Carrier recovery circuit.

摘要

A carrier-wave regeneration circuit for use in a demodulator for a 2<n>-phase PSK modulated signal comprises a phase-locked loop including a voltage-controlled oscillator 7 and an automatic frequency control (AFC) loop for avoiding the pseudo-lock-in phenomenon. The AFC loop is comprised of two differentiating circuits (21, 25) two mixer circuits (22, 26), and a difference circuit (27) and forms a symmetrical structure so as to exclude undesired noise thereby carrying out a stable AFC operation.