JP2017060086A - Waveguide tube slot antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waveguide tube slot antenna capable of stably exhibiting desired antenna characteristics.SOLUTION: There is provided a waveguide tube slot antenna A which includes a waveguide tube 10 that has a waveguide 2 extending in a tube axis direction and is made from a resin, and a plurality of radiation slots 3 provided on the waveguide tube 10, where the waveguide tube 10 is formed of first and second waveguide formation members 11, 12, each having a cross-section with ends in each portion in an extension direction of the waveguide 2 and defining the waveguide 2 when being coupled with the other side. The waveguide tube slot antenna A has a core bar 20 arranged in the tube axis direction, and the core bar 20 is held by both of first and second waveguide tube formation members 11 and 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a waveguide slot antenna.

  As is well known, a waveguide slot antenna is used in various devices (systems) having a wireless communication function in a high frequency band (for example, a millimeter wave band) or a low frequency band (for example, a centimeter wave). It is used as an antenna for transmitting and receiving radio waves). Millimeter-wave radio waves are used in, for example, in-vehicle radar systems, and centimeter-wave radio waves are used in satellite broadcasting systems such as broadcasting satellites (BS) and communication satellites (CS), wireless LANs, and Bluetooth (registered trademark). ) And other data transmission systems, electronic fee collection systems (ETC (registered trademark)), and the like. The millimeter wave band radio wave is a radio wave having a wavelength of 1 to 10 mm and a frequency of 30 to 300 GHz, and the centimeter wave band radio wave is a radio wave having a wavelength of 10 to 100 mm and a frequency of 3 to 30 GHz.

  In order to promote cost reduction of various systems having a wireless communication function, it is necessary to reduce the cost of the waveguide slot antenna. Therefore, the present applicant has proposed a resin-made waveguide slot antenna in the following Patent Document 1. More specifically, a resin-made waveguide having a waveguide extending in the tube axis direction, in which the defined surface of the waveguide is coated with a conductive coating, and the waveguide in the tube axis direction. And a plurality of radiating slots provided at predetermined intervals along the waveguide, and the waveguide has an end shape in cross section (cross section orthogonal to the tube axis direction), and is coupled to the other side of the waveguide. Is a waveguide slot antenna composed of first and second waveguide forming members that define

JP 2014-60700 A

By the way, especially in an application for transmitting and receiving radio waves in a low frequency band, it is necessary to increase the antenna size (increase the length of the antenna) in relation to the wavelength. In the waveguide slot antenna described in Patent Document 1, When the size is increased, undesired deformation of the waveguide (either one or both of the waveguide forming members), for example, warping or bending in the direction along the tube axis direction is likely to occur due to a temperature change or the like. . And when the above deformation occurs,
・ The shape accuracy of the waveguide is adversely affected and the propagation efficiency of radio waves is reduced.
-A gap is generated at the coupling part of both waveguide forming members, and radio waves propagating through the waveguide through this gap are likely to leak to the outside.
Therefore, the desired antenna characteristics cannot be stably exhibited.

  In view of the above circumstances, an object of the present invention is to make it possible to prevent the deformation of the waveguide forming member due to temperature change as much as possible, and to thereby stably exhibit desired antenna characteristics. It is to realize a tube slot antenna.

  The present invention, which was created to achieve the above object, includes a waveguide made of a resin having a waveguide extending in the direction of the tube axis, the defined surface of the waveguide being covered with a conductive coating, and a waveguide. A waveguide slot antenna having a plurality of radiation slots provided at predetermined intervals along the tube axis direction of the wave tube, wherein the waveguide has an end in cross section at each part in the extending direction of the waveguide Formed of the first and second waveguide forming members that form a waveguide by being coupled to the other side, and having a cored bar arranged along the tube axis direction The cored bar is held by both the first and second waveguide forming members.

  As described above, if both the first and second waveguide forming members hold the core metal (core metal extending in the tube axis direction) arranged along the tube axis direction, both waveguides are provided. Since the bending rigidity and torsional rigidity of the waveguide composed of the combined tube-forming members can be increased, the deformation of the waveguide (particularly warping / bending in the direction along the tube axis direction) hardly occurs due to temperature changes. Become. For this reason, the waveguide slot antenna which can reduce the possibility that the above-mentioned malfunctions occur as much as possible and can stably exhibit desired antenna characteristics can be realized.

