JP2006211116A - Multi-beam feed horn, frequency converter and multi-beam antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable it to use one multi-beam feed horn common to a reflecting mirror of distinct aperture. <P>SOLUTION: Two horns 6 and 8 are approached and provided in response to these geostationary satellites, so that the radio wave transmitted from the two sets of the geostationary satellites which has been arranged adjoining to an geostationary orbit must carry out incidence when the geostationary orbits are arranged near the focal position of the reflecting mirror of a predetermined aperture. A partition plate 22 is arranged between the horns 6 and 8, and projects from the apertures of the horns 6 and 8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a multi-beam feed horn that is provided in a single reflecting mirror, has a plurality of horns corresponding to a plurality of satellites, and receives radio waves from the satellites to which these horns correspond. The present invention relates to an integrally formed frequency converter and a multi-beam antenna provided with this multi-beam feed horn or frequency converter.

  In recent years, a plurality of communication satellites are approaching and launched on the same orbit. Radio waves from these close communication satellites are received by an antenna having one reflector and a plurality of horns. An example of such an antenna is disclosed in Patent Document 1, for example.

  In the technique of Patent Document 1, a multi-beam feed horn is disposed in the vicinity of the focal position of the reflecting mirror. In this multi-beam feed horn, two waveguides are arranged in parallel, and a horn is attached to the tip of each of the waveguides. These horns are integrally formed and configured to be detachable from the waveguide. There are two types of integrated horns, one for large calibers and one for small calibers, corresponding to reflectors with different calibers.

  In general, the aperture of the reflecting mirror is related to the gain of the antenna using the reflecting mirror. When a large gain is required, a reflecting mirror having a large aperture is used. When the apertures of the reflecting mirrors are different, the positions where the radio waves are reflected by the reflecting mirrors are different, and the distances between these convergence positions are also different. In order to cope with this, in Patent Document 1, two types of horns are prepared in order to increase the number of components that can be used in common in reflectors having different calibers, and either horn is selected according to the caliber of the reflector. I use it.

JP 2002-124820 A

  In the technique of Patent Document 1, a waveguide can be used in common for reflectors having different diameters, but a horn needs to be prepared corresponding to reflectors having different diameters. When horns are prepared for reflectors having different calibers as described above, a mold must be prepared for each horn, resulting in an increase in cost.

  An object of the present invention is to provide a multi-beam feed horn that can be used for a reflector having a different aperture while using a horn prepared for a reflector having a specific aperture. Another object of the present invention is to provide a frequency converter provided with the multi-beam feed horn as described above. Another object of the present invention is to provide a multi-beam antenna including a multi-beam feed horn as described above or a frequency converter formed integrally with the multi-beam feed horn.

  The multi-beam feed horn according to the present invention has a plurality of horns. When these horns are placed near the focal position of a reflector with a predetermined aperture, radio waves transmitted from multiple geostationary satellites placed adjacent to each other on the geostationary orbit of the universe are incident on the corresponding horn. The horns are provided close to each other. As the reflector, for example, a symmetric parabolic reflector, an offset parabolic reflector, a cylindrical parabolic reflector, or the like can be used. Each horn has an opening at the front end, and the rear end is connected to the waveguide. The front end is formed larger than the rear end. Each horn can be formed in an inverted truncated cone shape, for example. Each horn can have the same shape. A partition plate is disposed between adjacent ones of the plurality of horn portions. This partition plate protrudes from the opening of the adjacent horn part. As the partition plate, a conductive plate or a dielectric plate can be used. The protruding amount of the partition plate is preferably about 0.2 to 0.4 with respect to the opening diameter of the horn (diameter on the tip side), for example. A frequency converter can be provided integrally with the multi-beam feed horn. A multi-beam antenna can be configured by combining the multi-beam feed horn or the frequency converter with a reflecting mirror.

  By providing the partition plate, the radio wave traveling straight toward the partition plate wraps around due to the diffraction phenomenon, and the radio wave comes to the inner side from the position that should arrive when there is no partition plate in any horn. As a result, radio waves having intervals that are not originally incident on the horn are incident on the horn, and can be used with a reflector having a large aperture.

  The partition plate can be detachably provided. If comprised in this way, this multi-beam feed horn can be used also for reflectors with a large aperture by attaching a partition plate to a multi-beam feed horn manufactured for a reflector with a small aperture, for example.

  Each said horn part can be formed integrally. In this case, a corrugate is formed so as to surround each horn part. If comprised in this way, the manufacture will become easy.

