Scalable Large-Signal Modeling for GaN HEMTs Including Kink Effect

An improved scalable large-signal model for gallium nitride high-electron-mobility transistors (GaN HEMTs) based on the EEHEMT model is proposed. The derived DC model can accurately predict the current-voltage behavior including the kink effect over a wide range of bias points by introducing the parameter $V_{\textrm {kink}}$ and new equations using fitting parameters. To ensure the scalability of the model, the scaling rules are modified. The proposed model has been validated by comparing the measured and modeled DC I–V characteristics and multibias scattering parameters (S-parameters) up to 40 GHz for GaN HEMTs with different gate widths including $2\times 25~\mu $ m, $2\times 50~\mu $ m, $2\times 75~\mu $ m, and $2\times 100~\mu $ m gate width (number of gate fingers $\times $ unit gate width).