Physical Insight Into Frequency-Dependent Nonlinearities in AlGaN/GaN HEMTs

Abstract

[EN]We investigate the frequency-dependent nonlinearities of an AlGaN/GaN high electron mobility transistor (HEMT) involved in terahertz (THz) detection by means of 2-D Monte Carlo (MC) simulations. The analysis shows that, below 1 THz, the responsivity roll-off is mainly governed by the passive microwave behavior of the device rather than by any limitation of the intrinsic detection mechanism. At higher frequencies, an inverse extraction method able to provide the intrinsic nonlinearity coefficients of the device reveals just a marginal broad enhancement around 1 THz, followed by a steep roll-off.