the waveguide so that the phases of the radio waves radiated from each opening are in the same phase.

[0066] Here, the phase of the radio waves radiated by the antenna device will be described with reference to an illustrative hollow waveguide 100 shown in FIGS. 6 to 9. As shown in FIG. 6, the hollow waveguide 100 is formed to extend in the X direction D1 and has a rectangular cylindrical shape with a dimension in the Z direction D3 smaller than the dimension in the Y direction D2. The X direction D1 shown in FIG. 6 is the direction in which energy is supplied to the hollow waveguide 100 to propagate radio waves within the hollow waveguide 100, and corresponds to the tube axis direction Dax of the first waveguide section 20 and the second waveguide section 30 of this embodiment. The Y direction D2 is a direction perpendicular to the X direction D1 and corresponds to the stacking direction Dst of the first waveguide section 20 and the second waveguide section 30 of this embodiment. The Z direction D3 is a direction perpendicular to the X direction D1 and the Y direction D2 and corresponds to the tube width direction Dcr of the first waveguide section 20 and the second waveguide section 30 of this embodiment.

[0067] The hollow waveguide 100 has a hollow waveguide 100a whose cross section perpendicular to the X direction D1 is rectangular and extends in the Y direction D2, and which propagates radio waves therethrough. The hollow waveguide 100 has a wall with a constant thickness in the cross section perpendicular to the X direction D1. That is, like the hollow waveguide 100, the hollow waveguide 100a has a rectangular cross section perpendicular to the X direction D1 that extends in the Y direction D2. The hollow waveguide 100 has two wide wall portions 110 that face each other and extend in the X direction D1 and the Y direction D2, and two narrow wall portions 120 that face each other and extend in the X direction D1 and the Z direction D3. The dimension of each of the two wide wall portions 110 in the Y direction D2 is greater than the dimension of each of the two narrow wall portions 120 in the Z direction D3. The hollow waveguide 100 a is formed by being surrounded by two wide wall portions 110 and two narrow wall portions 120 .

[0068] In the hollow waveguide 100 thus formed, energy is supplied from one side to the other in the X direction D1 to propagate radio waves in the TE10 mode. TE10 mode refers to the Transverse Electric 10 mode. In this case, an electric field is generated in the hollow waveguide 100a in the direction along the Z direction D3, as shown by the solid arrow in FIG. 7. The direction of this electric field alternates along the X direction D1 between a direction from one side to the other in the Z direction D3 and a direction from the other side to one side in the Z direction D3.

[0069] Furthermore, as the electric field is generated, a magnetic field is generated in the hollow waveguide 100a in a spiral direction that spirals in a substantially square shape in a plan view that is viewed in a direction along the Z direction D3, as shown by the dashed arrows in Fig. 7. Multiple magnetic fields are generated side by side along the X direction D1 as the electric field is generated, and the spiral directions of adjacent magnetic fields are opposite to each other. Furthermore, the interval between adjacent magnetic fields is equal to the guide wavelength λ g This allows the radio wave to propagate along the X direction D1 within the hollow waveguide 100a.

[0070] Next, when forming multiple radiation ports 130 in a hollow waveguide 100 in which such electric and magnetic fields are generated within the hollow waveguide 100a, limitations on the arrangement due to differences in the arrangement of the radiation ports 130 will be described with reference to FIGS. 8 and 9. FIG. 8 shows an example in which two radiation ports 130 are arranged in only one narrow wall portion 120 of two narrow wall portions 120 and two wide wall portions 110 surrounding the hollow waveguide 100a. In contrast, FIG. 9 shows an example in which three radiation ports 130 are arranged in only one wide wall portion 110 of two narrow wall portions 120 and two wide wall portions 110 surrounding the hollow waveguide 100a. In addition, in FIGS. 8 and 9, the electric field generated in the hollow waveguide 100a is indicated by a solid line, and the magnetic field generated in the hollow waveguide 100a is indicated by a dashed line. In the examples shown in Figures 8 and 9, in a hollow waveguide 100 in which the propagation mode of radio waves is TE10 mode, in both examples, each of the multiple radiation ports 130 is arranged so that the phases of the radio waves emitted from each of the radiation ports 130 are in phase.

[0071] Specifically, when two radiation ports 130 are arranged in the narrow wall portion 120, the two radiation ports 130 need to be arranged side by side along the X direction D1 at a position where the direction of the magnetic field is along the X direction D1, as shown in Fig. 8. When two radiation ports 130 are arranged side by side along the X direction D1 in the narrow wall portion 120 in this way and are excited at each of the two radiation ports 130, the distance between the two radiation ports 130 is set to be equal to the guide wavelength λ g It is necessary to set the dimension to a positive multiple of the length of

[0072] The distance between the two radiation ports 130 is set to the wavelength λ g 8, it is possible to align the directions of the magnetic fields at the two radiation ports 130. This makes it possible to make the phases of the radio waves radiated from the two radiation ports 130 the same. That is, when two radiation ports 130 are arranged in the narrow wall portion 120 and the propagation mode of the radio waves is the TE10 mode, in order to make the phases of the radio waves radiated from each radiation port 130 the same, the distance between the two radiation ports 130 must be at least equal to the guide wavelength λ gTherefore, when a plurality of radiation ports 130 are arranged in narrow wall portion 120, the dimension of the antenna device in X direction D1 tends to increase.

[0073] In FIG. 8, the distance between the two radiation ports 130 is equal to the guide wavelength λ g 8, the distance between the two radiation ports 130 is equal to the guide wavelength λ g When the provisional radiation port 130 is placed at a position where the length is half of the wavelength λ g The direction of the magnetic field of the temporary radiation port 130 is opposite to the direction of the magnetic field of the two radiation ports 130 that are separated by half the length of the temporary radiation port 130. In this case, the phase of the radio waves emitted from the temporary radiation port 130 is opposite to the phase of the radio waves emitted from each of the two radiation ports 130. For this reason, the phase of the radio waves emitted from the temporary radiation port 130 cannot be made to be the same as the phase of the radio waves emitted from the two radiation ports 130 adjacent to the temporary radiation port 130, making it difficult to obtain a high gain.

[0074] Next, a case where three radiation ports 130 are arranged in the wide wall portion 110 will be described with reference to Fig. 9. As shown in Fig. 9, when excitation is performed using each of the three radiation ports 130 arranged in the wide wall portion 110, two of the three radiation ports 130 need to be arranged side by side along the X direction D1 at positions where the direction of the magnetic field is along the X direction D1. Furthermore, the remaining radiation port 130 of the three radiation ports 130 can be arranged at a position shifted in the Y direction D2 from the two radiation ports 130, so that the direction of the magnetic field is opposite to that of the two radiation ports 130.

[0075] When the two radiation ports 130 are arranged side by side in the X direction D1 in the wide wall portion 110 in this way, the distance between the two radiation ports 130 is equal to the guide wavelength λ g In addition, the distance in the X direction D1 between each of the two radiation ports 130 arranged in the X direction D1 and one radiation port 130 arranged with a shift in the Y direction D2 must be set to a dimension that is a positive multiple of the length of the guide wavelength λg That is, when three radiation ports 130 are arranged in the wide wall portion 110, they are alternately shifted to one side and the other in the Y direction D2, and the length of the radiation port 130 is set to a dimension equal to the length of the guide wavelength λ in the X direction D1. g It is necessary to arrange the radiation ports 130 at intervals equal to a positive multiple of half the length of the radiation port 130.

[0076] In this way, the distance between each of the three radiation ports 130 in the X direction D1 is set to the guide wavelength λ g 9, it is possible to align the magnetic field directions of the three radiation ports 130. This makes it possible to make the phases of the radio waves emitted from the three radiation ports 130 the same. Therefore, when three radiation ports 130 are arranged in the wide wall portion 110 and the propagation mode of the radio waves is the TE10 mode, the distance between the three radiation ports 130 in the X direction D1 is set to be equal to the guide wavelength λ g That is, when the radiation port 130 is disposed in the wide wall portion 110, the guide wavelength λ g The radiation ports 130 can be arranged side by side in the X direction D1 while being alternately shifted in the Y direction D2 every half the length of the radiation port 130.

[0077] For this reason, when the radiation outlets 130 are arranged in the wide wall portion 110 of the hollow waveguide 100, the number of radiation outlets 130 can be made larger than when the radiation outlets 130 are arranged in the narrow wall portion 120 of the hollow waveguide 100 having the same dimension in the X direction D1. As a result, when the radiation outlets 130 are arranged in the wide wall portion 110, a higher gain can be obtained than when the radiation outlets 130 are arranged in the narrow wall portion 120 having the same dimension in the X direction D1. In other words, when the number of radiation outlets 130 is the same, when the radiation outlets 130 are arranged in the wide wall portion 110, the dimension of the hollow waveguide 100 in the X direction D1 can be made smaller than when the radiation outlets 130 are arranged in the narrow wall portion 120.

[0078] However, in a configuration in which radiation outlets 130 are arranged in the wide wall portion 110, in addition to arranging multiple radiation outlets 130 in a row in the X direction D1, radiation outlets 130 must also be arranged at positions shifted in the Y direction D2 from the radiation outlets 130 arranged in the X direction D1. Generally, when arranging radiation outlets 130 in the wide wall portion 110, the size of the wide wall portion 110 in the Y direction D2 must be about half the length of the free space wavelength λ0 to the length of the free space wavelength λ0. For example, g When the distance is 6.0 mm and the free space wavelength λ0 is 3.92 mm, the size of the wide wall portion 110 in the Y direction D2 is 1.98 mm to 3.92 mm.

[0079] As a result, in a configuration in which the radiation outlet 130 is arranged in the wide wall portion 110, the size in the Y direction D2 is more than twice as large as in a configuration in which the radiation outlet 130 is arranged in the narrow wall portion 120. For this reason, when the radiation outlet 130 is arranged in the wide wall portion 110, the dimension of the hollow waveguide 100 in the Y direction D2 is larger than when the radiation outlet 130 is arranged in the narrow wall portion 120 of a hollow waveguide 100 that has the same dimension in the X direction D1.

[0080] As described above, when the propagation mode of the radio wave in the hollow waveguide 100 extending in the X direction D1 is the TE10 mode, the direction of the magnetic field generated in the hollow waveguide 100 is the guide wavelength λ g Therefore, when multiple radiation ports 130 are arranged in the narrow wall portion 120 and the radio waves from each radiation port 130 are made to have the same phase, the spacing between each of the multiple radiation ports 130 is set to be equal to the guide wavelength λ g Therefore, the dimension of the hollow waveguide 100 in the X direction D1 tends to be large.