  As described above, according to the present invention, one multi-beam feed horn can be used for any reflecting mirror having a different diameter by providing a partition plate in a detachable manner. Also, an integrated frequency converter using such a multi-beam feed horn can be used with any of a plurality of types of reflecting mirrors having different apertures. In addition, in a multi-beam antenna equipped with such a multi-beam feed horn or frequency converter, it becomes possible to share the multi-beam feed horn or frequency converter with a reflector having a different diameter by attaching and detaching a partition plate. Cost can be reduced.

  A multi-beam feed horn according to an embodiment of the present invention is arranged near the focal position of a reflecting mirror (not shown), for example, an offset parabolic reflector, and has a plurality of different diameters, for example, a diameter of 40 cm, It can be used in common with the one of 45 cm.

  This multi-beam feed horn was originally designed to correspond to a caliber having a diameter of 40 cm, and a plurality of, for example, two units launched at intervals of, for example, about 4 degrees close to a stationary orbit in outer space. This is for receiving a radio wave of a GHz band, for example, 12 GHz band transmitted from a geostationary satellite, for example, a communication satellite.

  This multi-beam feed horn has two waveguides 2 and 4 as shown in FIG. These two waveguides 2 and 4 are configured, for example, as circular waveguides, and both are arranged close to each other so that their central axes are parallel to each other. The rear end portions of these waveguides 2 and 4 are closed, and in the vicinity of these rear end portions, although not shown, an ultra-high frequency signal in the GHz band received by the multi-beam feed horn is, for example, in the middle of the 1 GHz band. A frequency converter that converts the frequency into a frequency signal is integrally provided, and an ultra-high frequency signal propagated through the waveguides 2 and 4 is supplied to the frequency converter.

  Both ends of the waveguides 2 and 4 are opened, and horns 6 and 8 are integrally formed in the openings. The horns 6 and 8 have the same shape and are formed in a frustum having an open front end portion and a rear end portion, for example, a truncated cone shape. These horns 6 and 8 have a circular opening on the front end side on the same surface, and a circular opening on the rear end side is also on the same surface (the front end surfaces of the waveguides 2 and 4). The circular opening on the front end side has a larger diameter than the circular opening on the rear end side, and the center of the circular opening on the rear end side is located on the central axis of the waveguides 2 and 4. In addition, the center of the circular opening on the tip side is somewhat located on the outer side of the center axis along the waveguides 2 and 4.

  The corrugates 12 and 14 are formed so as to cover the horns 6 and 8 together, and the planar shape is substantially oval, and each has substantially the same shape. These corrugates 12 and 14 have their openings located on the same plane as the openings on the tip side of the horns 6 and 8. The boundary portions 18 of the horns 6 and 8 are located on the extended lines of the boundaries 16a and 16b of the corrugates 12 and 14.

  Recesses 20a and 20b having the same shape are formed outside the corrugates 12 and 14 so as to be substantially perpendicular to the boundary portions 16a, 16b and 18. The recesses 20a and 20b are both formed in an arc shape.

  For example, the opening on the front end side of the horns 6 and 8 is formed with a diameter of about 25 mm, the diameter of the opening at the rear end is formed with about 19.6 mm, and the height is formed with about 10 mm. That is, the ratio of the diameter of the front end side opening, the diameter of the rear end side opening, and the height is 2.5 to 2: 1. When these feed horns 6 and 8 are arranged in the vicinity of a focal position of a reflector having a predetermined aperture, for example, a diameter of 40 cm, for example, an offset parabolic reflector (not shown), the feed horns 6 and 8 are launched close to a stationary orbit, for example. The above dimensions are set so that radio waves from, for example, a geostationary satellite launched at 124 degrees and 128 degrees east longitude, for example, a communication satellite, enter the horns 6 and 8. The corrugates 12 and 14 are formed to have a depth of about 6 mm, a maximum diameter of about 33 mm, and a minimum diameter of about 27 mm. The recesses 20a and 20b are formed to have a depth of about 8 mm.

