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 pHEMT in GaAs technology, aimed at cold-FET mixer design, is considered as case study