[0081] On the other hand, when a plurality of radiation ports 130 are arranged in the wide wall portion 110 and the radio waves from each radiation port 130 are in phase, the wavelength λ g The radiation ports 130 can be arranged side by side in the X direction D1 while being alternately shifted in the Y direction D2 every half the length of the narrow wall portion 120. Therefore, compared to when a plurality of radiation ports 130 are arranged in the narrow wall portion 120, the dimension of the hollow waveguide 100 in the X direction D1 can be made smaller, but the dimension in the Y direction D2 is likely to be larger.

[0082] Therefore, when multiple radiation ports 130 are arranged in the narrow wall portion 120 of the hollow waveguide 100 extending in the X direction D1, it is difficult to reduce the dimension of the antenna device in the X direction D1. Also, when multiple radiation ports 130 are arranged in the wide wall portion 110 of the hollow waveguide 100 extending in the X direction D1, it is difficult to reduce the dimension of the antenna device in the Y direction D2. Furthermore, according to careful studies by the inventors, it has been found that when multiple radiation ports 130 are arranged in a straight line along the X direction D1, the side lobes of the radio waves radiated from the antenna device tend to become large.

[0083] Here, the inventors verified a change in phase when a supply unit 210 for supplying energy was connected to one side in the Y direction D2 of a distribution waveguide 200 extending in the X direction D1 shown in Fig. 10 and radio waves were distributed into two within the distribution waveguide 200. The distribution waveguide 200 is formed so that its dimension in the Z direction D3 is larger than its dimension in the Y direction D2, and has a supply port 220 to which the supply unit 210 is connected and a distribution path 200a inside which the radio waves propagate. The distribution path 200a is connected to the supply unit 210 extending in the Y direction D2. In this verification, the radio waves were propagated in the TE10 mode, as in the case of propagating radio waves in the hollow waveguide 100.

[0084] In this way, in the distribution waveguide 200 extending in the X direction D1, when energy is supplied from one side in the Y direction D2 to propagate radio waves, the radio waves propagated in the distribution path 200a are distributed to one side and the other side in the X direction D1 at the supply port 220. Then, one of the radio waves distributed in the distribution path 200a propagates to one side in the X direction D1, and the other propagates to the other side in the X direction D1.

[0085] According to careful investigations by the inventors, when energy is supplied to distribution path 200a from the Y direction D2, the directions of the electric fields generated at locations that are the same distance from the location where supply port 220 is connected on one side and the other side in the X direction D1 are opposite to each other, as shown by the arrows in Fig. 11. Therefore, the radio waves distributed by distribution path 200a and propagated the same distance to one side and the other side in the X direction D1 have opposite phases to each other.

[0086] The direction of the electric field generated at a position slightly away from the position where the supply port 220 is connected to one side in the X direction D1 is the same as the direction of the electric field generated at a position slightly away from the position where the supply port 220 is connected to the other side in the X direction D1, and the direction of the electric field is the same as the direction of the electric field generated at a position slightly away from the position where the supply port 220 is connected to the other side in the X direction D1. g Therefore, the electric field generated at a location separated by half the size of the distribution path 200a is slightly propagated to one side in the X direction D1, and the electric field generated at a location separated by half the size of the distribution path 200a is slightly propagated to the other side in the X direction D1. g The radio waves propagating at half the amplitude of the radiated wave are in phase with each other.

[0087] Therefore, by configuring the branch waveguide 200 to supply energy from one side in the Y direction D2, the distance between the two openings that radiate the radio waves can be set to the guide wavelength λ g However, if three or more openings for emitting radio waves are arranged along the X direction D1 in the distribution waveguide 200 extending in the X direction D1, the dimension in the X direction D1 increases, making it difficult to reduce the dimension of the antenna device in the X direction D1.

[0088] For this reason, the inventors have considered reducing the dimensions of the antenna device 1 in both the X direction D1 and the Y direction D2 by making the shape of the waveguide that propagates radio waves into a folded U-shape in the antenna device 1 of this embodiment. Specifically, they have considered a configuration in which the waveguide is folded back 180° using the first waveguide section 20, the second waveguide section 30, and the distribution section 40, and the first radiation opening 50 is arranged in the first waveguide section 20, and the second radiation opening 60 is arranged in the second waveguide section 30. Then, the aperture pitch PT between the first radiation opening 50 and the second radiation opening 60 is set to be equal to the guide wavelength λ gIt was investigated that the phases of the radio waves radiated from the first radiation opening 50 and the second radiation opening 60 would be in phase by setting the size of the opening 50 to half of the above.

[0089] However, to make the radio waves emitted in this shape have the same phase, it is necessary to make the direction of the magnetic field generated at the first radiation opening 50 and the direction of the magnetic field at the portion of the second waveguide section 30 where the first radiation opening 50 overlaps with the pipe width direction Dcr opposite to each other, as shown in Fig. 11. In other words, it is necessary to make the phase of the radio waves propagated through the first waveguide 20a up to the first radiation opening 50 and the phase of the radio waves propagated through the second waveguide 30a up to the portion where the first radiation opening 50 overlaps with the pipe width direction Dcr opposite to each other.

[0090] Therefore, in the antenna device 1 of this embodiment, the distribution section 40 can make the phases of the radio waves propagated up to the portions where the first waveguide section 20 and the second waveguide section 30 overlap in the pipe width direction Dcr opposite to each other. Specifically, the distribution section 40 of this embodiment can invert the phase of the radio waves propagated from the feed opening 411 to the second connection section 31 relative to the phase of the radio waves propagated from the feed opening 411 to the first connection section 21.

[0091] The configuration of the distributor 40 for inverting the phase of the radio wave propagated to the first connection portion 21 and the phase of the radio wave propagated to the second connection portion 31 will be described with reference to FIG. 12. FIG. 12 is a simplified schematic diagram of the antenna device 1 to explain the configuration of the distributor 40 for inverting the phase of the radio wave propagated to the first connection portion 21 and the phase of the radio wave propagated to the second connection portion 31. In FIG. 12, arrows indicate the directions of the electric fields generated in the feed line 10a, the first waveguide 20a, the second waveguide 30a, and the distribution waveguide 40a. In this embodiment, an example will be described in which energy is supplied so that an electric field is generated in the feed line 10a from one side to the other side in the tube axis direction Dax, as shown in FIG.

[0092] 12, when the center of the power feed opening 411 in the tube axis direction Dax is defined as the power receiving center Ec, the distance in the tube axis direction Dax from the power receiving center Ec to the first connection portion 21 is defined as the first distance Ds1. Furthermore, the distance in the tube axis direction Dax from the power receiving center Ec to the distribution end wall 431 is defined as the second distance Ds2. The first distance Ds1 is the distance in the tube axis direction Dax from the other end of the distribution portion 40 in the tube axis direction Dax to the power receiving center Ec. The second distance Ds2 is the distance in the tube axis direction Dax from one end of the distribution portion 40 in the tube axis direction Dax to the power receiving center Ec.

[0093] The first distance Ds1 in this embodiment is set so that when radio waves are propagated from the power supply section 10 to the first distribution section 41, the electric field at the part of the first waveguide section 20 facing the first radiation opening 50 is directed from the other side to one side in the tube width direction Dcr.

[0094] Furthermore, the second distance Ds2 in this embodiment is set so that when radio waves are propagated to the first distribution unit 41, the direction of the electric field generated at a predetermined portion of the second distribution unit 42 is opposite to the direction of the electric field generated at a portion of the first distribution unit 41 that overlaps with that portion in the tube axis direction Dax. For example, the second distance Ds2 is set so that the direction of the electric field generated at a portion that overlaps with the power receiving center Ec of the first distribution unit 41 in the tube axis direction Dax is opposite to that of the electric field generated at a portion that overlaps with the power receiving center Ec of the second distribution unit 42 in the tube axis direction Dax.

[0095] That is, the second distance Ds2 is set so that the phase of the radio wave propagated to a predetermined portion of the second distribution unit 42 is opposite to the phase of the radio wave propagated to a portion of the first distribution unit 41 that overlaps with the predetermined portion in the tube axis direction Dax. For example, the second distance Ds2 is set so that the phase of the radio wave propagated to a portion that overlaps with the power receiving center Ec of the second distribution unit 42 in the tube axis direction Dax is opposite to the phase of the radio wave when propagated from the first power feeding unit 11 to the first distribution unit 41. In other words, in the distribution unit 40, the first distance Ds1 and the second distance Ds2 are set so that the phase of the radio wave propagating to the first connection portion 21 of the first waveguide unit 20 and the phase of the radio wave propagating to the second connection portion 31 of the second waveguide unit 30 are opposite to each other.

[0096] For example, the first distance Ds1 is equal to the guide wavelength λ g When the second distance Ds2 is set to a value within a range of 1 / 20 to 1 / 10 of the guide wavelength λ g The first distance Ds1 and the second distance Ds2 are set to any value within a range of 1 / 5 to 1 / 4 of the above. However, the first distance Ds1 and the second distance Ds2 are merely examples, and the present invention is not limited to these.

[0097] By setting the first distance Ds1 and the second distance Ds2 in this manner, the direction of the electric field at the first connection part 21 and the direction of the electric field at the second connection part 31 can be made opposite to each other, as shown in Fig. 12. Furthermore, the phase direction of the radio wave propagated to the first connection part 21 and the phase direction of the radio wave propagated to the second connection part 31 can be made opposite to each other.

[0098] This allows the electric field directions to be opposite to each other at portions of the first waveguide section 20 and the second waveguide section 30 that overlap with each other in the pipe width direction Dcr. Therefore, the electric field direction at the portion of the first waveguide section 20 facing the first radiation opening 50 and the electric field direction at the portion of the second waveguide section 30 that overlaps with the first radiation opening 50 in the pipe width direction Dcr can be opposite to each other. This is because, as described above, the first waveguide section 20, the second waveguide section 30, and the distributor 40 have the same cross-sectional shape perpendicular to the direction in which the radio waves propagate.

[0099] Therefore, the phase directions of the radio waves propagated to the portions of the first waveguide section 20 and the second waveguide section 30 that overlap each other in the tube width direction Dcr can be made opposite to each other. Then, the phase of the radio waves propagated to the portion of the first waveguide section 20 that faces the first radiation opening 50 and the phase of the radio waves propagated from that portion to the tube axis direction Dax with the guide wavelength λ g The phase of the radio waves propagated to the portion facing the second radiation opening 60, which is half the distance from the first radiation opening 50, can be made to be in phase with the radio waves radiated from the first radiation opening 50 and the second radiation opening 60. Therefore, the phases of the radio waves radiated from the first radiation opening 50 and the second radiation opening 60 can be made to be in phase with each other. Then, the radio waves radiated from the antenna device 1 can be amplified, thereby improving the magnitude of the gain.