  In the above-described configuration, at least one of the first and second waveguide forming members may be a resin injection molded product (resin injection molded product using a core metal as an insert part) integrally including a core metal. it can. In this way, at least deformation due to one of the molding contractions can be prevented as much as possible. For this reason, it is possible to prevent as much as possible the deterioration of the coupling accuracy between the waveguide forming members due to deformation due to molding shrinkage, and through this, the waveguide slot antenna with excellent antenna characteristics can be stabilized. Can be obtained.

  In the above configuration, the core metal is constituted by a combination of the first core metal and the second core metal, and the first waveguide forming member is a resin injection molding integrally including the first core metal. Product (resin injection-molded product using the first cored bar as an insert part), and the second waveguide forming member is a resin injection-molded product (second molded unit) integrally including the second cored bar. It is also possible to use a resin injection-molded product using the second cored bar as an insert part. In this way, both the first and second waveguide forming members can be prevented from being deformed due to molding shrinkage as much as possible, so that the waveguide slot antenna having further excellent antenna characteristics. Can be obtained stably.

  The core metal may be embedded in the wall portion of the waveguide, or a part thereof may be exposed on the outer surface of the waveguide.

  Both the first and second waveguide forming members may have a concave cross section.

  As described above, according to the present invention, it is possible to prevent the deformation of the waveguide (waveguide forming member) due to temperature change as much as possible, so that desired antenna characteristics can be stably exhibited. It is possible to realize a waveguide slot antenna that can be used.

(A) is a schematic plan view of an antenna unit provided with a waveguide slot antenna according to the present invention, and (b) is a rear view of the same. (A) is a schematic cross-sectional view of the waveguide slot antenna according to the first embodiment of the present invention, and (b) is a schematic cross-sectional view taken along line YY shown in FIG. 1 (a). (A) is a schematic perspective view showing an example of an assembly method of the waveguide slot antenna shown in FIG. 2, and (b) and (c) are schematic perspective views showing another example of the assembly method of the antenna. It is. FIG. 4A is a schematic perspective view of a waveguide slot antenna according to a second embodiment of the present invention before assembly, and FIG. 4B is a schematic perspective view of the antenna. (A) is a partial plan view of a waveguide slot antenna according to a third embodiment of the present invention, (b) is a schematic cross-sectional view taken along line XX shown in (a), and (c) is a diagram. (A) It is a YY line schematic sectional drawing shown in a figure. (A) is a schematic cross-sectional view of a waveguide slot antenna according to a fourth embodiment of the present invention, and (b) is a schematic cross-sectional view of a waveguide slot antenna according to a fifth embodiment of the present invention. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIGS. 1A and 1B show a schematic plan view and a schematic rear view of an antenna unit 1 including a waveguide slot antenna A according to the first embodiment of the present invention. An antenna unit 1 shown in FIG. 1 is for transmitting and receiving centimeter-wave radio waves, and includes a plurality of (in the illustrated example, five) waveguide slot antennas A connected in parallel and each conductor. A feeding waveguide 9 [indicated by a two-dot chain line in FIG. 1B] for supplying high-frequency power (radio wave) to the wave tube slot antenna A is provided. There are no particular limitations on the means for connecting the waveguide slot antennas A in parallel. For example, fixing means such as adhesion, double-sided tape fastening, and concave-convex fitting can be used alone or in combination of two or more. Of the five waveguide slot antennas A, for example, the antenna A arranged at the center can function as a radio wave transmitting antenna, and two antennas A arranged on both sides of the antenna A can receive radio waves. It can function as an antenna. When the antenna unit 1 is used for transmitting and receiving radio waves in the 24 GHz band, the size of each waveguide slot antenna A is, for example, a dimension in the tube axis direction (up and down direction in FIG. 1): 100 mm, The dimension in the width direction (left and right direction in FIG. 1) is 20 mm, and the dimension in the height direction (direction perpendicular to the sheet in FIG. 1) is 5 mm.

  Next, the detailed structure of each waveguide slot antenna A will be described. As shown in FIGS. 2A and 2B, the waveguide slot antenna A includes a waveguide 10 having a waveguide 2 extending in the tube axis direction and a tube axis direction of the waveguide 10. A plurality of radiating slots 3 provided at predetermined intervals along the waveguide 10 and a feeding slot 5 provided at one end in the tube axis direction of the waveguide 10 and supplying high-frequency power to the waveguide 2. As shown in FIG. 1A, the radiation slot 3 of the present embodiment is provided such that a straight line extending through the center in the width direction is inclined by 45 ° with respect to the tube axis direction. The inclination angle of the radiating slot 3 with respect to can be set as appropriate according to the application.

