KR960002460B1 - Waveguide to microstrip conversion means in a satellite broadcasting adaptor - Google Patents

Abstract

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Description

Coaxial Waveguide Converter and Converter for Satellite Broadcasting Antenna

1 is a perspective view showing the internal structure of a coaxial waveguide transducer according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram comparing the conversion loss characteristics of the first probe with the conventional coaxial waveguide converter shown in FIG. 21 and the coaxial waveguide converter of the first embodiment shown in FIG.

3 is a characteristic diagram comparing the conversion loss characteristics of the second probe between the conventional coaxial waveguide converter shown in FIG. 21 and the coaxial waveguide converter of the first embodiment shown in FIG.

4 is a characteristic diagram comparing cross polarization characteristics of a first probe between the conventional coaxial waveguide transducer shown in FIG. 21 and the coaxial waveguide transducer of the first embodiment shown in FIG.

FIG. 5 is a characteristic diagram comparing cross polarization characteristics of a second probe between the conventional coaxial waveguide transducer shown in FIG. 21 and the coaxial waveguide transducer of the first embodiment shown in FIG.

6 is a perspective view showing the internal structure of a coaxial waveguide converter according to a second embodiment of the present invention.

7 is a perspective view showing the internal structure of a coaxial waveguide transducer according to a third embodiment of the present invention.

8 is a perspective view showing the internal structure of a coaxial waveguide transducer according to a fourth embodiment of the present invention.

9 is a plan view showing a coaxial waveguide converter according to a fifth embodiment of the present invention.

FIG. 10 is a sectional view taken along X-X of the coaxial waveguide transducer of the fifth embodiment shown in FIG.

11 is a perspective view showing the internal structure of a coaxial waveguide transducer according to a sixth embodiment of the present invention.

12 is a plan view showing a coaxial waveguide converter according to a seventh embodiment of the present invention.

13 is a cross-sectional view taken along X-X of the coaxial waveguide converter shown in FIG. 12. FIG.

FIG. 14 is a perspective view of an LNB having a coaxial waveguide converter according to a second embodiment shown in FIG.

FIG. 15 is an exploded perspective view of the LNB shown in FIG. 14. FIG.

FIG. 16 is a block diagram showing a transmission line switch circuit having another matching circuit included in the LNB shown in FIG.

FIG. 17 is a plan view showing a coaxial waveguide transducer according to an eighth embodiment in which the coaxial waveguide transducer of the second embodiment shown in FIG.

FIG. 18 is a characteristic diagram showing the relationship between the cross polarization characteristic and the maximum noise index and the first and second input polarization angle differences in the second embodiment shown in FIG.

FIG. 19 is a characteristic diagram showing the cross polarization characteristic and the relationship between the maximum noise index and the first and second input polarization angle differences of the coaxial waveguide converter of the eighth embodiment shown in FIG.

20 is a perspective view showing the internal structure of a conventional coaxial waveguide transducer.

21 is a perspective view showing the internal structure of another conventional coaxial waveguide transducer.

* Explanation of symbols for main parts of the drawings

3,23,33,43: 1st probe 4,26,36,46: 2nd probe

5,21,31,41,55,61: first waveguide 6,22,32,42,62: second waveguide

7,17,25,35,45a: Matching means 11,24,34,37,44: First paragraph

12,27,37,47: Second paragraph 71: Horn

83: first amplifier circuit 84: second amplifier circuit

The present invention relates to coaxial waveguide transducers, and more particularly to coaxial waveguide transducers for receiving first and second linearly polarized waves that are orthogonal to one another.

Background Art Conventionally, an outdoor converter for satellite broadcast reception is mounted on an outdoor antenna for receiving two independent linear polarizations (horizontal polarization and vertical polarization) that are orthogonal to each other.

20 is a perspective view showing the internal structure of a coaxial waveguide converter used in a conventional outdoor converter for satellite broadcast reception. Referring to FIG. 20, a conventional coaxial waveguide transducer includes a circular waveguide 101, a first microstrip circuit board 102 installed at a predetermined position on the outer circumference of the circular waveguide, and a first microstrip circuit board 102 on the first microstrip circuit board 102. As shown in FIG. The first probe 105 is attached and protrudes to the inside through the opening of the circular waveguide 101, and the circular waveguide 101 at a quarter wavelength downward from the position where the first probe 105 is attached. A second probe 106 formed to protrude into the circular waveguide 101 at an interval of about 1/2 wavelength from the first probe 105 downwardly from the first terminal 105. And the second probe 106 is installed through the opening of the circular waveguide 101 and is directed downward from the second microstrip circuit board 103 and the second probe 106 provided at the outer circumference of the circular waveguide 101. Obtain the short-circuit terminal (short board) 107 provided at intervals of 1/4 wavelength The.

