Waveguide, method of manufacturing the waveguide, and antenna

Abstract

To achieve miniaturization of a waveguide while favorably maintaining frequency characteristics of the waveguide.SOLUTION: A waveguide 1 includes a first conductor plate 11 and a second conductor plate 12 in contact with the first conductor plate 11. The first conductor plate 11 includes: a groove portion 111 that has a rectangular cross section and that is formed parallel to a first main surface, which is a flat surface of the first conductor plate 11 on the second conductor plate 12 side, such that the longitudinal direction thereof becomes a first direction; and a first vertical tube portion 112 formed in a direction away from the second conductor plate 12 in a second direction orthogonal to the first direction and the first main surface, with a branch position in the groove portion 111 as a starting point. The second conductor plate 12 includes a reflection portion 122 that is inserted into the groove portion 111 in a manner protruding from a second main surface, which is a flat surface of the second conductor plate 12 in contact with the first main surface, and has a reflection surface R that reflects a radio wave, propagated along the groove portion 111, toward the first vertical tube portion 112.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a waveguide, a method for manufacturing a waveguide, and an antenna. [Background technology]

[0002] BACKGROUND ART Conventionally, a bent waveguide in which a plurality of waveguides with different directions are connected is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-20077 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional waveguides are constructed by fitting a metal member with a 45-degree tapered surface on one side into the intersection of two orthogonal waveguides, and then covering the waveguide and metal member with a metal plate. As the frequency of the signal transmitted by the waveguide increases, the diameter of the waveguide and the metal member must be reduced. However, when the diameter of the waveguide and the metal member are reduced, the problem of the misalignment of the metal member having a greater effect on the frequency characteristics of the waveguide arises.

[0005] The present invention has been made in view of these points, and has as its object to realize a miniaturized waveguide while maintaining good frequency characteristics of the waveguide. [Means for solving the problem]

[0006] A first aspect of the present invention provides a waveguide having a first conductor plate and a second conductor plate in contact with the first conductor plate, wherein the first conductor plate has a groove portion with a rectangular cross section formed parallel to a first main plane which is the plane of the first conductor plate facing the second conductor plate so that its longitudinal direction is a first direction, and a first vertical pipe portion formed starting from a branching position in the groove portion and facing away from the second conductor plate in a second direction perpendicular to the first direction and the first main plane, and the second conductor plate has a reflecting portion inserted into the groove in a manner protruding from the second main plane which is the plane of the second conductor plate in contact with the first main plane, and having a reflecting surface which reflects radio waves propagated along the groove portion toward the first vertical pipe portion.

[0007] The reflective surface may have a reflective area located between a position in the first direction on a surface of the first vertical tube section that is closest to the side on which the radio waves are incident and a position in the first direction on a surface of the first vertical tube section that is farthest from the side on which the radio waves are incident.

[0008] The position in the first direction of a first end portion of the reflecting surface on the side of the first conductor plate may be the same as the position in the first direction of the surface of the first vertical pipe section that is farthest from the incident side where the radio waves are incident, and the position in the first direction of a second end portion of the reflecting surface that is opposite the first end portion may be between the position in the first direction of the surface of the first vertical pipe section that is closest to the incident side and the position in the first direction of the surface of the first vertical pipe section that is farthest from the incident side.

[0009] The second conductor plate may further have a second vertical pipe portion extending in the second direction from an end of the groove portion opposite to the side on which the first vertical pipe portion is formed and penetrating the second conductor plate.

[0010] The inner width of the waveguide as defined by the rectangular waveguide standard is Wa [mm], and the speed of light is C0 [10 6m / s, the frequency of the radio waves may be 1.4×C0 / (2×Wa) [GHz] or more and 1.7×C0 / (2×Wa) [GHz] or less, and the distance between an outer surface of the reflecting portion parallel to the first direction and an inner surface of the groove portion parallel to the first direction may be 12% or more and less than 38% of the distance between the two inner surfaces of the groove portion.

