JPH0563407A - Parallel polarization polarizer - Google Patents

Abstract

PURPOSE:To provide the parallel polarization polarizer almost completely preventing the leakage of the received radio waves to the transmission terminal side and easy to take the impedance matching of a coupling hole. CONSTITUTION:A coupling hole 4, having a dipole antenna 4a of 1/4-length of the wave length of a low frequency band, resonates at a low frequency band and prevents the leakage of the received radio wave to a low-pass preventing filter 3 almost completely. A high-pass preventing filter 2 is of a corrugated construction whose corrugated depth is nearly 1/4-length of the guide wave length (lambdag) in the high-frequency band and whose corrugated width is the length obtaining the required filter characteristic. An equivalent short surface is in the nearest corrugated groove 2a. The coupling hole will not be affected by electrical influence from the corrugated groove 2a in the high-band preventing filter in the case of heading for a primary radiator 11 from this equivalent short surface and located at the lambdag/4. Thus, the impedance matching can be taken easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel polarization demultiplexer for an antenna feeding device used in a micro satellite communication earth station.

[0002]

2. Description of the Related Art A parallel polarization demultiplexer is a demultiplexer for demultiplexing two electromagnetic waves whose planes of polarization are parallel to each other and whose frequencies are different from each other. For example, in FIG.
The ones shown in are known. In FIG. 3, reference numeral 1 is a rectangular waveguide. One end 11 of the rectangular waveguide 1 is an input / output end (primary radiator end) with the primary radiator, and the other end 10 is a reception radio wave output end (reception end). The rectangular waveguide 1 is provided with a coupling hole 4, and the coupling hole 4 is
Short side direction (vertical direction in the figure) in the cross section orthogonal to the tube axis
From the primary radiator side 11 of the side wall on one end side (upper side in the drawing) toward the receiving end 10 at an appropriate distance. Although the coupling hole 4 is illustrated as a rectangle, it may be an ellipse.

Reference numeral 3 is a rectangular waveguide type low-pass blocking filter. The low-pass blocking filter 3 is formed by sharing the one end-side sidewall including the coupling hole 4 on the outer surface of the one end-side sidewall of the rectangular waveguide 1 in the lateral direction. An input end (transmission end) 9 for transmitting radio waves is provided on the reception end 10 side of FIG.

Reference numeral 2 is a high-frequency blocking filter.
The high-frequency blocking filter 2 is a filter having a corrugated structure formed on a side wall of the rectangular waveguide 1 on the other end side (the lower side in the drawing) in the short-side direction, and is arranged from the primary radiator side 11 to the receiving end. 10 to the receiving end 1 from an appropriate distance.
A plurality of corrugates are arranged toward 0. Here, in this corrugated structure, as shown in the figure, a plurality of corrugations are arranged at regular intervals in the pipe axis direction (that is, the width of the corrugated groove 2a orthogonal to the pipe axis and the corrugated width in the pipe axis direction are constant), In addition, the depth of the corrugated groove 2a is the deepest in the center of the array (the depth is approximately 1/4 of the guide wavelength so that the impedance is maximized in the high frequency band), and from the center of the array to the end. It is designed so that it becomes shallower toward the bottom.

In the above structure, the transmission radio wave (radio wave in the low frequency band) is converted from the coaxial mode to the waveguide mode at the coaxial type transmission end 9, passes through the low-frequency blocking filter 3 and passes through the coupling hole 4. It is propagated to the rectangular waveguide 1 and goes to the primary radiator side 11. A corner piece 5 provided at a corner immediately above the coupling hole 4 is for aligning a 90 ° bend. At this time, the high frequency rejection filter 2
The transmission radio wave entering the rectangular waveguide 1 through the coupling hole 4 is prevented from propagating toward the receiving end 10.

A received radio wave (radio wave in a high frequency band) enters the rectangular waveguide 1 from the primary radiator side 11, propagates in the high frequency blocking filter 2 and goes to the receiving end 10. At this time,
The low-frequency blocking filter 3 blocks the reception radio wave from propagating toward the transmission end 9 through the coupling hole 4 by using the cutoff characteristic of the waveguide.

