Millimeter-Wave Small-Signal Model Using A Coplanar Waveguide De-Embedded Sub-Model for HEMT

Abstract

We propose in this study an approach to highly reliable extraction method for parasitic elements of the 0.1 mu m GaAs metamorphic high electron mobility transistors. This method utilizes the de-embedding scheme for the coplanar waveguide (CPW) feeding structure by considering the distributed extrinsic parasitic elements in our small-signal model. The parasitic extrinsic capacitances are determined by modeling a PI equivalent circuit including the interaction between the sub-model (the model after de-embedding) and the CPW feedings. Extractions for 2 x 10 mu m, 2 x 20 mu m, 2 x 30 mu m, and 2 x 70 mu m), and our S-parameter prediction shows the best agreement with the measurements in a frequency range of 0.5-110 GHz (0.5 GHz step) among the small-signal models reported to date.