Nonlinearity Index in Harmonic Analysis

Abstract

A nonlinear index in harmonic analysis is proposed. The index is defined as the ratio of the amplitude of the output fundamental harmonics to that of all harmonics when a sinusoidal input is fed to a nonlinear element. It could serve as a back-up tool to guess the precision of describing function approach. As an illustrative example, correspondence is examined between accuracy and the index in the analysis of relay feedback systems by describing function method.