Impact of Output Conductance on Current-Gain Cut-Off Frequency in InxGa1-xAs/In0.52Al0.48As Quantum-Well High-Electron-Mobility Transistors on InP Substrate

In this study, we investigated the impact of intrinsic output conductance (g(oi)) on the short-circuit current-gain cut-off frequency (f(T)) in InxGa1-xAs/In0.52Al0.48As quantum-well (QW) high-electron-mobility transistors. At its core, we attempted to extract values of f(T) using a simplified small-signal model (SSM) of the HEMTs and to derive an analytical formula for f(T) in terms of extrinsic model parameters that are related with intrinsic model parameters of a general SSM. We projected how f(T) was influenced by g(oi) in HEMTs, emphasizing that the improvement in electrostatic integrity would also be of critical importance to fully benefit from scaling down L-g.