JPS62244Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an orthogonally polarized parabolic antenna using a loop-coupled coaxial waveguide converter at one terminal of a polarization splitter of a primary radiator.

Conventionally, a parapolar reflector antenna that can share orthogonal polarization has a polarization splitter 2 of a primary radiator held on a reflector 1 by a support mechanism 4, as shown in FIGS. 1a and 1b, for example. Two feeding coaxial tubes 3 come out from the duplexer 2 so as to be orthogonal to each other. This has disadvantages such as deterioration of radiation characteristics due to scattering of the radiated electric field and reduction of gain due to the asymmetry of the feeding coaxial tube 3. In addition, the terminal of the feed coaxial tube 3 that comes out to the back of the parapolar reflector 1 comes out from a place 90 degrees away from the outer periphery of the reflector, so after attaching the parapolar antenna to the steel tower, the feeder that connects to the equipment is connected. The work involved in attaching the wires to each terminal was complicated.

An antenna with a structure as shown in FIGS. 2a and 2b was also considered, but the structure of the polarization splitter of the primary radiator was complicated because it required a coaxial tube 5 bent at 90 degrees.

An object of the present invention is to provide a parapolar antenna for orthogonal polarization that solves these conventional problems.

In this invention, a loop-coupled coaxial waveguide converter is installed so that power can be fed from the same direction to the polarization splitter of the primary radiator, and the power feeding coaxial tubes can be concentrated in the same plane. It is.

The loop-coupled coaxial waveguide converter used in this invention uses a general rectangular waveguide, so it suppresses disturbances caused by higher-order modes and has good electrical characteristics such as return loss (VSWR) over a wide band. It can be set to any value.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 3 is a front view and a side view of an embodiment of the present invention. This idea provides a loop-coupled coaxial waveguide converter at one terminal of the polarization splitter 6 of the primary radiator so that the feed coaxial tube 3 from the polarization splitter 6 is positioned in the same direction with respect to the antenna axis. It is composed of

4a and 4b show another embodiment similar to that shown in FIG. 3, but in addition, the power supply part of the power supply coaxial pipe can be taken out from the center of the parapolar reflector 1, and the power supply part of the power supply coaxial tube can be taken out from the center of the parapolar reflector 1. Since the distance between the mirror and the power supply input/output end is narrowed, workability such as connection and direction adjustment of the power supply line can be improved.

FIG. 5 shows a partially cutaway view of an embodiment of a polarization splitter 6 of a primary radiator equipped with a loop-coupled coaxial waveguide converter 10 used in the present invention. Since this loop-coupled coaxial waveguide converter 10 has a center conductor 11 that can be bent by 90 degrees, the terminals 7 can be provided in the same direction as the terminals 8 of a normal coaxial waveguide converter.
A blocking plate 9 is provided between these coaxial waveguide converters.

According to the present invention, the structure of the primary radiator is simple because the two feeding coaxial tubes are grouped together in the same plane, and since they are integrated, the deterioration of the radiation characteristics due to the feeding coaxial tube is prevented, and the phase plane is disturbed. The gain can be significantly improved. According to the present invention, the reflection loss can be sufficiently large as shown in FIG. 6a, and the coupling attenuation can also be sufficiently large as shown in FIG. 6b. Therefore, when used at both terminals of a dual-polarization type feed line, a feed system with a simple structure can be constructed.

Further, in the present invention, a rectangular waveguide has been described as an example, but it is clear that similar effects can be obtained even when a circular waveguide is used.

[Brief explanation of drawings]

Figures 1a and b and Figures 2a and b are plan and side views of a conventional orthogonally polarized parapolar antenna with a primary radiator, Figures 3a and b, and Figures 4a and b are the original A plan view and a side view of the first and second embodiments of the invention, FIG. 5 is a partially cutaway perspective view of the inside of the polarization splitter of the primary radiator used in the invention, and FIGS. FIG. 4 is a frequency characteristic diagram of VSWR and coupling attenuation of the polarization splitter according to the invention. In the figure: 1... Parapolar reflector, 2, 6... Polarization splitter for the primary radiator, 3, 5... Power supply coaxial tube, 4... Primary radiator support mechanism, 7... Terminal, 8... Terminal ,
9...Mode blocking plate.

Claims (1)

[Scope of utility model registration request] At the two coaxial feed ends of the polarization splitter of the primary radiator,
Providing a coaxial waveguide converter in which the center conductor is directly extended and coupled within the waveguide, and a loop-coupled coaxial waveguide converter in which the center conductor is bent at 90 degrees within the waveguide and coupled. A parabolic antenna for shared orthogonal polarization is characterized in that these two feeding ends are coupled on the same plane.