An improved parasitic resistance extraction strategy alongside the effect of Cds at low gate bias voltages for AlGaN/GaN HEMTs

Abstract

An improved parasitic resistance extraction from small-signal equivalent-circuit and effect of C ds in GaN HEMTs is presented. Parasitic capacitances are evaluated at ‘cold pinch off’ condition. More accurate extraction method of parasitic resistance is presented at low gate bias voltages compared to earlier published work. The impact of drain to source capacitance (C ds ) at low gate bias voltage is also reported in this manuscript. The validity of proposed parasitic resistance extraction procedure and effect of drain to source capacitance (C ds ) has been verified through error analysis with the measured S-parameters data of 0.8-μm of AlGaN/GaN high electron mobility transistor consisting 2 × 200-μm gate width. Proposed method shows good harmony between simulated and measured data up to 40 GHz frequency.