  As shown in FIGS. 2A and 2B, the waveguide 10 is a rectangular waveguide having a rectangular cross section at each portion in the extending direction of the waveguide 2. More specifically, it includes a top wall 10a and a bottom wall 10b that are parallel to each other, side walls 10c and 10d that are parallel to each other, and end walls 10e and 10f that close one end and the other end opening in the tube axis direction. . The plurality of radiation slots 3 are provided on the top wall 10a, and the power supply slot 5 is provided on the bottom wall 10b. In the present embodiment, the cross-sectional dimensions of the top wall 10a and the bottom wall 10b are longer than the cross-sectional dimensions of the side walls 10c and 10d. In the following, for convenience of explanation, the side on which the top wall 10a is provided is referred to as the upper side, and the side on which the bottom wall 10b is provided is referred to as the lower side, but the usage mode of the waveguide slot antenna A is not limited. .

  The top wall 10a is provided with a plurality of recesses 4 opened on the outer surface thereof along the tube axis direction, and one radiation slot 3 is opened on the inner bottom surface of each recess 4. In this embodiment, although the hollow part 4 is formed in perfect circle shape by planar view, the hollow part 4 can also be formed in rectangular shape, ellipse shape, etc. by planar view. By providing such a depression 4, unnecessary radiation, also called a grating lobe, is suppressed.

  The waveguide 10 is formed by joining the first and second waveguide forming members 11 and 12 whose cross sections in the extending direction of the waveguide 2 have end shapes. Specifically, as shown in FIG. 2A, the top wall 10a provided with the radiation slot 3, and the side walls 10c and 10d and the end walls 10e and 10f partly (upper part) are integrated. A first waveguide forming member 11, a bottom wall 10 b provided with a power supply slot 5, and a side wall 10 c, 10 d and the remaining portions (lower portions) of the end walls 10 e, 10 f are integrated into a second waveguide. The waveguide 10 is formed by coupling the forming member 12. In short, the waveguide 10 of the present embodiment includes a first waveguide forming member 11 having a concave shape with the transverse section opened downward, and a second waveguide with the concave shape having the transverse section opened upward. It is formed by joining the waveguide forming member 12.

  The first waveguide forming member 11 is a resin injection-molded product, and the radiation slot 3 and the recessed portion 4 are molded at the same time as the injection molding. The second waveguide forming member 12 is also an injection molded product of resin, and the power supply slot 5 is molded simultaneously with the injection molding. As the molding resin for the waveguide forming members 11 and 12, for example, at least one thermoplastic resin selected from the group of liquid crystal polymer (LCP), polyphenylene sulfide (PPS) and polyacetal (POM) is used as a base resin. One or a plurality of fillers such as glass fiber (GF) and carbon fiber (CF) are added to the base resin as necessary. Among the resins exemplified above, LCP is preferable in that it has excellent shape stability compared to PPS and the like and can suppress the amount of burrs generated during molding.

  The surface that defines the waveguide 2 in the first waveguide forming member 11 and the surface that defines the waveguide 2 in the second waveguide forming member 12 are enlarged in FIG. It is covered with a conductive film 6 as shown in the figure. As a result, radio waves can be smoothly propagated along the waveguide 2. Note that the conductive coating 6 may be formed over the entire surface of both the waveguide forming members 11 and 12. In this way, the masking forming operation before the formation of the conductive film 6 and the masking removing operation after the formation of the conductive film 6 are not required. The manufacturing cost can be reduced.

  The conductive coating 6 may be composed of a single-layer metal plating coating, but here, the first coating 6a deposited on the waveguide forming members 11 and 12 and deposited on the first coating 6a. The conductive film 6 is composed of the formed second film 6b. The first coating 6a can be a plating coating of metal such as copper, silver, gold, etc. that is particularly excellent in electrical conductivity (propagation of radio waves), and the second coating 6b can be made of a durable (anti-resistance) such as nickel. It is possible to obtain a metal plating film having excellent corrosion resistance. By making the conductive coating 6 have such a laminated structure, high conductivity and high durability can be imparted to the conductive coating 6 at the same time, and the amount of expensive metals such as copper and silver used. It is possible to suppress the increase in cost.