[0100] Next, the differences between the antenna device 1 of this embodiment and an antenna device of a comparative example to be compared with the antenna device 1 of this embodiment will be described with reference to Figs. 13 to 16. Figs. 13 and 14 show the shape and various dimensions of a comparison waveguide 300 of the antenna device of the comparative example. Furthermore, Figs. 15 and 16 will be used to describe the results of a computer simulation comparing the gain of the antenna device 1 of this embodiment with the gain of the antenna device of the comparative example.

[0101] 13 and 14, the comparative waveguide 300 has a shape along the tube axis direction Dax and does not have a configuration equivalent to the distribution section 40, and two comparative radiation openings 310 are formed along the tube axis direction Dax. In addition, these two comparative radiation openings 310 have a distance in the tube axis direction Dax that is equal to the in-tube wavelength λ in order to make the phases of the radio waves radiated from the two comparative radiation openings 310 the same. g That is, the size is set to 6.0 mm, which is double the size of 3.0 mm that is the size of the aperture pitch PT in the antenna device 1 of this embodiment.

[0102] Furthermore, the comparative radiation aperture 310 is not inclined relative to the direction along the stacking direction Dst. The comparative waveguide 300 has a dimension in the tube axis direction Dax of 9.52 mm and a dimension in the tube width direction Dcr of 0.85 mm. Except for these, the antenna device of the comparative example and the antenna device 1 of this embodiment have similar structures. In this way, when two comparative radiation apertures 310 are arranged in the comparative waveguide 300 along the tube axis direction Dax, the dimension in the tube axis direction Dax is larger than the axial dimension Dx of this embodiment.

[0103] Furthermore, the above computer simulation comparing the antenna device 1 of this embodiment with the antenna device of the comparative example yielded the results shown in Fig. 15 and Fig. 16. Fig. 15 is a graph showing the gain distribution in the antenna device of the comparative example, and Fig. 16 is a graph showing the gain distribution in the antenna device 1 of this embodiment.

[0104] The solid lines shown in Figures 15 and 16 represent the gain distribution on a plane perpendicular to the tube axis direction Dax, and the dashed lines shown in Figures 15 and 16 represent the gain distribution on a plane perpendicular to the tube width direction Dcr. Note that Figures 15 and 16 show the gain distributions obtained when radio waves with a frequency of 76.5 GHz are input to antenna device 1 and the antenna device of the comparative example.

[0105] 15 and 16, the maximum gain obtained from the antenna device of the comparative example and the maximum gain obtained from antenna device 1 were approximately the same. Specifically, the maximum gain obtained from the antenna device of the comparative example was 10.32 dBi. In contrast, the maximum gain obtained from antenna device 1 of this embodiment was 10.31 dBi. Thus, the difference between the maximum gain obtained from the antenna device of the comparative example and the maximum gain obtained from antenna device 1 was 0.01 dBi.

[0106] 15 and 16, the antenna device 1 of this embodiment was able to suppress the side lobes more than the antenna device of the comparative example. Therefore, the difference between the main lobe and the side lobe in the antenna device of the comparative example could be made to be significantly different from the difference between the main lobe and the side lobe in the antenna device 1 of this embodiment.

[0107] Specifically, the difference between the maximum value of the main lobe and the maximum value of the side lobe in the antenna device of the comparative example was 4.43 dBc, which was a relatively small value. In contrast, the difference between the maximum value of the main lobe and the maximum value of the side lobe in the antenna device 1 of this embodiment was 18.31 dBc, which was a relatively large value. Furthermore, the antenna device 1 was able to improve the difference between the maximum value of the main lobe and the maximum value of the side lobe by 13.88 dBc compared to the antenna device of the comparative example.

[0108] Incidentally, when the antenna device 1 is used for object detection, if the difference between the maximum value of the main lobe and the maximum value of the side lobe is small, it can cause detection errors due to detecting the side lobe. Therefore, in general, it is desirable that the difference between the maximum value of the main lobe and the maximum value of the side lobe is as large as possible. For example, it is desirable that the difference between the maximum value of the main lobe and the maximum value of the side lobe is 17 dBc or more. The antenna device 1 of this embodiment was able to achieve a difference between the maximum value of the main lobe and the maximum value of the side lobe of 18.31 dBc. Therefore, when the antenna device 1 is used for object detection, detection errors due to detecting the side lobe can be suppressed.

[0109] As described above, in the antenna device 1 of this embodiment, the first waveguide section 20 extends in the tube axis direction Dax and has the first connection section 21 connected to the distribution section 40 on one side in the tube axis direction Dax. The second waveguide section 30 extends in the tube axis direction Dax and has the second connection section 31 connected to the distribution section 40 on one side in the tube axis direction Dax. The first connection section 21 and the second connection section 31 overlap in the tube axis direction Dax. The first radiation opening section 50 and the second radiation opening section 60 are arranged with their positions shifted in the tube axis direction Dax. The distribution section 40 has a feed opening 411 in the tube width direction Dcr and is folded back from one side in the tube axis direction Dax to the other side so that radio waves can propagate to the first connection section 21 of the first waveguide section 20 and the second connection section 31 of the second waveguide section 30 that are adjacent to each other with the partition wall section 13 interposed therebetween. Then, the distributor 40 causes the phases of the radio waves propagating to the first connecting portion 21 and the second connecting portion 31 to be opposite to each other.

[0110] According to this, the phase of the radio wave propagating to the portion facing the first radiation opening 50 in the first waveguide portion 20 is adjusted to the in-guide wavelength λ g The phase of the radio wave propagating to the portion facing the second radiation opening 60, which is half the distance from the first radiation opening 50, can be made the same as the phase of the radio wave propagating to the portion facing the second radiation opening 60. Therefore, the phases of the radio waves radiated from the first radiation opening 50 and the second radiation opening 60 can be made the same. Then, the radio waves radiated from the antenna device 1 can be amplified, thereby improving the magnitude of the gain.

[0111] Furthermore, the axial dimension Dx can be made smaller than in a configuration in which a portion that radiates radio waves is arranged along the extension direction of a single waveguide, such as the hollow waveguide 100 and the comparative waveguide 300. For example, compared to a configuration in which two radiation ports 130 are arranged in the narrow wall portion 120 of the hollow waveguide 100, the axial dimension Dx can be made smaller by using a configuration that includes the first waveguide portion 20, the second waveguide path 30a, and the distribution portion 40.

[0112] Furthermore, compared to a configuration in which three radiation ports 130 are arranged in the wide wall portion 110 of the hollow waveguide 100, the width direction dimension Dr can be made smaller by configuring the waveguide that propagates the radio waves to have the first waveguide portion 20, the second waveguide line 30a, and the distribution unit 40. Even when compared to the combined dimension of the width direction dimension Dr and the dimension in the pipe width direction Dcr of the power feeding unit 10, this combined dimension can be made smaller than the dimension in the pipe width direction Dcr of the hollow waveguide 100 in which the radiation ports 130 are arranged in the wide wall portion 110. Furthermore, compared to a configuration in which two comparison radiation openings 310 are arranged in the comparison waveguide 300, the axial direction dimension Dx can be made smaller by configuring the waveguide that propagates the radio waves to have the first waveguide portion 20, the second waveguide line 30a, and the distribution unit 40.

[0113] Furthermore, the antenna device 1 of this embodiment can suppress side lobes compared to the antenna device of the comparative example described above, and can improve the difference between the maximum value of the main lobe and the maximum value of the side lobe. Therefore, compared to a configuration in which a portion that radiates radio waves is arranged in the direction in which a single waveguide extends, it is possible to suppress side lobes while preventing the antenna device 1 from becoming larger in size.

[0114] Furthermore, according to the above embodiment, the following effects can be obtained.

[0115] (1) In the above embodiment, the first waveguide section 20 has a one-side first narrow wall surface 25 and an other-side first narrow wall surface 26 extending in the tube axis direction Dax and the tube width direction Dcr, and a one-side first wide wall surface 23 and an other-side first wide wall surface 24 extending in the tube axis direction Dax and the stacking direction Dst. The second waveguide section 30 has a one-side second narrow wall surface 35 and an other-side second narrow wall surface 36 extending in the tube axis direction Dax and the tube width direction Dcr, and a one-side second wide wall surface 33 and an other-side second wide wall surface 34 extending in the tube axis direction Dax and the stacking direction Dst. The size of each of the one-side first narrow wall surface 25 and the other-side first narrow wall surface 26 in the tube width direction Dcr is smaller than the size of each of the one-side first wide wall surface 23 and the other-side first wide wall surface 24 in the stacking direction Dst. The size in the tube width direction Dcr of the one-side second narrow wall surface 35 and the other-side second narrow wall surface 36 is smaller than the size in the stacking direction Dst of the one-side second wide wall surface 33 and the other-side second wide wall surface 34. The first radiation opening 50 is arranged on the one-side first narrow wall surface 25 side of the first waveguide section 20. The second radiation opening 60 is arranged on the one-side second narrow wall surface 35 side of the second waveguide section 30.

[0116] This allows the widthwise dimension Dr to be smaller than when the first radiation opening 50 is arranged on the first wide wall surface 23 side of the first waveguide section 20 and the second radiation opening 60 is arranged on the second wide wall surface 34 side of the second waveguide section 30.

[0117] (2) In the above embodiment, the distribution section 40 has the first distance Ds1 and the second distance Ds2 set so that the phases of the radio waves propagating to the first connection section 21 of the first waveguide section 20 and the second connection section 31 of the second waveguide section 30 are opposite to each other.

[0118] According to this, by adjusting the dimensions of each of the first distance Ds1 and the second distance Ds2, the phases of the radio waves propagating to each of the first connection portion 21 and the second connection portion 31 can be easily made to be opposite phases to each other.

[0119] (3) In the above embodiment, the first radiation opening 50 has a first communication port 52 communicating with the first waveguide section 20 and a first radiation opening 51 opening toward the external space, and is formed as a through hole whose inner diameter widens from the first communication port 52 toward the first radiation opening 51. The second radiation opening 60 has a second communication port 62 communicating with the second waveguide section 30 and a second radiation opening 61 opening toward the external space, and is formed as a through hole whose inner diameter widens from the second communication port 62 toward the second radiation opening 61.

[0120] This allows the gain of the antenna device 1 to be increased compared to when the first radiation aperture 50 and the second radiation aperture 60 are through holes with a constant inner diameter.

[0121] (4) In the above embodiment, the antenna device 1 includes a power supply portion 10 that is connected to the power supply opening 411 and forms a power supply line 10a that forms a propagation path for propagating radio waves to the branch waveguide 40a. A part of the power supply portion 10 is bent with respect to the pipe width direction Dcr.

[0122] According to this, even if there is little space around the first waveguide section 20 to place the power supply section 10, by bending the power supply section 10, it is possible to easily connect the power supply section 10 to the first waveguide section 20.

