FREQUENCY MODULATED DETECTION CIRCUIT

摘要

a frequency phase converting circuit for frequency and phase-converting a frequency converting signal as an input signal; a phase detecting unit for outputting a detected waveform by a phase difference between an output signal of the frequency phase converting circuit and the frequency converting signal; and a low-pass filter for integrating the output waveform of the phase detecting unit to output the integrated result as a voice signal, wherein the frequency phase converting circuit includes a first low-pass filter for shifting a frequency modulating signal by a 90deg., a first amplifier for inputting the shifted signal of the first low-pass filter to amplify the input signal; and a band-pass filter connected to the first amplifier.