Novel HEMT Models with Improved Higher-Order Derivatives and Extracting Their Parameters Using Multibias S-Parameters

Novel two HEMT models are suggested in the paper with improved accuracy of higher-order derivatives, which is very important for modeling radio-frequency devices as mixers, etc. The proposed modifications of the models are based on empirical relations for the transconductance dependence on gate-source voltage. Moreover, a way is suggested how to extract the model parameters of various nonlinear HEMT models from a measured multibias s-parameter data set. The proposed extraction procedure is based on a three-step identification procedure that uses robust optimization methods. Finally, various HEMT models -- including the proposed ones -- are compared in terms of the root-mean-square error of DC characteristics and multibias s-parameters.