JPH03250802A - Polarization coupler - Google Patents

Abstract

PURPOSE:To miniaturize this coupler without degrading the electric characteristic by adopting the structure of dual waveguide for a high frequency branching waveguide and a low frequency branching waveguide. CONSTITUTION:A rectangular high frequency branching waveguide 6 extracting a signal at a high frequency band via a coupling hole 4 is provided on a main circular waveguide 3 being a common waveguide transmitting linearly polarized waves (electric field vectors) 1, 2 with a different frequency and a rectangular low frequency branching waveguide 7 extracting a signal at a low frequency band via a coupling hole 5 is connected to the main circular waveguide 3. Then the rectangular low frequency branching waveguide 7 and the rectangular high frequency branching waveguide 6 are combined at the back by using an end face 3a and the center axis of an H plane 12 of the both is made coincident with the guide axis of the main circular waveguide 3 to form the dual waveguide structure. Thus, the antenna is miniaturized without degrading the electric performance.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a polarization splitter, particularly to a polarization splitter used in a branch feed section of an antenna device used in a microsatellite communication earth station. Regarding improvements.

[Prior Art] Conventionally, this type of polarization splitter is as shown in section 5,
The main circular waveguide 22 having the horn 21 is a common waveguide that propagates signals in different frequency bands, and this main circular waveguide 22 includes a low frequency branching waveguide that branches signals in a low frequency band. 23 and a high frequency branching waveguide 24 for branching high frequency band signals.

The low frequency branch waveguide 23 and the high frequency branch waveguide 24 are equipped with a power amplifier (PA) and a low noise amplifier (L).
A power feeding unit 25a having a power supply unit 25a (NA).

25b is provided, and recently there have been an increase in the number of small antennas that include these configurations.

[Problem to be solved by the invention] However, in the conventional polarization splitter, as shown in FIG. If the width of the transducer becomes large and it is used as the primary radiation feeding section of a parabolic antenna, especially for smaller antennas, there is a problem of increased blocking and deterioration of electrical performance.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to obtain a polarization splitter which can be made smaller in width and which can reduce the size of the antenna without deteriorating the electrical performance. shall be.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides a polarization splitter that separates linearly polarized signals of different frequencies from two mutually parallel waveguides. A common waveguide through which linearly polarized signals propagate, a rectangular low-frequency branching waveguide that has a filter that blocks signals in the high frequency band and extracts signals in the low frequency band, and a rectangular low frequency branch waveguide that blocks signals in the low frequency band. a rectangular high-frequency branching waveguide having a filter for extracting signals in a high-frequency band; The double waveguide structure is aligned with the tube axis of the waveguide, and the low frequency branch waveguide has a wavelength of approximately 1 wavelength within the common waveguide of the low frequency band signal from the end face of the common waveguide. The high-frequency branch waveguide is connected via a coupling hole drilled in the tube wall at the position of The low frequency branch waveguide is located at a position where the low frequency branch waveguide is connected through a coupling hole formed in the tube wall opposite to the above-mentioned low frequency branch waveguide.

Furthermore, the common waveguide may be a conically tapered waveguide.

Further, a metal plate or a metal rod may be placed at a position perpendicular to the electric field vector on the side opposite to the end surface of the coupling hole of the low frequency branch waveguide and the high frequency branch waveguide.

[Function] According to the above configuration, among the radio wave signals transmitted through the common waveguide, high-frequency odd waves are sent to the high-frequency branch waveguide via the high-frequency coupling hole, and low-frequency odd waves are sent to the high-frequency branch waveguide through the high-frequency coupling hole. The signal is branched into the low frequency branch waveguide through the coupling hole. in this case,
Since the high-frequency branch waveguide and the low-frequency branch waveguide have a double waveguide structure, the electrical characteristics do not deteriorate, and the duplexer can be made smaller.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of a polarization splitter according to the first embodiment, in which linearly polarized waves (electric field vectors) with different frequencies l
, 2, the main circular waveguide 3 is a common waveguide that transmits
A rectangular high-frequency branch waveguide 6 is provided to take out a high-frequency band signal through the coupling hole 4, and a rectangular low-frequency branch waveguide 7 is connected to take out a low-frequency band signal through the coupling hole 5. has been done.

That is, the coupling hole 4 is connected to the tube wall at a length position of -+/2 (in, 1 is the internal wavelength of the common waveguide in the low frequency band) from the end surface 3a which is the short surface of the main circular waveguide 3. A high frequency branch waveguide 6 is connected to this coupling hole 4 . The high frequency branch waveguide 6 is equipped with a filter 8 that blocks signals in a low frequency band, and thereby allows signals in a high frequency band to be taken out from a terminal 9.

On the other hand, the coupling hole 5 is approximately λ, 2/2 from the end surface 3a.
(λ, 2 is the internal wavelength of the common waveguide in the high frequency band) is provided on the tube wall at a length position, and the low frequency branch waveguide 7 is connected to this coupling hole 5. The low frequency branch waveguide 7 is equipped with a filter 10 that blocks signals in the high frequency band, so that the signals in the low frequency band can be taken out from the terminal 11.

