Nippon Steel Corporation

System Uniques Corporation

Nippon Hoso' Kyokai

Nemoto Project Industry Co., Ltd.

Kazuro Kato

Masahiro Uematsu

Ryuichi Hiratsuka

Yasuhiro Ito

Shigeru Yamazaki

Kenji Ohmaru

Isao Nemoto

Tetsumi Harakawa

Attitude control is implemented by detecting the phase difference between signals received by at least two antennas and detecting the angle of deflection between the direction of arrival of radio signals and the antenna beams. By using antennas that are separately driven, within the plane of rotation in which the deflection angle is to be detected, the phase of the received signals can be shifted equivalently to when the antennas are driven as a consolidated unit. Also, when at least three antennas are used in an orthogonal arrangement for detecting the deflection angle in two directions, the antennas are divided into two groups which are individually driven. This reduces the inertia of the moving parts and enables the size and weight of the drive mechanisms to be reduced. In addition, two orthogonal functions are used to represent the phase of the deflection angle of the direction of arrival of the radio wave and the antenna beam as a multiplicity of quadrants, and by storing these, when there is a change in the deflection angle, the sequence of change can be traced back and the control effected accordingly. This enables error to be eliminated.

Antenna apparatus and attitude control method

A satellite tracking antenna system comprises three or four plane antennas juxtaposed on a single plane. A first and a second antenna are juxtaposed in an azimuth direction, and a phase difference between signals received by these antennas is detected in order to determine a declination of an antenna unit with respect to the satellite as viewed in the azimuth direction. The first and a third antenna are juxtaposed in an elevation direction, and a phase difference between signals received by these antennas is detected to determine a declination of the antenna unit with respect to the satellite as viewed in the elevation direction. The antenna unit is driven so as to reduce these declinations to zero. Stated differently, values of a sine and a cosine function are extracted which have a phase difference between signals received by a pair of antennas as a parameter, and a tangent value representing the ratio therebetween is calculated and is then inversely converted to provide phase difference information.

Antenna system

Growing community of inventors

Yokohama, Japan

Kazuro Kato