JPS6351701A - Orthogonal polarization branching filter - Google Patents

Abstract

PURPOSE:To branch two signals of different frequency bands, each of which is an orthogonal polarized wave simultaneously, by providing two pairs of conductive thin plates, and four coupling holes at a circular main wave guide, and providing a filter to cut an unrequired wave, at the coupling hole. CONSTITUTION:The titled filter is constituted of two sheets of orthogonal conductive thin plates, or plural number of conductive bars 4, 4, provided at the circular main wave guide 3 as an electrically equivalent shielding plane, four coupling holes 5 and 8 provided on the wall plane of the circular main waveguide 3, and four filters 6 and 9 to block the unrequired wave provided in each sub waveguide being connected to respective coupling hole. At this time, assuming that the guidewave lengths of the signals of a first frequency band, and a second frequency band are set as lambdag1, and lambdag2, respectively, the coupling holes 5 and 8 are positioned at positions of lambdag1/4, and lambda g2/4 from the end parts of the conductive thin plates. A vertical polarized wave 1 and a horizontal polarized wave 2 pass the coupling holes 5 and 8, and are guided to a rectangular sub waveguide by the conductive thin plates 4, 4 that are the electrically equivalent shielding planes. And the unrequired wave is blocked by the filters 6 and 9, and it is possible to branch the signal to desired horizontal and vertical polarized waves 7, 10-12, independently.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an antenna feeding system used in a communication system in which signals of two frequencies and signals of t are used with orthogonal polarization. , particularly regarding waveguide type orthogonal polarization splitters.

[Conventional technology]

In general, circular waveguides are widely used as waveguides that transmit signals in two frequency bands with two polarized waves orthogonal to each other and with each polarized wave. The diameter of the circular waveguide through which each signal is split is selected so that only the TB+1 mode, which is the fundamental mode of the circular waveguide, propagates in the frequency band to be split into two. Conventionally, when the frequency difference between two frequency bands is very close, the optimum waveguide diameter for demultiplexing in each band can be selected, so the electrical equivalent cutoff plane essential for a polarization demultiplexer is , were created by taking advantage of the blocking characteristics due to the difference in waveguide diameter.

On the other hand, if the frequency difference between the two frequency bands is small, a waveguide with sufficient cutoff characteristics to split the waves into two cannot be used, so a polarization splitter as shown in Figure 2 is used. There is. In this method, a part of a circular main wave tube 3 has a filter 15 structure, and the blocking characteristics of the filter 15 are used to perform demultiplexing. As another example, as shown in FIG. 3, vertical polarization 1. Split horizontally polarized wave 2 into two frequency bands at once.

After that, another branching filter 17.17 is used to perform frequency division on each polarized wave to achieve the desired level.

Some obtain vertical polarization 7, 10, 11, 12.

[Problem that the invention seeks to solve]

As mentioned above, when the frequency difference between two frequency bands is small, the orthogonal polarization branching filter shown in FIG.
Since the demultiplexing section for the first frequency band is a balanced circuit, the combining circuit 14 must be used in the rectangular sub-waveguide, which not only complicates the structure.

It is difficult to manufacture a wave device 15 having a circular waveguide section.

On the other hand, in the duplexer shown in Fig. 3, orthogonal polarization 1,
2 across two frequency bands and polarized by − degrees,
Furthermore, the signals in the first and second frequency bands must be separated by frequency demultiplexers 17 and 17, which complicates the configuration.

[Means for solving problems]

As a means for solving the above-mentioned problem, the orthogonal polarization splitter of the present invention provides a first
and a second circular main waveguide that transmits signals in two frequency bands, two sets of orthogonal conductor thin plates (or a plurality of conductor bars).
are arranged to be spaced apart in the tube axis direction, and on one wall surface on a plane perpendicular to the conductor thin plate surface in the circular main wave tube, about λg 1/4 away from each conductor thin plate end, a first frequency band waveguide is arranged. 1
A total of four second coupling holes for the second frequency band are provided on the wall surface of the circular main waveguide facing the first coupling hole at a distance of about λg2/4, and the first coupling hole A wave device for reflecting a signal in the second frequency band is provided in the sub-waveguide connected to the second coupling hole, and a wave device for reflecting the signal in the first frequency band is provided in the sub-waveguide connected to the second coupling hole. A filter is installed.