Here, the electric field vector of the transmitted radio wave propagating in the low-pass filter 3 and the electric field vector of the received radio wave carried in the rectangular waveguide 1 are both vectors oriented in the lateral direction of the waveguide. And both radio waves are polarized waves parallel to each other.

[0008]

In the above-mentioned conventional parallel polarization polarization demultiplexer, since the transmitted and received radio waves are polarized waves parallel to each other, the received radio wave entering the rectangular waveguide from the end of the primary radiator is low. It is difficult to completely prevent the leak to the band stop filter side, that is, the leak to the transmitting end side.

Further, in the conventional corrugated structure of the high-frequency blocking filter, the equivalent short-circuit surface having the maximum impedance in the high frequency band enters the center of the high-frequency blocking filter, so that the coupling hole is formed in the high-frequency blocking filter. When it is provided at a quarter of the guide wavelength from the equivalent short plane, the coupling hole is affected by the corrugated groove of the high frequency blocking filter in the high frequency band, and there is a problem that it is difficult to achieve impedance matching.

It is an object of the present invention to provide a parallel polarization demultiplexer having a structure that almost completely prevents received radio waves from leaking to the transmission end side and facilitates impedance matching of coupling holes. is there.

[0011]

In order to achieve the above-mentioned object, the parallel polarization polarization demultiplexer of the present invention has the following structure. That is, in the parallel polarization polarization demultiplexer of the present invention, one end in the tube axis direction is an input / output end (primary radiator end) with the primary radiator and the other end is an output end (reception end) of the received radio wave, A rectangular waveguide in which a coupling hole is provided at the primary radiator end side of a lateral wall on one side in the lateral direction in a cross section orthogonal to the tube axis; and an outer surface of the lateral wall on one side in the lateral direction of the rectangular waveguide. A rectangular waveguide type filter formed by sharing the one end side sidewall with the other end side wall of the filter waveguide facing the one end side sidewall. A low-pass blocking filter that is provided with a transmission end) and propagates the transmission radio wave to the end of the rectangular waveguide on the side of the primary radiator through the coupling hole, and blocks the reception radio wave from propagating to the transmission end. A plurality of corrugations along a tube axis in a predetermined region of the other side wall of the rectangular waveguide on the other end side in the lateral direction. A parallel-polarization demultiplexer having a corrugated high-pass filter having a corrugated structure; a dipole antenna having a length of ¼ of a wavelength of a low frequency band provided in the coupling hole; In the corrugated structure of the band rejection filter, the corrugated depth orthogonal to the tube axis is all about 1/4 of the in-tube wavelength in the high frequency band, and the corrugated width in the tube axis direction can obtain desired filter characteristics. It is the length;

[0012]

Next, the operation of the parallel-polarization polarization demultiplexer of the present invention constructed as described above will be described. According to the present invention, since the dipole antenna having a length of ¼ of the wavelength in the low frequency band is provided in the coupling hole, the coupling hole resonates in the low frequency band, and the received radio wave is prevented from leaking into the low frequency blocking filter. It can be almost completely stopped. Further, in the high-frequency rejection filter, the corrugated depth orthogonal to the tube axis is all about 1/4 of the in-tube wavelength in the high frequency band, and the corrugated width in the tube axis direction can obtain desired filter characteristics. Since the corrugated structure has a length, it is possible to eliminate the electrical influence of the corrugated groove in the high-frequency blocking filter on the coupling hole, and there is an advantage that impedance matching of the coupling hole can be easily achieved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a parallel polarization polarization demultiplexer according to an embodiment of the present invention. In FIG. 1, the same components as those in the conventional example (FIG. 3) are designated by the same reference numerals.

In the present invention, the high-frequency rejection filter 2 is shown in FIG.
As described in detail in (1), the depth of the corrugated groove 2a is the same in all corrugations (approximately 1/4 of the in-tube wavelength in the high frequency band), and the corrugations in the tube axis direction of each corrugate are formed. The width is a corrugated structure having a length that allows desired filter characteristics to be obtained. Therefore, in the high frequency blocking filter 2, the equivalent short surface 6 having the maximum impedance is located at the position of the corrugated groove 2a closest to the primary radiator side 11.

