JP2014165790A - Reception antenna device, and manufacturing method of mirror surface-corrected reflector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reception antenna device for receiving radiation power of satellite communication or satellite broadcast radiated from a geostationary satellite of a reception object, and to provide a manufacturing method of a mirror surface-corrected reflector.SOLUTION: A reception antenna device 10 comprises a mirror surface-corrected reflector 11 and a power feeding part 12 for receiving reception radio waves of radiation power reflected by the mirror surface-corrected reflector 11. A manufacturing method of the mirror surface-corrected reflector 11 includes: calculating a coordinate area determined from a geostationary orbit in a view from a plurality of reception areas with respect to a geostationary satellite of a reception object with a parabolic surface having a fixed curvature, and arranging gain constraint points in an area covering the geostationary orbit and an area at a specific orbit position; and correcting a mirror surface shape of the parabolic surface by giving a first gain limit value relating to the specific orbit position and a second gain limit value relating to the area determined by the geostationary orbit.

Description

  The present invention relates to a satellite communication or satellite broadcast receiving antenna technology, and more particularly, to a receiving antenna device and a mirror-shaped modified reflector for receiving radiated power of satellite communication or satellite broadcast radiated from a stationary satellite to be received. It relates to a manufacturing method.

  Conventional receiving antennas for satellite communication or satellite broadcasting using offset reflectors (for example, see Non-Patent Document 1), using dielectric lenses (for example, see Patent Document 1), and waveguides A device using a slot array (see, for example, Patent Document 2) is known.

  As a general satellite broadcast receiving antenna, an offset reflector antenna as shown in Non-Patent Document 1 is used. The offset reflector is excellent in that it reduces the degradation of the sidelobe characteristics caused by the blocking of the primary radiator. Note that the reference pattern related to the antenna performance of the receiving antenna is defined by the recommendation of ITU-R (for example, see Non-Patent Document 2).

  On the other hand, as a satellite-mounted antenna device used for satellite broadcasting, satellite communication, or the like, a technique for forming a beam shape by a mirror-shaped modified reflector is disclosed (for example, see Patent Documents 3, 4, and 5). The techniques disclosed in these Patent Documents 3, 4, and 5 are intended to easily form a radiated power pattern having a complicated shape. In addition to the known examples shown in these patent documents, there are many practical examples in the satellite broadcasting and satellite communication regarding the use of the mirror-surface modified reflector. However, no practical example or known example of a receiving antenna for satellite communication or satellite broadcasting using a mirror-shaped reflecting mirror from the viewpoint of the radiated power receiving side is known.

  The current geostationary satellites are located at regular intervals on the geostationary orbit as defined in ITU-R (“Radio Communication Rules” Appendix No. 30, 2.4.1). For example, broadcasting satellites are in orbital positions at intervals of 6 degrees.

JP-A-4-74005 Japanese Patent Laid-Open No. 7-106847 Japanese Patent No. 3043768 Japanese Patent No. 2825907 Japanese Patent No. 3322897

Nagasaka et al., “Prototype of a 21GHz Band Satellite Broadcasting Receiver Antenna”, IEICE Technical Report, Vol.35 No.31, pp.53-56, July 2011 Recommendation ITU-R BO.1900, “Reference receive earth station antenna pattern for the broadcasting-satellite service in the band 21.4-22 GHz in Regions 1 and 3”, January 2012

  As a receiving antenna for satellite communication or satellite broadcasting, an aperture efficiency of 60% to 80% is maintained, and deterioration of sidelobe characteristics is further reduced (for example, a margin from a reference pattern of BO.1900 is 5 dB or more). Is desired. In particular, from the viewpoint of improving the antenna performance, it is effective to obtain the gain difference of the first side rope with respect to the main lobe, and the gain margin of the first side rope is larger than the reference pattern of BO.1900. It is preferable (for example, 6 dB or more).

  As described above, an offset reflecting mirror is used for a general conventional satellite broadcasting receiving antenna. The offset reflector is a reflector that has a parabolic surface with a constant curvature, and a feeding part is arranged at a position where the reception point of the radiated power is offset, and has a sidelobe characteristic caused by blocking of the primary radiator. Although degradation can be reduced, the margin from the reference pattern of BO.1900 (hereinafter referred to as BO.1900) defined in the ITU-R recommendation is only about 4 dB. The antenna performance of the receiving antenna using the offset reflecting mirror is such that the gain margin of the first side rope is only about 2.5 dB to 3 dB with respect to the reference pattern of BO.1900.

