Comparison of Linearity and Intermodulation Distortion Metrics for T - and Pi - Gate HEMT

Abstract

This paper presents a comprehensive analysis of a Pi ( $\pi$ ) - Gate AlGaN/GaN HEMT based on TCAD Simulations. For model validation, the simulation deck of T - Gate AlGaN/GaN HEMT has been calibrated with respect to an experimental data. The calibrated structure is further used for optimizing $\pi$ - Gate HEMT architecture. Comparisons demonstrate an improvement in terms of the lower Intermodulation Distortion by 24% and higher Linearity metric by almost 10 times in case of $\pi$ - Gate HEMT while maintaining similar I ON /I OFF , device power and slightly lower cut - off frequency. This enforces the suitability of $\pi$ Gate HEMT architecture for milli - meter wave applications and low noise amplifiers (LNA) and emphasizes that a suitably deigned and fabricated $\pi$ Gate HEMT can substantially improve the device linearity along with lower intermodulation distortion. All the performance analysis has been carried out using the Atlas TCAD simulator available from Silvaco.