A Systematic State–Space Approach to Large-Signal Transistor Modeling

A state-space approach to large-signal (LS) modeling of high-speed transistors is presented and used as a general framework for various model descriptions of the dispersive features frequently observed for HEMTs at low frequency. Ensuring unrestricted LS-small-signal (SS) model compatibility, the approach allows to construct LS models from multibias SS S-parameter measurements. A general transformation between state-space models is derived, which are equivalent in the SS limit, but nonequivalent under LS stimuli. This transformation has the potential to compensate deviations observed by comparing model predictions with LS measurements and to find an optimum state linear LS model without any change of the SS behavior