A new MESFET nonlinear model

In this paper, a new empirical model for the dc I – V characteristics of a GaAs MESFET transistor is presented. The conventional approach for modeling the dc I – V characteristics of a MESFET transistor adopts the hyperbolic‐tangent dependence on V ds through the observation of the I ds versus V ds curve. The derived model is capable of accurately modeling the device current–voltage behavior in different operation regions. The new model equations describe the device drain current as a polynomial of the effective gate–source voltage V eff , which is in turn a rational function of V gs , and the parameters for the polynomial vary with V ds . Model parameter extraction is made for a 0.5 μm gate‐length MESFET device. Measured and modeled results are compared, and good agreement is obtained. A comparison among the proposed model, Curtice's and Chalmers' model, and Parker's model are also made in this paper. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 226–230, 2001.