Small-Versus Large-Signal Extraction of Charge Models of Microwave FETs

In this letter we extract the parameters of the charge equations of a microwave transistor nonlinear model which is available in commercial CAD tools. In particular, the charge model parameters are extracted starting from small- and large-signal measurements. A better accuracy can be achieved when using large-signal measurements since the model parameters are obtained from experimental data which better reproduce the actual operating condition of the device under test. An advanced 0.15×300 μm2 pHEMT in GaAs technology, aimed at cold-FET mixer design, is considered as case study.