EXTRACTION OF BIAS-DEPENDENT SOURCE AND GATE RESISTANCE FROM MEASUREDS-PARAMETERS UNDER ALL BIAS CONDITIONS

An accurate determination of the series resistances with physical mean ing is extremely important for the characterization and modeling of FE T's. In this paper, we discussed the bias-dependent behavior of the so urce and gate resistance of GaAs MESFETs. A new analytical method is p resented to extract these resistance at all bias conditions from measu red S-parameters. This method enables the calculation of the equivalen t circuit elements quickly. An application of this new technique to ex tract the source and gate resistance of GaAs MESFET reveals a bias-dep endent behavior for both resistance. The influence of bias on these re sistance is significant under all bias conditions and must be carefull y estimated if an accurate modelling of the MESFET behavior is require d.