Noise characteristics of AlInN/GaN HEMTs at microwave frequencies

The microwave noise parameters measured on AlInN/GaN HEMTs devices with different gate length values are presented in this paper. 0.15-μm HEMTs achieve a maximum current density of 700 mA/mm at V_Gs = 0 V and a measured extrinsic transconductance of 350 mS/mm. The current gain cutoff frequency and the maximum oscillation frequency are 40 GHz and 70 GHz, respectively. At 10 (20) GHz, the device exhibits a minimum noise figure of 0.8 dB (1.8) dB with an associated power gain of 14 (8.8) dB. Below 8 GHz, the gate leakage current and a generation-recombination noise source with a very short time constant limit the noise performance.