A Verilog-based temperature-dependent BSIM4 model for RF power LDMOSFETs

A BSIM4 model was modified to include the dynamic self-heating effect for accurate prediction of large-signal behavior of RF power Si LDMOSFETs. The model captures the temperature dependence of transconductance, threshold voltage, drain resistance and breakdown voltage. The model is verified against measured large-signal behavior, including output power, efficiency and linearity, as a function of input power as well as source and load impedances. In addition, the model accurately predicts the variation of intermodulation distortion with quiescent drain current. The model is scaleable and has been verified on transistors of different gate widths. The model is implemented in the Verilog-A format, making it portable to many popular circuit simulators.