[0123] (First modified example of the first embodiment) In the first embodiment described above, an example has been described in which the first radiation opening 50 is a through hole whose inner diameter widens from the first communication port 52 toward the first radiation opening 51, and whose cross section perpendicular to the stacking direction Dst is formed as an oval shape extending in the tube axis direction Dax. Also, in the first embodiment described above, an example has been described in which the second radiation opening 60 is a through hole whose inner diameter widens from the second communication port 62 toward the second radiation opening 61, and whose cross section perpendicular to the stacking direction Dst is formed as an oval shape extending in the tube axis direction Dax. However, the shapes of the first radiation opening 50 and the second radiation opening 60 are not limited to this.

[0124] 17 and 18, the first radiation opening 50 may be formed as a through hole having a constant inner diameter from the first communication port 52 to the first radiation opening 51. The second radiation opening 60 may be formed as a through hole having a constant inner diameter from the second communication port 62 to the second radiation opening 61.

[0125] Furthermore, although not shown, the first radiation opening 50 and the second radiation opening 60 may be formed so that the cross-sectional shape perpendicular to the stacking direction Dst is a perfect circle, an ellipse, a rectangle, a diamond, or other shape other than an oval.

[0126] (Second modified example of the first embodiment) In the above-described first embodiment, an example was described in which the cross-sectional shapes perpendicular to the direction in which the radio waves propagate in the first radiation opening 50, the second radiation opening 60, and the distribution section 40 are rectangular shapes extending in the stacking direction Dst, but this is not limited to this.

[0127] For example, as shown in Fig. 19, the first waveguide section 20, the second waveguide section 30, and the distribution section 40 may have a cross-sectional shape perpendicular to the direction of radio wave propagation that is oval and extends in the stacking direction Dst. Alternatively, as shown in Fig. 20, the first waveguide section 20, the second waveguide section 30, and the distribution section 40 may have a cross-sectional shape perpendicular to the direction of radio wave propagation that is formed by connecting two trapezoids in which the size of the pipe width direction Dcr increases toward the center in the stacking direction Dst. Alternatively, as shown in Fig. 21, the first waveguide section 20, the second waveguide section 30, and the distribution section 40 may have a cross-sectional shape perpendicular to the direction of radio wave propagation that is continuously increased in size in the pipe width direction Dcr toward the center in the stacking direction Dst. The first waveguide section 20, the second waveguide section 30 and the distribution section 40 may each be formed in an arc shape on one side and the other side of the stacking direction Dst of the cross-sectional shape perpendicular to the direction in which the radio waves propagate.

[0128] In the above embodiment, the first distance Ds1 is equal to the guide wavelength λ gThe second distance Ds2 is set to a value within a range of 1 / 20 to 1 / 10 of the guide wavelength λ g In the above example, the first distance Ds1 and the second distance Ds2 are set to any value within a range of 1 / 5 to 1 / 4 of the above value. However, if the cross-sectional shapes of the first waveguide section 20, the second waveguide section 30, and the distributor section 40 that are perpendicular to the direction in which the radio waves propagate are different from an elliptical shape, the first distance Ds1 and the second distance Ds2 may be changed.

[0129] The reason for this is that when the cross-sectional shape is changed, the reflection direction of the radio waves when reflected within the first waveguide section 20, the second waveguide section 30, and the distribution section 40 changes from the elliptical cross-sectional shape of the first waveguide section 20, the second waveguide section 30, and the distribution section 40. For this reason, the first distance Ds1 and the second distance Ds2 are set appropriately in accordance with the cross-sectional shapes of the first waveguide section 20, the second waveguide section 30, and the distribution section 40 so that the phases of the radio waves propagating to the first connection section 21 and the second connection section 31, respectively, are opposite to each other.

[0130] (Third modified example of the first embodiment) In the first embodiment described above, an example has been described in which the distance from the feed aperture 411 in the tube axis direction Dax of the first radiation aperture 50 is smaller than that of the second radiation aperture 60, but the present invention is not limited to this.

[0131] 22 to 24, the distance from the power feed opening 411 in the tube axis direction Dax of the second radiation opening 60 may be smaller than that of the first radiation opening 50, and the second radiation opening 60 may be formed at a position closer to the power feed opening 411 than the first radiation opening 50. In this case, the first distance Ds1 corresponds to the distance from the power receiving center Ec to the second connection portion 31 in the tube axis direction Dax.

[0132] (Fourth Modification of the First Embodiment) In the above-described first embodiment, an example has been described in which one first radiation opening 50 is connected to the first waveguide section 20, one second radiation opening 60 is connected to the second waveguide section 30, and the antenna device 1 has two radiation openings. However, the numbers of first radiation openings 50 and second radiation openings 60 are not limited to this.

[0133] 25 to 27, two first radiation openings 50 may be connected to the first waveguide section 20, and two second radiation openings 60 may be connected to the second waveguide section 30, so that the antenna device 1 has four radiation openings. Alternatively, although not shown, the antenna device 1 may have three first radiation openings 50 and three second radiation openings 60, or may have five or more first radiation openings 50 and five or more second radiation openings 60. Furthermore, the numbers of first radiation openings 50 and second radiation openings 60 may be equal to or different from each other.

[0134] (Fifth modified example of the first embodiment) In the first embodiment described above, an example has been described in which a part of the power supply portion 10 is bent at 90 degrees with respect to the tube width direction Dcr, but the present invention is not limited to this.

[0135] 28 and 29, the power supply section 10 may be formed in a straight line without being bent. Alternatively, although not shown, the power supply section 10 may be formed with a portion bent at an angle other than 90°. The shape of the power supply section 10 can be set appropriately depending on the space present around the first waveguide section 20.

[0136] (Second embodiment) Next, a second embodiment will be described with reference to FIG. 30. In this embodiment, the shape of the distribution section 40 is different from that of the first embodiment. Other than this, the second embodiment is similar to the first embodiment. Therefore, in this embodiment, the differences from the first embodiment will be mainly described, and descriptions of the same parts as the first embodiment may be omitted.

[0137] 30, in the distribution section 40 of this embodiment, the first distribution section 41 is formed to include a first inclined surface 412 that extends at an incline with respect to the tube axis direction Dax and the tube width direction Dcr. Also, in the distribution section 40, the second distribution section 42 is formed to include a second inclined surface 421 that extends at an incline with respect to the tube axis direction Dax and the tube width direction Dcr.

[0138] The first inclined surface 412 is configured by a part of a surface on one side in the tube width direction Dcr among the four surfaces surrounding the distribution waveguide 40a in the first distribution section 41. The first inclined surface 412 faces the distribution waveguide 40a and is inclined from the other side to one side in the tube axis direction Dax so as to approach the center of the distribution section 40 in the tube width direction Dcr. In other words, the first inclined surface 412 is inclined so as to approach the second waveguide section 30 of the first waveguide section 20 and the second waveguide section 30 adjacent to each other with the partition wall section 13 interposed therebetween.

[0139] The first inclined surface 412 is formed from a midpoint in the tube axis direction Dax of the first distribution section 41 to the distribution end wall 431 of the third distribution section 43. That is, in the first distribution section 41 of this embodiment, the other side in the tube axis direction Dax of the surface on one side in the tube width direction Dcr is formed along the tube axis direction Dax, and the one side in the tube axis direction Dax is formed inclined with respect to the tube axis direction Dax.

[0140] The second inclined surface 421 is configured by a part of the surface on the other side in the tube width direction Dcr among the four surfaces surrounding the distribution waveguide 40a in the second distribution section 42. The second inclined surface 421 faces the distribution waveguide 40a and is inclined from the other side to one side in the tube axis direction Dax so as to approach the center of the distribution section 40 in the tube width direction Dcr. In other words, the second inclined surface 421 is inclined so as to approach the first waveguide section 20 of the first waveguide section 20 and the second waveguide section 30 adjacent to each other with the partition wall section 13 interposed therebetween.

[0141] The second inclined surface 421 is formed from a midpoint in the tube axis direction Dax of the second distribution section 42 to the distribution end wall 431 of the third distribution section 43. That is, in the second distribution section 42 of this embodiment, the other side in the tube axis direction Dax of the surface on the other side in the tube width direction Dcr is formed along the tube axis direction Dax, and one side in the tube axis direction Dax is formed inclined with respect to the tube axis direction Dax.

[0142] The first inclined surface 412 and the second inclined surface 421 are formed so that their dimensions in the tube axis direction Dax are equal to each other and their dimensions in the tube width direction Dcr are equal to each other. That is, the first inclined surface 412 and the second inclined surface 421 have the same inclination angle, which is the angle with respect to the tube axis direction Dax. Hereinafter, the distance from one end of the first inclined surface 412 to the other end in the tube axis direction Dax is referred to as a third distance Ds3, and the distance from one end of the second inclined surface 421 to the other end in the tube axis direction Dax is referred to as a fourth distance Ds4. In this embodiment, the third distance Ds3 and the fourth distance Ds4 are formed so that they are equal to each other.

[0143] In the distribution unit 40 of this embodiment formed in this manner, radio waves introduced into the distribution waveguide 40a propagate through the first distribution unit 41, the third distribution unit 43, and the second distribution unit 42, and are then folded back. At this time, the propagation distance of the radio waves changes compared to the configuration of the first embodiment that does not have the first inclined surface 412 and the second inclined surface 421. Therefore, the amount of phase change when the radio waves propagate through the distribution waveguide 40a changes.

[0144] For this reason, the first distance Ds1, the second distance Ds2, the third distance Ds3, and the fourth distance Ds4 in this embodiment are set so that, when radio waves are propagated to the first distribution unit 41, the direction of the electric field generated at a predetermined portion of the second distribution unit 42 is opposite to the direction of the electric field generated at a portion of the first distribution unit 41 that overlaps with the predetermined portion in the tube axis direction Dax. In other words, in the distribution unit 40, the first distance Ds1, the second distance Ds2, the third distance Ds3, and the fourth distance Ds4 are set so that the phases of the radio waves propagating to the first connection unit 21 and the phases of the radio waves propagating to the second connection unit 31 are opposite to each other.

[0145] Other configurations are the same as those of the first embodiment. The antenna device 1 of this embodiment can obtain the same effects as those of the first embodiment, which are achieved by a configuration similar to or equivalent to that of the first embodiment.

[0146] Furthermore, by configuring the antenna to have the first inclined surface 412 and the second inclined surface 421 as in this embodiment, even if it is difficult to ensure the second distance Ds2, the phase of the radio waves propagating to the first connection portion 21 and the phase of the radio waves propagating to the second connection portion 31 can be made to be opposite phases.

