An improved MESFET model for prediction of intermodulation load-pull characterization

The contribution of the cross terms to the prediction of GaAs MESFET intermodulation load-pull behaviour can be important, and a method is presented for the complete experimental characterization of the drain-source current nonlinearities. An accurate characterization of the nonlinear distortion caused by the Ids(Vgs,Vds) current in a MESFET does not allow the common approach of splitting this nonlinear equivalent circuit element in two-voltage dependent nonlinear current sources, Gm(Vgs) and Gds(Vds). By an improved laboratory characterization procedure, it was possible to show that the cross terms of the Ids(Vgs,Vds) Taylor series expansion can give an important contribution to the prediction of a MESFET's intermodulation load-pull behaviour.<<ETX>>