JP2578754Y2 - Circularly polarized planar antenna - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circularly polarized planar antenna in which the distance between two parallel metal plates forming a waveguide is made smaller than a predetermined distance.

[0002]

2. Description of the Related Art In recent years, with various proposals of communication and broadcasting systems using microwave circularly polarized waves, various studies have been made on circularly polarized antennas for transmitting and receiving these microwave circularly polarized waves. As well as being proposed. As one of them, there is a circularly polarized planar antenna using a curl antenna element as a circularly polarized antenna element for radiating circularly polarized waves. To explain this in more detail, a hollow disk-shaped waveguide as a waveguide distributor is formed of two circular metal plates that are parallel and separated by a predetermined distance, and a power supply unit is disposed at the center thereof. . A plurality of curled antenna elements are protruded from one metal plate by penetrating the shaft portion from the outside in an insulated state. In addition, a short-circuit plate is provided on the outer peripheral edge of the hollow disk-shaped waveguide, so that the inside of the waveguide is airtight so that moisture does not enter. This is to prevent a change in frequency characteristics due to dew condensation on the waveguide wall.

[0003]

In the above-mentioned circularly polarized planar antenna, a large number of curled antenna elements are required to be protruded to obtain a desired antenna gain. It is necessary that the waveguide has a large metal plate area. For this reason, the metal plate is easily deformed by external force or the like. In addition, since the inside of the waveguide is airtight, the internal pressure becomes lower than that of the atmosphere due to the effect of a large temperature drop, and there is a possibility that a force for indenting the metal plate may act. For these reasons, when the metal plate is deformed inward and the distance between the two metal plates is shortened, the band of the frequency signal that can be transmitted changes, and the characteristics of the waveguide as a waveguide distributor change. There was a problem of doing.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a circularly polarized planar antenna in which a distance between two metal plates constituting a waveguide is made smaller than a predetermined distance. Aim.

[0005]

In order to achieve the above object, a circularly polarized planar antenna according to the present invention comprises a waveguide formed of two metal plates arranged in parallel and separated by a predetermined distance. A circularly polarized planar antenna in which a power supply unit is provided inside a waveguide, and a plurality of circularly polarized antenna elements are provided on one of the metal plates so as to protrude by penetrating the shaft part from the outside; The shaft portion of the element is penetrated and protruded through the one metal plate via an insulator made of an insulating resin, and a column-shaped support member integrally formed with the insulator by outsert molding is used as the two sheets. It is arranged between metal plates, and is configured to restrict the distance between the metal plates from becoming smaller than the predetermined interval.

[0006]

According to the present invention, since the columnar support member is provided between the two metal plates to restrict the distance between the metal plates from becoming smaller than the predetermined distance, the predetermined distance can be easily maintained even if the metal plate is thin. Also, since a columnar support member formed by outsert molding integrally with the insulator is disposed between the metal plates,
The number of assembling steps for arranging the columnar support member is omitted, and the number of parts does not increase. Furthermore, since the supporting members provided between the metal plates are columnar, most of the space between the metal plates other than the supporting members is filled with air, and the dielectric loss is extremely small.

[0007]

1 and 2 show an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a longitudinal sectional view of one embodiment of the circularly polarized planar antenna of the present invention, and FIG. 2 is a plan view of FIG.

In the figure, a hollow disk-shaped waveguide as a waveguide distributor is formed by two circular metal plates 10 and 12 which are separated by a predetermined distance in parallel. Then, insulators 14, 14... Are formed by outsert molding using insulating resin in holes formed in a large number of one metal plate 10, respectively. At the same time, the columnar support members 16, 16 ... of a predetermined distance from the back surface of the metal plate 10 to the other metal plate 12 are provided.
Are connected to the insulators 14, 14... At appropriate positions by outsert molding and the communication member 1.
8, 18,... Are integrally formed. Each of the insulators 14, 14,... Has a curl antenna element 20, 20,.
Are inserted through the metal plate 10 from the outside. Further, the outer peripheral edge of the other metal plate 12 is formed in a cylindrical shape and is in close contact with the one metal plate 10, and the short-circuit plate 24 is constituted by the cylindrical portion. Further, a power supply unit 26 derived from the converter 25 is disposed in the waveguide from the center of the other metal plate 12. The two metal plates 10 and 12 and the short-circuiting plate 24 of the cylindrical portion are configured so that the inside of the waveguide is airtight, and consideration is given to preventing dew condensation or the like from occurring on the inner wall due to intrusion of moisture. ing.

