An Improved GaAs FET Nonlinear Model Suitable for Intermodulation Analysis of Amplifiers, Switches and Resistive Mixers

This paper presents an IDS(VGS,VDS) model to represent PHEMT behavior in the reverse ) 0 ( < DS V , and forward zone ) 0 ( > DS V . The model predicts with high accuracy the measured data as well as higher orders derivatives of the transconductance over a large range of VDS bias. These characteristics are important for the analysis of intermodulation distortion using harmonic balance or Volterra series. Using the improved IDS(VGS,VDS) model along with an empirical model to simulate the nonlinear behavior of gate-source capacitance, CGS, and gate-drain capacitance, CGD, a GaAs FET nonlinear model suitable for intermodulation analysis of amplifiers, switches and resistive mixers is presented