An EM-based approach to model a gallium nitride HEMT in a custom common-gate configuration

This paper describes a simple, EM-based approach to accurately predict the frequency behavior of a custom common-gate (CG) Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) starting from a similar device, but in the most frequently available standard common-source (CS) configuration. The proposed approach exploits electromagnetic (EM) simulations and measured scattering parameters of the reference CS device to represent its extrinsic and intrinsic sections, respectively. Then, the frequency behavior of the CG device is obtained by combining the CS intrinsic section data with the information extracted from the EM simulations of the passive parts of the CG layout. In particular, an 8×130 μm CS GaN HEMT has been adopted as reference device to predict the behavior of an 8×150 μm GaN HEMT in a custom CG configuration. Experimental results confirm the ability of the proposed method to accurately predict the behavior of the custom CG device up to 30 GHz.