Prediction of IMD behaviour in LDMOS transistor amplifiers using a physics-based large signal compact model

In this paper, intermodulation distortion (IMD) analysis is carried out for silicon-on-insulator lateral double-diffused metal-oxide-semiconductor using a physics-based large signal model implemented in Verilog-A. The model is found to predict the static and dynamic characteristics accurately along with the higher order derivatives of transconductance and capacitances in all regions of operations. A power amplifier (PA) is designed both within the TCAD mixed-mode simulation framework and circuit simulator using the Verilog-A compact model. One-tone and two-tone analysis are carried out for the PAs designed in TCAD and circuit simulators. It is found that the Verilog-A compact model can accurately predict the existence of double IMD sweetspots for class AB operation when compared with the TCAD results. Also for the output power, power gain and power added efficiency, the model predictions are in agreement with those of the TCAD simulation data.