A Mixed-Domain Modeling Method for Microwave Nonlinear Systems and Semiconductor Devices in High-Frequency Applications

A mixed-domain nonlinear modeling approach based upon a cubic Volterra kernel representation is presented in this paper, arising from an on-going investigation and validation of Volterra models for nonlinear circuits and systems operating at high frequencies. The proposed models overcome the main problem in Volterra representation of nonlinear ordinary differential equations by adopting Digital Filter Theory and Least Square Based Higher-Order Spectra Techniques. The validity of the proposed modeling approach has been established by deriving Volterra models of test nonlinear circuits and good agreement has been obtained between SPICE simulations and results calculated using the proposed technique.