  The conductive coating 6 (6a, 6b) can be formed by, for example, an electrolytic plating method or an electroless plating method, but the electroless plating method is preferable. This is because the electroless plating method is more advantageous in securing desired antenna characteristics because it is easier to obtain the conductive coating 6 (6a, 6b) having a uniform thickness than the electrolytic plating method. If the film thickness of the conductive coating 6 is too thin, the durability becomes poor. Conversely, if the film is too thick, it takes a long time to form the coating, resulting in high costs. From this point of view, the thickness of the conductive coating 6 is preferably 0.2 μm or more and 1.5 μm or less. When the conductive coating 6 has a laminated structure of the first coating 6a and the second coating 6b as in the present embodiment, the film thickness of the first coating 6a and the second coating 6b is, for example, 0.1. It can be about -1.0 micrometer and about 0.1-0.5 micrometer.

  The waveguide 10 constituting the waveguide slot antenna A further includes a cored bar 20 disposed along the tube axis direction and held by both the first and second waveguide forming members 11 and 12. . As shown in FIG. 3, the cored bar 20 is made of a rectangular (rectangular) plate-like member extending in the tube axis direction, and one surface thereof is arranged along the vertical direction (the height direction of the waveguide 10). In the standing posture, they are embedded in the side walls 10c and 10d. That is, in the present embodiment, the pair of core bars 20 is not exposed on either the inner side surface (waveguide 2) or the outer side surface of the waveguide 10. The cored bar 20 can employ, for example, a plate member made of sintered metal mainly composed of iron or copper, in addition to a metal plate such as stainless steel, brass, and aluminum (aluminum alloy). In addition, in order to further improve the propagation property of the radio wave propagating through the waveguide 2, it is particularly preferable to employ a brass plate or an aluminum plate having excellent conductivity as the cored bar 20.

The pair of cored bars 20 and 20 adopts either of the means (procedures) shown in the following (1) to (3), for example, so that both the first and second waveguide forming members 11 and 12 are used. Can be held in.
(1) While fitting the upper part of the metal cores 20 and 20 into the holding part 11a provided on the first waveguide forming member 11 (the part constituting the side walls 10c and 10d), The lower portion is fitted into a holding portion 12a provided on the second waveguide forming member 12 (the portion constituting the side walls 10c and 10d thereof) [see FIG. 3 (a)].
(2) The second waveguide forming member 12 is used as an insert part so that the lower portion of the core metal 20, 20 is integrally held by the second waveguide forming member 12. The portions constituting the side walls 10c, 10d of the first waveguide forming member 11 after the injection molding with resin, the upper portions of the core bars 20, 20 (portions protruding from the second waveguide forming member 12) Are fitted to the holding portions 11a respectively provided in FIG. 3 (see FIG. 3B).
(3) The first waveguide forming member 11 is made of resin using the core metals 20 and 20 as insert parts so that the upper portions of the core metals 20 and 20 are integrally held by the first waveguide forming member 11. After the injection molding, the lower portions (portions protruding from the first waveguide forming member 11) of the core bars 20, 20 constitute the side walls 10c, 10d of the second waveguide forming member 12. It fits into the holding | maintenance part 12a provided in each part [refer FIG.3 (c)].

  In the present embodiment, by adopting the above means (2), the pair of core bars 20 and 20 are held by both waveguide forming members 11 and 12. Here, in the case of adopting the above means (2), the vertical dimension of the holding portion 11a provided in the first waveguide forming member 11 is the upper portion of the core metal 20 to be held by the holding portion 11a. If the dimension is smaller than the vertical dimension, the two opposing surfaces of the first waveguide forming member 11 and the second waveguide forming member 12 cannot be brought into contact with each other (between the two waveguide forming members 11 and 12). This may cause a bad influence on the antenna characteristics. Therefore, the vertical dimension of the holding part 11a is set larger than the vertical dimension of the upper part of the cored bar 20 to be held by the holding part 11a. Even when the above means (1) or (3) is employed, the vertical dimension of the holding portions 11a and 12a is set for the same reason.

