A new extraction method of GaN switch-HEMT small-signal model with capacitance scanning algorithm

In this letter, a new extraction method of GaN switch-HEMT small-signal model with capacitance scanning algorithm is proposed. In the algorithm, the proportional relationship among intrinsic Cgs, Cgd and parasitic Cg is scanned based on a simplified small-signal model without any approximations for capacitance. Comparing with the measured S parameters, optimized model parameters with the minimum error, especially the parasitic Cg, are achieved without assistance of extra methods such as EM analysis. Using this method, the accurate small-signal model for a 0.25μm gate-length GaN switch-HEMT up to 26.5GHz is extracted. This convenient method can be used for both GaN and GaAs switch-HEMT.