  In addition, the receiving antenna using the dielectric lens is obtained by replacing the reflector portion of the offset reflector antenna with a dielectric lens, and its characteristics are the same as those of the offset reflector antenna.

  A receiving antenna using a waveguide slot array is for in-vehicle use and has a low receiving gain of about 25 dBi and is not suitable for a receiving antenna for a fixed satellite broadcast.

  Furthermore, practical examples and known examples of receiving antennas for satellite communication or satellite broadcasting that use mirror-shaped reflecting mirrors are not known from the viewpoint of the reception side of radiated power. Assuming from the conventional technology of a satellite-mounted antenna device adopting a mirror-shaped modified reflector, in view of adopting a mirror-shaped modified reflector as a receiving antenna, the aperture efficiency is maintained at 60% to 80%, Even if the mirror surface modification is attempted from a parabolic surface having a certain curvature by simply placing gain constraint points in all regions other than the main lobe so as to further reduce the degradation of the side lobe characteristics, it is almost the same as the offset reflector. Only moderate characteristics can be obtained (Reference Example 1 described later).

  In addition, for example, since a broadcasting satellite is in an orbital position with an interval of 6 degrees, as a receiving antenna device for a stationary satellite to be received, in order to equally reduce interference waves from other stationary satellites, a certain curvature is used. Calculate the coordinate region (ie, the region covering the geostationary orbit) that is determined by the geostationary orbit seen from various parts of Japan for the geostationary satellite to be received on the parabolic surface, and place the gain constraint point. Even if the desired gain limit value for reducing the interference wave is given and the mirror surface shape of the parabolic surface is modified, the side lobe level in the direction other than the stationary orbital surface greatly increases, so that the aperture efficiency is about 65%. It decreases (Reference Example 2 described later). In this case, the mirror surface modification amount (absolute value) also becomes relatively large.

  The present invention has been made in view of the above-mentioned problems, and a receiving antenna device for efficiently receiving the radiated power of satellite communication or satellite broadcast radiated from a stationary satellite to be received and a method of manufacturing a mirror-shaped modified reflector The purpose is to provide.

  In the present invention, since the side lobe level in the adjacent satellite direction is higher than the side lobe level in the other geostationary satellite directions, it is noted that reducing the side lobe level in the adjacent satellite direction is most effective. Design a modified reflector. Note that the orbit interval of communication satellites is determined by international adjustment and is not necessarily 6 degrees apart.

  More specifically, in the present invention, in forming the mirror surface shape of the mirror-shaped reflecting mirror, a coordinate region determined by a stationary orbit viewed from various parts of Japan with respect to a stationary satellite to be received on a parabolic surface having a certain curvature. (That is, the region covering the geosynchronous orbit) is calculated, the gain constraint points are arranged in the region covering the geosynchronous orbit and the region of the specific orbital position, and the first relating to the specific orbital position (for example, the orbital position of the adjacent satellite) A gain limit value (for example, a value lower than 5 dB from the gain value related to the sidelobe characteristic defined by the reference pattern, and a value lower by 10 dB in the embodiment described later), and a second gain limit related to the region covering the stationary orbit A mirror surface modified reflector is formed by giving a value (for example, a value lower than 3 dB from the gain value defined by the reference pattern) and modifying the mirror surface shape of the parabolic surface That. A satellite communication or satellite broadcast receiving antenna apparatus is configured using the mirror-surface modified reflector.

  Thereby, the radio waves of the target geostationary satellite can be received, and interference waves from other geostationary satellites can be effectively reduced. In an embodiment described later, the aperture efficiency is 75%, and the mirror surface modification amount (absolute value) is 1.2 mm at the maximum, so that the efficiency as a receiving antenna is high and the burden on the manufacturing surface can be reduced.

