| 摘要 |
PURPOSE:To accurately compensate the degradation of the cross polarized wave of an up link by electrically detecting the cross polarized wave compensation amount of a down link. CONSTITUTION:As for the beacon signal S 7 of a down link, the degradation of a cross polarized wave is compensated by a servo circuit composed of a linearly polarized wave converter 7, a circularly polarized wave converter 8, a cross polarized wave degradation detector 16, a calculation circuit 15 and a driving circuit 14. At this time, when the calibration signal S 13a from an oscillator 13 is supplied to the input terminal of the linearly polarized wave converter 7 by circularly polarized waves via a signal coupler 6, a cross polarized wave degradation detector 17 for calibration signal detects the data S 20 of the degradation of the cross polarized wave of a down link. A calculation circuit 18 calculates compensation amount S 21 of the degradation of the cross polarized wave of an up link based on this data S 20. A driving circuit 19 rotates and drives the linearly polarized wave converter 3 and circularly by polarized wave converter 4 for the compensation of the degradation of the cross polarized wave of the up link by the rotation angle corresponding to this compensation amount S 21. |
