| 摘要 |
PURPOSE:To stabilize demodulating operation by forming a carrier signal without using a phase control loop and a multilication circuit to simplify the constitution and reduce the adjusting position. CONSTITUTION:Reference signals G, K phase-locked to a carrier wave of a modulation signal are formed in the timing shifted by each prescribed time from each phase change point of an inputted DPSK modulation signal; and a phase comparator circuit 7 compares the phase between the signals G, K and the modulation signal. Further, the output of the circuit 7 is sampled by a data clock C generated in synchronizing with a phase changing point detecting output at the center of each data section to reproduce sequentially the data. Thus, a phase control loop and a multiplication circuit are not required, thereby simplifying the constitution, and since each section consists of a digital logical circuit, the adjusting positions are decreased and a stable demodulating operation is realized. |