  That is, the receiving antenna device of the present invention is a receiving antenna device that receives the radiated power of satellite communication or satellite broadcasting radiated from a geostationary satellite to be received, and is a parabolic surface having a certain curvature. A coordinate region determined by geostationary orbits as viewed from a plurality of receiving areas with respect to a geostationary satellite is calculated, gain constraint points are arranged in an area covering the geostationary orbit and an area of a specific orbital position, and the first relating to the specific orbital position. And the second gain limit value relating to the region determined by the geostationary orbit and the mirror-shaped modified reflector whose mirror surface shape is modified, and the radiation reflected by the mirror-shaped modified reflector And a power feeding unit that receives a received radio wave of power.

  Further, in the receiving antenna device of the present invention, the plurality of receiving areas include areas of the Japanese archipelago, and the antenna gain at the time of reception by the power feeding unit is within a predetermined error in any of the areas of the Japanese archipelago. It is characterized by having equal gain performance. For example, when used in various places in Japan, the same design is designed to obtain the same performance.

  Further, in the receiving antenna device of the present invention, the specific orbital position may be other geostationary in the range of +3 to +30 degrees and -3 to -30 degrees with respect to the orbital position of the stationary satellite to be received. It is characterized by one or more orbital positions related to the satellite.

  Further, in the receiving antenna device of the present invention, the first gain limit value is a value lower than 5 dB from a gain value related to a side lobe characteristic of a reference pattern defined by an ITU-R recommendation. .

  In the receiving antenna apparatus of the present invention, the second gain limit value is a value lower than 3 dB from a gain value related to a sidelobe characteristic of a reference pattern defined by an ITU-R recommendation. .

  Furthermore, the method of manufacturing a mirror-shaped reflecting mirror of the present invention is a method of manufacturing a mirror-shaped reflecting mirror in a receiving antenna device that receives radiated power of satellite communication or satellite broadcasting radiated from a geostationary satellite to be received. From the plurality of regions, a step of setting a parabolic reflector having a constant curvature and a predetermined curvature at a predetermined arrangement position, a step of setting a plurality of reception areas, a step of determining a geostationary satellite to be received, Calculating a viewed geostationary orbit, calculating a coordinate area determined by the geostationary orbit viewed from the plurality of areas, and arranging a gain constraint point in an area covering the geostationary orbit and a specific orbital position; and A first gain limit value related to a specific trajectory position, a second gain limit value related to a region defined by the geostationary orbit, and a peak gain value related to the main lobe are set. The mirror surface shape of the reflecting mirror is modified by adjusting the mirror surface shape so as to satisfy the first gain limit value, the second gain limit value, and the peak gain value related to the main lobe at the set gain constraint point. A step of determining a pattern, and a step of shaping the mirror-shaped modified reflector based on the mirror-shaped pattern. For example, the mirror-finished reflecting mirror according to the present invention can be designed to obtain the same performance with the same design when used in various places in Japan.

  According to the present invention, for example, interference waves from other geostationary satellites such as adjacent geostationary satellites can be reduced, and the reception quality of the target satellite communication or satellite broadcast radio waves can be further improved. Further, according to the present invention, the above-described effects can be obtained with a receiving antenna device of the same design in various parts of Japan. For example, if the receiving antenna device according to the present invention is applied to a 21 GHz band (21.4 GHz to 22.0 GHz) satellite broadcasting system that is promising for future super high-definition broadcasting, the reception quality is improved by reducing the interference wave from the adjacent satellite. It can be improved and the interruption time due to rain can be reduced.

  Furthermore, according to the present invention, since the characteristics are determined only by the shape of the reflecting mirror surface, there are no adjustment points at the time of manufacture, and mass production is easy.

  Further, according to the present invention, the aperture efficiency can be made 75%, and interference waves can be reduced without increasing the aperture diameter, which is useful for space saving and cost reduction.

