| 摘要 |
PURPOSE:To obtain a stable-operation circuit where a time required for synchronization establishment of a phase synchronous circuit, which is utilized for a receiving unit, etc., of the phase modulation system, is short and phase jitter is small after synchronization establishment. CONSTITUTION:Signal Sc of a frequency N-number times as high as the frequency of input signal Si is oscillated by clock oscillator 3 and is counted by counter 201 in digital control pulse generation circuit 2, and at a certain number time, pulse S2 is inputted to phase comparator 1 to compare pulse S2 and input signal Si in phase, and phase difference signal S3 and polarity signal S4 are generated. Synchronization state discriminator 5 discriminates the synchronization state between signals Si and S2 in response to phase difference signal S3 and supplies the result to correcting signal generator 4 as syncrhonization state signal Ss, and generator 4 supplies correction quantity PR for phase correction of signal S2 to counter 201 in pulse generator 2 on a basis of synchronization state signal Ss and signals S3 and S4 and corrects the phase of signal S2 and performs the control to achieve phase synchronization. |
