JP2002118401A - Converter from circularly polarized wave to linearly polarized wave and converter for satellite reception - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a low cost, a high productivity and a stabilized performance of a converter from circularly polarized wave to linearly polarized wave and a converter for satellite reception. SOLUTION: A feedome covering a feed horn and a λ/4 phase plate provided in a circular wave guide are molded integrally with a dielectric material in order to reduce costs, improve the productivity and stabilize the performance by reducing variations of assembly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circular polarization-linear polarization converter and a satellite reception converter (International Patent Classification H01P1) used for down converters for satellite broadcasting or communication reception by broadcasting satellites and communication satellites. / 17)

[0002]

2. Description of the Related Art In recent years, satellite broadcasting has reached the popularization period,
By the end of the year, BS broadcasts have also been digitized, and new services such as data broadcasts are expected to be provided and further spread. In addition, a communication satellite will be launched in the same orbit as the BS during the year 2000, and the need for a shared antenna with the BS is increasing. Below is the conventional circular polarization
The linear polarization converter will be described with reference to FIG. FIG. 4 is a side sectional view of a conventional circular polarization-linear polarization converter. In FIG. 4, 1 is a fidome, 2 is a feed horn, 3 is a circular waveguide, and 4 is a λ / 4 phase plate.

[0003] The operation of the conventional circularly-polarized to linear polarization converter constructed as described above will be described below.

The left-handed and right-handed circularly polarized signals incident from the front of the fidome 1 are converged by a feed horn 2 and guided to a λ / 4 phase plate 4 provided in a circular waveguide 3. When passing through the / 4 phase plate 4, the horizontal polarization component and the vertical polarization component of the incident circular polarization signal have the same phase, and are converted into linear polarization. By the above operation, when the incident wave is left-handed circularly polarized light, it is converted into a linearly polarized electric field component parallel to the X axis in FIG. 4, and when the incident wave is right-handed circularly polarized electric field component parallel to the Y axis. Is converted into a linearly polarized wave.

The ends of the fidome and the λ / 4 phase plate on the fidom side are respectively located between the free space and the feed horn,
Acts as an impedance transformer for matching between the feed horn and the circular waveguide.

[0006]

However, in the configuration of the above-mentioned conventional example, a screw or an adhesive is required to fix the λ / 4 phase plate 4 to the circular waveguide 3. The four-phase plate 4 must be fixed to the feed horn using a highly water-resistant silicone-based adhesive different from the adhesive used for fixing the phase plate 4, so that workability is extremely poor and cost is high. Since there are two matching portions acting as impedance transformers at the fidome and the end on the fidom side of the λ / 4 phase plate, there has been a problem that material variations and assembly variations are likely to occur.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, is a low cost, is excellent in mass productivity, and realizes a good cross-polarization characteristic with little assembly variation. It is intended to provide a converter.

[0008]

SUMMARY OF THE INVENTION To achieve these objects, a circularly-polarized-to-linearly polarized wave converter and a satellite receiving converter according to the present invention are provided. A plate is provided, and the λ / 4 phase plate and a fidome covering a feed horn provided at one end of the circular waveguide are integrally formed.

According to the present invention, it is possible to realize a circular polarization-linear polarization converter and a satellite reception converter that are low in cost, have excellent mass productivity, and can obtain good cross polarization characteristics with little assembly variation. it can.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The invention according to claim 1 of the present invention comprises a circular waveguide having a .lambda. / 4 phase plate made of a dielectric material. A circularly-polarized to linearly-polarized wave converter constituted by integrally forming a fidome covering a feed horn provided at one end with a fidom integrated with a λ / 4 phase plate and adhesive to the feed horn In this case, the λ / 4 phase plate is also fixed at the same time, so that a low cost and excellent mass productivity circular polarization-linear polarization converter can be obtained. The matching portion acting as an impedance transformer, which was required at two places at the end of the phase plate on the fidome side, can be reduced to one place, and a good intersection can be achieved by reducing material and assembly variations. Polarization characteristics are stable It has the effect of being obtained.

[0011] The invention according to claim 2 of the present invention provides a 12G
A probe for converting a microwave signal in the Hz band into a TEM wave, a plurality of low-noise amplifiers, a mixer circuit, a local oscillator and an intermediate frequency amplifier, wherein the circular polarization-linear polarization converter according to claim 1 is provided. This is a satellite receiving converter equipped. By fixing the fidome integrated with the λ / 4 phase plate to the feed horn with an adhesive, the λ / 4 phase plate is also fixed at the same time, so low cost and excellent mass productivity. In addition to the above, a satellite receiving converter can be obtained, and at the same time, in the conventional example, the matching section which functions as an impedance transformer, which is required at two places, that is, the fidom and the end on the fidom side of the λ / 4 phase plate, is reduced to one. This makes it possible to stably obtain good cross-polarization characteristics by reducing material and assembly variations.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 is a side sectional view of a circular polarization-linear polarization converter according to a first embodiment of the present invention.

