  Small- and large-signal RF characteristics were measured on AlN GaN HEMTs
with 80-160 nm gate length and 100-300 {\mu}m width. Consistent with the
literature, current-gain cut-off frequency and maximum frequency of oscillation
were found to increase with inverse gate length and independent of gate width.
For the first time, output power and efficiency were reported at the high end
of Xband, and were comparable to the best reported at 2 GHz and insensitive to
gate length or width. These results suggest that the AlN/GaN HEMTs can be
further scaled for even higher frequency and higher power performance.
