Experimental determination of on and off state small-signal equivalent circuit of /spl delta/-doped PHEMTS

A simple and accurate method for extracting on and off state equivalent circuit for double heterojunction /spl delta/-doped PHEMTs was developed, which is quite useful for switching applications. The circuit elements are extracted from the S-parameters of PHEMTs. Parasitic inductances L/sub g/, L/sub d/ and L/sub s/ were determined from the on-wafer-short S-parameter data. We have observed skin effect on the series resistive elements of on-wafer-short, which has been given due consideration in our model. The model has been verified by comparing the measured S-parameter data against those calculated from the on and off state equivalent circuits of PHEMTs.