A new analytical model for the GaAs MESFET in the saturation region

A model that provides the static characteristics and the elements of the equivalent electrical scheme is presented. It is based on an approximate quadratic form for the depleted region under the gate when the electron velocity reaches the saturation velocity. The potential in the channel is calculated using Poisson´s equation and taking into account the variation of the electron density inside it. The main physical phenomena such as edge effects, overshoot velocity, and carrier injection in the buffer layer are also taken into account. Theoretical and experimental results for the I-V characteristics, transconductance, output conductance, gate-source capacitance, and gate-drain capacitance are presented for a submicrometer-gate MESFET. The results calculated using this model agree well with experimental data