Multiple bandwidth FM demodulator

摘要: A multiple bandwidth quadrature type FM demodulator employs a double-balanced mixer supplied with frequency modulated IF signal directly and through one of selectable plurality bandpass circuits each having different bandwidth, linear phase shift versus characteristic producing 90 DEG at the whereby to produce output level that varies as function input signal, including bias control circuit for establish normalized all filters full modulation further establishing balanced respect ground or other reference potential regardless filter employed.