In this work, an accurate analysis of state-of-the- art high-frequency and high-power High Electron Mobility Transistor (HEMT) devices has been performed by using both commercial simulation tools and a full band Cellular Monte Carlo (CMC) simulator, in order to investigate the most important factors allowing improvements in reliability and manufacturability of AlGaN/GaN HEMTs at mm-wave frequencies. The effects of polarization charge on the electrostatic potential distribution across the heterostructure of a GaN HEMT device was first investigated. Subsequently, an intensive ...