| 摘要 |
PURPOSE:To make the relation in phase of a side band and a carrier constant for the full time, by executing the phase feedback of a real time without using a filter and a limiter. CONSTITUTION:A switching circuit 11 is provided between a phase detector 7 and a phase shifter 3, and a detecting signal is led to an inversional amplifier 12 in a period in which a loop becomes positive feedback, so that it is prevented that the loop characteristic becomes positive feedback. In this case, a switching circuit 11 is switched by the timing by which an input signal of a modulator 4 zero crosses, and is made to have an effect of a usual feedback loop when the input signal of the modulator 4 is positive, and an effect for inserting an invertor 12 into the loop when said signal is negative. |
