Unique and physically meaningful extraction of the bias-dependent series resistors of a 0.15 /spl mu/m PHEMT demands extremely broadband and highly accurate measurements

In addition to known extraction results this paper is focusing on the bias-dependence of the series resistors of a 0.15 /spl mu/m PHEMT with physics-related values. It is shown that nearly all model parameters of a 20-element device model can be obtained applying known fitting procedures. However taking into account nowadays available measurement uncertainties this approach fails in the determination of the bulk resistors R/sub s/ and R/sub d/. Therefore a novel highly sensitive two-frequency parameter extraction procedure is proposed. Based on simulation and experimental data it is shown that S-parameter data at least above 70 GHz are needed to obtain reliable results. The extracted frequency-dependent element value distribution directly reflects the measurement uncertainties.