JPS6251801A - Orthogonal polarizer - Google Patents

Abstract

PURPOSE:To avoid interference between branch waveguide synthesis circuits and to atain miniaturization by using a shift bent waveguide with ridge between a coupling part of a main waveguide and a filter. CONSTITUTION:Dimensions of shift bent waveguides 4a-4d with ridge and position of low-pass filters 5a-5d are decided so as to provide an electric field wall at the coupling hole at a high frequency band f2 thereby avoiding the interference to a low frequency band f1. Further, the shift bent waveguides 4a-4d with ridge are formed as E bent at 90 deg. While being displaced into the guide axis direction of the main waveguide 1, then coupling holes 3a, 3c of a horizontal polarized wave are shifted to coupling holes 3b, 3d of the vertical polarized wave in the guide axis direction of the main waveguide 1 so as to miniaturize the polarized branch. On the other hand, although deterioration in the band characteristic through the shift bent waveguide structure, the band characteristic is improved by providing a ridge to form the ridged bent waveguides.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an orthogonal polarization splitting device used in microwave and sub-millimeter wave antenna power feeding devices.

[Conventional technology]

In communication using microwaves or quasi-millimeter waves, a frequency reuse method that simultaneously uses orthogonal polarization is adopted in order to effectively utilize frequencies. In addition, in order to perform transmission and reception at the same time, most of the antennas used for this type of communication use orthogonal polarization of linearly polarized waves or circularly polarized waves for two separated frequency bands. Among the polarization splitters used in the antenna feeder of this type of antenna, the low frequency band (fl) is polarized, and then the high frequency band (f
2) In a demultiplexer that adopts a method of polarizing and demultiplexing, two mutually orthogonal polarized waves in the low frequency band (fl) are simultaneously polarized and demultiplexed without affecting the radio waves in the high frequency band (f2) at all. An orthogonal polarization splitter is required. This type of polarization splitter uses a high frequency band (
In order to polarize only the low frequency band (fl) by suppressing the polarization characteristics of f2) and the excitation of higher-order modes, the part that performs polarization must have small coupling to higher-order modes and be axially symmetrical. It is necessary to construct a coupling circuit that maintains the This type of demultiplexing device uses a 90°
A balanced polarization demultiplexing device that simultaneously demultiplexes orthogonal polarized waves through four coupling holes cut in the tube axis direction with an interval of .degree. is effective.

This type of polarization splitting device combines four coupling holes and a branching waveguide with a low-pass filter or a bandpass filter, each independently coupled to each polarization component, using a magic T. Then, two orthogonal polarization components are detected independently while separating the high frequency band.

[Problems that the invention attempts to solve]

Conventional polarization splitting devices of this type perform polarization side synthesis using a combination of a normal curved waveguide and a magic T, which results in a large structure that makes it difficult to install on a small antenna. There is a drawback.

An object of the present invention is to provide an orthogonal polarization splitting device that does not have the above-mentioned drawbacks.

[Means for solving problems]

The present invention provides a circular or square waveguide as a main transmission line that simultaneously transmits two or more frequencies with two orthogonal polarizations;
A branch transmission line that is independently coupled to the main transmission line through four coupling holes arranged symmetrically around the waveguide, and two sets of branch transmission lines that are orthogonal to each other are connected to each set. In the orthogonal polarization demultiplexing device, which simultaneously demultiplexes mutually orthogonal polarized waves of at least one frequency, the branch transmission line coupled to the main transmission line is connected to the central portion of the orthogonal polarization demultiplexing device. It is characterized by being composed of a shift bend waveguide with a ridge and a 90° bend within the electric surface while being displaced in the direction of the main transmission line.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a partially cross-sectional side view showing the structure of the orthogonal polarization splitter of the present invention, and FIG. 2 is a cross-sectional view showing the structure of the orthogonal polarization splitter of the present invention. 1 is a structural cross-sectional view of a shift bend waveguide with a ridge showing the characteristics of the structure.

In FIGS. 1 and 2, in order to perform frequency separation, the main circular waveguide 1 includes step conversion sections 2 for impedance matching, and adjacent thereto, axially symmetrical step conversion sections 2 are provided at every 90° on the circumference. Four coupling holes 3a, 3b, 3c, 3 cut in the direction
d is provided.

These coupling holes are arranged symmetrically within a plane perpendicular to the tube axis of the main circular waveguide 1 in order to suppress the excitation of higher-order modes and the induction of polarization characteristics for radio waves of high frequency (f2). There is. Therefore, these four binding holes 3a, 3b, 3c
, 3d, in order to separate the low frequencies (fl) while performing polarization separation.
It is necessary to separately synthesize the radio wave components combined by (8, 3C) and (3b, 3d). two orthogonal polarization components,
That is, the branch waveguide synthesis circuit for fl (H) of the horizontally polarized wave fr (H) and the vertically polarized wave L (V) is coupled to the main circular waveguide 1 via the coupling holes 3 a and 3 c. ridged shift bend waveguides 4a, 4c.

It is composed of low pass filters 5a, 5c and magic T6. On the other hand, the branched waveguide synthesis circuit for f, (v) includes shift bend waveguides 4b, 4 with ridges coupled to the main circular waveguide 1 via coupling holes 3b, 3d.
d, low-pass filters 5b, 5d, and magic T7.