[0011] A method for manufacturing a waveguide according to a second aspect of the present invention includes the steps of: forming a groove having a rectangular cross section in a first conductor plate material, the groove having a longitudinal direction that is a first direction and that is parallel to a first main plane of the first conductor plate material; manufacturing a first conductor plate by forming a vertical tubular portion in the first conductor plate material, the vertical tubular portion extending from a branching position in the groove as a starting point, in a second direction that is perpendicular to the first direction and the first main plane; manufacturing a second conductor plate by forming a reflective portion in a second conductor plate material different from the first conductor plate material, the reflective portion having a reflective surface that reflects radio waves that have propagated along the groove toward the vertical tubular portion, the reflective portion protruding from a second main plane that is in contact with the first main plane in the second conductor plate material; and, after forming the first conductor plate and the second conductor plate, joining the first conductor plate and the second conductor plate so that the first main plane and the second main plane are in contact with each other with the reflective portion inserted in the groove.

[0012] An antenna according to a third aspect of the present invention comprises an antenna element having an antenna port and a waveguide connected to the antenna port, the waveguide being a waveguide having a first conductor plate and a second conductor plate in contact with the first conductor plate, the first conductor plate having a groove portion with a rectangular cross section formed parallel to a first main plane which is the plane of the first conductor plate facing the second conductor plate so that its longitudinal direction is a first direction, and a first vertical pipe portion formed starting from a branching position in the groove portion and facing away from the second conductor plate in a second direction perpendicular to the first direction and the first main plane, the second conductor plate having a second vertical pipe portion formed between the antenna port and the groove portion in the second direction, and a reflecting portion inserted into the groove in a manner protruding from the second main plane which is the plane of the second conductor plate in contact with the first main plane, the second conductor plate having a reflecting surface which reflects radio waves propagated along the groove portion towards the first vertical pipe portion. [Effects of the Invention]

[0013] According to the present invention, it is possible to achieve miniaturization of the waveguide while maintaining good frequency characteristics of the waveguide. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view showing an outline of the configuration of a waveguide 1. [Figure 2] FIG. 2 is an exploded view of a region of the waveguide 1. [Figure 3] FIG. 2 is an enlarged view of a partial area of ​​the waveguide 1. [Figure 4] FIG. 10 is a diagram for explaining parameters used in a simulation. [Figure 5] FIG. 10 is a diagram showing the simulation results of the L_ref dependency of the transmission characteristics of the waveguide 1. [Figure 6] FIG. 10 is a diagram showing the simulation results of the L_ref dependency of the transmission characteristics of the waveguide 1. [Figure 7] FIG. 10 is a diagram showing the simulation results of the d_x dependence of the transmission characteristics of the waveguide 1. [Figure 8] FIG. 10 is a diagram showing the simulation results of the d_x dependence of the transmission characteristics of the waveguide 1. [Figure 9] FIG. 10 is a diagram showing the simulation results of the d_x dependency of the reflection characteristics of the waveguide 1. [Figure 10] FIG. 10 is a diagram showing the simulation results of the d_x dependency of the reflection characteristics of the waveguide 1. DETAILED DESCRIPTION OF THE INVENTION

[0015] [Configuration of Waveguide 1] Fig. 1 is a perspective view showing an outline of the configuration of a waveguide 1. Fig. 2 is an exploded view of a partial area of ​​the waveguide 1. Fig. 3 is an enlarged view of a partial area of ​​the waveguide 1.

[0016] As shown in FIG. 1, waveguide 1 is configured to be connected to antenna element 2. An antenna is configured by connecting antenna element 2 to waveguide 1. Waveguide 1 has a waveguide that propagates radio waves input from the output port of antenna element 2. Waveguide 1 propagates the radio waves input from antenna element 2 to a position different from the output port of antenna element 2 and then outputs the radio waves. In the example shown in FIG. 1, waveguide 1 has two waveguides, but waveguide 1 may have one waveguide or three or more waveguides.

[0017] The waveguide 1 has a first conductor plate 11 and a second conductor plate 12 in contact with the first conductor plate 11. The first conductor plate 11 and the second conductor plate 12 are made of, for example, rectangular metal plates (e.g., copper), but the shapes of the first conductor plate 11 and the second conductor plate 12 are arbitrary. In order to facilitate alignment of the first conductor plate 11 and the second conductor plate 12 during manufacturing of the waveguide 1, it is desirable that the shapes of the first conductor plate 11 and the second conductor plate 12 are such that, when the first conductor plate 11 and the second conductor plate 12 are in contact with each other, multiple side surfaces of the first conductor plate 11 and multiple corresponding side surfaces of the second conductor plate 12 are positioned on the same plane.