The first probe 105 and the short circuit terminal 104 are provided so that the direction in which they extend is approximately the same. The first probe 105 and the second probe 106 are provided so that their extending directions are perpendicular to each other. The first probe 105 is for detecting the horizontal polarization 1, and the second probe 106 is for detecting the vertical polarization 2. The short terminal (short rod) 104 is for reflecting the horizontal polarization 1 to be detected by the first probe 105, and the short terminal (short plate) 107 reflects the vertical polarization 2 and is It is intended to be detected by the two probes 106.

In general, two probes are required to receive two types of linearly polarized waves that are orthogonal to each other by a single waveguide. Each probe receives a signal having a polarization plane parallel to the probe. In order to suppress the interference of signals having a polarization plane other than the polarization plane parallel to the probe to improve cross polar discrimination, the first probe 105 of the circular waveguide 101 is shown in FIG. ) And the second probe 106 need to be orthogonal to each other and at the same time spaced in the axial direction. In order to improve the input VSWR (Voltage Standing Wave Ratio) of the waveguide and to suppress the conversion loss between the first probe 105 and the second probe 106 in a wide band, the first probe as shown in FIG. It is necessary to make the interval between the 105 and the short rod 104, and the interval between the second probe 106 and the shovel plate 107 as quarter wavelengths, respectively.

21 is a perspective view showing the internal structure of another conventional coaxial waveguide transducer. Referring to FIG. 21, another conventional coaxial waveguide transducer includes a circular waveguide 201, a microstrip circuit board 202 provided at a predetermined position around the circular waveguide 201, and a microstrip circuit board 202. Installed in the first probe 203 and the microstrip circuit board 202 formed to protrude into the circular waveguide 201 and into the circular waveguide 201 in a direction orthogonal to the first probe 203 in the same plane. And a second probe 204 formed to protrude, and a short-circuit terminal (short plate) 205 provided at an interval of 1/4 wavelength downward from the first probe 203 and the second probe 204. . In another conventional coaxial waveguide transducer, the first probe 203 and the second probe 204 are formed on the same plane. Thus, by providing the 1st probe 203 and the 2nd probe 204 on the same plane, a device can be miniaturized.

In the structure of the conventional coaxial waveguide transducer shown in FIG. 20 as described above, the cross polarization characteristic is reduced by suppressing the interference between the signal received by the first probe 105 and the signal received by the second probe 106. In order to make it favorable, the 1st probe 105 and the 2nd probe 106 are set to the structure about 1/2 wavelength apart.

However, in such a structure, since the first probe 105 and the second probe 106 are not coplanar, both the first probe 105 and the second probe 106 are directly connected to a single microstrip circuit board. It was difficult to connect. As a result, as shown in FIG. 20, two microstrip circuit boards between the first microstrip circuit board 102 and the second microstrip circuit board 103 were required. Therefore, there is a problem that the cost can not be reduced and the mass productivity cannot be improved because the number of parts increases and the manufacturing process becomes complicated. Moreover, since the distance between the 1st probe 105 and the 2nd probe 106 becomes long, the circular waveguide 101 becomes structurally long. As a result, there has been a problem that it is difficult to reduce the size and weight of the device.

In the other conventional coaxial waveguide transducer shown in FIG. 21, as described above, since the first probe 203 and the second probe 204 are on the same plane, the apparatus can be miniaturized. However, in the structure shown in FIG. 21, since the first probe 203 and the second probe 204 are on the same plane, they are each interfered with signals having a polarization plane other than the polarization plane to be received. As a result, there was a problem that the cross-polarization characteristic is lowered.

As described above, conventionally, in order to obtain good cross-polarization characteristics and input VSWR, the size of the device has to be abandoned and the shape must be increased. In addition, in order to reduce the size of the device, when the first probe 203 and the second probe 204 are formed on the same plane, there is a problem in that the cross polarization characteristics are deteriorated.

One object of the present invention is to attain miniaturization in a coaxial waveguide transducer and to obtain good cross polarization characteristics by effectively preventing two probes from affecting each other probe.

It is still another object of the present invention to form the output terminals of the respective probes of the two converter portions in the same plane in the coaxial waveguide transducer.

It is yet another object of the present invention to reduce the cost of the device and to improve the mass productivity of the coaxial waveguide converter.

In one aspect of the invention, a coaxial waveguide transducer is a coaxial waveguide transducer for receiving first and second linearly polarized waves that are orthogonal to each other, comprising: a first waveguide, a second waveguide connected substantially perpendicular to the first waveguide, and A first probe for detecting a first linearly polarized wave installed in the first waveguide, a second probe for detecting a second linearly polarized wave installed in the second waveguide, and a matching means for guiding the second linearly polarized wave to the second waveguide. Equipped.

In operation, the second waveguide is connected to be substantially orthogonal to the first waveguide, the first waveguide is provided with a first probe for detecting the first linearly polarized wave, and the second waveguide is provided with a first probe for detecting the second linearly polarized wave. Since two probes are provided and matching means for guiding the second linearly polarized wave to the second waveguide are provided, the distance between the first probe and the second probe is increased without increasing the size of the apparatus.

