Nonlinear Modeling of RF Switch Based on COMSOL Parameter Extraction

This paper presents the modeling of nonlinear characteristics of radio frequency (RF) switches based on parameter extraction in COMSOL Multiphysics. We separate the nonlinearity of RF switch to transistor nonlinearity and substrate nonlinearity of the internal Silicon-on-insulator field effect transistors (SOI MOSFETs). In COMSOL, the parameters related to the substrate part are extracted, and the equivalent expression of the buried oxide layer capacitance is obtained. By stacking SOI MOSFETs, the nonlinear model and harmonic characteristics of RF switch will be discussed. Compared with the literature, the model shows pretty good non-linear predictability.