Here, λg1+λg2 are the first . FIG. 7 shows the pipe wavelength of a circular main wave tube for a signal in a second frequency band.

〔Example〕

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

FIG. 1 shows an embodiment of the present invention. The structure consists of 9 circular main waveguides 3 with 2 parts provided as electrically equivalent blocking surfaces.
Two orthogonal conductor thin plates (or multiple conductor bars may also be used) 4
, 4 and 1 Four coupling holes 5 and 8 provided on the wall of the circular main waveguide 3 and four wave devices for blocking unnecessary waves provided in each sub-waveguide connected to each coupling hole. It consists of 6 and 9.

Here, when the channel wavelengths of the signals in the first frequency band and the second frequency band are respectively λg1+λg2.

The positions of the coupling holes 5 and 8 are as shown in FIG.
λg1 is provided at a position -, from the end of the force U.

The vertically polarized wave 1 and the horizontally polarized wave 2 are guided to the rectangular sub-waveguide through coupling holes 5 and 8 by thin conductor plates 4 and 4 which are electrically equivalent blocking surfaces. Then, unnecessary waves are blocked by a filter 6°9, and each desired horizontal and vertical polarized wave 7, 10, 1
1.12 can be separated independently.

In the case where conductor rods are provided in place of the thin conductor plates 4 in the two circular main waveguides 3, four to five or more conductor rods may be provided so as to be on the same plane or more as the thin conductor plates 4 and extend in the diametrical direction.

〔Effect of the invention〕

As explained above, one aspect of the present invention is to provide a circular main waveguide with two sets of orthogonal conductor thin plates (or a plurality of conductor bars).

By providing four coupling holes in the wall surface of the circular main waveguide and providing a wave device for cutting unnecessary waves in those coupling holes, P#f can be obtained without providing a two-combination circuit or another branching filter.
It is simple to construct and has the effect of being able to separate signals in two frequency bands at once, each of which has orthogonal polarization.

Last date

[Brief explanation of drawings]

FIG. 1 shows a perspective view of an embodiment of an orthogonal polarization splitter according to the present invention, and FIGS. 2 and 3 each show a perspective view of a conventional orthogonal polarization splitter. In fig. 3: circular main wave tube, 4: thin conductor plate, 6: second frequency band blocking rectangular filter, 9: second frequency band blocking rectangular filter. Figure 1 1: Vertical polarization 7: First round a
Several bands horizontal 1 wave 2: horizontal polarization
8: 2nd frequency @, *M coupling hole 3: Circular main wave tube
9: Second frequency band blocking type 4: Conductor thin plate
Rectangular filter 10: second round 8
Number 5: Connection hole for first frequency losing zone 11: Second frequency losing zone vertical alignment lII wave 12: First round a losing zone i, ! Polarization 6: 2nd frequency band blocking rectangular filter Figure 2 13: Hybrid node 14: Synthesizing circuit 15: #I 2 a Loss band blocking type circular filter 16: 1st round, 1st round rectangular sub 4 seat pipe Figure 3 18: Connection hole

Claims (1)

[Claims] 1. A circular main wave tube that simultaneously transmits signals in two frequency bands, first and second, in two linearly polarized waves orthogonal to each other, and four rectangular sub wave tubes that are connected to the circular main wave tube through coupling holes. In an orthogonal polarization splitter configured with a waveguide, two sets of orthogonal conductor thin plates (or a plurality of conductor bars) are provided in the circular main waveguide separated from each other in the tube axis direction, and the ends of each conductor thin plate are Approximately 1/4・λg_1 (However, λg_1
is the internal wavelength of the circular waveguide for the signal in the first frequency band).A first waveguide dedicated to the first frequency band is installed on one wall surface on a plane perpendicular to the conductor thin plate surface in the circular main waveguide which is separated from the circular waveguide. In addition to providing a coupling hole, a coupling hole is provided on the wall surface of the circular main waveguide facing the first coupling hole at a distance of about 1/4·λg_2 (where λg_2 is the internal wavelength of the circular waveguide of the second frequency band signal). A filter for reflecting the second frequency band signal is provided in a sub-waveguide connected to the first coupling hole, and a filter for reflecting the second frequency band signal is provided in the sub-waveguide connected to the second coupling hole. An orthogonal polarization demultiplexer, characterized in that the filter is provided with a filter that reflects the first frequency band signal.