| 摘要 |
PROBLEM TO BE SOLVED: To extend the upper limit frequency of input FM signal while reducing power consumption and cost. SOLUTION: A voltage amplitude detector 1 detects the voltage amplitude of an input FM signal. An attenuator 2 lowers the amplitude of the FM signal in proportion to the frequency, and a voltage amplitude detector 3 outputting an FM signal having a lowered amplitude detects the voltage amplitude of an FM signal attenuated by the attenuator 2. An amplitude variation detctor 4 determines the ratio between the amplitude value detected by the voltage amplitude detector 1 and the amplitude value detected by the voltage amplitude detector 3, and generates an output signal varying on the time axis depending on the variation in ratio thus determined as an FM demodulation signal. COPYRIGHT: (C)2006,JPO&NCIPI
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