It is a figure which shows the structure of the receiving antenna apparatus of the satellite communication or satellite broadcasting of one Embodiment by this invention. It is a figure which shows the manufacturing method of the mirror surface reflection reflector of one Example by this invention. It is a figure which shows the geostationary orbit seen from the receiving point on the ground, and shows the definition of coordinates. It is a figure which illustrates the geostationary orbit seen from the receiving antenna apparatus of various parts of Japan regarding the geostationary satellite located in the equator 110 degree equator sky. It is a figure which shows the gain restraint point arrange | positioned around the orbit position of an adjacent satellite regarding the manufacturing method of the mirror surface modification reflector of one Example by this invention. It is a figure which shows the gain restraint point arrange | positioned so that a static orbit may be covered regarding the manufacturing method of the mirror surface modification reflecting mirror of one Example by this invention. It is a figure which shows the mirror surface shape (modification amount from a parabolic surface) when the mirror surface modification reflector with respect to the geostationary satellite located in 110 degrees east longitude is formed regarding the manufacturing method of the surface modification reflector of one Example by this invention. is there. The antenna gain characteristic (radiation pattern) of the receiving antenna apparatus according to the first embodiment of the present invention is set as a difference with respect to BO.1900 (the specified value [dBi] of the receiving antenna apparatus gain [dBi] −BO.1900 according to the present invention)). FIG. It is a figure which shows the antenna gain characteristic (radiation pattern) of the receiving antenna apparatus of Example 1 which concerns on invention. It is a figure which shows the antenna gain characteristic (radiation pattern) of the receiving antenna apparatus of Example 2 which concerns on this invention. It is a figure which shows the antenna gain characteristic (radiation pattern) of the receiving antenna apparatus of Example 3 which concerns on this invention. It is a figure which shows the antenna gain characteristic (radiation pattern) of the receiving antenna apparatus of Example 4 which concerns on this invention. As a reference example, it is a figure shown about the antenna gain at the time of trying a mirror surface modification by arrange | positioning a gain restraint point in all the areas | regions assumed from a prior art as a reference example. FIG. 10 is a diagram illustrating antenna gain when a mirror surface modification is attempted by arranging a gain constraint point on a geosynchronous orbit without considering the orbit position of an adjacent satellite as Reference Example 2;

  Hereinafter, a manufacturing method of a receiving antenna device and a mirror-surface modified reflector according to an embodiment of the present invention will be described with reference to the drawings.

[Receiving antenna device]
FIG. 1 shows a configuration of a receiving antenna device 10 according to an embodiment of the present invention. The receiving antenna device 10 according to the present embodiment is a device that receives the radiated power of satellite communication or satellite broadcasting radiated from a geostationary satellite to be received, and includes a mirror-finished reflecting mirror 11 and a power feeding unit 12. The mirror-surface modified reflector 11 according to the present invention has a smooth surface whose shape has been modified in advance from the parabolic surface of the modification standard by a manufacturing method described in detail later. The power feeding unit 12 has the same configuration as an existing receiving antenna. In FIG. 1, the antenna diameter D of the mirror-shaped reflecting mirror 11 with respect to the received radiated power is typically 45 cm, and the F / D ratio with respect to the focal length F when collecting the received radio wave to the power feeding unit 12 is 0.47. However, it is not necessary to limit to these numerical values.

  The mirror-shaped reflecting mirror 11 according to the present invention calculates a coordinate region (that is, a region covering a geosynchronous orbit) determined by geosynchronous orbits as viewed from various parts of Japan with respect to a geostationary satellite to be received on a parabolic surface having a certain curvature. In order to reduce the interference wave with respect to this gain constraint point, a gain constraint point is placed in a region covering the geostationary orbit and a region of a specific orbit position (for example, the orbit position of an adjacent satellite). A first gain limit value related to the position (for example, a value lower than 5 dB from the gain value related to the sidelobe characteristic defined by the reference pattern) and a second gain limit value related to the region determined by the geostationary orbit (for example, the reference pattern (A low value of 3 dB or more from the specified gain value) and the mirror surface shape of the parabolic surface is modified.

(Manufacturing method of mirror-surface modified reflector)
Then, with reference to FIG. 2, the manufacturing method of the reflecting mirror 11 by the mirror surface modification reflecting mirror which concerns on this invention is demonstrated. FIG. 2 is a diagram illustrating a method of manufacturing a mirror-shaped modified reflector according to an embodiment of the present invention. The design procedure of the mirror-finished reflecting mirror described below can perform shape calculation using a computer, and based on the mirror-like shape pattern of the designed mirror-finished reflecting mirror, a mirror-shaped reflector using a mold It is also possible to form a mirror-surface modified reflector by modifying the shape such as cutting out from an actual reflector having a parabolic surface of the modification standard.