In another aspect of the present invention, a converter of a satellite broadcasting antenna having a coaxial waveguide converter is configured to detect a first waveguide, a second waveguide connected to be substantially orthogonal to the first waveguide, and a first linearly polarized wave provided in the first waveguide. A first probe for the second waveguide, a second probe for detecting the second linearly polarized wave installed in the second waveguide, a matching means for guiding the second linearly polarized wave to the second waveguide, and the first waveguide is not connected to the second waveguide. It is provided at the end of the side which is not provided, and has a horn for guiding a 1st and 2nd linear polarization to a 1st waveguide.

In operation, a coaxial waveguide transducer includes a first waveguide, a second waveguide connected to be substantially orthogonal to the first waveguide, a first probe installed at the first waveguide for detecting the first linearly polarized wave, and a second waveguide. And a second probe for detecting the second linearly polarized wave, and a matching means for guiding the second linearly polarized wave to the second waveguide, the first waveguide having a first waveguide at the end of the side where the second waveguide is not connected to the second waveguide. And a horn for guiding the second linearly polarized wave to the first waveguide, so that the distance between the first probe and the second probe is increased without increasing the size of the coaxial waveguide converter, and the satellite broadcasting antenna having such a coaxial waveguide converter is provided. The converter can be miniaturized.

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described based on drawing.

Referring to FIG. 1, the coaxial waveguide converter of the present embodiment is a circular waveguide 5 connected to a fed horn (not shown), and a circular waveguide 5 integrally connected to the circular waveguide 5. Substrate 10 consisting of a rectangular waveguide 6 formed to extend in a direction substantially perpendicular to 5) and a teflon interposed between the circular waveguide 5 by a circular waveguide 5 at a predetermined position of the circular waveguide 5. And a microstrip circuit board 8 formed on the upper surface of the base 10, a ground plane 9 formed on the lower surface of the base 10 to constitute an upper surface of the rectangular waveguide 6, and a base. A first probe 3 composed of a microstrip circuit board 8 and a microstrip line 13b and formed to protrude into the circular waveguide 5, and connected to the microstrip line 13a and being rectangular. Second strip formed by protruding into the waveguide 6 Matching reflective ribs 7 formed at corners of the corners of the lobe 4, the connecting portion between the circular waveguide 5 and the rectangular waveguide 6, the shorting terminal A surface 11, and the shorting terminal B surface 12 ).

The first probe 3 is for detecting the horizontal polarization 1, and the second probe 4 is for detecting the vertical polarization 2. The short-circuit terminal A surface 11 reflects the horizontal polarization 1 and is for detection by the first probe 3. The 1st probe 3 and the short circuit terminal A surface 11 are provided at intervals of 1/4 wavelength. The matching reflective rib 7 is for inverting only the vertical polarization 2 by 90 degrees in the direction of the second probe 4. Moreover, the short-circuiting terminal B surface is for reflecting the vertical polarization 2 reflected by the matching reflection rib 7 again, and detecting it to the 2nd probe 4. As shown in FIG. The second probe 4 and the short terminal B surface 12 have an interval of 1/4 wavelength.

Next, the operation of the coaxial waveguide converter of the present embodiment will be briefly described.

First, two kinds of linearly polarized waves (horizontal polarization 1 and vertical polarization 2) orthogonal to each other introduced by a primary radiator (not shown) are transmitted into the circular waveguide 5. The horizontally polarized wave 1 parallel to the first probe 3 is reflected by the short-circuit terminal A surface 11 separated from the first probe 3 by a quarter wavelength, and as a result, the horizontally polarized wave 1 is not reflected. The reflected horizontal polarization 1 is matched. This matched horizontal polarization 1 is detected by the first probe 3 and transmitted to the microstrip line 13b.

In addition, the vertically polarized wave 2 transmits in the circular waveguide 5 almost unaffected by the first probe 3. Therefore, the misalignment and passage loss of the vertically polarized wave 2 are reduced by the matching reflective ribs 7 which hardly affect the horizontal polarized wave 1. In this state, the vertically polarized wave 2 is bent 90 degrees into the rectangular waveguide 6 and transmitted. The vertical polarization 2 is reflected by the short terminal B surface 12, and as a result, the non-reflected vertical polarization 2 and the reflected vertical polarization 2 are matched. This matched vertical polarization 2 is detected by the second probe 4 and transmitted to the microstrip line 13a.

As described above, in the present embodiment, the first probe is respectively provided on the circular waveguide 5 and the rectangular waveguide 6 while using the orthogonal transducer shape in which the circular waveguide 5 and the rectangular waveguide 6 orthogonal thereto are formed integrally. (3) and the second probe 4 are provided. By configuring in this way, the space | interval between the 1st probe 3 and the 2nd probe 4 can be enlarged, without making a device large in size as conventionally, As a result, a favorable cross-polarization characteristic can be acquired, aiming at miniaturization of a device. .

