Baseband demodulator for FM and/or AM signals

摘要: A demodulator of the type employed in a "zero-IF" system uses local oscillator for providing quadrature output signals at center frequency received signal to be demodulated. The has first and second mixers separately mixing with provide each outputs said mixers. These are low pass filtered. includes third fourth mixer respectively receiving an input one signals. At another receive derived from variable controlled (VCO) is independent signal. applied inputs difference amplifier, which controls VCO automatic control mode (AFC) cause amplifier demodulation FM Additional provided mix signals, appearing such additional being summed demonstration AM independently demodulation.