Compact dc model of GaAs FET's for large-signal computer calculation

A modified, simple and fairly accurate explicit expression of dc current-voltage characteristics of GaAs FET's is presented. A departure from the square-law behavior in saturation of the short channel transistor is induced by introducing drain-source voltage bias dependent pinch-off potential. The model proposed here needs four parameters extracted by the global curve-fitting technique of a measured family of drain current-voltage characteristics. A comparison with other dc compact models of MESFET's valid over the entire range of drain-source voltages shows good compromise between simplicity and accuracy of the model proposed in this paper. The model can be easily implemented in programs of computer-aided analysis and design of circuits with GaAs FET's.