  From the above, in the waveguide slot antenna A (waveguide 10) according to the present embodiment, the first waveguide forming member 11 is injection-molded with a resin, and the core bars 20 and 20 are used as insert parts. After the waveguide forming member 12 is injection-molded with resin, the conductive coating 6 is formed on the surface defining the waveguide 2 of both the waveguide forming members 11 and 12, and then both waveguides are formed. This is completed by joining the members 11 and 12 together. The method of joining the first waveguide forming member 11 and the second waveguide forming member 12 is arbitrary. For example, the adhesive applied to the contact portions of the two waveguide forming members 11 and 12 is cured. Adhesion or welding for welding the waveguide forming members 11 and 12 to each other at the contact portion between the two waveguide forming members 11 and 12 can be employed. In addition to this, both the waveguide forming members 11, 12 are fitted (press-fitted) into the concave portions provided in either one of the two waveguide forming members 11, 12. Can also be combined. It is also possible to couple the waveguide forming members 11 and 12 using the cored bar 20. Specifically, for example, the upper portion of the cored bar 20 is press-fitted (fitted with an interference fit) into the holding portion 11a provided on the first waveguide forming member 11, and is filled with an adhesive. For example, the adhesive may be cured after the upper portion of the core bar 20 is fitted to the portion 11a.

  In the case where an adhesive is used to join the two waveguide forming members 11 and 12, for example, a thermosetting adhesive, an ultraviolet curable adhesive, an anaerobic adhesive, or the like is used as the adhesive. However, in the case of a thermosetting adhesive that requires heat treatment when the adhesive is cured, the resin-made waveguide forming members 11 and 12 may be deformed or the like with heat treatment. Therefore, an ultraviolet curable adhesive or an anaerobic adhesive is preferable as the adhesive. In addition, since the adhesive is generally an insulator, if the adhesive adheres to the defined surface of the waveguide 2, there is a possibility that the radio wave propagation may be adversely affected. For this reason, when an adhesive is used to join the two waveguide forming members 11 and 12, it is important to pay attention so that the adhesive does not adhere to the defined surface of the waveguide 2.

  As described above, in the waveguide slot antenna A of the present embodiment, both the first and second waveguide forming members 11 and 12 hold the cored bar 20 arranged along the tube axis direction. doing. In this way, since the bending rigidity and torsional rigidity of the waveguide 10 are increased, even if one or both of the waveguide forming members 11 and 12 are deformed due to a temperature change or the like, the deformation Can be regulated by the cored bar 20. For this reason, the deformation of the waveguide forming members 11 and 12 causes a deviation in the shape accuracy of the waveguide 2, thereby reducing the radio wave propagation property. A gap is generated at the coupling portion between the two waveguide forming members 11 and 12. The possibility that a problem such as leakage of radio waves propagating through the waveguide 2 through the gap leaks to the outside can be reduced as much as possible. Therefore, the waveguide slot antenna A that can stably exhibit desired antenna characteristics can be realized.

  In particular, in the present embodiment, the second waveguide forming member 12 is a resin injection-molded product (resin injection-molded product using the core metal 20 as an insert part) integrally including the core metal 20. As for the second waveguide forming member 12, deformation due to molding shrinkage can be prevented as much as possible. For this reason, it is possible to prevent as much as possible a decrease in the coupling accuracy between the waveguide forming members 11 and 12 due to deformation accompanying the molding shrinkage of the second waveguide forming member 12, and through this. The waveguide slot antenna A having excellent antenna characteristics can be stably mass-produced.

  The waveguide slot antenna A according to the first embodiment of the present invention has been described above. However, the waveguide slot antenna A may be appropriately modified without departing from the gist of the present invention. Is possible. Hereinafter, other embodiments of the present invention will be described with reference to the drawings. However, configurations similar to those of the first embodiment described above are denoted by common reference numerals, and redundant description is omitted as much as possible.

  FIG. 4 (particularly FIG. 4B) shows a schematic perspective view (schematic perspective view including a transverse section) of the waveguide slot antenna A according to the second embodiment of the present invention. The main difference between the waveguide slot antenna A shown in the figure and the waveguide slot antenna A is that the core metal 20 embedded in each of the side walls 10c and 10d of the waveguide 10 is used as the first core. A resin injection-molded product (first cored bar) that is composed of a combination of the gold 20A and the second cored bar 20B, and the first waveguide forming member 11 is integrally formed with the first cored bar 20A. 20A is a resin injection-molded product using insert parts), and the second waveguide forming member 12 is a resin injection-molded product (second core metal) integrally including a second metal core 20B. 20B is a resin injection molded product using insert parts).

