Abstract: This paper uses a new GaN HEMT small signal model that includes 22 elements and increases the conductance of Ggsf and Ggdf and has parallel gate-source capacitance Cgs and gate-drain capacitance Cgd,which can reflect the gate’s leakage current.The results show that this model can improve the fitting precision and makes more sense in the physical domain.This paper improves the extraction method for extrinsic capacitance parameters,which can extract the new gate-field plate and source-field plate devices’ small-signal parameters effectively.It can reflect the physical characteristics of GaN devices accurately from the extracted parameters.

Key words: GaN HEMT, small-signal, optimize, modeling