[0018] The first conductor plate 11 has a groove 111 and a first vertical pipe section 112. The second conductor plate 12 has a second vertical pipe section 121 and a reflecting section 122. In Fig. 1, a first waveguide extending from the second vertical pipe section 121a to the first vertical pipe section 112a via the groove 111a, and a second waveguide extending from the second vertical pipe section 121b to the first vertical pipe section 112b via the groove 111b are shown at positions symmetrical with respect to the antenna element 2. In the following explanation, the first waveguide extending from the second vertical pipe section 121a to the first vertical pipe section 112a via the groove 111a will be used as an example for detailed explanation.

[0019] The grooves 111 are formed parallel to the first main plane, which is the plane of the first conductor plate 11 on the second conductor plate 12 side, so that the longitudinal direction corresponds to the first direction. The cross section of the grooves 111 is rectangular. The first direction in the example shown in FIG. 1 is, for example, the longitudinal direction of the first conductor plate 11 and the second conductor plate 12, which is the Y direction in FIGS. 1 to 3.

[0020] A reflecting surface is formed at the end of the groove 111 corresponding to the position where it is coupled to the second vertical pipe section 121, in order to change the direction of radio waves incident in the Z direction from the antenna element 2 via the second vertical pipe section 121 to the Y direction. Since the propagation direction of the radio waves changes by 90° at the reflecting surface, the second vertical pipe section 121 and the groove 111 function as a first corner waveguide.

[0021] The first vertical pipe section 112 is formed starting from the branching position in the groove section 111 and extending away from the second conductor plate 12 in a second direction perpendicular to the first direction and the first main plane. The second direction is the thickness direction of the first conductor plate 11, which is the Z direction in FIGS. 1 to 3. The branching position is the center position of the first vertical pipe section 112 in the first direction, as indicated by the symbol B in FIG. 3. The first vertical pipe section 112 is formed so as to penetrate, for example, the waveguide 1. The cross section of the first vertical pipe section 112 is, for example, rectangular.

[0022] The second vertical pipe section 121 has one end coupled to the antenna element 2 and the other end coupled to the groove section 111. As shown in Figures 1 and 2, the second vertical pipe section 121 extends in a second direction from the end of the groove section 111 opposite to the side where the first vertical pipe section 112 is formed, and penetrates the second conductor plate 12. The cross section of the second vertical pipe section 121 is, for example, rectangular.

[0023] 3(a), the reflecting portion 122 is inserted into the groove portion 111 in a state in which it protrudes from the second main plane, which is the plane that contacts the first main plane of the second conductor plate 12. The reflecting portion 122 has a reflecting surface R that reflects the radio waves that have propagated in the Y direction along the groove portion 111 in the Z direction toward the first vertical pipe portion 112. Because the propagation direction of the radio waves changes by 90° at the reflecting surface R, the groove portion 111, the reflecting portion 122, and the first vertical pipe portion 112 function as a second corner waveguide.

[0024] The reflecting portion 122 may be formed by cutting a conductive plate with a drill, or may be bonded to the conductive plate in a pre-formed state. When the reflecting portion 122 is cut with a drill, it is difficult to form the reflecting surface R completely flat, so the reflecting surface R may be formed in a stepped shape.

[0025] The reflecting section 122 is inserted into an area of ​​the groove 111 that is farther from the branching position B than the second vertical pipe section 121 (the front right side in FIG. 3(a)). The width of the reflecting section 122 in a third direction (the X direction in FIGS. 1 to 3) perpendicular to the first and second directions is smaller than the width of the groove 111 in the third direction so that the reflecting section 122 can be accommodated in the groove 111. The end face of the reflecting section 122 opposite to the side on which the reflecting surface R is formed does not have to be in contact with the inner surface of the groove 111 as shown in FIG. 3(a), but may be in contact with the inner surface of the groove 111.

[0026] Fig. 3(b) is a cross-sectional view of the area shown in Fig. 3(a) taken along line AA. As shown in Fig. 3(b), the reflecting portion 122 does not have to be in contact with the lower surface of the groove portion 111, but may be in contact with the lower surface of the groove portion 111.

