Determination of GaAs MESFET parasitic resistances based on experimental measurements and nonlinear static modelling

A reliable technique for the determination of the parasitic resistances of a GaAs MESFET from DC measurements has many attractions for device modelling. Prior knowledge of these resistances provides a reliable foundation for obtaining small-signal and large-signal equivalent circuit models from S-parameter measurements etc. A number of authors have addressed this problem and have presented techniques which, although useful in many respects, suffer in practice from several limitations. The limitations range from an inability to determine all resistance values of interest, to a requirement for additional information (geometry, doping, etc.) or an unacceptably large uncertainty in measured values. The purpose of the authors contribution is to describe a relatively simple approach to the problem which enables all the resistance parameters to be determined simultaneously with comparatively good accuracy