Direct determination of the bias-dependent series parasitic elements in SiC MESFETs

We propose a simple and direct extraction procedure for the determination of bias-dependent parasitic resistive elements in SiC MESFETs. This extraction technique is based on a frequency evolution of measured Z-parameters of a metal semiconductor field effect transistor (MESFET) under active bias conditions. Using this method, the equivalent-circuit parameters of an SiC MESFET have been extracted at different bias points, and the variation of the bias-dependent series resistive elements studied. The measured and modeled S-parameters demonstrate a good correlation up to 20 GHz.