Interference detection circuit with discrimination by means of amplitudes of frequency domain definition

摘要

An interference detection circuit is described comprising means, in particular non linear means, for defining a discrimination curve in terms of instantaneous magnitude and instantaneous frequency, and means, in particular differential amplification means, for detecting whether a combination, in particular the product, of said instantaneous magnitude and said instantaneous frequency of the inputted signal exceeds the discrimination curve in which case control means control the gating of the inputted signal. The discrimination defining means have a control input for adaptation of the discrimination curve to the average instantaneous magnitude, in particular the product of the instantaneous magnitude and the instantaneous frequency of the input signal. Thus small as well as larger input signal amplitudes whereon interference is superimposed can be discriminated adequately and reliably in order to minimize audible effects of leaving out interfered part of the input signal.