[0147] (First modified example of the second embodiment) In the first embodiment described above, an example has been described in which the first distribution section 41 includes the first inclined surface 412 and the second distribution section 42 includes the second inclined surface 421, but this is not limiting. For example, the distribution section 40 may have a shape in which the first distribution section 41 includes the first inclined surface 412 but the second distribution section 42 does not include the second inclined surface 421. Alternatively, the distribution section 40 may have a shape in which the second distribution section 42 includes the second inclined surface 421 but the first distribution section 41 does not include the first inclined surface 412.

[0148] (Second Modification of the Second Embodiment) In the first embodiment described above, an example has been described in which the first inclined surface 412 and the second inclined surface 421 are formed so that their dimensions in the tube axis direction Dax and their dimensions in the tube width direction Dcr are equal, but this is not limiting. For example, the first inclined surface 412 and the second inclined surface 421 may have different dimensions in the tube axis direction Dax. Alternatively, the first inclined surface 412 and the second inclined surface 421 may have different dimensions in the tube width direction Dcr. In other words, the first inclined surface 412 and the second inclined surface 421 may have different inclination angles, which are angles with respect to the tube axis direction Dax.

[0149] (Third embodiment) Next, a third embodiment will be described with reference to FIG. 31 . This embodiment differs from the first embodiment in that the antenna device 1 includes a third waveguide section 70 in addition to the first waveguide section 20 and the second waveguide section 30 as waveguides, and a third radiation opening 80 connected to the third waveguide section 70. Furthermore, this embodiment differs from the first embodiment in that the distribution section 40 includes a fourth distribution section 44 and a fifth distribution section 45 in addition to the first distribution section 41, the second distribution section 42, and the third distribution section 43, and distributes radio waves to the first waveguide section 20, the second waveguide section 30, and the third waveguide section 70. Other than this, this embodiment is similar to the first embodiment. Therefore, in this embodiment, differences from the first embodiment will be mainly described, and descriptions of similar parts to the first embodiment may be omitted.

[0150] 31, the antenna device 1 of this embodiment has a third waveguide section 70 extending along the tube axis direction Dax. The antenna device 1 of this embodiment has a first waveguide section 20, a second waveguide section 30, a third waveguide section 70, and a distribution section 40 formed in a continuous line, and has a configuration having two folded-back sections.

[0151] The first waveguide section 20, the second waveguide section 30, and the third waveguide section 70 are arranged side by side in the tube width direction Dcr. The first waveguide section 20, the second waveguide section 30, and the third waveguide section 70 are arranged side by side in the tube width direction Dcr via the partition wall section 13. The third waveguide section 70 has a third connection section 71 connected to the distribution section 40 on one side in the tube axis direction Dax, and a third end wall 72 forming the end of the waveguide on the other side in the tube axis direction Dax. The third end wall 72 is formed of a planar wall extending in a direction perpendicular to the tube axis direction Dax.

[0152] The first waveguide section 20, the second waveguide section 30, and the third waveguide section 70 overlap at the positions of the tube axis direction Dax of the first connecting section 21, the second connecting section 31, and the third connecting section 71, respectively. Furthermore, the first waveguide section 20, the second waveguide section 30, and the third waveguide section 70 overlap at the positions of the tube axis direction Dax of the first end wall 22, the second end wall 32, and the third end wall 72, respectively. In other words, the first waveguide section 20, the second waveguide section 30, and the third waveguide section 70 have the same dimensions in the tube axis direction Dax.

[0153] A third waveguide 70a that extends in the tube axis direction Dax and propagates radio waves is formed inside the third waveguide section 70. Similar to the first waveguide 20a and the second waveguide 30a, the third waveguide 70a is formed between the first block BC1 and the second block BC2 as a cavity that extends in the tube axis direction Dax.

[0154] The third waveguide section 70 has the same configuration as the second waveguide section 30 in other respects. Specifically, the third waveguide section 70 is formed into a rectangular shape in a cross section perpendicular to the tube axis direction Dax, in which the size in the stacking direction Dst is larger than the size in the tube width direction Dcr. Furthermore, the dimension of the third waveguide section 70 in the stacking direction Dst is equal to the dimension of each of the first waveguide section 20 and the second waveguide section 30 in the stacking direction Dst. Furthermore, the dimension of the third waveguide section 70 in the tube width direction Dcr is equal to the dimension of each of the first waveguide section 20 and the second waveguide section 30 in the tube width direction Dcr.

[0155] The distribution section 40 of this embodiment includes a fourth distribution section 44 that extends along the tube axis direction Dax and is connected to the third connection section 71 of the third waveguide section 70, and a fifth distribution section 45 that extends along the tube width direction Dcr and is connected to the second distribution section 42 and the fourth distribution section 44. The second distribution section 42 and the fourth distribution section 44 are formed side by side in the tube width direction Dcr, with their respective central axes extending along the tube axis direction Dax. The second distribution section 42 and the fourth distribution section 44 are also formed side by side in the tube width direction Dcr, with the partition wall section 13 interposed therebetween.

[0156] The fourth distribution section 44 is a section that guides the radio waves introduced into the distribution section 40 to the third waveguide section 70. The other side of the fourth distribution section 44 in the tube axis direction Dax is connected to the third waveguide section 70, and one side in the tube axis direction Dax is connected to the fifth distribution section 45. The fourth distribution section 44 is connected to the power feeding section 10 via the fifth distribution section 45, the second distribution section 42, the third distribution section 43, and the first distribution section 41. The radio waves introduced from the power feeding opening 411 of the first distribution section 41 are introduced into the fourth distribution section 44 via the third distribution section 43, the second distribution section 42, and the fifth distribution section 45. The second distribution section 42 and the fourth distribution section 44 have the same dimensions in the tube axis direction Dax. The fifth distribution unit 45 extends along the tube width direction Dcr, and one side in the tube width direction Dcr is connected to the second distribution unit 42, and the other side in the tube width direction Dcr is connected to the fourth distribution unit 44. The fifth distribution unit 45 guides the radio waves propagated from the feed opening 411 of the first distribution unit 41 to the second distribution unit 42 to the fifth distribution unit 45.

[0157] The second distribution section 42 of this embodiment has a larger dimension in the tube axis direction Dax than the second distribution section 42 of the first embodiment. That is, the second distribution section 42 has a larger dimension in the tube axis direction Dax than the first distribution section 41. The second distribution section 42 is connected to the third distribution section 43 midway in the tube axis direction Dax, and is connected to one end of the second distribution section 42 in the tube axis direction Dax.

[0158] The distribution section 40, which is composed of the first distribution section 41, second distribution section 42, third distribution section 43, fourth distribution section 44, and fifth distribution section 45 formed in this manner, is bent by 90°, i.e., a right angle, at a portion where the second distribution section 42 and the fifth distribution section 45 are connected. Furthermore, the distribution section 40 is bent by 90°, i.e., a right angle, at a portion where the fourth distribution section 44 and the fifth distribution section 45 are connected. The distribution section 40 of this embodiment forms two folded sections that are folded back by 180° from one side to the other in the tube axis direction Dax so as to bypass the partition wall section 13.

[0159] The distribution unit 40 is connected to the adjacent first and second waveguide units 20 and 30 via the partition wall 13, and is further connected to the adjacent second and third waveguide units 30 and 70 via the partition wall 13. A distribution waveguide 40a for propagating radio waves is formed inside the distribution unit 40 by folding back. The distribution waveguide 40a is bent 180 degrees to form two cavities between the first block BC1 and the second block BC2. One side of the distribution unit 40 in the tube axis direction Dax is formed in a stepped shape, and the distribution unit 40 has two short-circuit portions on one side of the tube axis direction Dax. Specifically, the distribution unit 40 has a first distribution end wall 431 that forms part of the inner wall surface of the third distribution unit 43 and a second distribution end wall 451 that forms part of the inner wall surface of the fifth distribution unit 45. The first distribution end wall 431 and the second distribution end wall 451 are formed of planar walls that face the distribution waveguide 40a and extend in a direction perpendicular to the tube axis direction Dax.

[0160] The dimension of the fourth distribution section 44 in the stacking direction Dst is equal to the dimension of the first distribution section 41 and the second distribution section 42 in the stacking direction Dst. Furthermore, the dimension of the fourth distribution section 44 in the tube width direction Dcr is equal to the dimension of the first distribution section 41 and the second distribution section 42 in the tube width direction Dcr. The dimension of the fifth distribution section 45 in the stacking direction Dst is equal to the dimension of the third distribution section 43 in the stacking direction Dst, and the dimension of the fifth distribution section 45 in the tube axis direction Dax is equal to the dimension of the third distribution section 43 in the tube axis direction Dax.

[0161] This allows radio waves to propagate between the first waveguide 20a, the second waveguide 30a, the distribution waveguide 40a, and the feed line 10a of the feed unit 10. Specifically, radio waves introduced from the feed line 10a to the distribution waveguide 40a of the distribution unit 40 are distributed within the distribution waveguide 40a and propagated to the first waveguide 20a of the first waveguide unit 20, the second waveguide 30a of the second waveguide unit 30, and the third waveguide 70a of the third waveguide unit 70.

[0162] The antenna device 1 of this embodiment has a third radiation opening 80 in addition to the first radiation opening 50 and the second radiation opening 60. The third radiation opening 80 is formed as a through-hole that penetrates the second block BC2 in the stacking direction Dst, similar to the first radiation opening 50 and the second radiation opening 60. The third radiation opening 80 has a third radiation opening 81 that opens toward the external space of the antenna device 1 on one side in the stacking direction Dst.

[0163] The third radiation opening 80 has a cross section perpendicular to the stacking direction Dst that is formed into an oval shape extending in the tube axis direction Dax. That is, the dimension of the third radiation opening 80 in the tube width direction Dcr is smaller than the dimension in the tube axis direction Dax. Moreover, the third radiation opening 80 is formed into a tapered shape in which the inner diameter increases from the other side to one side in the stacking direction Dst. In other words, the third radiation opening 80 is formed as a through hole whose inner diameter increases as it approaches one side in the stacking direction Dst.

[0164] Furthermore, the second waveguide section 30 and the third waveguide section 70, which are adjacent to each other via the partition wall section 13, have the second radiation opening 60 and the third radiation opening 80 connected thereto at positions in the tube axis direction Dax that are different from each other, and are formed offset in the tube axis direction Dax. Specifically, in this embodiment, the third radiation opening 80 is formed on one side in the tube axis direction Dax compared to the second radiation opening 60. As a result, the distance in the tube axis direction Dax of the third radiation opening 80 from the feed opening 411 is shorter than the distance in the tube axis direction Dax between the second radiation opening 60 and the feed opening 411. In other words, the third radiation opening 80 is formed at a position closer to the feed opening 411 than the second radiation opening 60.