  First, the power feeding unit 12 and the reflecting mirror 11 are set to predetermined arrangement positions (for example, the values shown in FIG. 1) (step S1). Although there is no restriction | limiting in the aperture diameter of a reflective mirror, For example, the mirror surface modification reflective mirror is designed about the reflective mirror 11 about the antenna structure shown in FIG. At this time, the mirror surface shape of the reflecting mirror 11 is a parabolic surface having a certain curvature, and the mirror surface shape is modified by the following procedure to form a mirror surface modified reflecting mirror having a smooth surface.

  Next, a reception area (for example, each area of the Japanese archipelago) consisting of a plurality of reception areas is set (step S2).

  Next, the geostationary satellite to be received is determined (step S3). By determining the geostationary satellite to be received, its geostationary orbit is also determined. FIG. 3 shows the geostationary orbit as seen from the receiving point on the ground and the definition of coordinates. For example, current geostationary satellites are defined as orbital positions of 110 degrees east longitude, 124 degrees east longitude, 128 degrees east longitude, 144 degrees east longitude, etc., depending on the satellite type.

  Next, the geostationary orbit seen from each area in the reception area is calculated (step S4). There are no restrictions on the orbits of the geostationary satellites to be received. For example, if the receiving antenna devices 10 in various parts of Japan are pointed at the geostationary satellites located 110 degrees above the equator, the geostationary orbit seen from the receiving antenna apparatuses 10 in various parts of Japan It becomes like 4. As shown in FIG. 4, it can be seen that the apparent geostationary orbit varies depending on the position of the reception point. It should be noted that although the geostationary satellite orbital positions vary depending on the satellite type, there are apparent geostationary orbits that are determined by the geostationary satellites. Note that the direction of adjacent geostationary satellites (hereinafter also referred to as “neighboring satellites”) varies depending on the position of the reception point (for example, a broadcasting satellite has a direction of ± 6 degrees in geostationary orbit).

  Next, within the range determined by the geostationary orbit seen from each region, that is, the coordinate region (ie, the geostationary orbit) determined by the geostationary orbit seen from all over Japan with respect to the geostationary satellite to be received on the parabolic surface having a certain curvature. And a gain constraint point is arranged in the region covering the stationary orbit and the region of the specific trajectory position (steps S5 and S6). That is, the design of the mirror-surface modified reflector requires a constraint point (gain constraint point) for setting a target value of gain. Therefore, gain restraint points are arranged in the region covering the geostationary orbit shown in FIG. By doing this, it is possible to design a mirror-reflecting reflector antenna that is the same at any receiving point in various parts of Japan and that reduces interference waves from adjacent satellites.

  As an example of arranging the gain constraint point in the region of the specific orbit position, for example, as shown in FIG. 5, the gain constraint point is arranged at coordinates corresponding to the orbit position of another geostationary satellite (step S5). As an example, the gain constraint point is arranged so as to cover the orbital position of an adjacent satellite (for example, the direction corresponding to the orbital position of 110 degrees ± 6 degrees east longitude) in the geostationary orbit. This gain constraint point is for reducing the sidelobe level in the direction of adjacent satellites.

  Further, as an example of arranging the gain constraint point in the region covering the geostationary orbit, as shown in FIG. 6, for example, the gain constraint point is arranged within a range determined by the geostationary orbit as viewed from each region (step S6). In other words, the gain constraint point is arranged so as to cover the stationary satellites other than the adjacent satellites. This is for setting the side lobe level other than the direction of the adjacent satellite to a specified value or less. Note that the order of steps S5 and S6 may be reversed.

  Here, since the vicinity of the origin (X = 0, Y = 0) (for example, a coordinate range of ± 0.05 from the origin) is the main beam region, only the restraint point for determining the peak gain should be arranged at the origin. Is preferred.

  Next, with respect to the gain constraint point arranged in the region of the specific orbit position shown in FIG. 5, that is, with respect to the gain constraint point corresponding to the adjacent satellite (for example, the direction corresponding to the orbit position of 110 degrees ± 6 degrees east longitude), A gain limit is set for a gain constraint point set in a region covering the geostationary orbit shown in FIG. 6 by setting a value lower than 5 dB (for example, a value lower by 10 dB) from the gain value related to the sidelobe characteristic defined by the reference pattern of 1900. A value (for example, a value 3 dB lower than the gain value related to the side lobe characteristic defined by the reference pattern of BO.1900) is set, and the peak gain value related to the main lobe corresponding to the origin coordinate (60% to 80% as the aperture efficiency) For example, 38.95 dBi) corresponding to an opening efficiency of 75% is set (step S7). For example, if the reception frequency is 21 GHz band (21.4 GHz to 22.0 GHz), the reference pattern of the satellite broadcast receiving antenna is defined by the BO.1900 reference pattern as an ITU-R recommendation.