In such a configuration, two metal plates 10,
The two support members 16, 16 ...
Is provided, and the supporting members 16, 16 are pressed against the metal plates 10, 12 by the force of the internal air contracting due to the external pressing force or the temperature drop and deforming the metal plates 10, 12 inward. Acts to prevent deformation. For this reason, even if the metal plates 10 and 12 are thin, they do not deform and the characteristics of the waveguide can be easily maintained. In addition, the weight of the entire antenna can be reduced by the thin portion.

Also, by forming the support members 16, 16... Integrally and simultaneously with the insulators 14, 14,... By outsert molding, the number of assembly steps for disposing the support members 16, 16,. Moreover, the number of parts does not increase.

Further, the cross-sectional area of the columnar support members 16, 16,... Is smaller than the area of the metal plates 10, 12, and the space between the metal plates 10, 12 is substantially the same as the other than the support members 16, 16,. Are filled with air, which has a dielectric constant of 1 and very little dielectric loss.

In the above embodiment, the metal plates 10, 12
Is a hollow disk-shaped waveguide having a circular shape and a power supply unit 26 disposed at the center. However, the invention is not limited to this, and a circularly polarized antenna element is arranged in a tube waveguide direction in a rectangular waveguide. May be. The circularly polarized antenna element is not limited to the curled antenna elements 20, 20,..., And may be composed of the shaft portions 22, 22 and a spiral-shaped portion connected to the tip thereof. The outer peripheral edge of one of the metal plates 12 is bent to form a cylindrical short-circuit plate 24, but the short-circuit plate 24 may be formed of another member. Furthermore, metal plate 1
The 0 and 12 and the short-circuiting plate 24 may be metal thin films formed on the surface of the resin by vapor deposition or plating.

[0013]

[Effects of the Invention] As described above, since the circularly polarized planar antenna of the present invention is constructed, the following special effects can be obtained.

In the circularly polarized planar antenna according to the first aspect, the columnar support member can regulate the deformation against the force acting to inwardly deform the metal plate. Therefore, the characteristics of the waveguide can be maintained with a simple structure. In addition, the thickness of the metal plate can be reduced, which is advantageous for reducing the weight of the entire antenna. In addition, since the support member is outsert molded at the same time as the insulator, the number of assembly steps in the production of the support member does not increase, and the number of parts does not increase, which is suitable for mass production. Further, since the supporting members provided between the metal plates are columnar, most of the space between the metal plates other than the supporting members is filled with air, the dielectric loss is extremely small, and the antenna gain is high accordingly. Things are obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of a circularly polarized planar antenna according to the present invention.

FIG. 2 is a plan view of FIG.

[Explanation of symbols]

 10, 12 metal plate 14 insulator 16 support member 20 curl antenna element 22 shaft portion 24 short-circuit plate 26 power supply portion

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01Q 13/08 H01Q 21/06 H01Q 21/24

Claims (1)

(57) [Scope of request for utility model registration] 1. A waveguide is formed by two metal plates arranged in parallel at a predetermined distance from each other, a power supply unit is provided inside the waveguide, and a plurality of circularly polarized plates are provided on one of the metal plates. In a circularly polarized planar antenna in which a wave antenna element is protruded by penetrating its axis from the outside, the axis of the circularly polarized antenna element is
The one metal plate is penetrated and protruded through an insulator made of an insulating resin, and a columnar support member formed by outsert molding integrally with the insulator is provided between the two metal plates. A circularly polarized planar antenna, wherein the distance between the metal plates is restricted to be smaller than the predetermined interval.