  As shown in FIG. 1, a partition plate 22 is detachably disposed between the recesses 20a and 20b. That is, as shown in FIG. 2A, screw holes 24a and 24b are formed in the recesses 20a and 20b, and the base portions 26a and 26b shown in FIG. 1C are accommodated in the recesses 20a and 20b. Screwed into the screw holes 24a, 24b. The partition plate 22 is made of, for example, a conductor such as metal, and extends from the recess 20a to the recess 20b through the boundary 16a of the corrugations 12 and 14, the boundary 18 of the horns 6 and 8, and the boundary 16b of the corrugations 12 and 14. It is growing. That is, the partition plate 22 is located between the horns 6 and 8 and has a substantially inverted U-shape. The partition plate 22 protrudes from the opening surface at the tip of the horns 6 and 8 by a predetermined distance L, for example, about 5.9 mm to about 7.9 mm. In this protruding state, the lower end 22b of the horizontal portion 22a of the partition plate 22 is in contact with the boundary portion 18 of the horns 6 and 8, and there is no electrical gap. The thickness of the horizontal portion 22 a is set to be equal to or less than the thickness of the tip of the boundary portion 18. The partition plate 22 is attached when the multi-beam feed horn is used with an offset parabolic reflector having a large aperture, for example, 45 cm.

  For example, when the multi-beam feed horn is used in the state where the partition plate 22 is not provided in the offset parabolic reflector having a diameter of 45 cm as shown in FIG. 4A, the multi-beam feed horn originally has a diameter of 40 cm. Therefore, the angle formed by the radio waves reflected by the reflecting mirror and incident on the horns 6 and 8 toward the reflecting mirror is about 4 degrees. However, in practice, as described above, the angle formed when the radio waves from the two communication satellites are directed to the reflecting mirror is about 4.5 degrees. Therefore, a partition plate 22 is provided in the multi-beam feed horn. When the partition plate 22 is provided, as shown in FIG. 3, the radio waves A, B, C, and D that come from the outside of the partition plate 22, that is, from the horn 6 side and collide with the tip of the partition plate 22 as viewed from the horn 8. If the partition plate 22 is not provided, it goes straight as indicated by a solid line and hardly enters the horn 8. However, as a result of providing the partition plate 22, these radio waves A, B, C, and D are diffracted and wrap around the lower side of the partition plate 22 as indicated by dotted lines, all as indicated by the symbols a, b, c, and d. Incident into the horn 8. Although not shown, the horn 6 also radiates from the outside of the partition plate 22 as viewed from the horn 6, that is, from the horn 8 side and collides with the tip of the partition plate 22 diffracts downward, and enters the horn 6. All incident. The angle that these incident radio waves make with the normal line standing on the reflecting mirror is larger than the angle that the incident radio wave makes with respect to the normal line standing on the reflecting mirror when there is no partition plate 22. That is, the angle formed when radio waves that can be incident on the partition plate 22 are directed toward the reflecting mirror is wider than the angle formed when the incident radio wave is directed toward the reflecting mirror without the partition plate 22. As shown exaggeratedly in FIG. 4B, the horns 6 and 8 can receive any radio waves having an angle of, for example, 4.5 degrees.

  FIG. 5 is a directional characteristic diagram when a horizontally polarized radio wave is received by using the multi-beam feed horn with an offset parabolic reflector having a diameter of 45 cm without providing the partition plate 22, and the peak in this case. The beam interval of the toe peak (the interval between the maximum values of the relative gains in the directivity of both radio waves) is about 4.064 degrees. FIG. 6 is a directional characteristic diagram when receiving the vertically polarized radio waves by using the multi-beam feed horn together with the offset parabolic reflector having a diameter of 45 cm without providing the partition plate 22. The peak-to-peak beam spacing is about 4.037 degrees.

  FIG. 7 is a directional characteristic diagram when each of the horizontally polarized radio waves is received using the multi-beam feed horn with an offset parabolic reflector having a caliber of 45 cm by projecting the partition plate 22 by about 4.9 mm. In this case, the peak-to-peak beam interval is about 4.398 degrees. FIG. 8 is a directional characteristic diagram when vertically polarized radio waves are received using the above-mentioned multi-beam feed horn together with an offset parabolic reflector having a diameter of 45 cm by projecting the partition plate 22 by about 4.9 mm. In this case, the beam interval of the peak-to-peak is about 4.344 degrees.

  FIG. 9 is a directional characteristic diagram when each of the horizontally polarized radio waves is received using the above-mentioned multi-beam feed horn with an offset parabolic reflector having a diameter of 45 cm by projecting the partition plate 22 by about 5.9 mm. In this case, the beam interval of the peak-to-peak is about 4.339 degrees. FIG. 10 is a directional characteristic diagram when vertically polarized radio waves are received using the above-mentioned multi-beam feed horn together with an offset parabolic reflector having a caliber of 45 cm by projecting the partition plate 22 by about 5.9 mm. In this case, the peak-to-peak beam spacing is about 4.452 degrees.