In FIG. 1, 1 is a fidome, 2 is a feed horn, 3 is a circular waveguide, and 4 is a λ / 4 phase plate. The operation of the thus-configured circular polarization-linear polarization converter will be described below.

The left-handed and right-handed circularly polarized signals incident from the front surface of the fidome 1 are converged by the feed horn 2 and are integrally formed with the fidome 1 provided in the circular waveguide 3. When passing through the λ / 4 phase plate 4, the horizontal polarization component and the vertical polarization component of the incident circularly polarized wave signal have the same phase, and are converted into linearly polarized waves. By the above operation, when the incident wave is a left-handed circularly polarized wave, it is converted into a linearly polarized electric field component parallel to the X axis in FIG.
In the case of right-handed circular polarization, it is converted into a linear polarization of an electric field component parallel to the Y axis.

In this embodiment, the fidome and the λ / 4
The connection part of the phase plate is tapered, but other shapes that do not disturb the input impedance (for example, U-shape)
Needless to say, the same effect can be obtained.

FIG. 2 is a side sectional view of a converter for satellite reception according to a second embodiment of the present invention.
Shows a block diagram.

In FIG. 2, 1 is a fidome, 2 is a feed horn, 3 is a circular waveguide, 4 is a λ / 4 phase plate, 5 and 6 are probes, 7 is a printed circuit board, 8 is a shield case, and 9 is an intermediate. It is a frequency output part, and 10a in FIG.
10b and 10c are low noise amplifiers, 11 is a local oscillator, 12 is a mixer circuit, and 13 is an intermediate frequency amplifier. The operation of the above-described satellite receiving converter will be described below.

The left-handed and right-handed circularly polarized signals incident from the front surface of the fidome 1 are converged by the feed horn 2 and are integrated with the fidome 1 provided in the circular waveguide 3 to form a λ / 4 phase plate 4. When passing through the λ / 4 phase plate 4, the horizontal polarization component and the vertical polarization component of the incident circularly polarized wave signal have the same phase, and are converted into linearly polarized waves. With the above operation, the probe 5 parallel to the X axis on the printed circuit board 7 when the incident wave is left-handed circularly polarized light, and the probe 5 parallel to the Y axis on the printed circuit board 7 when the incident wave is right-handed circularly polarized light 6 is converted into a TEM wave.

Thereafter, the signals are amplified by the low-noise amplifiers 10a and 10b corresponding to the respective probes and the common low-noise amplifier 10c.
It is converted to an intermediate frequency signal by mixing with the local signal supplied from 1. The intermediate frequency signal is amplified by the intermediate frequency amplifier 12 and output from the intermediate frequency output unit 9.

In this embodiment, the probe is constituted by a pattern on a printed circuit board, but it is needless to say that the same effect can be obtained by using a metal bar or the like.

[0022]

As described above, according to the present invention, a circular waveguide is provided with a .lambda. / 4 phase plate made of a dielectric, and the .lambda. / 4 phase plate and a feeder provided at one end of the circular waveguide. A circular polarization-to-linear polarization converter and a satellite reception converter in which low cost, excellent mass productivity, and good cross polarization characteristics with little assembling variation can be obtained by integrally forming the dome covering the horn. Is realized.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a circular polarization-linear polarization converter according to a first embodiment of the present invention.

FIG. 2 is a side sectional view of a converter for satellite reception according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a converter for satellite reception according to a second embodiment of the present invention;

FIG. 4 is a side sectional view of a conventional circularly-polarized to linear polarization converter.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fidome 2 feed horn 3 circular waveguide 4 λ / 4 phase plate 5, 6 probe 7 printed circuit board 8 shield case 9 intermediate frequency output unit 10 a, 10 b, 10 c low noise amplifier 11 local oscillator 12 mixer circuit 13 intermediate frequency amplifier

Claims (4)

[Claims] In a circularly-polarized-to-linearly polarized wave converter using a λ / 4 phase plate, a λ / phase converter made of a dielectric material is provided in a circular waveguide.
A circularly-polarized-to-linearly polarized wave converter comprising a four-phase plate and integrally molding the λ / 4 phase plate and a fidome covering a feed horn provided at one end of a circular waveguide. 2. A 12 GHz band microwave signal is transmitted by a TEM.
A probe for converting to a wave, a plurality of low noise amplifiers, a mixer circuit, a local oscillator and an intermediate frequency amplifier,
A satellite receiving converter comprising the circular polarization-linear polarization converter according to claim 1. 3. The circularly polarized to linearly polarized wave converter according to claim 1, wherein a dielectric having a relative dielectric constant of 2 to 5 is used for the fidome and the λ / 4 phase plate. 4. The satellite receiving converter according to claim 2, wherein a dielectric having a relative dielectric constant of 2 to 5 is used for the fidome and the λ / 4 phase plate.