Single and double-gate based AlGaN/GaN MOS-HEMTs for the design of low-noise amplifiers: a comparative study

In this study, a 60 nm gate length double-gate AlGaN/GaN/AlGaN metal-oxide-semiconductor high-electron-mobility transistor (MOS-HEMT) is proposed and different electrical characteristics, such as DC, small-signal, radio-frequency (RF) and high-frequency noise performances of the devices are characterised through TCAD device simulations. The results of double-gate MOS-HEMT are compared with the TCAD simulation results as well as with available experimental data of single-gate AlGaN/GaN MOS-HEMT having a similar gate length available from the literature. It is observed that the double-gate AlGaN/GaN/AlGaN MOS-HEMT shows good sub-threshold slope, improved ON current, short-channel effect immunity, improved RF and noise performance. A look-up table-based Verilog-A model is developed for both devices and the models are incorporated into the Cadence EDA tool to utilise the proposed device in circuit simulations. The Verilog-A model is applied to design a 1-20 GHz wideband feedback cascode low-noise amplifier (LNA). Performance variability of LNA due to single- and double-gate MOS-HEMT is also investigated.