Evaluation and Comparison of Small Signal AC Parameters of submicron GaAs FET from its Measured DC Characteristics with Lowest RMS Error

Abstract

In this paper we discuss the comparison and evaluation of small signal AC parameters of GaAs Field Effect Transistor (FET) from its measured DC characteristics. For this purpose five different FET models i.e., Curtice, Materka, Statz, Ahmed and Noor, have been presented and their ability to simulate submicron GaAs FET‟s characteristics is checked by MATLAB.A technique is applied to estimate intrinsic small signal parameters of GaAs FET. In this technique DC characteristics of a device are first evaluated. The observed characteristics are then simulated by using two GaAs FET DC models which simulate the submicron GaAs FET‟s I-V Characteristics. Those models are Noor and Ahmed model. During AC parameters extraction process, once a good DC match is attained then by employing simulated I-V characteristics, intrinsic small signal parameters are evaluated for which a complete set of mathematical expressions has been discussed.