| 摘要 |
PROBLEM TO BE SOLVED: To provide a carrier wave reproducing circuit with which a carrier wave can be satisfactorily reproduced even on the condition of the adverse reception state of a modulated wave and pull-in time can be shortened. SOLUTION: Concerning this reproducing circuit, a first complex multiplier 8 generates a first frequency converted signal by multiplying a first local oscillating signal into an input modulated wave and a second complex multiplier 11 generates a second frequency converted signal by multiplying a second local oscillating signal. In an automatic frequency control(AFC) loop, the frequency of the first local oscillating signal is controlled and in a phase locked loop(PLL), the phase of the second local oscillating signal is controlled so as to synchronize the phase with the modulated wave. In this case, after the AFC loop is operated by a loop control circuit 27, the PLL is operated and when phase synchronism is not established, the PLL is operated again after an offset adding circuit 19 is operated for applying offset to the first local oscillating signal. |