In this embodiment, the output end of the first probe 3 and the output end of the second probe 4 can be arranged on the same plane so that only one microstrip circuit board 8 can be configured. That is, the conventional coaxial waveguide converter shown in FIG. 20 by connecting the microstrip lines 13a and 13b formed on the microstrip circuit board 8 to the second probe 4 and the first probe 3 respectively. Unlike this, a configuration by one microstrip circuit board 8 is possible. As a result, the number of parts can be reduced and the cost of the apparatus can be reduced.

In addition, by forming the upper surface portion of the rectangular waveguide 6 as the ground surface 9 constituting the rear surface of the base 10 of the microstrip circuit board 8, the component shape can be simplified and the component material can be reduced. Therefore, mass productivity can be improved and cost can be reduced.

2 to 5, first, the conversion loss characteristics are not significantly different from the conventional coaxial waveguide converter shown in FIG. 21 and the coaxial waveguide converter of the first embodiment shown in FIG. However, with regard to the cross polarization characteristics, it was found that the coaxial waveguide converter of the first embodiment shown in FIG. 1 is superior to the conventional coaxial waveguide converter shown in FIG. As described above, in the coaxial waveguide converter of the first embodiment shown in FIG. 1, performance improvement such as miniaturization and cross polarization characteristics can be achieved.

Referring to FIG. 6, in the second embodiment, unlike the first embodiment shown in FIG. 1, the cross section on the side of the circular waveguide 5 of the matching reflective rib 17 is formed on the inner wall surface of the circular waveguide 5; It is provided in the position with predetermined space | interval. Even in this configuration, the same input VSWR characteristic and cross polarization characteristic as in the coaxial waveguide transducer of the first embodiment shown in FIG. 1 can be obtained. In addition, one performance may be superior to the other in the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. 6 depending on the input frequency. In this case, a coaxial waveguide transducer having excellent performance may be selected according to the frequency band.

7 is a perspective view showing the internal structure of the coaxial waveguide defender according to the third embodiment of the present invention. Referring to FIG. 7, the coaxial waveguide converter of the third embodiment is integrally connected with a rectangular waveguide (square waveguide) 55 and a rectangular waveguide 55 connected to a primary radiator (horn) (not shown). And a rectangular waveguide (square waveguide) 6 formed in a direction substantially orthogonal to the direction in which the rectangular waveguide 55 extends, and sandwiched by a rectangular waveguide 55 at a predetermined position of the rectangular waveguide 55. A ground plane constituting the upper surface of the rectangular waveguide 6 formed of the base 10 formed of the base 10, the microstrip circuit board 8 formed on the upper surface of the base 10, and the lower surface of the base 10. (9), a first probe (3) composed of a base (10), a micro strip circuit board (8), and a micro strip line (13b) and formed to protrude into the rectangular waveguide (55), and a micro strip line ( Access 13a) A second probe 4 protruding into the inside of the high rectangular waveguide 6, a matching reflective rib 7 formed at the corner of the connection portion between the rectangular waveguide 55 and the rectangular waveguide 6, and a short circuit The terminal A surface 11 and the short circuit terminal B surface 12 are provided. The first probe 3 is a probe for receiving a first linearly polarized wave 301, and the second probe 4 is a probe for receiving a second linearly polarized wave 302. The rectangular waveguide 55 is a first probe. It has a square or nearly square shape for passing the linearly polarized wave 301 and the second linearly polarized wave 302. The matching reflective ribs 7 are for impedance matching the rectangular waveguide 55 and the rectangular waveguide 6 to reflect the second linearly polarized wave 302 by 90 ° toward the second probe 4. The short-circuiting terminal A surface 11 has a function of inverting the first linearly polarized wave 301 and leading it to the first probe 3. In addition, the short-circuit terminal B surface 12 has a function of reflecting the second linearly polarized wave 302 and leading it to the second probe 4.

Thus, in the third embodiment, unlike the first and second embodiments, the rectangular waveguide 55 is also employed in the waveguide on the input side. In this configuration, the same effects as in the coaxial waveguide transducers of the first and second embodiments can be obtained. That is, by forming the orthogonal transducer shape by the rectangular waveguide 55 and the rectangular waveguide 6 orthogonal to it, the distance between the 1st probe 3 and the 2nd probe 4 can be distanced while miniaturizing. Accordingly, since the first probe 3 and the second probe 4 do not influence each other, good cross polarization characteristics and input VSWR characteristics are obtained.

Referring to FIG. 8, the coaxial waveguide transducer of the fourth embodiment is a circular waveguide 21 and a rectangular waveguide integrally connected with the circular waveguide 21 and formed in a direction orthogonal to the direction in which the circular waveguide 21 extends. (22), a first probe (23) provided to protrude in a predetermined direction in the cavity portion of the circular waveguide (21), a second probe (26) provided so as to protrude in a predetermined direction in the cavity portion of the rectangular waveguide (21), A matching reflection surface 25 provided at the junction between the circular waveguide 21 and the rectangular waveguide 22, and between the first probe 23 and the matching reflection surface 25, the same as the first probe 23 The short circuit (short rod) 24 provided so that it may become a direction, and the short circuit board 27 provided in the edge part of the rectangular waveguide 22 by the 2nd probe 26 at predetermined intervals. The first probe 23 and the shorting rod 24 are provided at intervals of a quarter wavelength. The shorting plate 27 and the second probe 26 have a quarter wavelength spacing.