  FIG. 11 is a directional characteristic diagram when each of the horizontally polarized radio waves is received using the multi-beam feed horn with an offset parabolic reflector having a caliber of 45 cm by projecting the partition plate 22 by about 6.9 mm. In this case, the peak-to-peak beam interval is about 4.227 degrees. FIG. 12 is a directional characteristic diagram when vertically polarized radio waves are received using the above-mentioned multi-beam feed horn together with an offset parabolic reflector having a caliber of 45 cm by projecting the partition plate 22 by about 6.9 mm. In this case, the peak-to-peak beam interval is about 4.428 degrees.

  FIG. 13 is a directional characteristic diagram when horizontally polarized radio waves are received using the above-mentioned multi-beam feed horn together with an offset parabolic reflector having a diameter of 45 cm by projecting the partition plate 22 by about 7.9 mm. In this case, the beam interval of the peak-to-peak is about 4.334 degrees. FIG. 14 is a directional characteristic diagram when vertically polarized radio waves are received using the above-mentioned multi-beam feed horn together with an offset parabolic reflector having a caliber of 45 cm by projecting the partition plate 22 by about 7.9 mm. In this case, the peak-to-peak beam spacing is about 4.452 degrees.

  FIG. 15 is a directional characteristic diagram when horizontally polarized radio waves are received using the above-mentioned multi-beam feed horn with an offset parabolic reflector having a diameter of 45 cm by projecting the partition plate 22 by about 9.4 mm. In this case, the beam interval of the peak-to-peak is about 4.172 degrees. FIG. 16 is a directional characteristic diagram when vertically polarized radio waves are received using the above-mentioned multi-beam feed horn together with an offset parabolic reflector having a caliber of 45 cm by projecting the partition plate 22 by about 9.4 mm. In this case, the beam interval of the peak-to-peak is about 4.374 degrees.

  FIG. 17 is a directional characteristic diagram when each of the horizontally polarized radio waves is received using the multi-beam feed horn with an offset parabolic reflector having a diameter of 45 cm by projecting the partition plate 22 by about 11.4 mm. In this case, the beam interval of the peak-to-peak is about 4.130 degrees. FIG. 18 is a directional characteristic diagram when vertically polarized radio waves are received using the above-mentioned multi-beam feed horn together with an offset parabolic reflector having a diameter of 45 cm by projecting the partition plate 22 by about 11.4 mm. In this case, the beam interval of the peak-to-peak is about 4.236 degrees.

  FIG. 19 is a directional characteristic diagram when horizontally polarized radio waves are received using the above-mentioned multi-beam feed horn with an offset parabolic reflector having a diameter of 45 cm by projecting the partition plate 22 by about 13.4 mm. In this case, the peak-to-peak beam interval is about 4.175 degrees. FIG. 20 is a directional characteristic diagram when vertically polarized radio waves are received using the above-mentioned multi-beam feed horn together with an offset parabolic reflector having a caliber of 45 cm by projecting the partition plate 22 by about 13.4 mm. In this case, the peak-to-peak beam interval is about 4.302 degrees.

  For example, Sky Perfect TV using two communication satellites launched at 124 degrees and 128 degrees east longitude! Is viewed using an offset parabolic reflector with a 45 cm aperture, the theoretical value of the peak-to-peak beam spacing of radio waves transmitted from both communication satellites is 4.42 degrees in Wakkanai and 4.61 degrees in Okinawa. The average is 4.52 degrees. As is clear from the directivity characteristic diagrams of FIGS. 8 to 19, the deviation of the beam interval of about ± 0.3 degrees does not affect the peak level and is within the allowable range. Accordingly, the design value is set to 4.5 degrees, the partition plate 22 is provided, and the protruding amount is about 5.9 mm, about 6.9 mm, about 7.9 mm as described above (about 0 as compared with the diameter of the tip opening of the horn 8). .25 to about 0.34), a multi-beam feed horn for an offset parabolic reflector having a diameter of 40 cm can be used for an offset parabolic reflector having a diameter of 45 cm.

  Moreover, when used as a multi-beam feed horn for a caliber of 40 cm, the partition plate 22 may be used without being attached. Therefore, it is possible to use each of the offset parabolic antennas with different apertures by manufacturing only one type of multi-beam feed horn.