Ridged shift bend waveguides 4a, 4b, 4c.

4d characterizes the present invention with continuous displacement in the tube axis direction of the main circular waveguide 1 and eight bends of 90° in order to avoid structural interference of the composite circuit with orthogonal polarization relationship. It is a waveguide. Low pass filters 5a, 5b, 5c, 5
d indicates binding holes 3a and 3b.

This is to block high frequency (f2) radio waves that are combined at 3c and 3d. Also, Magic T 6. T7 is a waveguide type hybrid that combines the same polarized wave components coupled through the opposing coupling holes (3a, 3c) and (3b, 3d) of the main circular waveguide 1 in the same phase.

Namely Magic T6. T7 has an 8-sided arm as an output terminal, and an E-sided arm is terminated without reflection.

The specifications of the shift bend waveguides 4a, 4b, 4c, and 4d with ridges and the positions of the low-pass filters 5a, 5b, 5c, and 5d are such that radio waves of high frequency (f2) can be transmitted through the coupling hole groups 3a,
3b, 3c, 3d and a branching waveguide synthesis circuit, in order to avoid interference in the polarization/demultiplexer section for low frequency (fl) radio waves, an electric field wall ( The transverse electric field is determined to be zero). The ridged shift bend waveguide has 8 bends of 90° while being largely displaced in the tube axis direction of the main circular waveguide 1, so that the equivalent cross section in the transmission direction for low frequency (fl) radio waves is similar to that of a normal waveguide. In order to avoid deterioration of transmission characteristics due to a smaller cross section than the wave tube, a ridge is provided in the center to widen the electrically equivalent cross section and improve transmission characteristics.

In the orthogonal polarization branching device having the above configuration, one terminal #1 of the main circular waveguide 1 has an orthogonal polarization r, (V/H) of a lower frequency than the antenna side and an orthogonal polarization f2 of a higher frequency. (
V/H) is input, and the terminal #1 side waveguide transmits a low frequency orthogonal polarized wave fl (V/H) and a high frequency orthogonal polarized wave f2 (V/H). The other terminal #2 waveguide of the main circular waveguide 1 is selected as a cutoff region for the low frequency f, and transmits only the high frequency orthogonally polarized wave f2 (V/H). The step conversion unit 2 performs impedance matching between the terminal #1 side waveguide and the terminal #2 side waveguide.

The low-frequency horizontally polarized waves f1 are combined through coupling holes 3a and 3c, passed through low-pass filters 5a and 5c, respectively, and synthesized with magic T6, and detected at detection terminal #3.

On the other hand, the low frequency vertically polarized wave r, (v) is the coupling hole 3b,
3d, and low-pass filters 5b and 5, respectively.
d, are combined by magic T7, and detected by detection terminal #4. For such polarization side synthesis, according to this embodiment, a shift bend waveguide with a ridge is used as the connecting waveguide connecting the coupling hole and the low-pass filter, so that the polarization of the branch waveguide can be adjusted. Interference occurring during wave side synthesis can be prevented.

In this way, low frequency (fl) radio waves are demultiplexed,
At the terminal 2 of the main circular waveguide 1, there is a high frequency orthogonal polarization f2.
(V/H) is detected.

In the above embodiments, a circular waveguide was used as the main transmission line, but it is clear that a square waveguide can also be used. Furthermore, although a low-pass filter is used in the synthesis circuit, a band-pass filter may also be used. moreover,
In the above embodiment, two signals are simultaneously polarized perpendicular to the main transmission line.
Although the present invention is not limited to this, the present invention can be applied to an orthogonal polarization demultiplexing device that transmits three or more frequencies and simultaneously demultiplexes at least one frequency of mutually orthogonal polarized waves. Of course.

〔Effect of the invention〕

As explained above, according to the present invention, by using a shift bend waveguide with a ridge between the coupling part of the main waveguide and the filter, structural interference between the branch waveguide synthesis circuits can be avoided and the path can be shortened. Since it is possible to combine the polarized waves over a long length, it is possible to provide a small and low-loss polarization demultiplexing device.

[Brief explanation of drawings]

FIG. 1 is a partially cross-sectional side view of a polarization splitter that is an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a polarization splitter that is an embodiment of the invention. 1 ・・・・・・・・・・・・ Main circular waveguide 2
・・・・・・・・・・・・・・・ Step conversion section 3
a, 3b, 3c, 3d ・” coupling hole 4a,
4b, 4c, 4d... Ridged shift bend waveguide 5a, 5b, 5c, 5d... Low pass filter 6.7... Magic T agent Patent attorney Yoshi Iwasa Sachi↑f2Cv/H> Figure 1 Figure 2

Claims (1)

[Claims] (1) A circular or square waveguide as the main transmission line that simultaneously transmits two or more frequencies with two orthogonal polarizations, and four coupling holes arranged symmetrically around the waveguide. branch transmission lines each independently coupled to the main transmission line;
a combining circuit unit that independently combines two sets of branch transmission lines that are orthogonal to each other, and at least one
In an orthogonal polarization demultiplexing device that simultaneously demultiplexes polarized waves whose frequencies are orthogonal to each other, the branch transmission line coupled to the main transmission line has a ridge in the center and displaces the electric surface while being displaced in the direction of the main transmission line. An orthogonal polarization splitting device comprising a shift bend waveguide with a ridge having an inner 90° bend.