Also in the coaxial waveguide converter of the fourth embodiment, the same effects as in the coaxial waveguide converter of the first, second and third embodiments can be obtained. That is, by forming the orthogonal transducer shape by the circular waveguide 21 and the rectangular waveguide 22 orthogonal to it, the distance between the 1st probe 23 and the 2nd probe 26 can be distanced while miniaturizing. . Accordingly, since the first probe 23 and the second probe 26 do not influence each other, good cross polarization characteristics and input VSWR characteristics are obtained. In the fourth embodiment, unlike the first, second and third embodiments, a rod-shaped short-circuit rod 24 is used as the reflector of the first probe 23.

In operation, similarly to the first, second and third embodiments, horizontal polarization (not shown) is received using the shorting rod 24 and the first probe 23, and vertical polarization (not shown) is matched. It receives using the reflective surface 25, the short circuit board 27, and the 2nd probe 26. As shown in FIG. The coaxial waveguide converter of the fifth embodiment shown in FIGS. 9 and 10 is an application example of the coaxial waveguide converter of the fourth embodiment shown in FIG.

9 and 10, the coaxial waveguide transducer of this embodiment is a rectangle formed integrally connected with the circular waveguide 31 and the circular waveguide 31 and extending in a direction perpendicular to the circular waveguide 31. A microstrip circuit board 38 provided so as to be sandwiched by the waveguide 32, the circular waveguide 31 and the rectangular waveguide 32, and the microstrip lines 39a formed on the microstrip circuit board 38; 39b), the microstrip line 39b extends into the cavity portion of the circular waveguide 31 as it is, and the microprobe line 39a is connected to the microprobe line 39a and projects into the cavity portion of the rectangular waveguide 32. The formed second probe 36, the matching reflecting surface 35 formed at a position where the circular waveguide 31 and the rectangular waveguide 32 cross at right angles, and formed on the cross section of the rectangular waveguide 32 and the second probe 1/4 wavelength at 36 1/4 of the first probe 33 formed in the same direction as the first probe 33 and formed between the shorting plate 37 and the first probe 33 and the matching reflective surface 35 formed at intervals. Shorting rods (short rods) 34 are provided at intervals of the wavelength.

As described above, in the fifth embodiment, the output terminal 36a and the first probe 33 of the second probe 36 are formed on the same plane, so that only one microstrip circuit board 38 can be configured. That is, since the output end 36a of the first probe 33 and the second probe 36 are coplanar, they are respectively connected to the micro strip lines 39b and 38a formed on the same micro strip circuit board 38. I can connect it. As a result, the coaxial waveguide converter of this embodiment can be constituted only by the single microstrip circuit board 38. Therefore, the number of parts can be reduced as compared with the conventional one, and as a result, the mass productivity can be improved and the cost of the apparatus can be reduced.

11 is a perspective view showing the internal structure of a coaxial waveguide converter according to a sixth embodiment of the present invention. Referring to FIG. 11, the coaxial waveguide transducer of the sixth embodiment is integrally connected with the rectangular waveguide (square waveguide) 61 on the input side and the rectangular waveguide 61 and in a direction substantially perpendicular to the rectangular waveguide 61. A circular waveguide 62 formed to extend, a microstrip circuit board 38 provided to be sandwiched by the rectangular waveguide 61 and the circular waveguide 62, and a microstrip line formed on the microstrip circuit board 38 39a and 39b, the first probe 33 formed by extending the microstrip line 39b into the cavity portion of the rectangular waveguide 61, and the cavity of the circular waveguide 62 connected to the microstrip line 39a. A second probe 36 formed so as to project negatively, a mating reflective surface 35 formed at a position where the rectangular waveguide 61 and the circular waveguide 62 cross at right angles, and a cross section of the circular waveguide 62; 2nd The short circuit plate 37 formed at intervals of a quarter wavelength in the probe 36 and the first probe 33 and the matching reflecting surface 35 are formed, and the first probe 33 and the direction thereof are oriented. A short bar (short rod) 34 which is the same and is spaced apart by a quarter wavelength from the first probe 33 is provided. The rectangular waveguide 61 has a square or nearly square shape for passing the first linearly polarized wave 301 and the second linearly polarized wave 302 orthogonal to the first linearly polarized wave 301. Circular waveguide 62 has a function of passing second linearly polarized wave 302. The first probe 33 is for receiving the first linearly polarized wave 301, and the second probe 36 is for receiving the second linearly polarized wave 302. The shorting rod 34 has a function of guiding the first linearly polarized wave 301 to the first probe 33 reflected. In addition, the short-circuit rod 37 has a function of reflecting the second linearly polarized wave 302 and leading it to the second probe 36. The matching reflecting plate 35 is for reflecting the second waveguide 302 90 ° in the direction of the second probe 36 by impedance matching the rectangular waveguide 61 and the circular waveguide 62.

