| 摘要 |
PURPOSE:To separate a stereo signal well surely and stably, by extracting pilot signal components from two demodulation signals to correct the phase error of a reproducing carrier wave corresponding to the carrier wave to be modulated in the AM stereo receiver. CONSTITUTION:When pilot components in outputs of multipliers 6 and 7 for a phase error phi are denoted as P1 and P2, P1=-(1/2)Psinphi and P2-(1/2)Pcosphi are true, and these pilot components are extracted by BPFs 10 and 11. These signals P1 and P2 are multiplied in a multiplier 12, and DC components A(phi) having the phase error discrimination characteristics are extracted by an LPF13. This signal A(phi) controls a local oscillator 3. Thus, a carrier wave generator 5 utilizes the fact that the phase difference between an input signal and an output signal is changed by the input signal frequency to correc the phase error. |