[0027] As shown in Figure 3(b), the reflecting surface R has a reflecting area located between position P1 in the first direction on the surface of the first vertical tube section 112 closest to the side where the radio waves are incident, and position P2 in the first direction on the surface of the first vertical tube section 112 farthest from the side where the radio waves are incident.

[0028] As an example, the position in the first direction of the first end E1 of the reflecting surface R on the side of the first conductor plate 11 is the same as the position P2 in the first direction of the surface of the first vertical pipe section 112 that is farthest from the incident side where the radio waves are incident. The position in the first direction of the second end E2 of the reflecting surface R on the opposite side to the first end E1 is between the position P1 in the first direction of the surface of the first vertical pipe section 112 that is closest to the incident side and the position P2 in the first direction of the surface of the first vertical pipe section 112 that is farthest from the incident side. By providing the reflecting surface R in such a position, the radio waves reflected by the reflecting surface R are more likely to propagate along the first vertical pipe section 112 without hitting the bottom surface of the groove section 111. As a result, a decrease in the intensity of the radio waves output from the waveguide 1 can be prevented.

[0029] [Method of manufacturing the waveguide 1] An example of a method for manufacturing the waveguide 1 will now be described. First, a first conductor plate material and a second conductor plate material are prepared before processing. Then, a groove 111 with a rectangular cross section is formed in the prepared first conductor plate material so that its longitudinal direction is in a first direction and parallel to a first main plane of the first conductor plate material. A reflective surface inclined at 45° with respect to the first main plane and the first direction is formed at one end of the groove 111. An end face perpendicular to the first main plane and the first direction is formed at the other end of the groove 111.

[0030] Next, a first vertical pipe portion 112 is formed in the first conductor plate material, starting from the branch position in the groove portion 111 and extending in a second direction perpendicular to the first direction and the first main plane, thereby completing the first conductor plate 11. The groove portion 111 and the first vertical pipe portion 112 may be formed by any method, but for example, the groove portion 111 and the first vertical pipe portion 112 can be formed by a milling machine.

[0031] Before or after processing the first conductor plate material, or in parallel with processing the first conductor plate material, the second vertical pipe section 121 and the reflecting section 122 are formed on the unprocessed second conductor plate material. Specifically, the second conductor plate material is processed by scraping away areas other than the reflecting section 122 from the unprocessed second conductor plate material, so that the reflecting section 122 remains in a protruding form. Thereafter, the second vertical pipe section 121 is formed, thereby completing the second conductor plate 12. The second vertical pipe section 121 and the reflecting section 122 can be formed by any method, and a milling machine, for example, can be used.

[0032] After forming the groove 111, the first vertical pipe section 112, the second vertical pipe section 121, and the reflecting section 122, the first conductor plate 11 and the second conductor plate 12 are joined together so that the first main plane of the first conductor plate 11 (the surface on the side where the groove 111 is formed) and the second main plane of the second conductor plate 12 (the surface on the side where the reflecting section 122 is formed) are in contact with each other with the reflecting section 122 inserted into the groove 111. When the first conductor plate and the second conductor plate have the same planar shape, the first conductor plate 11 and the second conductor plate 12 are joined together so that the four sides of the first conductor plate and the four sides of the second conductor plate coincide with each other, thereby making it possible to insert the reflecting section 122 into a desired position with high precision.

[0033] [Simulation Results] The results of simulating the characteristics of the waveguide 1 will be described below with reference to Figures 4 to 9. Figure 4 is a diagram for explaining the parameters used in the simulation.

[0034] Fig. 4(a) is a cross-sectional view taken along line AA, equivalent to Fig. 3(b). Fig. 4(b) is a view showing the waveguide 1 as viewed from the end of the first vertical pipe section 112 toward the second conductor plate 12. When cutting the groove 111 with a drill, it is difficult to make the corner of the groove 111 a right angle, so in Fig. 4(b), the corner of the right end of the groove 111 is arc-shaped.

