An approach to extract extrinsic parameters of HEMTs

To extract extrinsic resistances, conventional cold-FET methods require add itional DC measurements or channel technological parameters. Additionally, the methods need at least two sets of cold-FET S-parameters measured at dif ferent cold-FET bias conditions in order to completely determine gate and d rain pad capacitance as well as extrinsic gate, source and drain inductance and their resistances. One set of S-parameters handles the extraction of e xtrinsic inductances, and the other set extracts the gate and drain pad cap acitance. To be free from additional DC measurement or channel technologica l parameters and reduce the number of sets of cold-FET S-parameters, we pro pose a cold-FET method that can extract all the extrinsic elements includin g the gate and drain capacitance, using only one set of cold-FET S-paramete rs. The method has shown excellent agreement between modeled and measured S -parameters up to 62 GHz at 56 different normal operating bias points.