  Next, the mirror surface shape of the reflecting mirror 11 is modified so as to satisfy the gain limit value at the set gain constraint point and the peak gain value related to the main lobe, and the mirror surface pattern of the mirror surface modifying reflector is determined (step S8). For example, to achieve the set target gain value, the mirror shape is modified from the parabolic surface using an optimization technique such as MinMax method, genetic algorithm (GA), or steepest descent method to form a smooth surface. To do. Therefore, the mirror surface pattern can be automatically calculated using a computer.

  Based on the specular pattern designed by the above procedure, the specular modified reflector 11 is formed.

Example 1
For example, when the mirror-shaped modified reflector 11 that receives a stationary satellite located 110 degrees above the east longitude on the equator is specifically designed to reduce interference waves from adjacent satellites (orbit positions at 110 degrees ± 6 degrees east longitude) The mirror surface shape (the amount of modification from the parabolic surface) is as shown in FIG. 8 shows the difference between the antenna gain characteristic (radiation pattern) of the receiving antenna apparatus 10 according to the present invention and the BO.1900 (the gain [dBi] of the receiving antenna apparatus 10 according to the present invention−BO.1900 defined value [ dBi]). In FIG. 8, when the antenna gain characteristic (radiation pattern) of the receiving antenna apparatus 10 according to the present invention is compared with BO.1900, the antenna gain characteristic of the receiving antenna apparatus 10 according to the present invention ( The radiation pattern) is 10 dB lower than the specified value of BO.1900 in the area corresponding to the adjacent satellite, and 3 dB lower than BO.1900 in the other geostationary orbit areas. .

  Furthermore, with respect to the antenna gain of the receiving antenna device 10 according to the present invention on a plane AA ′ (hereinafter referred to as a 30-degree plane) rotated 30 degrees from the X axis in FIG. FIG. 9 shows a comparison with the specified value of BO.1900. The peak gain is 38.96 dBi (opening efficiency is 75%). The gain margin from the reference pattern of the third side rope corresponding to the direction of the adjacent satellite is only about 3.5 dB to 4 dB in the receiving antenna of the offset reflector, but 10 dB or more in the receiving antenna device 10 according to the present invention. I understand that

  That is, the receiving antenna device 10 of the present embodiment has equal gain performance within a predetermined error (that is, within a measurement error range) as an antenna gain at the time of reception by the power feeding unit 12 in any region of the Japanese archipelago. It becomes like this.

  Unlike the present invention, in view of adopting a mirror-reflecting mirror for the receiving antenna, the aperture efficiency is maintained at 60% to 80% and the deterioration of the side lobe characteristics is further reduced so as to reduce the deterioration of the side lobe characteristics. From the prior art, it is assumed that mirror correction is attempted from a parabolic surface having a certain curvature by arranging gain constraint points in all regions. As Reference Example 1, FIG. 13 shows antenna gain when gain constraint points are arranged in all regions other than the main lobe and mirror surface modification is attempted. As shown in FIG. 13, when the mirror surface modification is attempted by arranging the gain constraint points in all the regions other than the main lobe, the side lobe characteristics of ± 3 degrees and ± 5 degrees are slightly different from those of the offset reflector. However, it can be seen that only approximately the same characteristics are obtained, and the margin from BO.1900 becomes a limit value with a value less than 5 dB.

  In addition, for example, since a broadcasting satellite is in an orbital position with an interval of 6 degrees, as a receiving antenna device for a stationary satellite to be received, in order to equally reduce interference waves from other stationary satellites, a certain curvature is used. Calculate the coordinate region (ie, the region covering the geostationary orbit) that is determined by the geostationary orbit seen from various parts of Japan for the geostationary satellite to be received on the parabolic surface, and place the gain constraint point. FIG. 14 shows a reference example 2 in which a desired gain limit value for reducing the interference wave is given to modify the mirror surface shape of the parabolic surface. As shown in FIG. 14, although an effective margin is ensured for the side lobe characteristics, the side lobe level in the direction other than the stationary orbital surface is greatly increased, so that the aperture efficiency is reduced to about 65%.

