JPH0229001A - Polarization coupler - Google Patents

Abstract

PURPOSE:To facilitate the machining and to reduce the cost by providing a polarized wave filter to a 1st waveguide able to propagate both orthogonal polarized waves, branching the 2nd and 3rd waveguides from the 1st waveguide in parallel with each other and providing a polarized wave rotary reflector to one end of the 1st waveguide. CONSTITUTION:When a square waveguide 1 is excited from a rectangular waveguide 2 or 3, the square waveguide 1 is excited by the 1st polarized wave in any case. The 1st polarized wave excited from the square waveguide 2 is reflected in a conductor plate 4 and not coupled with the square waveguide 3 and appears at the opening of the square waveguide 1 as the 1st polarized wave as it is. The 1st polarized wave excited from the square waveguide 3 is reflected in the conductor plate 4, reflected in a 90 deg. phase shift plate 5 and a short-circuit end, becomes the 2nd polarized wave and appears at the opening through the conductor plate 4. Since the conductor plate 4 and the 90 deg. phase shift plate 5 fitted to the square waveguide 1 are fitted in parallel with a reference face or at a simple angle as 45 deg. and the number of the plates is small, the machaning is easily implemented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polarization splitter, and more particularly to a polarization splitter used in a linearly polarized dual-polarization antenna or the like.

[Conventional technology]

A conventional polarization splitter will be described with reference to the drawings.

FIG. 2 is a perspective view of a first example of a conventional polarization splitter.

The conventional example shown in FIG. 2 includes a rectangular waveguide 6 with one end short-circuited, and rectangular waveguides 7 and 8 branching from two adjacent sides of the rectangular waveguide 6. .

When the rectangular waveguide 6 is excited from the rectangular waveguide 7, the rectangular waveguide 6 is excited with a polarized wave having an electric surface parallel to the side surface to which the rectangular waveguide 7 is connected, and this polarized wave is generated by the rectangular waveguide. It is not connected to tube 8. The same applies to the rectangular waveguide 8, so the second
In the conventional example shown in the figure, the inputs from the rectangular waveguides 7 and 8 can be combined into the rectangular waveguide 6 as mutually orthogonal double-sided waves, and
The orthogonal double-sided waves input from the open end of the rectangular waveguide 6 can be separated into one polarized wave into the rectangular waveguide 7 and the other polarized wave into the rectangular waveguide 8. Note that a circular waveguide may be used instead of the rectangular waveguide 6. In each case, the rectangular waveguides 7 and 8 diverge from the rectangular waveguide 6 or from the circular waveguide instead in directions 90 degrees different from each other.

FIG. 3 is a front view of a dual polarization parabolic antenna using the conventional example shown in FIG.

The parabolic antenna shown in FIG. 3 has a primary radiator (not shown) placed near the focal point of the parabolic reflector 9.
A rectangular waveguide 6 is connected to the secondary radiator, and rectangular waveguides 7 and 8 branching from the rectangular waveguide 6 are arranged as feeders.

Since the two rectangular waveguides 7 and 8 block the aperture of the parabolic reflector 9, they deteriorate the polarization separation and sidelobe characteristics of the antenna. If the rectangular waveguides 7 and 8 can be branched in directions parallel to each other, the area that blocks the aperture plane will be halved, so that deterioration in polarization separation and sidelobe characteristics can be reduced.

FIG. 4 is a partially cutaway perspective view of a second example of a conventional polarization splitter.

The conventional example shown in Fig. 4 is a circular waveguide lO with one end short-circuited.
Rectangular waveguides 11 and 12 are branched in parallel directions from the rectangular waveguides 11 and 12, and a large number of conductor rods 13 are inserted between the rectangular waveguides 11 and 12.
By providing this, it can operate as a polarization demultiplexer.

The end of the circular waveguide 10 on the rectangular waveguide 12 side is short-circuited, and the conductor bar 13 closest to this end is connected to the rectangular waveguide 11.1.
2, the conductor rods 13 furthest from the short-circuit surface are provided perpendicular to this plane, and the conductor rods 13 in the middle have an installation angle sequentially with respect to the conductor rods 13 at both ends. It rotates sequentially while maintaining an interval of about 1/10 the tube wavelength.

The plane of polarization of the polarized wave (in the circular waveguide 10) that is incident on the group of conductor rods 13 such that the electric plane is perpendicular to the conductor rod 13 at the frontmost side rotates according to the rotation of the mounting angle of each conductor rod 13. However, after passing the last conductor bar 13, it is rotated by 90 degrees.

On the other hand, most of the polarized waves that are incident on the nearest conductor bar 13 so that the electric surface is parallel to them are reflected. Due to the above action of the group of conductor rods 13, the polarized wave excited from the rectangular waveguide 12 has its plane of polarization rotated by 90 degrees and is output from the open end of the circular waveguide 10, which is different from the rectangular waveguide 11. Not combined. On the other hand, the polarized wave excited from the rectangular waveguide 11 is output from the open end without rotating the plane of polarization, and is not coupled to the rectangular waveguide 12. Therefore, the conventional example shown in FIG. 4 also operates as a polarization splitter.

[Problem to be solved by the invention]

The above-mentioned conventional polarization splitter in which two branch waveguides can be installed parallel to each other requires a large number of conductor rods to be installed at equal intervals, and the installation angles must be rotated at equal intervals. Therefore, machining for this attachment is not easy and is expensive.

An object of the present invention is to provide a polarization splitter that is easy to machine and can be manufactured at low cost.