As a result, when the coupling hole 4 is provided at a length of ¼ of the guide wavelength (λ _g ) from the equivalent short surface 6,
As shown in FIG. 2, the coupling hole 4 can be provided between the primary radiator side 11 and the high-frequency blocking filter 2, is not affected by the corrugated groove 2a, and can easily achieve impedance matching.

Since the operation for the transmission radio wave is similar to the conventional one, although not described again, the transmission radio wave which is converted from the coaxial mode to the waveguide mode at the coaxial type transmission end 9 and is carried in the low-frequency blocking filter 3 is described. , Short side direction (vertical direction in the figure) E
_TX (electric field vector 7) is the main polarization (Fig. 2).

Further, the received radio wave which enters the rectangular waveguide 1 from the side of the primary radiator 11 and propagates in the high-frequency blocking filter 2 is in the lateral direction (vertical direction in the figure) E _RX (electric field vector 8)
Is the main polarization (Fig. 2). That is, as described above, the transmitted radio wave and the received radio wave are polarized waves parallel to each other.

Then, part of the received radio wave tries to enter the low-frequency blocking filter 3 side through the coupling hole 4. However, in the present invention, the dipole antenna 4a is provided in the coupling hole 4. Since the dipole antenna 4a has a length of 1/4 of the wavelength of the low frequency band, the coupling hole 4
Resonates in the low frequency band.

As a result, the received radio wave which has leaked from the coupling hole 4 to the low-frequency blocking filter 3 side is blocked by the coupling hole 4, and the leaking to the low-frequency blocking filter 3 side is almost completely prevented. it can.

[0020]

As described above, according to the parallel polarization demultiplexer of the present invention, 1/4 of the wavelength in the low frequency band is formed in the coupling hole.
Since the dipole antenna having the length of 1 is provided, the coupling hole resonates in the low frequency band, and the received radio wave can be almost completely prevented from leaking into the low frequency blocking filter. Further, in the high-frequency rejection filter, the corrugated depth orthogonal to the tube axis is all about 1/4 of the in-tube wavelength in the high frequency band, and the corrugated width in the tube axis direction can obtain desired filter characteristics. Since the corrugated structure has a length, it is possible to eliminate the electrical influence of the corrugated groove in the high-frequency blocking filter on the coupling hole, and there is an advantage that impedance matching of the coupling hole can be easily achieved.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a parallel polarization polarization demultiplexer according to an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of the parallel polarization polarization demultiplexer of the present invention.

FIG. 3 is a configuration block diagram of a conventional parallel polarization polarization demultiplexer.

[Explanation of symbols]

 1 Rectangular Waveguide 2 High Frequency Blocking Filter 2a Corrugated Groove 3 Low Frequency Blocking Filter 4 Coupling Hole 4a Dipole Antenna 5 Corner Piece 6 Short Surface 9 Transmitting End 10 Receiving End 11 Primary Radiator Side

Claims (1)

[Claims] 1. A short side in a cross section orthogonal to the tube axis, wherein one end in the tube axis direction is an input / output end with the primary radiator (primary radiator end) and the other end is an output end (reception end) of received radio waves. A rectangular waveguide in which a coupling hole is provided on the side wall of the one end side of the primary radiator on the side of the one end side; and the one side wall is shared by the outer surface of the one side wall of the rectangular waveguide in the lateral direction. A rectangular waveguide type filter to be formed, wherein an input end (transmission end) of a transmission radio wave is provided on the reception end side of the other side wall of the filter waveguide facing the side wall on the one end side. A low-pass blocking filter for blocking the propagation of a received radio wave to the transmission end by propagating a rectangular wave to the end of the rectangular waveguide on the primary radiator side through the coupling hole; Corrugated with a plurality of corrugations arranged along the pipe axis in a prescribed area on the side wall on the other end side in the direction A parallel polarization polarization demultiplexer comprising: a high-frequency rejection filter; a dipole antenna having a length of ¼ of a wavelength in a low frequency band provided in the coupling hole; and a corrugate of the high-frequency rejection filter. The structure is such that the corrugated depths orthogonal to the tube axis are all about 1/4 of the in-tube wavelength in the high frequency band, and the corrugated widths in the tube axis direction are such that desired filter characteristics can be obtained respectively. A parallel polarization polarization demultiplexer characterized by the above.