Plasma Mode HEMTs with RTD Gate and Multiple 2DEG Channels for Stable Terahertz Operation

We demonstrate that plasma wave instability in a grated and RTD-gated high electron mobility transistor (HEMT) leads to terahertz emissions. Numerical calculations are provided using a new full wave Maxwell-hydrodynamic solver that incorporates a novel excitation term to account for RTD gate loading, necessary for amplification. Using the proposed solver, an accurate plasma wave model is presented, accounting for non-uniform surroundings and finite dimensions of the 2DEG layer, within the HEMT. We estimate that hundreds of nanowatts of power can be generated with sufficient channel length. Also, 6 dB improvements in the transmission spectra at room temperature is proposed, using a 4 channel HEMT configuration, as opposed to single 2DEG layer.