Noise suppression cct. for radio LF signals - has dynamic limiter and regulator with feedback to op. amp. at limiter input

摘要

The noise suppression circuit, for LF signals in radio receivers, has a dynamic limiter in the path of the signal which limits the amplitude of signal components with sudden spikes. The limited signal is coupled back to the non-inverting input of an operational amplifier at the limiter's input. A regulating stage is connected after the limiter and reduces signals that fall within its regulating range by amounts proportional to the amplitude of the operational amplifier's output, i.e. the lower the output, the greater the reduction. Several limiters with different time constants may be connected together in a chain.