Thus, in the sixth embodiment, unlike the fifth embodiment shown in Figs. 9 and 10, the rectangular waveguide 61 is adopted as the waveguide on the input side, and the circular waveguide is used as the waveguide orthogonal to the rectangular waveguide 61. 62) is adopted. In the sixth embodiment, as in the fifth embodiment, the output terminal 36a and the first probe 33 of the second probe 36 are formed on the same plane, so that only one microstrip circuit board 38 can be formed. It becomes possible. That is, since the output terminals 36a of the first probe 33 and the second probe 36 are coplanar, they are respectively connected to the micro strip lines 39b and 39a formed on the same micro strip circuit board 38. I can connect it. Thus, the coaxial waveguide converter of the sixth embodiment can be constructed with only a single microstrip circuit board 38. As a result, the number of parts can be reduced as compared with the conventional one, so that the mass productivity can be improved and the cost of the apparatus can be reduced.

The seventh embodiment shown in FIGS. 12 and 13 is also an application example of the fourth embodiment shown in FIG.

12 and 13, the coaxial waveguide transducer of the present embodiment is a rectangle formed integrally connected with the circular waveguide 41 and the circular waveguide 41 and extending in a direction orthogonal to the circular waveguide 41. Microstrip lines 48a and 49b formed on the microstrip circuit board 48 and the microstrip circuit board 48 provided to be sandwiched by the waveguide 42, the circular waveguide 41 and the rectangular waveguide 42. ), The first probe 43 formed by the micro strip line 49b protruding into the cavity in the circular waveguide 41, the second probe 46 formed by the micro strip line 49a extending as it is, and the second A shorting plate 47 integrally provided with the rectangular waveguide 42 so as to form a predetermined space in the upper portion of the probe 46, matching mating reflection surfaces 45a and 45b provided at the ends of both sides of the cavity of the rectangular waveguide; Probe 43 Short circuit rods (short rods) 44 are provided between the reflective surfaces 45a and attached in the same direction as the first probes 43 at a quarter wavelength with the first probes 43. do.

Thus, in the seventh embodiment, the rectangular waveguide 42 (E corner or E band) having two matching reflecting surfaces 45a and 45b in its corner portion is used, thereby providing not only the first probe 43 but also the first probe 43. The two probes 46 may also be formed as strip lines. As a result, the number of parts can be further reduced and the apparatus can be simplified, and mass productivity can be effectively improved.

FIG. 14 is a perspective view showing a converter of a satellite broadcasting antenna (LNB (Low Noise Blockdown Converter)) having the coaxial waveguide converter of the second embodiment shown in FIG. FIG. 15 is an exploded perspective view showing the converter of the satellite broadcasting antenna shown in FIG. 14 and 15, the converter of the satellite broadcasting antenna includes the coaxial waveguide converter of the second embodiment shown in FIG. In addition, a primary radiator (horn) is provided at a distal end portion of the circular waveguide 5 constituting the coaxial waveguide converter to guide the first and second linearly polarized light reflected by a reflector (not shown) to the circular waveguide 5. 71 is provided. The coaxial waveguide transducer is covered with a chassis 72 and a back cover 73. The chassis 72 and back cover 73 are provided for protection of the environment of the microstrip circuit board 8, stabilization of circuit operation, and shielding against unnecessary radiation signals. In addition, the microstrip circuit board 8 amplifies a signal received by the first probe 3 and the second probe 4 and has a frequency conversion function. The F connector 74 serving as the signal output terminal of the LNB is provided at the side portion of the chassis 72. As shown in FIG. 15, an angle 75 is provided between the back cover 73 and the microstrip circuit board 8 for fixing the microstrip circuit board 8 and stabilizing the circuit operation. It is installed.

As described above, in the LNB shown in FIGS. 14 and 15, the coaxial waveguide transducer of the second embodiment shown in FIG. 6 is provided, whereby the coaxial waveguide transducer can be configured as one microstrip circuit board 8. . As a result, the number of parts can be reduced, and the cost can be reduced as a whole of the LNB equipment. In addition, by configuring the ground plane 9 constituting the back surface of the base 10 of the upper portion of the rectangular waveguide 6, the microstrip circuit board 8 can simplify the shape of the part and reduce the part material. have. Therefore, mass productivity can be aimed at and cost can be reduced. In addition, the coaxial waveguide converter of the second embodiment shown in FIG. 6 can simultaneously achieve miniaturization and performance improvement such as cross polarization characteristics, and the LNB incorporating this has the same effect. In another embodiment, the LNB incorporating the coaxial waveguide converter has the same effect.