  Therefore, according to the receiving antenna device 10 of the present embodiment, it is possible to efficiently reduce interference waves from geostationary satellites and improve the reception quality of target satellite broadcast waves. In addition, it is possible to configure the receiving antenna device 10 having the mirror-shaped modified reflecting mirror 11 that equally reduces interference waves at any receiving point in various parts of Japan.

  In addition, in the receiving antenna apparatus 10 of Example 1 shown in FIGS. 7-9, about the mirror-shaped reflex reflector 11 which receives the geostationary satellite located in the equator 110 degrees east longitude as an object of reception (110 degrees ± 6 degrees east longitude) In this example, the interference wave is particularly reduced, but the specific orbital position is not limited to the orbital position of the adjacent satellite, and +3 degrees to the orbital position of the stationary satellite to be received. The effect according to the present invention can be obtained by providing a gain constraint point for one or more orbital positions related to other geostationary satellites in the range of +30 degrees and -3 degrees to -30 degrees.

  Here, it has been confirmed that it is difficult to achieve the orbital position of ± 2 degrees with respect to the orbital position of the receiving target geostationary satellite, because it falls within the main lobe range. At orbital positions that are more than 30 degrees apart, the gain is so small that the influence of the interference wave can be ignored, as can be seen from the prescribed value of BO.1900. Hereinafter, with respect to the receiving antenna device 10 of each embodiment when gain constraint points are provided at orbital positions of ± 5 degrees, ± 4 degrees, and ± 3 degrees with respect to the orbit position of the geostationary satellite to be received, FIG. 12 shows.

(Example 2)
The receiving antenna device 10 according to the second embodiment is configured to receive interference waves from adjacent satellites (orbital positions of 110 degrees ± 5 degrees east) with respect to the mirror-shaped modified reflector 11 that receives a geostationary satellite located 110 degrees above the equator east. It is an example formed so as to reduce. With respect to the receiving antenna device 10 of the second embodiment, as in the first embodiment, the receiving antenna of the conventional offset reflector and the BO.1900 on the plane AA ′ (30-degree plane) rotated 30 degrees from the X axis. FIG. 10 shows a comparison with the specified value. It can be seen that the antenna performance (side lobe characteristics in the direction of adjacent satellites) is also improved in the receiving antenna device 10 of the second embodiment as compared with the receiving antenna of the offset reflector.

(Example 3)
The receiving antenna device 10 according to the third embodiment particularly receives interference waves from adjacent satellites (orbit positions of 110 degrees ± 4 degrees east longitude) with respect to the mirror-shaped modified reflector 11 that receives a stationary satellite located 110 degrees above the equator east. It is an example formed so as to reduce. In the receiving antenna apparatus 10 of the third embodiment, as in the first embodiment, the receiving antenna of the conventional offset reflector and the BO.1900 are rotated on a plane AA ′ (30-degree plane) rotated 30 degrees from the X axis. FIG. 11 shows a comparison with the specified value. It can be seen that also in the receiving antenna apparatus 10 of the third embodiment, the antenna performance (side lobe characteristics in the direction of adjacent satellites) is improved as compared with the receiving antenna of the offset reflector.

Example 4
The receiving antenna device 10 according to the fourth embodiment particularly receives interference waves of adjacent satellites (orbit positions of 110 degrees ± 3 degrees east longitude) with respect to the mirror-shaped modified reflector 11 that receives a stationary satellite located 110 degrees above the equator east longitude. It is an example formed so as to reduce. In the receiving antenna device 10 of the fourth embodiment, as in the first embodiment, the receiving antenna of the conventional offset reflector and the BO.1900 are formed on a plane AA ′ (30-degree plane) rotated 30 degrees from the X axis. FIG. 12 shows a comparison with the specified value. It can be seen that also in the receiving antenna device 10 of the fourth embodiment, the antenna performance (side lobe characteristics in the adjacent satellite direction) is improved as compared with the receiving antenna of the offset reflector.

