JPH02113707A - Antenna system - Google Patents

Abstract

PURPOSE:To access plural satellites parted largely by forming a reflecting mirror comprising a parabolic plane of rotation with plural partial approximated spherical mirrors and providing primary radiators corresponding to each approximated spherical mirrors and the parabolic mirror of rotation respectively. CONSTITUTION:The system is provided with parts 1a, 1b of parabolic mirror of rotation able to be approximated by spherical mirrors, primary radiators 2a, 2b opposite to the reflecting mirrors 1a, 1b approximated as spherical faces, and a primary radiator 2 regarding the reflecting mirrors 1a, 1b as an offset parabolic antenna. A ray radiated from a point F is reflected in the parabolic face AB and is radiated toward the #1 satellite, and a ray radiated from a midpoint f1 is reflected in an approximated spherical face AC and directed toward the #2 satellite, and similarly the ray radiated from a midpoint f2 is directed to the #3 satellite. The apex angle of three beams reaches nearly 90 deg. and the direction of the angle is made coincident with the direction of the center of radius of curvature of the parabolic parts in use. Thus, the antenna can access plural satellites located remotely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an antenna device used for satellite communication.

[Conventional technology]

FIG. 3 is a diagram showing a conventional antenna device, in this case an offset parabolic antenna. In this figure, 1 is a part of a reflecting mirror forming a paraboloid of revolution, MF is its axis of rotation, and F is its focal point. Further, 2 is a primary radiator.

Next, the operation will be explained. - After being reflected by the reflector 1, the light beam from the secondary radiator 2 is AA', BB' parallel to the axis MF.
is radiated into space like this. Here, a portion of the reflecting mirror corresponding to AB operates as an antenna. This is Offse
This is a 7-parabolic operation.

When directing a plurality of satellites using such a reflector antenna, a method is used in which other horns for other satellites are placed near the focal point F, as shown in FIG. This is called a multi-beam antenna. When the primary radiators of other horns are 20, the light beam from the primary radiator 2C when the -order radiators 2 and 20 are lined up is reflected by the reflector 1 and then radiated in a direction θ away from the front direction. Ru. This indicates that it is possible to simultaneously access satellites at θ elongation.

That is, by using a single reflector, two different satellites can be accessed from two -order radiators. However, since the two primary radiators are placed adjacent to each other, the elongation angle θ is usually limited to 5 to 8 times the beam width even if a gain reduction of 2 dB is allowed. (Literature “Antenna Engineering Handbook; edited by Institute of Electronics and Communication Engineers, Chapter 4, Open-face antenna, 4.5.3 Multi-beam antenna technology”) [Problem to be solved by the invention] The conventional antenna device is configured as described above. Therefore, when aiming at multiple satellites, the limit of the beam elongation is as low as 5 to 8 times the beam width, and there is a problem in that satellites that are far apart cannot be accessed at the same time.

This invention was made to solve the above-mentioned problems, and allows simultaneous access to multiple satellites that are far apart. Specifically, the elongation angle between beams is 10
It is an object of the present invention to obtain an antenna device that can easily realize a value that is twice or more.

[Means for Solving the Problems] An antenna device according to the present invention partially approximates a paraboloid of revolution reflection mirror to a spherical mirror, and a primary radiator corresponding to the paraboloid of revolution mirror and each approximate spherical mirror. It has been established.

Further, a plurality of spherical mirrors are arranged to approximately constitute one paraboloid of revolution mirror, and a primary radiator is provided corresponding to each of the spherical mirrors and the approximate paraboloid of revolution mirror.

[Effect]

In this invention, by partially approximating one parabolic mirror of revolution to a spherical mirror, or by arranging a plurality of spherical mirrors to approximately constitute one parabolic mirror of revolution, beam separation can be achieved. The angle is larger, allowing access to multiple satellites that are far apart at the same time.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, la and lb are parts of parabolic mirrors of revolution that can be approximated to spherical mirrors, 2a and 2b are primary radiators facing the reflecting mirrors 1a and lb, which are regarded as spherical surfaces, respectively, and 2 is the primary radiator that faces the reflecting mirrors 1a and lb, respectively. A primary radiator with an off-cent parabola; 3 is the radiation direction of the light beam emitted from the primary radiator 2; 3a;
3b are the radiation directions of the light beams emitted from the primary radiators 2a and 2b, respectively, and the light beam 3 is directed to the #1 satellite, and the light wA3a.

3b will head towards satellite #2 and satellite #3, respectively.

0. is the radius of curvature (=r-) that best fits the parabola AC and is centered on the ellipse, and f, , f are OIM +
, Oz is the midpoint of Mz.

FIG. 2 shows the principle of operation of a spherical mirror antenna, in which the light rays emitted from F are reflected by the spherical mirror and then radiated into space as light rays parallel to the axis OM.

In FIG. 1, the rays emitted from F are reflected by paraboloid AB and then directed toward satellite #1. Further, the light beam emitted from fl is reflected by the approximate spherical surface AC and then heads toward the #2 satellite.

Similarly, the light beam emitted from f2 heads toward the #3 satellite. As is clear from this figure, the elongation angle of the three beams is approximately 90
The direction of the elongation angle corresponds to the direction of the center of curvature of the parabolic part used.

FIG. 5 is a three-dimensional illustration of the apparatus shown in FIG.

In this way, the -order radiator 2 irradiates the entire reflecting mirror, while
Parts 1a and 1b of the parabola are respectively connected to the primary radiator 2
The operation shown in FIG. 1 is established by the irradiation of a and 2b.

FIG. 6 is a diagram showing the radiation pattern of the device according to this embodiment, where 4 is the radiation pattern from the entire reflecting mirror 1, 4a,
4. b are radiation patterns from the reflecting mirrors 1a and lb as proximal spherical surfaces, respectively.

In addition, in the above embodiment, one part of the parabola (paraboloid of revolution) is approximately treated as a spherical mirror, and the primary radiator is placed at an intermediate position on the straight line connecting the center of the spherical mirror and the center of curvature of the sphere. Although it has been described that an antenna device capable of pointing to multiple satellites simultaneously can be provided by spraying the air onto the spherical mirror, the same effect can be obtained even when a parabola is approximately constructed from a small spherical mirror.

FIG. 7 shows an antenna device according to this embodiment, and by synthesizing a parabola from the divided mirror surfaces of spherical mirrors 5a to 5n, it is possible to provide an antenna that can point to (n+1) satellites simultaneously.

〔Effect of the invention〕

As described above, according to the present invention, one parabolic mirror surface is used, a part of the parabolic mirror surface is approximated to a spherical mirror, and a plurality of primary radiators are used, or a plurality of spherical mirrors are used and one parabolic mirror surface is approximated to a spherical mirror. Since the mirror surface is configured approximately and a plurality of primary radiators are used, it is possible to realize an antenna device that can simultaneously point to a large number of satellites that are far apart.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an antenna device according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the operation of a spherical mirror antenna, FIG. 3 is a diagram showing a conventional antenna device, and FIG. 4 is a multi-beam diagram. A diagram for explaining the operation of the antenna, FIG. 5 is a three-dimensional configuration diagram showing the antenna device of FIG. 1, FIG. 6 is a diagram showing the radiation pattern of the antenna device of FIG. 1, and FIG. 7 is a diagram of the present invention. It is a figure which shows the antenna apparatus by other Example. 1 is parabola; 1. a, lb are divided parabolas, 2
．． 2a, 2b are primary radiators; 3.3a, 3b are rays toward the satellite; 4, 4. a, 4b are radiation patterns, 5a, 5
b, -, 5n is a spherical mirror. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) In an antenna device for simultaneous multi-satellite pointing, a reflecting mirror consisting of one paraboloid of revolution is made up of a plurality of partial approximate spherical mirrors, each corresponding to the paraboloid of revolution and each approximate spherical mirror. An antenna device characterized by comprising a primary radiator. (2) In an antenna device that can simultaneously point to multiple satellites, a plurality of spherical mirrors are arranged to approximately constitute one parabolic mirror of revolution, and each spherical mirror and the approximate parabolic mirror of revolution correspond to each other. An antenna device characterized by comprising a primary radiator.