Volterra kernels extraction from frequency-domain data for weakly non-linear circuit time-domain simulation

Volterra series have been popular in non-linear system analysis and modeling for a long time. Volterra representation adapts the convolution concept from linear time-invariant (LTI) systems, generalizes it to “super convolutions” and, hence, are able to characterize the dynamical behavior of non-linear circuits using familiar LTI techniques. It is extensively used in white-box verification problems where small order distortion terms occur such as transistor circuits. This paper presents an experiment with finite order non-linear circuits and uses frequency-domain data obtained from Harmonic Balance (HB) simulation to extract Volterra kernels.