How Large-Signal Measurement Techniques Improve the Accuracy of Microwave Transistor Nonlinear Models

The advent of the GaN technology has posed new challenges in microwave transistor nonlinear modelling, thereby leading to a great proliferation of new analytical and behavioral formulations oriented to CAD design. Despite such a proliferation, the formulations adopted by foundries, which are the only ones actually exploited by microwave circuit designers, remain always pretty limited. As a provocation, not so far from reality, one could say that foundries use only the Angelov's model (and its derivatives). In this paper, the current scenario of nonlinear modelling will be discussed, putting in evidence the fundamental, silent role that new large-signal characterization techniques are playing in advancing microwave transistor model accuracy.