More on nonlinear distortion correction

Further consideration is given to basic amplitude limitations which may apply to the complementary distortion method of nonlinear distortion correction. It is found, in disagreement with others, that points at which the differential gain is zero or infinite do not limit the amplitude over which complete correction is possible but that relative maxima, minima, gain zeros, and infinite-gain points in the characteristic do set limitations when the usual simply connected tandem configuration is employed. When the characteristic to be corrected is multiple valued or passes through points of zero or infinite gain within a given amplitude range, a multiply connected correction circuit must be used for perfect correction of distortion over the amplitude range in question.