A temperature-dependent nonlinear analytic model for AlGaN-GaN HEMTs on SiC

A temperature-dependent large-signal model for continuous-wave (CW) and pulsed-mode operation is presented and applied to aluminum gallium nitride, gallium nitride (AlGaN-GaN) high electron-mobility transistors (HEMTs) on silicon-carbide (SiC) substrates. The model includes thermal, RF dispersion, and bias-dependent capacitance model elements, and is suitable for application with a harmonic-balance simulator. Temperature- and bias-dependent on-wafer pulsed I-V and S-parameter measurements from 27°C to 200°C are used to examine trapping and thermal effects, and to determine temperature- and bias-dependent parameterized model coefficients for the nonlinear model. Large-signal measurement and model results are presented for 2 × 0.35 μm × 125 μm and 12 × 0.35 μm × 125 μm GaN HEMTs fabricated on SiC. The nonlinear model shows good agreement with measured CW power sweep data at an elevated temperature of 150°C under more than 5-W power dissipation, and with measured pulsed load-pull data.