Microwave characteristics of AlxGa1-xN/InxGa1-xN/GaN-based HEMT using propagation delay model

A new GaN-based high electron mobility transistor (HEMT) structure is proposed to study DC, RF and microwave characteristics using TCAD tool and propagation delay model. The proposed device is embedded into the circuit and its circuit characteristics are also studied and presented in this paper. Apart from DC and small-signal characteristics, we have investigated various microwave parameters such as maximum allowable gain (MAG), maximum stable gain (MSG), Rollet stability factor (K), Mason's unilateral gain (MUG), cutoff frequency (f
_T
), maximum frequency of oscillation (f
_max
), two port network parameters such as input/output reflection parameters (S
₁₁
, S
₂₂
) followed by Smith chart. We have determined the range of frequency where proposed HEMT will be used as stable amplifier/oscillator. The cut-off frequency of such structure is found to be 32 GHz and noteworthy.