Determination of the small-signal parameters of an AlGaAs/GaAs MODFET

Abstract

The small-signal equivalent-circuit parameters of an AlGaAs/GaAs MODFET are derived by a first-order perturbation around the two-region DC model of a FET. For the first time the contribution of the AlGaAs electrons is included by using an accurate charge-control model. The charge-control model uses mixed quantum mechanical and classical approach to determine the density of channel electrons and AlGaAs neutral donors as a function of rate voltage. The model predictions show good agreement with experimental results for both low and high drain bias voltages.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>