Small signal modeling of AlGaN/GaN HEMTs with consideration of CPW capacitances

Abstract

Given the coplanar waveguide (CPW) effect on AlGaN/GaN high electron mobility transistors at a high frequency, the traditional equivalent circuit model cannot accurately describe the electrical characteristics of the device. The admittance of CPW capacitances is large when the frequency is higher than 40 GHz; its impact on the device cannot be ignored. In this study, a small-signal equivalent circuit model considering CPW capacitance is provided. To verify the model, S -parameters are obtained from the modeling and measurements. A good agreement is observed between the simulation and measurement results, indicating the reliability of the model.

Small-signal model parameter extraction for AlGaN/GaN HEMT

“…During the last decade, a large number of papers have presented different approaches for extracting the small-signal model (SSM) parameters of AlGaN/GaN HEMT. In Reference [4], an improved small-signal equivalent circuit model was proposed by considering the co-planar waveguide effect capacitances. In Reference [5], a method for extracting parasitic resistances and parasitic inductances was introduced by biasing the device with low DC forward gate current and by floating the drain.…”