[0035] As shown in FIG. 4(a), the distance between the bottom surface of the reflecting portion 122 and the lower inner surface of the groove portion 111 is defined as d_z×Wa. The distance between the branching position B and the end face of the reflecting portion 122 opposite the reflecting surface R is defined as L_ref×Wa. The distance between the branching position B and the end face of the groove portion 111 is defined as L_wg×Wa. As shown in FIG. 4(b), the distance between the side face of the reflecting portion 122 and the inner surface of the groove portion 111 is defined as d_x×Wa. Here, Wa is the inside width defined by the rectangular waveguide standard. As an example, for a WR-3 waveguide, Wa = 0.864 mm. The position where the side face of the groove portion 111 in the longitudinal direction begins to curve inward is defined as the end face of the groove portion 111.

[0036] 5 and 6 are diagrams showing simulation results of the L_ref dependency of the transmission characteristics of the waveguide 1. Specifically, Fig. 5 and Fig. 6 show the frequency characteristics of the transmission coefficient S21 when (L_wg - L_ref) × Wa = 0.1 mm, d_z × Wa = 0.05 mm, and d_x × Wa = 0.138 mm. It was confirmed that no resonance point occurs in the transmission coefficient S21 when the frequency of the radio waves propagating through the waveguide 1 is in the range of 240 GHz to 300 GHz, as long as L_ref is in the range of 0.45 to 0.60, 0.90 to 1.20, or 1.60 to 1.90.

[0037] This frequency range varies depending on the size of the waveguide. In other words, the width of the waveguide as defined by the rectangular waveguide standard is Wa [mm], and the speed of light is C0 [10 6 When the wave velocity is [m / s], it was confirmed that the frequency of the radio waves is between 1.4×C0 / (2×Wa) [GHz] and 1.7×C0 / (2×Wa) [GHz].

[0038] 7 and 8 are diagrams showing simulation results of the d_x dependency of the transmission characteristics of the waveguide 1. Specifically, Fig. 7 and Fig. 8 show the frequency characteristics of the transmission coefficient S21 when (L_wg-L_ref)×Wa=0.1 mm, d_z×Wa=0.05 mm, and L_ref=0.105. It was confirmed that when d_x is 0.12 or more, no resonance point occurs in the transmission coefficient S21 when the frequency of the radio waves propagating through the waveguide 1 is in the range of 240 GHz or more and 300 GHz or less.

[0039] 9 and 10 are diagrams showing simulation results of the d_x dependency of the reflection characteristics of the waveguide 1. Specifically, Fig. 9 and 10 show the frequency characteristics of the input reflection coefficient S11 when (L_wg-L_ref)×Wa=0.1 mm, d_z×Wa=0.05 mm, and L_ref=0.105. It was confirmed that when d_x is 0.38 or more, the input reflection coefficient S11 deteriorates when the frequency of the radio waves propagating through the waveguide 1 is in the range of 240 GHz or more and 300 GHz or less.

[0040] 7 and 8 and the results shown with reference to Figures 9 and 10, it was confirmed that it is desirable for d_x to be equal to or greater than 0.12 and less than 0.38. In other words, it was confirmed that it is desirable for the distance d_x × Wa between the outer surface of the reflecting portion 122 parallel to the first direction and the inner surface of the groove portion 111 parallel to the first direction to be equal to or greater than 12% and less than 38% of the distance between the two inner surfaces of the groove portion 111.

[0041] [Effect of Waveguide 1] As described above, the waveguide 1 is composed of the first conductor plate 11 and the second conductor plate 12. The first conductor plate 11 has a groove 111 with a rectangular cross section that is formed parallel to the first main plane of the first conductor plate 11 so that its longitudinal direction is the first direction, and a first vertical pipe portion 112 that is formed starting from a branching position B in the groove 111 and facing away from the second conductor plate 12. The second conductor plate 12 has a reflecting portion 122 that is inserted into the groove 111 in a manner that protrudes from a second main plane that is a plane that contacts the first main plane of the second conductor plate, and that has a reflecting surface R that reflects radio waves propagated along the groove 111 toward the first vertical pipe portion 112.

[0042] With this configuration of waveguide 1, reflecting portion 122 can be fixed at a desired position with high precision by aligning first conductor plate 11 and second conductor plate 12. As a result, the waveguide can be made smaller while maintaining good frequency characteristics.