  In this way, both the first and second waveguide forming members 11 and 12 can be prevented from being deformed due to molding shrinkage as much as possible. The coupling accuracy can be further increased. Therefore, the waveguide slot antenna A having further excellent antenna characteristics can be realized. In the present embodiment, as shown in FIGS. 4A and 4B, the second cored bar 20B (the upper end) is provided with respect to the recess provided in the first cored bar 20A (the lower end). The cored bar 20 made of a combination of both the cored bars 20A and 20B is realized by press-fitting the convex part. In addition to the above press-fitting, both the cores 20A and 20B can be coupled by means such as adhesion, combined use of press-fitting and adhesion, and the like. Moreover, both the waveguide forming members 11 and 12 can be coupled by an arbitrary method.

  5A to 5C conceptually show a partial plan view, a transverse sectional view, and a longitudinal sectional view of a waveguide slot antenna A according to a third embodiment of the present invention. In the waveguide slot antenna A of this embodiment, as shown in FIG. 5A, a radiating slot array in which a plurality of radiating slots 3 are arranged at predetermined intervals along the tube axis direction is provided on the waveguide 10. Two rows are provided in the width direction, and the arrangement positions of the radiation slots 3 constituting one radiation slot row and the radiation slots 3 constituting the other radiation slot row are different from each other in the tube axis direction. In brief, in the waveguide slot antenna A of this embodiment, a plurality of radiation slots 3 and recesses 4 are arranged in a staggered manner.

In addition, the waveguide slot antenna A (waveguide 10) of this embodiment is disposed in parallel with the side walls 10c and 10d as shown in FIGS. It further includes a branch wall 10g that branches into the waveguides 2A and 2B, and a plurality of inner walls 13 that reduce the cross-sectional area of the waveguide 2 (2A and 2B) at the position where the radiation slot 3 is formed. The inner wall 13 is erected on the inner bottom surface of the bottom wall 10b. Of the two inner walls 13, 13 adjacent in the tube axis direction, the height dimension of the inner wall 13 on the side relatively close to the power supply slot 5 is h _1. When the height dimension of the inner wall 13 relatively far from the power supply slot 5 is h ₂ , the inner wall 13 is formed so as to satisfy the relational expression h ₁ ≦ h ₂ [enlarged view in FIG. reference]. One radiation slot row is formed along the waveguide 2A, and the other radiation slot row is formed along the waveguide 2B.

As described above, if the inner wall 13 for reducing the cross-sectional area of the waveguide 2 is provided at the position where the radiation slot 3 is formed, the radiation efficiency of the radio wave propagating through the waveguide 2 can be increased. In particular, of the two inner walls 13 and 13 adjacent in the tube axis direction, the height dimension of the inner wall 13 on the side relatively close to the power supply slot 5 is h ₁ , and the inner wall 13 on the side relatively far from the power supply port 5 is. When the height dimension is h ₂ , if the relational expression h ₁ ≦ h ₂ is satisfied, the amount of radio waves radiated to the outside of the antenna A through each radiation slot 3 is changed between the radiation slots 3. It becomes difficult to vary, and it is possible to radiate a substantially equal amount of radio waves from each radiation slot 3. Therefore, it is possible to avoid variations in antenna performance in each part of the tube axis direction as much as possible, and the reliability of the waveguide slot antenna A is improved.

  The waveguide 10 constituting the waveguide slot antenna A of this embodiment also has an end-shaped cross section at each part in the extending direction of the waveguide 2, and at least the defined surface of the waveguide 2 is the conductive coating 6. The first and second waveguide-forming members 11 and 12 made of resin covered with are joined together. Specifically, a first wall 10a provided with the radiating slot 3 and the depression 4 and a side wall 10c, 10d, an end wall 10e, 10f, and a part of the branch wall 10g (upper part) are integrated. The second waveguide having the waveguide forming member 11, the bottom wall 10b provided with the feeding slot 5, the side walls 10c and 10d, the end walls 10e and 10f, and the remainder (lower part) of the branch wall 10g. The waveguide 10 is formed by coupling with the wave tube forming member 12.