Then, the low frequency branch waveguide 7 and the high frequency branch waveguide 6
are combined behind the end surface 3a, and the central axis of the H plane 12 of both is made to coincide with the tube axis of the main circular waveguide 3, forming a double waveguide structure.

The first embodiment has the above configuration, and its operation will be explained below.

First, linearly polarized waves 1.2 with different frequencies parallel to each other propagate through the main circular waveguide 3, and a low frequency signal l passes through the coupling hole 5 of the main circular waveguide 3 into a low frequency branch guide. The signal will pass through the tube 7 and be output from the terminal 11, and since the low frequency blocking filter 8 is connected to the high frequency branch waveguide 6, the low frequency signal will not be output to the high frequency terminal 9. .

Similarly, the high frequency signal 2 passes through the high frequency branch waveguide 6 from the coupling hole 4, is outputted to the terminal 9 via the high frequency branch waveguide 6, and is output to the low frequency branch waveguide 7 for high frequency. No data is transmitted due to the presence of terminal IO.

FIG. 2 shows a second embodiment that has a configuration that can transmit broadband radio waves well. In this second embodiment, as shown in FIG. 1, the common waveguide is replaced with a conical taper waveguide. 13, transmission and reception can be made possible even when the frequency band is far apart. Further, in this case, it becomes possible to provide the high-frequency coupling hole 4 in a location where unnecessary higher-order modes do not occur, and there is also the advantage that deterioration of electrical characteristics due to unnecessary higher-order modes can be improved.

FIG. 3 shows a third embodiment for suppressing radiation of cross-polarized waves, and as shown in the figure, this third embodiment is arranged at the front stage of the coupling hole 4.5 (on the opposite side of the end surface 3a). ) by providing a metal septum 14 perpendicular to the electric field vector, radiation of cross-polarized waves can be suppressed.

FIG. 4 shows the configuration of an embodiment, for example, a PA (
A configuration in which a power amplifier)/LNA (low noise amplifier) is mounted is shown, and a PA/LNA section 15 is provided at the terminal 9 of the high frequency branch waveguide 6 and the terminal 11 of the low frequency branch waveguide 7. In this way, the size of the polarization splitter in the width direction can be reduced.

[Effects of the Invention] As explained above, according to the present invention, a low frequency branch waveguide and a high frequency branch waveguide are combined, and the central axis of the H plane of both coincides with the tube axis of the common waveguide. The low frequency branch waveguide is connected to the tube wall at a position approximately 1/2 of the wavelength within the common waveguide of the low frequency band signal from the end face of the common waveguide. The high frequency branch waveguide is connected to the low frequency branch at a position approximately 1/2 of the wavelength of the high frequency band signal within the common waveguide from the end face of the common waveguide. Since the connection is made through a coupling hole drilled in the tube wall opposite to the waveguide, it is possible to concentrate the transmitting/receiving terminals of the duplexer near the propagation axis without degrading electrical performance. It is possible to make the antenna smaller by configuring it with a smaller width.

Further, by using a conically tapered waveguide as the common waveguide, it is possible to widen the transmission frequency band.

Further, by placing a metal plate or a metal rod at a position perpendicular to the electric field vector on the side opposite to the end surface of the coupling hole, it is possible to suppress radiation of cross-polarized waves.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of a polarization splitter according to the first embodiment of the present invention, FIG. 2 is a perspective view showing the configuration of the polarization splitter according to the second embodiment, and FIG. is a perspective view showing the configuration of a polarization splitter according to the third embodiment, and FIG.
FIG. 5 is a perspective view showing the structure of a conventional polarization splitter. 3. Main circular waveguide as common waveguide 4.5. Coupling hole: High frequency branch waveguide: Low frequency branch waveguide: Low frequency rejection filter 11: Terminal: High frequency rejection filter 14: Metal septum 15: PA/LNA part

Claims (3)

[Claims] (1) In a polarization splitter that separates linearly polarized signals of different frequencies from two mutually parallel waveguides, a common waveguide through which linearly polarized signals of different frequencies propagate;
A rectangular low-frequency branching waveguide that has a filter that blocks signals in a high frequency band and extracts signals in a low frequency band, and a rectangular low frequency branch waveguide that has a filter that blocks signals in a low frequency band and extracts signals in a high frequency band a high-frequency branch waveguide, and the low-frequency branch waveguide and the high-frequency branch waveguide are combined so that the center axis of the H plane of both coincides with the pipe axis of the common waveguide. The low-frequency branch waveguide has a waveguide structure, and the low-frequency branch waveguide has a coupling hole formed in the tube wall at a position approximately 1/2 the wavelength of the low-frequency band signal within the common waveguide from the end face of the common waveguide. The high frequency branch waveguide is located at a position approximately half the wavelength of the high frequency band signal within the main circular waveguide from the end face of the common waveguide, and is connected to the low frequency branch waveguide. is a polarization splitter characterized in that it is connected via a coupling hole drilled in the opposite tube wall. (2) The polarization splitter according to claim 1, wherein the common waveguide is a conically tapered waveguide. (3) A metal plate or a metal rod is placed at a position perpendicular to the electric field vector on the side opposite to the end surface of the coupling hole of the low frequency branch waveguide and the high frequency branch waveguide. 2. The polarization splitter according to 1 or 2.