[0165] The first radiation opening 50 and the third radiation opening 80 are formed at positions overlapping each other in the tube width direction Dcr. That is, the third radiation opening 80 has an in-tube wavelength λ gThe third radiation opening 80 is formed away from the second radiation opening 60 on one side in the tube axis direction Dax by half of the distance from the second radiation opening 60. Specifically, the center of the third radiation opening 80 in the tube axis direction Dax is formed shifted by 3.0 mm on one side in the tube axis direction Dax from the center of the second radiation opening 60 in the tube axis direction Dax.

[0166] In this embodiment, the distribution unit 40 can make the phases of the radio waves propagated up to the portions where the second waveguide unit 30 and the third waveguide unit 70 overlap in the tube axis direction Dax opposite to each other. Specifically, the distribution unit 40 of this embodiment can invert the phase of the radio waves propagating from the fourth distribution unit 44 to the third connection unit 71 relative to the phase of the radio waves propagating from the second distribution unit 42 to the second connection unit 31.

[0167] 31, the distance in the tube axis direction Dax from the power receiving center Ec to the second distribution end wall 451 is referred to as a fifth distance Ds5. In FIG. 31, the distance in the tube axis direction Dax from the power receiving center Ec to the first connection portion 21 is indicated as a first distance Ds1, as in the first embodiment, and the distance in the tube axis direction Dax from the power receiving center Ec to the distribution end wall 431 is indicated as a second distance Ds2, as in the first embodiment.

[0168] As in the first embodiment, the first distance Ds1 and the second distance Ds2 are set so that the phase of the radio waves propagated to a predetermined portion of the second distribution unit 42 is opposite to the phase of the radio waves propagated to a portion of the first distribution unit 41 that overlaps with the predetermined portion in the tube axis direction Dax. In other words, in the distribution unit 40, the first distance Ds1 and the second distance Ds2 are set so that the phase of the radio waves propagating to the first connection portion 21 of the first waveguide portion 20 and the phase of the radio waves propagating to the second connection portion 31 of the second waveguide portion 30 are opposite to each other.

[0169] The fifth distance Ds5 is set so that the phase of the radio waves propagated to a predetermined portion of the second distribution section 42 is opposite to the phase of the radio waves propagated to a portion of the fourth distribution section 44 that overlaps with that portion in the tube axis direction Dax. In other words, the second distance Ds2 and the fifth distance Ds5 of the distribution section 40 are set so that the phase of the radio waves propagating to the second connection portion 31 of the second waveguide section 30 and the phase of the radio waves propagating to the third connection portion 71 of the third waveguide section 70 are opposite to each other.

[0170] When the first distance Ds1, the second distance Ds2, and the fifth distance Ds5 are set in this manner, the phase of the radio wave propagating to the first connecting portion 21, the phase of the radio wave propagating to the second connecting portion 31, and the phase of the radio wave propagating to the third connecting portion 71 are all in phase. For example, when the first distance Ds1 is equal to the in-pipe wavelength λ g When the second distance Ds2 and the fifth distance Ds5 are set to a value within a range of 1 / 20 to 1 / 10 of the guide wavelength λ g The distances are set to any value within a range of 1 / 5 to 1 / 4 of the above-mentioned first distance Ds1, second distance Ds2, and fifth distance Ds5. However, the first distance Ds1, second distance Ds2, and fifth distance Ds5 are merely examples, and the present invention is not limited to these.

[0171] This allows the electric field directions to be opposite to each other at portions of the first waveguide section 20 and the second waveguide section 30 that overlap with each other in the pipe width direction Dcr. Furthermore, the electric field directions to be opposite to each other at portions of the second waveguide section 30 and the third waveguide section 70 that overlap with each other in the pipe width direction Dcr can be made opposite to each other. This allows the phase directions of radio waves propagating to portions of the first waveguide section 20, the second waveguide section 30, and the third waveguide section 70 that overlap with each other in the pipe width direction Dcr to be made opposite to each other.

[0172] The phase of the radio wave propagated to the portion of the first waveguide section 20 facing the first radiation opening 50 and the in-guide wavelength λ gThe phase of the radio wave propagated to the portion facing the second radiation opening 60 in the second waveguide section 30 can be made to be the same as the phase of the radio wave propagated to the portion facing the second radiation opening 60 in the tube axis direction Dax. g The phase of the radio waves propagated to the portion facing the third radiation opening 80, which is half the distance from the first radiation opening 50, can be made to be in phase with the phase of the radio waves radiated from the first radiation opening 50, the second radiation opening 60, and the third radiation opening 80. Therefore, the phases of the radio waves radiated from the first radiation opening 50, the second radiation opening 60, and the third radiation opening 80 can be made to be in phase with each other. Then, the radio waves radiated from the antenna device 1 can be amplified, thereby improving the magnitude of the gain.

[0173] Furthermore, the axial dimension Dx can be made smaller than in a configuration in which a portion that radiates radio waves is arranged along the direction in which a single waveguide extends. Therefore, compared to a configuration in which a portion that radiates radio waves is arranged along the direction in which a single waveguide extends, it is possible to suppress side lobes while preventing the antenna device 1 from becoming larger in size.

[0174] It should be noted that this embodiment is a modification based on the first embodiment, but it is also possible to combine this embodiment with the second embodiment described above.

[0175] (Fourth embodiment) Next, a fourth embodiment will be described with reference to Fig. 32. In this embodiment, the number of components constituting the antenna device 1 is different from that in the first embodiment. Other than this, the fourth embodiment is similar to the first embodiment. Therefore, in this embodiment, differences from the first embodiment will be mainly described, and descriptions of similar parts to the first embodiment may be omitted.

[0176] 32, the antenna device 1 of this embodiment is configured to include four each of the power feeding sections 10, first waveguide sections 20, second waveguide sections 30, distribution sections 40, first radiation openings 50, and second radiation openings 60 described in the first embodiment. As in the first embodiment, each of the four first radiation openings 50 is formed at a position closer to the power feeding opening 411 than the four second radiation openings 60. The four power feeding sections 10 are connected to one side of each of the four first waveguide sections 20 in the pipe width direction Dcr.

[0177] 32, a section consisting of one power feeding section 10, one first waveguide section 20, one second waveguide section 30, one distribution section 40, one first radiation opening section 50, and one second radiation opening section 60 is referred to as antenna section 1a. The configurations of the power feeding section 10, first waveguide section 20, second waveguide section 30, distribution section 40, first radiation opening section 50, and second radiation opening section 60 that make up antenna section 1a are the same as those described in the first embodiment. Antenna device 1 of this embodiment is configured with four antenna sections 1a lined up in the pipe width direction Dcr.

[0178] The feeding section 10, the first waveguide section 20, the second waveguide section 30, the dividing section 40, the first radiation opening section 50, and the second radiation opening section 60 that constitute each of the four antenna sections 1a have the same shape. For convenience, in Fig. 32, a reference numeral is assigned to a representative one of the four feeding sections 10, the first waveguide section 20, the second waveguide section 30, the dividing section 40, the first radiation opening section 50, and the second radiation opening section 60, and the reference numerals for the others are omitted.

[0179] This allows the phases of the radio waves radiated from the first radiation opening 50 and the second radiation opening 60 of each antenna portion 1a to be in phase. The radio waves radiated from each antenna portion 1a can be amplified to improve the gain. By combining the radio waves radiated from each antenna portion 1a, the radiated radio waves can be further amplified and the gain improved compared to a configuration in which the antenna device 1 has a single antenna portion 1a.

[0180] Furthermore, the axial dimension Dx can be made smaller than in a configuration in which each antenna unit 1a has a single waveguide and a portion that radiates radio waves is arranged in the direction in which the waveguide extends in the single waveguide. Therefore, compared to a configuration in which a portion that radiates radio waves is arranged in the direction in which the waveguide extends in the single waveguide in each antenna unit 1a, it is possible to suppress side lobes while preventing the antenna device 1 from becoming larger in size.

[0181] Although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with either the second or third embodiment described above.

[0182] (First modified example of the fourth embodiment) In the above-described fourth embodiment, an example has been described in which the power feeding portions 10 in each antenna portion 1a are connected to one side of the first waveguide portion 20 in the pipe width direction Dcr, but this is not limiting. For example, as shown in Fig. 33 , two of the power feeding portions 10 in each antenna portion 1a may be connected to one side of the first waveguide portion 20 in the pipe width direction Dcr, and the remaining two power feeding portions 10 may be connected to the other side of the first waveguide portion 20 in the pipe width direction Dcr.

[0183] (Second modified example of the fourth embodiment) In the above-described fourth embodiment, an example has been described in which the first radiation opening 50 in each antenna unit 1a is formed in a position closer to the feed opening 411 than the second radiation opening 60, but this is not limiting. For example, some of the second radiation openings 60 in each antenna unit 1a may be formed in a position closer to the feed opening 411 than the first radiation opening 50. Alternatively, all of the second radiation openings 60 in each antenna unit 1a may be formed in a position closer to the feed opening 411 than the first radiation opening 50.

[0184] (Third modified example of the fourth embodiment) In the above-described fourth embodiment, an example has been described in which the power supply section 10, the first waveguide section 20, the second waveguide section 30, the distribution section 40, the first radiation opening section 50, and the second radiation opening section 60 constituting each antenna section 1a have the same shape, but this is not limiting. For example, the power supply section 10, the first waveguide section 20, the second waveguide section 30, the distribution section 40, the first radiation opening section 50, and the second radiation opening section 60 constituting each antenna section 1a may have shapes that are partially different from those of the components constituting the other antenna sections 1a.

[0185] (Fifth embodiment) Next, a fifth embodiment will be described with reference to Figs. 34 to 36. This embodiment differs from the fourth embodiment in that a plurality of choke grooves 123 are formed in the antenna device 1. Other than this, this embodiment is similar to the fourth embodiment. Therefore, in this embodiment, differences from the fourth embodiment will be mainly described, and descriptions of similar parts to the fourth embodiment may be omitted.

[0186] As shown in FIGS. 34 to 36, in the antenna device 1 of this embodiment, a plurality of choke grooves 123 are formed on one side of the second block BC2 in the stacking direction Dst. The choke grooves 123 are formed by recessing the surface of the second block BC2 on one side in the stacking direction Dst. That is, the choke grooves 123 are grooves that are formed without penetrating the second block BC2 in the stacking direction Dst. The choke grooves 123 are formed deeper than half the dimension of the second block BC2 in the stacking direction Dst. In other words, the choke grooves 123 are formed from the center of the second block BC2 in the stacking direction Dst to the other side.