[0043] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments. [Explanation of symbols]

[0044] 1 waveguide 2 antenna elements 11 First conductor plate 12 Second conductor plate 111 Groove 112 1st vertical pipe section 121 2nd vertical pipe section 122 Reflector

Claims

1. A waveguide having a first conductor plate and a second conductor plate in contact with the first conductor plate, The first conductive plate is a groove portion having a rectangular cross section formed parallel to a first main plane, which is a plane of the first conductor plate on the second conductor plate side, so that a longitudinal direction thereof is a first direction; a first vertical pipe portion formed in a direction away from the second conductive plate in a second direction perpendicular to the first direction and the first main plane, with the branch position in the groove portion as a starting point; and the second conductor plate has a reflecting portion inserted into the groove portion in a manner protruding from a second main plane, which is a plane of the second conductor plate in contact with the first main plane, and having a reflecting surface that reflects the radio waves propagated along the groove portion toward the first vertical pipe portion; waveguide.

2. the reflecting surface has a reflecting region located between a position in the first direction of a surface of the first vertical tube section that is closest to the side onto which the radio waves are incident and a position in the first direction of a surface of the first vertical tube section that is farthest from the side onto which the radio waves are incident.

2. The waveguide of claim 1.

3. a position in the first direction of a first end portion of the reflecting surface on the side of the first conductor plate is the same as a position in the first direction of a surface of the first vertical pipe portion that is farthest from an incident side into which the radio wave is incident, a position in the first direction of a second end of the reflecting surface opposite to the first end is between a position in the first direction of a surface of the first vertical pipe section closest to the incident side and a position in the first direction of a surface of the first vertical pipe section farthest from the incident side; 3. A waveguide according to claim 1 or 2.

4. the second conductor plate further includes a second vertical pipe portion extending in the second direction from an end of the groove portion opposite to the side where the first vertical pipe portion is formed and penetrating the second conductor plate; 3. A waveguide according to claim 1 or 2.

5. The inner width of the waveguide as defined by the rectangular waveguide standard is Wa [mm], and the speed of light is C0 [10 ６ m / s], the frequency of the radio wave is equal to or greater than 1.4 × C0 / (2 × Wa) [GHz] and equal to or less than 1.7 × C0 / (2 × Wa) [GHz], a distance between an outer surface of the reflecting portion parallel to the first direction and an inner surface of the groove portion parallel to the first direction is 12% or more and less than 38% of a distance between the two inner surfaces of the groove portion; 3. A waveguide according to claim 1 or 2.

6. forming a groove having a rectangular cross section in a first conductive plate material such that its longitudinal direction is in a first direction and parallel to a first main plane of the first conductive plate material; a step of manufacturing a first conductor plate by forming a vertical tubular portion in the first conductor plate material, the vertical tubular portion extending from a branch position in the groove portion as a starting point and in a second direction perpendicular to the first direction and the first main plane; a step of manufacturing a second conductor plate by forming, in a second conductor plate material different from the first conductor plate material, a reflection portion having a reflection surface that reflects the radio waves propagated along the groove portion toward the vertical pipe portion, in the second conductor plate material in a manner that the reflection portion protrudes from a second main plane that contacts the first main plane; a step of forming the first conductor plate and the second conductor plate, and then joining the first conductor plate and the second conductor plate so that the first main plane and the second main plane are in contact with each other with the reflective portion inserted into the groove; A method for manufacturing a waveguide having the above structure.

7. an antenna element having an antenna port; a waveguide connected to the antenna port; and The waveguide has a first conductor plate and a second conductor plate in contact with the first conductor plate, The first conductive plate is a groove portion having a rectangular cross section formed parallel to a first main plane, which is a plane of the first conductor plate on the second conductor plate side, so that a longitudinal direction thereof is a first direction; a first vertical pipe portion formed in a direction away from the second conductive plate in a second direction perpendicular to the first direction and the first main plane, with the branch position in the groove portion as a starting point; and The second conductive plate is a second vertical pipe portion formed in the second direction between the antenna port and the groove portion; the second conductor plate includes a reflector inserted into the groove in a manner protruding from a second main plane, which is a plane of the second conductor plate in contact with the first main plane, and having a reflecting surface that reflects the radio waves propagated along the groove toward the first vertical pipe; An antenna having

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