A Symmetrical Model for Microwave Power AlGaAs/InGaAs pHEMTs for Switch Circuit Applications

In this paper, a nonlinear model of microwave power AlGaAs/InGaAs pseudomorphic high-electron mobility transistors (pHEMTs) for switch circuit applications is presented. The symmetrical property that allows for the interchange of the drain and the source is emphasized in the characteristic equations, preserving differentiable features to any orders for the entire bias range. Moreover, the subthreshold voltage, the gate leakage current, and the charge conservation for pHEMT device modeling are included for completeness. The model is validated by being used for a single-pole-single-throw switching circuit in a commercial simulation environment, and the harmonic and two-tone intermodulation distortion predictions (at both on and off states) are examined. The measurement data show quite good agreement with the simulation results, demonstrating the effectiveness of the proposed model.