[0187] The choke grooves 123 are formed along the tube axis direction Dax. That is, the choke grooves 123 are formed along the extension direction of the first waveguide portion 20 and the second waveguide portion 30. In the antenna device 1 in which four antenna portions 1a are arranged, each antenna portion 1a including a first waveguide portion 20 and a second waveguide portion 30 adjacent to each other with the partition wall portion 13 interposed therebetween, the choke grooves 123 are formed between each of the antenna portions 1a.

[0188] This makes it less likely that radio waves radiated from the first radiation opening 50 and the second radiation opening 60 of one of the four antenna units 1a will interfere with radio waves radiated from the first radiation opening 50 and the second radiation opening 60 of the other antenna units 1a, thereby improving isolation of radio waves radiated by the antenna device 1.

[0189] The other configurations are the same as those of the fourth embodiment. The antenna device 1 of this embodiment can obtain the same effects as those of the fourth embodiment, which are achieved by a configuration similar to or equivalent to that of the fourth embodiment.

[0190] (Sixth embodiment) Next, a sixth embodiment will be described with reference to Fig. 37. This embodiment differs from the first embodiment in that a plurality of antenna devices 1 are arranged on an electric substrate 4. Other than this, this embodiment is similar to the first embodiment. Therefore, in this embodiment, differences from the first embodiment will be mainly described, and descriptions of similar parts to the first embodiment may be omitted.

[0191] As shown in FIG. 37 , an array antenna 90 in which multiple antenna devices 1 are arrayed can be used to transmit radio waves transmitted and received by an MMIC 2. For example, the array antenna 90 is formed by aggregating the MMIC 2 sides of the first waveguide section 20 and the second waveguide section 30 of each of the multiple antenna devices 1. The array antenna 90 can be realized by enabling radio waves to propagate between the MMIC 2 and the power feed section 10, the first waveguide section 20, the second waveguide section 30, and the distribution section 40 of each of the antenna devices 1. The array antenna 90 has the choke grooves 123 described in the fifth embodiment formed between each of the multiple antenna devices 1. For convenience, in FIG. 37 , a reference numeral is assigned to a representative one of the power feed section 10, the first waveguide section 20, the second waveguide section 30, the distribution section 40, the first radiation aperture 50, and the second radiation aperture 60 of each of the antenna devices 1, and the reference numerals for the others are omitted.

[0192] As described in the above embodiment, the antenna device 1 of the present invention can be made compact, and therefore, a compact array antenna 90 can be realized by configuring an array antenna 90 using a plurality of such antenna devices 1. In addition, the input / output section 3 of the MMIC 2 can be connected to the first radiation aperture 50 and the second radiation aperture 60 of each antenna device 1, and therefore the gain of the array antenna 90 can be increased.

[0193] Other configurations are the same as those of the first embodiment. The antenna device 1 of this embodiment can obtain the same effects as those of the first embodiment, which are achieved by a configuration similar to or equivalent to that of the first embodiment.

[0194] Although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with any of the second to fifth embodiments described above.

[0195] (Seventh embodiment) Next, the seventh embodiment will be described with reference to FIG. 38. This embodiment differs from the first embodiment in that the MMIC 2 is mounted on one surface 4a of the electric substrate 4. Other than this, it is the same as the first embodiment. Therefore, in this embodiment, the differences from the first embodiment will be mainly described, and a description of the same parts as the first embodiment may be omitted.

[0196] As shown in Fig. 38, in the antenna device 1 of this embodiment, the MMIC 2 is mounted on one surface 4a of the electric board 4, rather than on the other surface 4b of the electric board 4. A gap for disposing the MMIC 2 is secured by a plurality of spacers 5 between the first block BC1 of the antenna device 1 and the one surface 4a of the electric board 4, and the MMIC 2 is disposed between the first block BC1 and the one surface 4a of the electric board 4. Note that in Fig. 38 and Figs. 40 to 42 described later, the solder Sd shown in Fig. 1 etc. is omitted.

[0197] In this embodiment, as in the first embodiment, the external port 6 is arranged to face the input / output unit 3 of the MMIC 2. This allows radio waves to propagate between the external port 6 and the input / output unit 3 of the MMIC 2. However, unlike the first embodiment, in this embodiment, the MMIC 2 is mounted on one surface 4a of the electric substrate 4 as described above, and therefore no substrate through-hole SH is formed in the electric substrate 4.

[0198] Other configurations are the same as those of the first embodiment. The antenna device 1 of this embodiment can obtain the same effects as those of the first embodiment, which are achieved by a configuration similar to or equivalent to that of the first embodiment.

[0199] It should be noted that although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with any of the second to sixth embodiments described above.

[0200] (Eighth embodiment) Next, the eighth embodiment will be described with reference to Figure 39. This embodiment differs from the first embodiment in that the spacer 5 is not provided. Other than this, it is the same as the ninth embodiment. Therefore, in this embodiment, the differences from the first embodiment will be mainly described, and the description of the same parts as the first embodiment may be omitted.

[0201] 39, the antenna device 1 of this embodiment is arranged so that the first block BC1 is in contact with one surface 4a of the electric substrate 4 without the spacer 5 described in the first embodiment. The MMIC2 is mounted on the other surface 4b of the electric substrate 4. A substrate through-hole SH is formed in the electric substrate 4 at a position facing the input / output unit 3 of the MMIC2, penetrating the electric substrate 4 in the stacking direction Dst. The external port 6 is arranged between the external port 6 and the input / output unit 3 of the MMIC2 so as to face the input / output unit 3 with the substrate through-hole SH sandwiched between them. This arrangement allows radio waves to propagate between the external port 6 and the MMIC2.

[0202] Other configurations are the same as those of the first embodiment. The antenna device 1 of this embodiment can obtain the same effects as those of the first embodiment, which are achieved by a configuration similar to or equivalent to that of the first embodiment.

[0203] It should be noted that although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with any of the second to sixth embodiments described above.

[0204] (Ninth embodiment) Next, the ninth embodiment will be described with reference to FIG. 40. This embodiment differs from the first embodiment in that connection wiring 3a and input / output circuits 3b are provided instead of the input / output unit 3. Other than this, this embodiment is similar to the first embodiment. Therefore, in this embodiment, differences from the first embodiment will be mainly described, and descriptions of similar parts to the first embodiment may be omitted.

[0205] 40, in this embodiment, instead of the input / output unit 3 of the MMIC 2, connection wiring 3a and input / output circuit 3b are provided on an electric substrate 4. The connection wiring 3a and input / output circuit 3b are configured by a conductive wiring pattern formed on the electric substrate 4.

[0206] The electric substrate 4 has an input / output circuit 3b formed on one surface 4a and connection wiring 3a formed on the other surface 4b. The electric substrate 4 is provided with a connection portion 3c that penetrates the electric substrate 4 and electrically connects the connection wiring 3a and the input / output circuit 3b. The connection portion 3c is formed, for example, by a through-hole. The input / output circuit 3b and the connection wiring 3a are electrically connected via the connection portion 3c. The input / output circuit 3b transmits and receives radio waves to and from the external port 6 of the antenna device 1. The input / output circuit 3b functions in the same way as the input / output portion 3 of the MMIC 2 in the first embodiment.

[0207] Other configurations are the same as those of the first embodiment. The antenna device 1 of this embodiment can obtain the same effects as those of the first embodiment, which are achieved by a configuration similar to or equivalent to that of the first embodiment.

[0208] It should be noted that although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with any of the second to sixth embodiments described above.

[0209] (Tenth embodiment) Next, the tenth embodiment will be described with reference to Figure 41. This embodiment differs from the ninth embodiment in that the spacer 5 is not provided. Other than this, it is similar to the ninth embodiment. Therefore, in this embodiment, differences from the ninth embodiment will be mainly described, and descriptions of similar parts to the ninth embodiment may be omitted.

[0210] 41 , the present embodiment does not include the spacer 5 of the ninth embodiment. The antenna device 1 of the present embodiment is arranged so that the first block BC1 contacts one surface 4a of the electric substrate 4 without the spacer 5 therebetween. The MMIC 2 is mounted on the other surface 4b of the electric substrate 4.

[0211] Furthermore, an input / output circuit 3b is formed on one surface 4a of the electric substrate 4, and connection wiring 3a is formed on the other surface 4b of the electric substrate 4. The electric substrate 4 is provided with a connection portion 3c that penetrates the electric substrate 4 and electrically connects the connection wiring 3a and the input / output circuit 3b. The connection portion 3c is formed, for example, by a through-hole. The input / output circuit 3b and the connection wiring 3a are electrically connected via the connection portion 3c.

[0212] The other configurations are the same as those of the 9th embodiment. The antenna device 1 of this embodiment can obtain the same effects as those of the 9th embodiment, which are achieved by a configuration similar to or equivalent to that of the 9th embodiment.

[0213] (Eleventh embodiment) Next, an eleventh embodiment will be described with reference to FIG. 42. This embodiment differs from the first embodiment in that an MMIC 2 is mounted on one surface 4a of an electric substrate 4, and connection wiring 3a and an input / output circuit 3b are provided instead of the input / output unit 3. Other than this, this embodiment is similar to the first embodiment. Therefore, in this embodiment, differences from the first embodiment will be mainly described, and descriptions of similar parts to the first embodiment may be omitted.

[0214] 42, in the antenna device 1 of this embodiment, the MMIC 2 is mounted on one surface 4a of the electric substrate 4, rather than on the other surface 4b of the electric substrate 4. A gap for arranging the MMIC 2 is secured by a plurality of spacers 5 between the first block BC1 of the antenna device 1 and the one surface 4a of the electric substrate 4, and the MMIC 2 is disposed between the first block BC1 and the one surface 4a of the electric substrate 4. Furthermore, in this embodiment, instead of the input / output unit 3 of the MMIC 2, connection wiring 3a and an input / output circuit 3b are provided on the electric substrate 4. The connection wiring 3a and the input / output circuit 3b are configured by a conductive wiring pattern formed on the electric substrate 4.

[0215] The connection wiring 3a is formed so as to be led out from the MMIC 2 along one surface 4a of the electric substrate 4. One end of the connection wiring 3a is electrically connected to a terminal of the MMIC 2, and the other end is electrically connected to an input / output circuit 3b. The input / output circuit 3b transmits and receives radio waves to and from the external port 6 of the antenna device 1. The input / output circuit 3b functions in the same way as the input / output unit 3 of the MMIC 2 in the first embodiment.

[0216] In this embodiment, the external port 6 is disposed so as to face the input / output circuit 3b. This allows radio waves to propagate between the external port 6 and the input / output circuit 3b. In this embodiment, since the MMIC 2 is mounted on one surface 4a of the electric substrate 4 as described above, no substrate through-hole SH is formed in the electric substrate 4.

[0217] Other configurations are the same as those of the first embodiment. The antenna device 1 of this embodiment can obtain the same effects as those of the first embodiment, which are achieved by a configuration similar to or equivalent to that of the first embodiment.