FIG. 16 is a block diagram for explaining the transmission line switch circuit of the LNB shown in FIG. 14 and FIG. Referring to FIG. 16, the transmission line switch circuit includes a first linear polarization input unit (first probe) 81 for receiving a first linear polarization and a first amplification circuit connected to the first linear polarization input unit 81. (83), a second linearly polarized wave input unit (second probe) 82 for inputting a second linearly polarized wave, a second amplifying circuit 84 connected to the second linearly polarized wave input unit 82, and a first The switching bias control circuit 85 and the common output terminal 86 of the amplifying circuit 83 and the second amplifying circuit 84 are provided. The first amplification circuit 83 and the second amplification circuit 84 each have a field effect transistor (FET) that is equivalent and has the same performance as an amplifying element. In operation, upon reception of the first linearly polarized wave, the first amplifier circuit 83 is turned ON, and the second amplifier circuit 84 is turned OFF. When the second linearly polarized wave is received, the first amplifier circuit 83 is turned off and the second amplifier circuit 83 is turned on.

FIG. 17 is a plan view showing the coaxial waveguide converter of the eighth embodiment in which the coaxial waveguide converter of the second embodiment shown in FIG. Referring to FIG. 17, in the coaxial waveguide transducer of the eighth embodiment, unlike the coaxial waveguide transducer of the second embodiment shown in FIG. 6, the first probe 93 is inclined by about 10 degrees. This is for the following reason. That is, the first probe 93 may theoretically be parallel to the polarization plane. However, the waveguide structure of the present invention is provided with a matching reflective rib 17 or the like in the waveguide, and has a second probe 4 in the rectangular waveguide 6. Therefore, the polarization plane is not always an ideal state. Consider this in the actual experimental results. FIG. 18 is a characteristic diagram showing a cross deviation characteristic of the coaxial waveguide converter of the second embodiment shown in FIG. 6 and a relationship between the maximum noise index NF _MAX and the first and second input polarization angle differences. Referring to FIG. 18, the first and second input polarization angle differences in which the maximum noise figure NF _MAX is the most suitable value and the first and second input polarization angle differences in which the cross polarization characteristic is the most suitable value are Different. Further, their first and second input polarization angle differences are lower than 90 degrees. Considering the actual standard value, there is no problem if NF = 1.5dB _max and the cross polarization characteristic is 20dBmin. However, considering the angular error when installing the antenna, the maximum noise figure (NF _MAX ) and the cross polarization characteristics are preferably both the first and second input polarization angle differences of 90 °. In this regard, in the eighth embodiment shown in FIG. 17, the first probe 93 is rotated about 10 degrees clockwise. Thus, the following effects are obtained. FIG. 19 is a characteristic diagram showing the relationship between the maximum noise figure and the cross polarization characteristic of the coaxial waveguide converter of the eighth embodiment shown in FIG. 17 and the first and second input polarization angle differences. Referring to FIG. 19, the best points between the maximum noise figure and the cross polarization characteristic are both located at the first and second input polarization angle differences of 90 degrees. Here, it is preferable to set the first and second input polarization angle differences to 90 ° because the downlink signal from the satellite is always horizontal and vertical, that is, the angle difference is 90 °, so that the coaxial waveguide converter built into the LNB also has an input polarization angle. This is because it is good that the difference shows the optimum performance at 90 °. In operation, the first linearly polarized wave is first received by the first probe 93. In addition, the first linearly polarized wave reflected by the lower short terminal A surface 11 is received by the first probe 93. The distance between the first probe 93 and the short terminal A surface 11 is theoretically λ / 4.

However, since the second linearly polarized wave is guided to the rectangular waveguide 6 and again to the amplifier through the second probe 4, the impedance in the waveguide is not in an ideal state (one probe for one waveguide). do. As a result, the polarization mode tends to rotate (clockwise) in the direction of the rectangular waveguide 6. Thus, the reflected wave of the first linearly polarized wave rotates clockwise. In order to improve such a phenomenon, the first probe 93 is installed at an angle of about 10 °. Therefore, the mismatching of the received wave and the reflected wave can be effectively eliminated. In addition, the increase in the reactance component by tilting the first probe 93 increases the conductance of the input side matching circuit included in the first amplifier circuit 83 shown in FIG. 16, so that matching with the amplifying element FET can be achieved. This can improve the deterioration of the maximum noise figure (NF _MAX ). As described above, in the present embodiment, when the polarization angle difference received by the first probe 93 and the second probe 4 is 90 °, the first probe 93 is about 10 ° so that the NF _MAX and the cross polarization characteristics become the best. Configure to tilt. At the same time, the conductance of the input matching circuit included in the first amplifier circuit 83 of the first probe 93 is increased.

As described above, according to the coaxial waveguide transducer of the present invention, an orthogonal transducer shape is adopted by the first waveguide and the second waveguide connected almost perpendicular to the first waveguide, and the first probe and the second probe are respectively provided in the first waveguide and the second waveguide. And a matching means for guiding the second linearly polarized wave to the second waveguide, thereby preventing the deterioration of performance such as the cross polarization characteristic without increasing the size of the apparatus as in the prior art, resulting in miniaturization. Particularly good cross polarization characteristics and input VSWR characteristics can be obtained. In addition, if the output terminal of the first probe and the output terminal of the second probe are formed on the same plane, the configuration can be achieved by a single microstrip circuit board, thereby achieving mass productivity and reducing the cost of the apparatus.

