Global modeling of terahertz plasmonic high electron mobility transistor using a complete hydrodynamic model

The global modeling of an unbiased/biased ungated high electron mobility transistor (HEMT) is presented. The complete hydrodynamic model is employed for the full-wave analysis of the structure, using the finite-difference time-domain numerical method. This model is based on the first three moments of the Boltzmann transport equation combined with Maxwell’s equations. Using the three moments of the transport equation, in contrast to the usual first two moments, allows us to take into account the variation of the transport parameters with the energy and the temperature. Therefore, the complete characteristics of the plasmons’ propagation along the ungated HEMT channel for low- and high-field conditions are achieved. Moreover, by applying this model to a metallic grating gate HEMT as a tunable resonant detector, the transmission spectra are obtained for various temperatures and electron densities for low- and high-field conditions. The results show the characteristics of the surface plasmons’ propagation are highly influenced by the excitation field level and accordingly cause transport parameter variations that can be described completely by our developed model.