A robust small-signal equivalent circuit model for AlGaN/GaN HEMTs up to 110 GHz

In this paper we present an accurate and robust small-signal equivalent circuit model(SSECM) for GaN/AlGaN HEMTs. To extend the operating frequency, a flexible equivalent circuit network for parasitic parameters is proposed. The equivalent circuit network is constructed by a number of (N) seriate equivalent resist, inductance and capacitance (Rn-Ln-Cn), which accounts for distribution effects of gate and drain feeding line. The number of seriate R-L-C can be chosen by the maximum operating frequency flexibly. As a result, we can get an accurate SSECM on certain frequency range with the minimum cost of extraction procedure and time. The proposed parasitic model has been added in the conventional SSECM and a GaN HEMT with gate length 0.1μm and 2×100μm is used for validation. The results show that the SSECM with N=2 and N=3 can well describe the scattering parameters with maximum frequency up to 66GHz and 110 GHz, respectively.