METHOD AND DEVICE FOR AUTOMATIC GAIN CONTROL AND DC COMPONENT BIAS ELIMINATION IN QUADRATURE-DEMODULATION RECEIVER

摘要

FIELD: radio receivers. ^ SUBSTANCE: proposed AGC device has variable-gain amplifier. Quadrature-demodulation step-down converted functions to convert output signal frequency into modulating frequency. Two active high-gain low-pass filters provide for suppressing beyond-the-band signal in modulating-signal frequency band. Circuit designed for suppressing dc component functions to suppress dc components generated by step-down converter and low-pass filter. AGC device also generates received signal power basing on output signal power. Saturating integrator compares power of signal received with that of reference signal and generates gain control signal by integrating power of signal received and gain control signal or declining integration considering reference signal values. ^ EFFECT: provision for eliminating dc component bias. ^ 11 cl, 13 dwg