  In the above embodiment, the protruding amount of the partition plate 22 is about 5.9 mm, about 6.9 mm, and about 7.9 mm. However, the present invention is not limited to this. For example, Sky Perfect TV! Even if the opening diameter of the horns 6 and 8 is different from that in the above embodiment, the horns 6 and 8 have different values, and the angle between two communication satellites launched adjacent to each other is different. If they are different, the amount of protrusion will also be different. In the above-described embodiment, the case where radio waves from two communication satellites are received has been described. However, radio waves from three communication satellites can also be received. In this case, three horns are arranged side by side, but a partition plate may be provided at each of the two boundary portions of the three horns. Further, in the above embodiment, the partition plate 22 is made of metal, but may be made of a dielectric, for example.

BRIEF DESCRIPTION OF THE DRAWINGS It is a top view of the multi-beam feed horn of one Embodiment of this invention, sectional drawing in alignment with the AA line in the top view, and a front view of the partition plate used for this multi-beam feed horn. FIG. 2 is a plan view of the multi-beam feed horn of FIG. 1 with a partition plate removed, and a cross-sectional view taken along line BB in the plan view. It is explanatory drawing of an effect | action of the partition plate in the multi-beam feed horn of FIG. It is the figure which showed typically the reception state of the electromagnetic wave in the state which has not provided the partition plate in the multi-beam antenna provided with the multi-beam feed horn of FIG. 1, and the state provided. FIG. 2 is a directional characteristic diagram when a horizontally polarized radio wave is received in a state where the partition plate is removed from the multi-beam feed horn of FIG. 1 and attached to an offset parabolic reflector having a diameter of 45 cm. FIG. 2 is a directional characteristic diagram when a vertically polarized radio wave is received with the partition plate removed in the multi-beam feed horn of FIG. 1 and attached to an offset parabolic reflector having a diameter of 45 cm. FIG. 2 is a directional characteristic diagram when a horizontally polarized radio wave is received in a state where the partition plate 22 protrudes about 4.9 mm and is attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a vertically polarized radio wave is received in a state where the partition plate 22 protrudes about 4.9 mm and is attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a horizontally polarized radio wave is received in a state where the partition plate 22 protrudes about 5.9 mm and is attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a vertically polarized radio wave is received in a state where the partition plate 22 protrudes about 5.9 mm and is attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a horizontally polarized radio wave is received with the partition plate 22 protruding about 6.9 mm and attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a vertically polarized radio wave is received with the partition plate 22 protruding about 6.9 mm and attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a horizontally polarized radio wave is received in a state where the partition plate 22 protrudes about 7.9 mm and is attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a vertically polarized radio wave is received in a state where the partition plate 22 protrudes about 7.9 mm and is attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 3 is a directional characteristic diagram when a horizontally polarized radio wave is received in a state where the partition plate 22 protrudes about 9.4 mm and is attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a vertically polarized radio wave is received with the partition plate 22 protruding about 9.4 mm and attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a horizontally polarized radio wave is received with the partition plate 22 protruding about 11.4 mm and attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a vertically polarized radio wave is received with the partition plate 22 protruding about 11.4 mm and attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a horizontally polarized radio wave is received with the partition plate 22 protruding about 13.4 mm and attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1. FIG. 2 is a directional characteristic diagram when a vertically polarized radio wave is received with the partition plate 22 protruding about 13.4 mm and attached to an offset parabolic reflector having a diameter of 45 cm in the multi-beam feed horn of FIG. 1.

Explanation of symbols

6 8 Horn 22 Partition plate

Claims (5)

Corresponding to these geostationary satellites so that radio waves transmitted from a plurality of geostationary satellites arranged adjacently on geostationary orbit are incident when arranged near the focal position of a reflector with a predetermined aperture A plurality of horns provided in close proximity;
A partition plate disposed between adjacent ones of the plurality of horns and protruding from an opening of the adjacent horn;
Multi-beam feed horn provided.   The multi-beam feed horn according to claim 1, wherein the partition plate is detachably provided.   2. The multi-beam feed horn according to claim 1, wherein the horns are integrally formed and a corrugate is formed so as to surround each horn.   A frequency converter in which the multi-beam feed horn according to claim 1, 2 or 3 is integrally formed. A multi-beam antenna comprising the multi-beam feed horn according to claim 1, 2 or 3, or the frequency converter according to claim 4.

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