[0218] It should be noted that although this embodiment is a modification based on the first embodiment, it is also possible to combine this embodiment with any of the second to sixth embodiments described above.

[0219] (Other embodiments) Representative embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as follows.

[0220] Although the MMIC 2 in the above-described embodiment transmits and receives radio waves, this is merely an example, and the antenna device 1 may be configured to transmit or receive radio waves only. Note that the antenna device 1 can also be applied to equipment that transmits and receives radio waves using semiconductor devices other than the MMIC 2.

[0221] In the above-described embodiment, the antenna device 1 is configured with a structure ST in which two blocks BC1 and BC2 are stacked in the stacking direction Dst, but it does not have to be configured with a structure ST having such a stacked structure.

[0222] In the above-described embodiment, an example has been described in which the dimensions in the tube axis direction Dax of the first waveguide section 20 and the second waveguide section 30 are equal to each other, but this is not limiting. The dimensions in the tube axis direction Dax of the first waveguide section 20 and the second waveguide section 30 may be different from each other as long as the positions of the tube axis direction Dax of the first connection section 21 and the second connection section 31 overlap.

[0223] In the above-described embodiment, an example has been described in which the dimensions of the first distribution section 41 and the second distribution section 42 in the tube axis direction Dax are equal to each other, but the present invention is not limited to this. The dimensions of the first distribution section 41 and the second distribution section 42 in the tube axis direction Dax may be different from each other.

[0224] In the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

[0225] In the above-described embodiments, when numerical values ​​such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers unless they are expressly stated as being essential or are clearly limited to a specific number in principle.

[0226] In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., the shapes, positional relationships, etc. are not limited to those unless otherwise specified or when they are limited in principle to specific shapes, positional relationships, etc.

[0227] (Aspects of the present disclosure) The present disclosure described above can be understood from the following viewpoints, for example. [First viewpoint] 1. An antenna device, comprising: a plurality of waveguide sections (20, 30, 70) each forming a waveguide path (20a, 30a, 70a) which is a propagation path of radio waves; a partition wall portion (13) disposed between the plurality of waveguide portions and separating the plurality of waveguide portions; a plurality of radiation openings (50, 60, 80) connected to the plurality of waveguide sections, respectively, for radiating the radio waves; a distribution section (40) having a feed opening (411) into which the radio waves are introduced and forming a distribution waveguide (40a) which is a propagation path through which the radio waves introduced from the feed opening are distributed to each of the plurality of waveguide paths and propagate; Each of the plurality of waveguide sections extends in a predetermined first direction (Dax), is formed side by side in a second direction (Dcr) perpendicular to the first direction, and has a connection section (21, 31, 71) on one side in the first direction that is connected to an end of the distributor on the other side in the first direction, and the positions of the connection sections in the first direction overlap each other, the plurality of radiation openings are arranged such that positions of two radiation openings connected to two adjacent waveguide sections among the plurality of waveguide sections via the partition wall section are shifted in the first direction, the distribution section has the feeding opening in the second direction, and is formed by folding back from one side to the other side in the first direction so that the radio waves can propagate to the connection portions of two adjacent waveguide sections among the plurality of waveguide sections via the partition wall section, and causes the phases of the radio waves propagating to the connection portions of the two waveguide sections to be opposite to each other. [Second viewpoint] When a direction orthogonal to the first direction and the second direction is defined as a third direction (Dst), each of the plurality of waveguide sections has a narrow wall surface (25, 26, 35, 36) extending in the first direction and the second direction and a wide wall surface (23, 24, 33, 34) extending in the first direction and the third direction, The narrow wall surface is formed so that the size in the second direction is smaller than the size in the third direction of the wide wall surface, The antenna device according to a first aspect, wherein the plurality of radiation openings are arranged on the narrow wall surface side of each of the plurality of waveguide sections. [Third Perspective] When the distance in the first direction from the other end of the distributor in the first direction to the feed opening is defined as a first distance (Ds1), and the distance in the first direction from one end of the distributor in the first direction to the feed opening is defined as a second distance (Ds2), The antenna device according to the first or second aspect, wherein the first distance and the second distance of the distribution section are set so that the phases of the radio waves propagating to the connection sections of the two waveguide sections are opposite to each other. [Fourth viewpoint] the distribution section has, at an end on one side in the first direction, a first inclined surface (412) that faces the distribution waveguide and extends at an incline with respect to the first direction and the second direction so as to approach one of the two waveguide sections as it moves from the other side to one side in the first direction, and a second inclined surface (421) that faces the distribution waveguide and extends at an incline with respect to the first direction and the second direction so as to approach the other of the two waveguide sections as it moves from the other side to one side in the first direction, When the distance in the first direction from the other end of the distribution unit in the first direction to the power feed opening is defined as a first distance (Ds1), the distance in the first direction from one end of the distribution unit in the first direction to the power feed opening is defined as a second distance (Ds2), the distance from one end of the first inclined surface in the first direction to the other end of the first inclined surface is defined as a third distance (Ds3), and the distance from one end of the second inclined surface in the first direction to the other end of the second inclined surface is defined as a fourth distance (Ds4), The antenna device according to the first or second aspect, wherein the first distance, the second distance, the third distance and the fourth distance of the distribution section are set so that the phases of the radio waves propagating to the connection sections of the two waveguides are opposite to each other. [Fifth viewpoint] The antenna device according to any one of the first to fourth aspects, wherein each of the plurality of radiation openings has a communication port (52, 62) communicating with the plurality of waveguide sections and a radiation opening (51, 61) opening toward external space, and is formed as a through hole whose inner diameter expands from the communication port toward the radiation opening. [Sixth viewpoint] a feeding section (10) that is connected to the feeding opening and forms a feeding path (10a) that forms a propagation path for propagating the radio wave in the branching waveguide; The antenna device according to any one of the first to fifth aspects, wherein the power supply section is formed so that a part of the power supply section is bent with respect to the second direction. [Seventh viewpoint] A choke groove (123) is provided to suppress interference of the radio wave, The plurality of waveguide sections are configured by arranging a plurality of antenna sections (1 a) each including two adjacent waveguide sections with the partition wall therebetween, The antenna device according to any one of the first to sixth aspects, wherein the choke groove is formed between a plurality of the antenna portions arranged side by side. [Explanation of symbols]

[0228] 13 Partition wall 20, 30, 70 Waveguide section 20a, 30a, 70a waveguide 21, 31, 71 Connections 40 Distribution section 40a distribution waveguide 50, 60, 80 Radiation opening 411 Power supply opening

Claims

1. 1. An antenna device, comprising: a plurality of waveguide sections (20, 30, 70) each forming a waveguide path (20a, 30a, 70a) which is a propagation path of radio waves; a partition wall portion (13) disposed between the plurality of waveguide portions and separating the plurality of waveguide portions; a plurality of radiation openings (50, 60, 80) connected to the plurality of waveguide sections, respectively, for radiating the radio waves; a distribution section (40) having a feed opening (411) into which the radio wave is introduced and forming a distribution waveguide (40a) which is a propagation path through which the radio wave introduced from the feed opening is distributed to each of the plurality of waveguide paths and propagates; each of the plurality of waveguide sections extends in a predetermined first direction (Dax), is formed side by side in a second direction (Dcr) perpendicular to the first direction, and has a connection section (21, 31, 71) on one side in the first direction that is connected to an end of the distributor on the other side in the first direction, and positions of the connection sections in the first direction overlap; the plurality of radiation openings are arranged such that positions of two radiation openings connected to two adjacent waveguide sections among the plurality of waveguide sections via the partition wall section are shifted in the first direction, the distribution section has the feed opening in the second direction, and is formed by folding back from one side to the other side in the first direction so that the radio waves can propagate to the connection portions of two adjacent waveguide sections among the plurality of waveguide sections via the partition wall section, and causes the phases of the radio waves propagating to the connection portions of the two waveguide sections to be opposite to each other.

2. When a direction orthogonal to the first direction and the second direction is defined as a third direction (Dst), each of the plurality of waveguide sections has a narrow wall surface (25, 26, 35, 36) extending in the first direction and the second direction and a wide wall surface (23, 24, 33, 34) extending in the first direction and the third direction, The narrow wall surface is formed so that the size in the second direction is smaller than the size in the third direction of the wide wall surface, The antenna device according to claim 1 , wherein the plurality of radiation openings are arranged on the narrow wall surface side of each of the plurality of waveguide sections.

3. When the distance in the first direction from the other end of the distributor in the first direction to the feed opening is defined as a first distance (Ds1), and the distance in the first direction from one end of the distributor in the first direction to the feed opening is defined as a second distance (Ds2), 3. The antenna device according to claim 1, wherein the first distance and the second distance of the distribution section are set so that the phases of the radio waves propagating to the connection sections of the two waveguide sections are opposite to each other.

4. The distribution section has, at an end on one side in the first direction, a first inclined surface (412) that faces the distribution waveguide and extends at an incline with respect to the first direction and the second direction so as to approach one of the two waveguide sections as it moves from the other side to one side in the first direction, and a second inclined surface (421) that faces the distribution waveguide and extends at an incline with respect to the first direction and the second direction so as to approach the other of the two waveguide sections as it moves from the other side to one side in the first direction, When the distance in the first direction from the other end of the distribution unit in the first direction to the power feed opening is a first distance (Ds1), the distance in the first direction from one end of the distribution unit in the first direction to the power feed opening is a second distance (Ds2), the distance from one end of the first inclined surface in the first direction to the other end of the first inclined surface is a third distance (Ds3), and the distance from one end of the second inclined surface in the first direction to the other end of the second inclined surface is a fourth distance (Ds4), 3. The antenna device according to claim 1, wherein the first distance, the second distance, the third distance, and the fourth distance of the distribution section are set so that the phases of the radio waves propagating to the connection sections of the two waveguide paths are opposite to each other.

5. 2. The antenna device according to claim 1, wherein each of the plurality of radiation openings has a communication port (52, 62) communicating with the plurality of waveguide sections and a radiation opening (51, 61) opening toward external space, and is formed as a through hole whose inner diameter expands from the communication port toward the radiation opening.

6. a feeding section (10) that is connected to the feeding opening and forms a feeding path (10a) that forms a propagation path for propagating the radio wave in the branching waveguide; The antenna device according to claim 1 , wherein the feeding portion is formed so that a portion of the feeding portion is bent with respect to the second direction.

7. A choke groove (123) is provided to suppress interference of the radio wave, The plurality of waveguide sections are configured by arranging a plurality of antenna sections (1 a) each including two adjacent waveguide sections with the partition wall therebetween, The antenna device according to claim 1 , wherein the choke groove is formed between a plurality of the antenna portions arranged side by side.

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