Physical/electromagnetic quasi-tridimensional analysis of high-frequency FET's

This letter presents an effective technique for the analysis of microwave and millimetre-wave field-effect transistors, based on geometrical and material data only. The intrinsic (active) part of the device is described by quasi-2D hydrodynamic transport equations, coupled to a numerical electromagnetic field solver in three dimensions that takes into account the passive (extrinsic) part of the structure, including connections and distributed propagation effects. The analysis is performed entirely in the time domain, and includes linear and non-linear operations of the device. Small-signal and large-signal results at microwave and millimetre-wave frequencies are presented for a 2x50 um HEMT device, and also for varying gate width, that demonstrate the capabilities of the technique. The feasibility of applications to the design and optimisation of high-frequency devices is demonstrated.