Temperature dependence of the Taylor series coefficients and intermodulation distortion characteristics of GaN HEMT
Résumé
This paper focused on nonlinear distortion modeling and characterization of AlGaN/GaN HEMT on SiC substrate using a two-tone intermodulation measurement. The variation of Taylor series coefficients with temperature: linear terms (G$_m$ and G$_d$$_s$), nonlinear terms (G$_m$$_2$ , G$_m$$_3$ , G$_d$$_s$$_2$, and G$_d$$_s$$_3$), and the cross terms (G$_m$$_d$, G$_m$$_d$$_2$, and G$_m$$_2$$_d$) are reported. Furthermore, in the saturation region, the magnitude of G$_d$$_s$ related linear, nonlinear, and cross terms (G$_d$$_s$, G$_d$$_s$$_2$, G$_d$$_s$$_3$, G$_m$$_d$, G$_m$$_d$$_2$, and G$_m$$_2$$_d$) are found to be minimal. This implies that the nonlinear distortion behavior of the device is transconductance-dependent. A temperature-dependent current-based empirical model taking into account bias, input power, and frequency for the nonlinearity of the device has been developed based on two-tone measurements. The modeled data are consistent with the twotone measurements, providing an effective means for analyzing these devices