[Means to solve the problem]

The polarization splitter of the present invention includes a first waveguide capable of propagating first and second polarized waves orthogonal to each other, and reflecting the first polarized wave propagating through the first waveguide. and a polarization filter that passes the second polarized wave, and a polarization filter that passes the second polarized wave, and the first polarization filter with this polarization filter in between.
second and third waveguides branching parallel to each other from the waveguide and electrically coupling only to the first polarized wave propagating through the first waveguide; and and a polarization rotating reflector that reflects the first or second polarized wave incident from one end of the tube as the second or first polarized wave.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIGS. 1(a) and 1(b) are a perspective view and a cross-sectional view of an embodiment of the present invention.

In the embodiment shown in FIGS. 1(a) and 1(b), the electric surface is the first
Figure (a) shows a rectangular waveguide 1 that can propagate first and second polarized waves parallel to the X direction and one end short-circuited, and one end of the rectangular waveguide 1 parallel to the It is configured to include rectangular waveguides 2 and 3 that branch out from the sides in parallel to each other, and a plurality of conductor plates 4 and a 90-degree phase shift plate 5 provided within the rectangular waveguide 1.

The conductor plate 4 is provided parallel to the X direction at a position sandwiched between the branch points of the rectangular waveguides 2 and 3, and reflects the first polarized wave propagating through the rectangular waveguide 1. It acts as a polarization filter that passes two polarized waves.

The 90 degree phase shift plate 5 is composed of a dielectric plate having a predetermined shape and dielectric constant and arranged at an angle of 45 degrees to the X direction. The 90-degree phase shift plate 5 and the short-circuited end of the rectangular waveguide l rotate the polarization plane of the first or second polarized wave incident toward the short-circuited end by 90 degrees, so that it becomes the second or first polarized wave. It acts as a reflective polarization rotating reflector.

When exciting the rectangular waveguide 1 from the rectangular waveguide 2 or 3, the rectangular waveguide 1 is excited in each case with the first polarization. The first polarized wave excited from the rectangular waveguide 2 is reflected by the conductor plate 4, does not couple with the rectangular waveguide 3, and is directly transmitted to the open end of the rectangular waveguide l as the first polarized wave. appear. The first polarized wave excited from the rectangular waveguide 3 is reflected by the conductor plate 4 and does not couple with the rectangular waveguide 2, but is reflected by the 90 degree phase shift plate 5 and the short-circuited end and becomes the second polarized wave. It becomes a polarized wave, passes through the conductor plate 4, and appears at the open end without being coupled to the rectangular waveguide 2.

Conversely, when the first polarized wave and the second polarized wave are input from the open end of the rectangular waveguide 1, all of the first polarized wave is output to the rectangular waveguide 2, and the second polarized wave is All are output to the rectangular waveguide 3.

The configuration and operation of the embodiment shown in FIGS. 1(a) and 1(b) as a polarization splitter have been described above.

The conductor plate 4 and 90 degree phase shift plate 5 attached to the rectangular waveguide 1 are
All of them are mounted parallel to the reference plane or at a simple angle of 45 degrees, and because there are only a small number of them, machining of the embodiments shown in Figures 1 (a) and (b) is easy. .

Note that, instead of the conductor plate 4, the polarization filter can also be configured by a plurality of conductor bars parallel to the X direction. It is not necessary to install these conductor bars at exactly equal intervals;
Since only the parallelism with the X direction needs to be accurately maintained, the installation is easy.

Furthermore, there are various configurations of the 90-degree phase shift plate 5. The figure shows a 90° retardation plate using a dielectric plate, but the rectangular waveguide 1 (
The same effect as a 90 degree phase shift plate can also be obtained by using capacitive metal rods or dielectric rods arranged diagonally (in cross section).

If this metal rod or dielectric rod is realized with a screw, it is convenient to adjust the rotation angle of the polarization plane to 90 degrees by adjusting its insertion length. A 90° phase shift plate can be constructed by combining a plurality of other types of phase shift elements.

Furthermore, a circular waveguide can also be used instead of the rectangular waveguide l.

〔Effect of the invention〕

As explained above, the present invention provides a polarization filter in a first waveguide capable of propagating orthogonally polarized waves, and a second waveguide that couples only one polarized wave with this polarization filter sandwiched between them. The third waveguide is branched from the first waveguide in parallel to each other, and the third waveguide is branched from the first waveguide in parallel to each other.
By providing a polarization rotation reflector at one end of the waveguide that rotates the plane of polarization by 90 degrees and reflects it, a polarization splitter is constructed.
Since it is easy to manufacture a polarization filter and a polarization rotating reflector, it is possible to provide an inexpensive polarization splitter in which the two branching waveguides are parallel to each other, and which is easy to manufacture.

Fig. 2 is a perspective view of the first example of a conventional polarization splitter, Fig. 3 is a front view of a polarization-sharing parabolic antenna using the conventional example shown in Fig. 2; FIG. 4 is a partially cutaway perspective view of a second example of a conventional polarization splitter.

■... Rectangular waveguide, 2, 3... Rectangular waveguide, 4... Conductor plate, 5... 90 degree phase shift plate.

Agent Patent Attorney Susumu Uchihara

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are perspective views (α
False

Claims (1)

[Claims] a first waveguide capable of propagating first and second polarized waves orthogonal to each other; a first waveguide that reflects the first polarized wave propagating through the first waveguide and passes the second polarized wave; a polarized wave filter, and electrically couples only the first polarized waves that are branched from the first waveguide parallel to each other and propagated through the first waveguide with this polarized wave filter in between. second and third waveguides; and a polarization rotating reflector that reflects the first or second polarized wave incident from one end of the first waveguide as the second or first polarized wave. A polarization splitter characterized by comprising: