JP2734264B2 - Mirror modified 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 shaped beam antenna for use on a satellite.

[0002]

2. Description of the Related Art As a conventional shaped beam antenna for mounting on a satellite, a shaped beam antenna sharing two orthogonal linear polarizations is generally used. This shaped beam antenna
As shown in FIG. 2, dedicated feeding horns 1 are used for the vertically polarized grid reflecting mirror 12 and the horizontally polarized grid reflecting mirror 13, respectively. In particular, in the Japanese archipelago elongated in the north and south, in order to obtain a shaped beam having a complicated irradiation pattern, power is supplied from a plurality of feed horns 1 to obtain a shaped beam.

[0003]

As described above, the conventional shaped beam grid reflector antenna requires the feed horn 1 for each of the vertically and horizontally polarized reflectors 12, 13. I have. Further, in order to obtain a complicated shaped beam, a plurality of feed horns 1 corresponding to the degree of complexity are required. For this reason, the power supply system becomes complicated,
There is a problem that it is against the weight reduction of the device.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a mirror-modified antenna that can obtain a shaped beam pattern for dual orthogonal polarization using one feed horn.

[0005]

In order to achieve the above object, according to the present invention, there are provided two polarization grid reflectors corresponding to two orthogonal polarizations and two orthogonal linear polarizations. An antenna comprising a feed horn for feeding power,
One feed horn is used, and the two polarization grid reflecting mirrors have respective focal positions coincident with each other at the installation position of the one feed horn, and each mirror surface forms an arbitrary shaped beam pattern. Has been modified as follows. According to a second aspect of the present invention, there is provided an antenna including two polarization grid reflectors corresponding to two orthogonal polarizations and a feed horn for feeding two orthogonal linear polarizations. The two polarization grid reflectors are modified so that their focal positions coincide at the installation position of the one feed horn, and the mirror surfaces have the same relative phase distribution on the aperture surface. Have been.

[0006]

According to the first aspect of the present invention, two orthogonally polarized waves radiated from the feed horn are reflected by the respective polarization grid reflecting mirrors. Thus, the two reflected polarizations form an arbitrary shaped beam pattern with the modified mirror surface. In the present invention according to claim 2, two orthogonally polarized waves radiated from the feed horn are reflected by the respective polarization grid reflecting mirrors. As a result, the two reflected polarizations form an arbitrary shaped beam pattern by equalizing the phase distribution on the aperture surface by the modified mirror surface.

[0007]

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a schematic configuration diagram of a mirror-modified antenna of the present embodiment. This mirror-surface modified antenna comprises one feed horn 1 and one vertical polarization reflection mirror 2 and one horizontal polarization reflection mirror 3 respectively. The feed horn 1 radiates two orthogonal linearly polarized waves, that is, a vertically polarized wave and a horizontally polarized wave. The vertical polarization reflector 2 and the horizontal polarization reflector 3 are grid reflectors, and correspond to the vertical polarization and the horizontal polarization radiated from the feed horn 1, respectively, and are orthogonal to the grid mirror surfaces 2a and 3 respectively.
a. The grid mirror surfaces 2a and 3a are modified so as to obtain a specific irradiation beam pattern. For example, in the case of FIG.
The grid mirror surfaces 2a and 3a of the radio wave reflected by 3 are modified so that the phase distribution on the aperture surface becomes equal. Further, the respective focal lengths are set such that the focal positions of the reflecting mirrors 2 and 3 come to the feeding horn 1.

Next, the operation of the mirror modified antenna will be described. First, the vertically polarized wave radiated from the feed horn 1 at the focal position is reflected on the grid mirror surface 2a of the vertically polarized wave reflecting mirror 2. Similarly, the horizontal polarization is reflected on the grid mirror surface 3a of the horizontal polarization reflector 3. The vertical and horizontal polarized waves reflected by the respective reflecting mirrors 2 and 3 have substantially the same irradiation beam pattern by the grid mirror surfaces 2a and 3a modified so as to equalize the phase distribution on the aperture surface. This makes it possible to obtain a complex shaped beam pattern that is shared by two orthogonal polarizations even with one feed horn 1.

[0009]

As described above, according to the present invention, it is possible to obtain a shaped beam pattern for dual orthogonal polarization using one feed horn. And the weight of the antenna itself can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a mirror-modified antenna of the present embodiment.

FIG. 2 is a schematic diagram of a configuration of a conventional antenna.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply horn 2 Vertical polarization reflector 2a Grid mirror 3 Horizontal polarization reflector 3a Grid mirror

Claims (2)

(57) [Claims] 1. An antenna comprising two polarization grid reflecting mirrors corresponding to two orthogonal polarizations and a feed horn for feeding two orthogonal linear polarizations, wherein one feed horn is provided, The two polarization grid reflecting mirrors are characterized in that their focal positions coincide with each other at the installation position of the one feeding horn, and the respective mirror surfaces are modified so as to form an arbitrary shaped beam pattern. Mirror modified antenna. 2. An antenna comprising two polarization grid reflectors corresponding to two orthogonal polarizations and a feed horn for feeding two orthogonal linear polarizations, wherein the feed horn is one, and The two polarization grid reflecting mirrors are modified so that their respective focal positions coincide with each other at the installation position of the one feed horn, and the respective mirror surfaces have the same relative phase distribution on the aperture surface. Mirror modified antenna.