Abstract

The paper describes a two-dimensional physical small-signal and noise model for GaAs MESFET's. The model can provide, on the basis of physical and geometrical input parameters only, a complete small-signal and noise performance characterization. The noise model is based on the efficient implementation of the classical impedance-field method for noise analysis within the framework of a frequency-domain numerical drift-diffusion physical model. Attention is devoted to the experimental validation of the model, which is carried out on a realistic case study (a 0.6um GMMT MESFET) by testing the DC, the small-signal and noise models against measurements. The role played by the high-field diffusivity in noise simulation is stressed and it is shown how a physics-based model for this parameter allows a good match to be achieved for both the noise figure and the optimum source impedance.