Modeling and realization of GaN-based dual-gate HEMTs and HPA MMICs for Ku-band applications

This paper reports on linear and nonlinear modeling and realization of AlGaN/GaN dual-gate HEMTs and high power amplifier (HPA) MMICs for Ku-band applications. A method to describe the extrinsic and intrinsic parts of the dual-gate structure separated from each other using a distributed modeling approach is demonstrated. A small-signal model based on this approach was developed. A scalable nonlinear model was obtained through enhancing the small-signal model by an intrinsic large-signal state-space kernel. The excellent capabilities of both the linear and nonlinear models are demonstrated on fabricated dual-gate HEMTs with 0.25 μm gate length and a total gate width between 0.3 mm and 0.8 mm with a varying number of fingers. A 14-18 GHz, 2.5 W high power amplifier was designed and realized to illustrate the suitability of the developed models for MMIC design.