| 摘要 |
PROBLEM TO BE SOLVED: To realize quick synchronism pulling-in by suppressing a difference between the frequency bands of reproducing carriers outputted from a voltage controlled oscillator when there is a modulation signal and when there is no modulation signal to a small level. SOLUTION: A level discrimination circuit 11 is allowed to discriminate whether the input level of a PSK modulation wave or a multi-valued QAM modulation wave is equal to or below a set level or not. When the circuit 11 discriminates that the input level is equal to or below the set level, a switch switches a phase controlled voltage output from an APC detection circuit 7 to a voltage signal generated from a fixed voltage signal generation circuit 8 to input the voltage signal to the voltage controlled oscillator 5. |
