Straightforward Modeling of Dynamic I–V Characteristics for Microwave FETs

This work presents a straightforward approach aimed at modeling the dynamic I–V characteristics of microwave active solid-state devices. The drain-source current generator represents the most significant source of nonlinearity in a transistor and, therefore, its correct modeling is fundamental to predict accurately the current and voltage waveforms under large-signal operation. The proposed approach relies on using a small set of low-frequency time-domain waveform measurements combined with numerical optimization-based estimation of the nonlinear model parameters. The procedure is applied to a gallium nitride HEMT and silicon FinFET. The effectiveness of the modeling procedure in terms of prediction accuracy and generalization capability is demonstrated by validation of the extracted models under operating conditions different than the ones used for the parameters estimation. Good agreement between measurements and model simulations is achieved for both technologies and in both low- and high-frequency range.