  Similarly, one or more orbit positions relating to other geostationary satellites within the range of +3 degrees to +30 degrees and -3 degrees to -30 degrees with respect to the orbit position of the target stationary satellite as a specific orbit position. By providing a gain constraint point for the antenna, the antenna performance can be improved as compared with the receiving antenna of the offset reflector. It should be noted that in providing a gain constraint point for a plurality of orbital positions with respect to the orbital position of a geostationary satellite to be received, gain margins in other regions decrease as the number of orbital positions is targeted. The one or more orbit positions related to other geostationary satellites that provide gain constraint points are preferably one or more and six or less.

  Although only specific embodiments have been described above, the present invention is not limited to this. For example, the reception frequency and geostationary satellite need not be limited to those described above. Further, there is no need to provide a restriction on the opening diameter of the receiving antenna device 10. Furthermore, it goes without saying that the polarization of the reception target may be either linear polarization or circular polarization.

  According to the present invention, interference waves from a geostationary satellite can be reduced, and the reception quality of a target satellite communication or satellite broadcast radio wave can be improved, which is useful for a satellite communication or satellite broadcast receiving antenna device. For example, if the receiving antenna device according to the present invention is adopted in a 21 GHz band (21.4 GHz to 22.0 GHz) satellite broadcasting system that is promising for future super high-definition broadcasting, interference waves from other satellites are reduced and reception quality is improved. In addition, the interruption time due to rainfall can be reduced.

DESCRIPTION OF SYMBOLS 10 Receiving antenna apparatus 11 Mirror surface reflection reflector 12 Feeding part

Claims (6)

A receiving antenna device for receiving radiated power of satellite communication or satellite broadcast radiated from a geostationary satellite to be received,
Calculates the coordinate area determined by the geostationary orbit seen from multiple reception areas for the satellite to be received on the parabolic surface having a certain curvature, and restricts the gain to the area covering the geostationary orbit and the area of the specific orbital position. A mirror-shaped modified mirror in which a point is arranged and a mirror shape of the parabolic surface is modified by giving a first gain limit value related to the specific orbital position and a second gain limit value related to the region determined by the stationary orbit When,
A power feeding unit that receives a received radio wave of the radiated power reflected by the mirror-surface modified reflector;
A receiving antenna device comprising:   The plurality of reception areas are areas of the Japanese archipelago, and the antenna gain at the time of reception by the power feeding unit has equal gain performance within a predetermined error in any of the areas of the Japanese archipelago. The receiving antenna device according to claim 1.   The specific orbital position covers one or more orbital positions related to other geostationary satellites within the range of +3 to +30 degrees and -3 to -30 degrees with respect to the orbital position of the target stationary satellite. The receiving antenna device according to claim 1, wherein the receiving antenna device is a receiving antenna device.   The first gain limit value is set to a value lower than 5 dB from a gain value related to a sidelobe characteristic of a reference pattern defined by an ITU-R recommendation. The receiving antenna device according to the item.   The second gain limit value is a value lower than 3 dB from a gain value related to a sidelobe characteristic of a reference pattern defined by an ITU-R recommendation. The receiving antenna device according to the item. A method of manufacturing a mirror-shaped modified reflector in a receiving antenna device that receives radiated power of satellite communication or satellite broadcasting radiated from a geostationary satellite to be received,
A step of setting a feeding portion and a parabolic reflector having a certain curvature at a predetermined arrangement position;
Setting multiple coverage areas;
Determining a geostationary satellite to be received;
Calculating a geosynchronous trajectory viewed from the plurality of regions;
Calculating a coordinate region determined by a stationary trajectory viewed from the plurality of regions and arranging a gain constraint point in a region covering the stationary trajectory and a region of a specific trajectory position;
Setting a first gain limit value for the particular trajectory position, a second gain limit value for a region defined by the geosynchronous trajectory, and a peak gain value for the main lobe;
The specular shape pattern of the specular modified reflector is determined by modifying the specular shape of the reflecting mirror so as to satisfy the first gain limiting value, the second gain limiting value and the peak gain value related to the main lobe at the set gain constraint point. And steps to
Based on the specular shape pattern, forming the specular reflection mirror,
A method of manufacturing a mirror-shaped modified reflector, comprising: