Low-Noise Microwave Performance of 0.1 $\mu$m Gate AlInN/GaN HEMTs on SiC

We report the first microwave noise characterization of AlInN/GaN HEMTs. Transistors with a 0.1 μ m gate implemented on a semi-insulating SiC substrate achieve a maximum current density of 1.92 A/mm at
V
_GS
= 0 V, a measured transconductance
g
_M
= 480 mS/mm, and a peak current gain cutoff frequency
f
_T
= 121 GHz with a simultaneous maximum oscillation frequency
f
_MAX
= 142 GHz. At 10 (20) GHz, our HEMTs exhibit a minimum noise figure
F
_min
of 0.62 (1.5) dB together with a high associated gain
G
_A
of 15.4 (13.3) dB. The
F
_min
values are among the lowest reported in nitride HEMTs, and the
G
_A
values are the best so far found in the literature, demonstrating the excellent potential of AlInN/GaN HEMTs for low-noise microwave applications.