Nonlinear deembedding of microwave large-signal measurements

The I-V dynamic characteristics of field-effect-transistors (FET) are determined through a nonlinear deembedding procedure at the current generator plane. More precisely, the knowledge of the parasitic elements and the nonlinear charges allows one to retrieve the intrinsic I-V functions starting from any experimental high-frequency load line. In this work, the nonlinear charge functions (Q-V) and the value of the parasitic elements are obtained directly by a small-set of nonlinear waveforms measured with a large-signal network analyzer. The proposed approach is general and independent on the device´s technology and can be advantageously exploited to determine the actual I-V characteristics without the need of an electro-thermal nonlinear model of the output current generator. The procedure is applied to a 0.25 um GaAs pHEMT.