Model for evaluation of terahertz plasma resonances in HEMT-based devices with grating gate

We propose simple analytical model for calculation of spatial distribution of the sheet electron density in the channel of high-electron mobility transistor (HEMT) periodically modulated by the bias voltage applied to grid-grating gate. The contribution of ungated regions of two-dimensional electron gas (2DEG) channel is taken into account. The developed model allows to evaluate resonant frequencies of plasma oscillations excited in such periodically modulated 2DEG channel. The proposed model can be useful in the interpretation of experimentally obtained data and optimization of the grating-gated HEMT-like structures for THz applications.