| 摘要 |
<p>A quadrature modulation circuit (300) of the present invention has a phase shifter (302) whose shifting amount is fixed at 90 degrees, a minute amount-phase shifter (303) whose shifting amount is variable, a detector (307) for detecting a RF signal supplied from the quadrature modulation circuit (300) by a direct voltage signal, and a control circuit (308) for generating a control signal in accordance with a direct voltage signal from the detector (307). The phase shifting amount of the minute amount-phase shifter (303) is adjusted by the control signal whereby a total amount of the phase shifting is maintained at 90 degrees. <IMAGE></p> |
