Consistent small-signal and large-signal extraction techniques for heterojunction FET's

A new method is reported to extract large-signal current and charge sources from the small-signal S-parameters of pseudomorphic heterojunction field effect transistors (PHFET's). This method produces a new intrinsic small-signal equivalent circuit topology with less constraints concerning the extraction of the large-signal current and charge sources. The main advantage of this new topology is charge conservation. The S-parameter measurements of a 0.2-/spl mu/m PHFET agrees well with the small-signal S-parameter data, obtained after evaluation of the new large-signal model at different bias points.>