Non-linear circuit used as compander - has two signal paths each with variable attenuator and limiter

摘要

The non-linear circuit is used as an expander and compressor. It converts an input signal of given frequency and variable amplitude into an output signal of the same frequency but of an amplitude that is a nonlinear function of the input amplitude. The input signal passes via two paths connecting two 3dB couplers. The first path contains a variable attenuator, a limiter and a second variable attenuator. The second path contains a variable attenuator, a limiter and a delay line. The advantage lies in having transfer characteristics that cannot be obtained with prior art nonlinear diodes and in having both its paths variable independently.