In addition, according to the converter of the satellite broadcasting antenna having the coaxial waveguide converter of the present invention, an orthogonal converter shape by a first waveguide and a second waveguide substantially perpendicular to the waveguide is adopted, and the first and second waveguides each have a first and a second waveguide. A coaxial waveguide transducer configured to provide two probes and a matching means for guiding the second linearly polarized wave to the second waveguide is provided so that the entire apparatus can be miniaturized and a good cross polarization characteristic and input VSWR characteristics can be obtained. Can be.

Claims (14)

A coaxial waveguide transducer for receiving first and second linearly polarized waves which are orthogonal to each other, wherein the coaxial waveguide transducer is provided in a first waveguide, a second waveguide connected to be orthogonal to the first waveguide, and the first waveguide, A first probe for detecting a first linearly polarized wave, a second probe installed in the second waveguide, and a matching means for guiding the second linearly polarized wave to the second waveguide. A coaxial waveguide converter, characterized in that provided. In a coaxial waveguide transducer for receiving first and second linearly polarized waves which are orthogonal to each other, the coaxial waveguide transducer includes a circular waveguide and a first probe for detecting the first linearly polarized wave provided at a predetermined position in the circular waveguide. A first converting portion having a first shorting portion provided in parallel with the first probe at predetermined intervals, a rectangular waveguide connected to the circular waveguide and orthogonal to the circular waveguide, and provided at a predetermined position of the rectangular waveguide. A second conversion portion having a second probe for detecting a second linearly polarized wave, a second shorting portion provided in parallel with the second probe at a predetermined interval, and a matching portion provided at a connection portion between the circular waveguide and the rectangular waveguide. A coaxial waveguide transducer comprising means. A coaxial waveguide transducer for receiving first and second linearly polarized waves which are orthogonal to each other, wherein the coaxial waveguide transducer is configured to detect a first rectangular waveguide and the first linearly polarized wave provided at a predetermined position in the first rectangular waveguide. A first probe for the first probe, a first converter having a first shorting portion provided in parallel with the first probe, a second rectangular waveguide connected to the first rectangular waveguide and orthogonal to the first rectangular waveguide; A second probe having a second probe for detecting the second linearly polarized wave provided at a predetermined position of the second rectangular waveguide, a second shorting portion provided in parallel with the second probe at a predetermined distance, and the second probe A coaxial waveguide transducer, comprising: matching means provided at a connection portion between the first rectangular waveguide and the second rectangular waveguide. The coaxial waveguide converter according to claim 1, wherein an output end of the first probe and an output end of the second probe are formed on the same plane. The coaxial waveguide converter according to claim 4, wherein the first and second probes are connected to microstrip lines formed on the same plane, respectively. The coaxial waveguide converter according to claim 4, wherein the first and second probes are formed on the same plane. 7. The coaxial waveguide transducer of claim 6, wherein the first and second probes are formed by micro strip lines. A coaxial waveguide transducer according to claim 1, wherein the matching means has a narrow rib shape. The coaxial waveguide converter according to claim 1, wherein the matching means is formed at predetermined intervals on an inner wall surface of the circular waveguide. A coaxial waveguide transducer as set forth in claim 1, wherein said matching means is also formed at the other end of the cavity of said first waveguide. 3. The coaxial waveguide transducer of claim 2, wherein the first shorting portion is a rod-shaped shorting rod. The coaxial waveguide converter according to claim 1, wherein one side of the first waveguide is formed by a ground plane on the back surface of the substrate on which a microstrip circuit is formed. A converter of a satellite broadcasting antenna having a coaxial waveguide converter for receiving first and second linearly polarized waves that are orthogonal to each other, the converter of the satellite broadcasting antenna comprising: a first waveguide and a second waveguide connected to the first waveguide orthogonally; A first probe installed in the waveguide, the first waveguide for detecting the first linearly polarized wave, a second probe installed in the second waveguide, for detecting the second linearly polarized wave, and the second linearly polarized wave; And a matching means for guiding the second waveguide, and a horn provided at an end of the side where the first waveguide is not connected to the second waveguide to guide the first and second linearly polarized waves to the first waveguide. Converter for satellite broadcasting antenna, characterized in that. 14. The apparatus of claim 13, further comprising a transmission line switch having first and second amplification circuits as amplifying means of the first and second linearly polarized waves, wherein the first amplification circuit is configured to receive the first linearly polarized wave. A first probe, said second amplification circuit including said second probe for receiving said second linearly polarized wave, said first probe having a noise figure upon receiving said first and second linearly polarized wave; And a fixed angle inclination such that the minimum received polarization angle difference and the maximum received polarization angle difference of the cross polarization characteristics are both 90 °.