  The waveguide slot antenna A of this embodiment also has a cored bar 20 that is disposed along the tube axis direction and is held by both the first and second waveguide forming members 11 and 12. The cored bar 20 is formed of a rectangular (rectangular) plate-like member extending in the tube axis direction, and is embedded in the side walls 10c and 10d and the branch wall 10g in a standing posture in which one surface is arranged along the vertical direction. ing. By disposing the cored bar 20 in the above-described manner, the waveguide slot antenna A of the present embodiment can also enjoy the same effects as the waveguide slot antenna A shown in FIG.

  In addition, although detailed illustration is abbreviate | omitted, in this embodiment, it is three core bars so that all the three core bars 20 may be hold | maintained integrally by either of the both waveguide formation members 11 and 12. FIG. The first and second waveguide forming members 11 and 12 can be injection-molded with resin using the insert 20 as an insert component, and the two cores 20 and 20 held by the side walls 10c and 10d are used as insert components. Either one of the wave tube forming members 11 and 12 is injection-molded with resin, and the other one of the waveguide forming members 11 and 12 is injection-molded with resin using the cored bar 20 held by the branch wall 10g as an insert part. You can also.

  FIG. 6A shows a schematic cross-sectional view of a waveguide slot antenna A according to the fourth embodiment of the present invention. The waveguide slot antenna A shown in the figure is a modification of the waveguide slot antenna A shown in FIGS. 5A to 5C, and the branch wall 10g is formed with the first and second waveguides. Only the members 11 and 12 are formed. That is, the branch wall 10g does not hold the cored bar 20. In FIG. 6A, a portion where the branch wall 10g of the second waveguide forming member 12 is formed with respect to a concave portion provided in a portion where the branch wall 10g of the first waveguide forming member 11 is formed. The branch wall 10g is formed by fitting (press-fitting) the convex portions provided on the wall.

  FIG. 6B shows a schematic cross-sectional view of a waveguide slot antenna A according to the fifth embodiment of the present invention. A waveguide slot antenna A shown in the figure is a modification of the waveguide slot antenna A shown in FIGS. 5A to 5C, and a core metal 20 held by a side wall 10c and a core held by a side wall 10d. One surface of the gold 20 is exposed to the outer surface of the waveguide 10. Although illustration is omitted, the same configuration may be adopted in the waveguide slot antenna A shown in FIGS.

  As described above, the waveguide slot antenna A according to the embodiment of the present invention described above has a feature that it is possible to prevent as much deformation as possible due to a temperature change or the like. Therefore, among the waveguide slot antennas, it is necessary to increase the antenna size (increase in the tube axis direction) particularly in relation to the wavelength, and the deformation is easily caused by a temperature change or the like. It can be preferably applied to a waveguide slot antenna for transmitting and receiving radio waves in the frequency band.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. The scope of the present invention is defined by the terms of the claims, and includes the equivalent meanings recited in the claims and all modifications within the scope.

DESCRIPTION OF SYMBOLS 1 Antenna unit 2 Waveguide 3 Radiation slot 5 Feed slot 10 Waveguide 11 1st waveguide formation member 12 2nd waveguide formation member 20 Core metal 20A 1st metal core 20B 2nd metal core A Waveguide slot antenna

Claims (5)

A waveguide made of resin having a waveguide extending in the tube axis direction, and a defined surface of the waveguide covered with a conductive coating, and provided at predetermined intervals along the tube axis direction of the waveguide A waveguide slot antenna comprising a plurality of radiating slots, wherein the waveguide has an end-shaped cross section at each portion in the extending direction of the waveguide and is coupled to the other side. And comprising the first and second waveguide forming members that define the waveguide,
A waveguide slot antenna comprising a cored bar arranged along the tube axis direction, the cored bar being held by both the first and second waveguide forming members .   2. The waveguide slot antenna according to claim 1, wherein at least one of the first and second waveguide forming members is a resin injection-molded product integrally including the cored bar. The metal core is a combination of a first metal core and a second metal core,
The first waveguide forming member is a resin injection-molded product integrally including the first core metal, and the second waveguide forming member is integrated with the second core metal. The waveguide slot antenna according to claim 1, wherein the waveguide slot antenna is a resin injection-molded product.   The waveguide slot antenna according to any one of claims 1 to 3, wherein a part of the cored bar is exposed on an outer surface of the waveguide.   The waveguide slot antenna according to any one of claims 1 to 4, wherein each of the first and second waveguide forming members has a concave cross section.

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