Detailed distortion analysis technique based on simulated large-signal voltage and current spectra

Abstract

This paper presents an analysis technique implemented on top of normal harmonic-balance simulation, where the simulated nonlinear voltage and current spectra is used for fitting a polynomial device model around the large-signal bias point. Further, using the fitted model and spectra of the controlling voltages, the detailed structure of the third-order intermodulation distortion is calculated using a simplified form of Volterra analysis. This detailed information can be used to find the dominant causes of distortion and possible cancellation mechanisms, to study the bandwidth-dependent memory effects caused by up- or down-converted mixing results, or to find harmonic matching impedances that minimize the overall distortion.