| 摘要 |
PURPOSE:To make it possible to put a cross polarization compensating circuit, arranged in a feeding system for an antenna, in the best state by controlling a phase difference board with a fixed angle by detecting an error signal by decomposing an arrival radio wave. CONSTITUTION:This unit is equipped with compensating circuit 11 composed of phase difference board 2 of 90 deg. and phase difference board 3 of 180 deg. against a signal from antenna 1, polarizer 6 for cross polarization components, and high- frequency couplers 9 and 10, receiver 14 which receives an output from coupler 9 as a reference signal and that from coupler 10 as an error signal and outputs a voltage in proportion to a set-angle error of phase difference board 3 and another voltage in proportion to that of phase difference board 2, and servomechanism 39 which drives boards 2 and 3 in accordance with an output from the receiver. Then, the receiver performs detection operations 27 and 28 by decomposing the error signal into components in phase with and 90 deg. out of phase with the reference signal; both components are obtained as voltages in proportion to set-angle errors of phase difference boards 3 and 2 and control is so dene that both voltages will be minimized. |
