| 摘要 |
PURPOSE:To eliminate the noise that is caused to a phase modulated signal when the degree of amplitude modulation becomes large for an AM stereo receiver that receives the modulated signal of amplitude phase, by sampling and holding the immediately preceding phase modulated signal in case the level of the amplitude demodulated signal is less than the reference level. CONSTITUTION:In case the level of an amplitude demodulated signal is low and the noise is caused at the valley part of an envelope curve, a sample holding command signal is produced from a voltage comparator 5 and applied to a sample holding circuit 4. The circuit 4 samples and holds the immediately preceding phase demodulated signal containing no noise based on the sample holding command signal and holds this state for the period during which the level is less than the reference value at the valley part of the envelope curve. |
