High-Power Ka-Band Performance of AlInN/GaN HEMT With 9.8-nm-Thin Barrier

We report the first CW Ka-band radio-frequency (RF) power measurements at 35 GHz from a passivated Al0.82In0.18N/GaN high-electron mobility transistor on SiC with 9.8-nm-thin barrier. This device delivered a maximum of 5.8 W/mm with a power-added efficiency of 43.6% biased at V-DS = 20 V and 10% I-DSS when matched for power at CW. The device was grown by metal-organic chemical vapor deposition with 2.8-mu m source-drain spacing and a gate length of 160 nm. An excellent ohmic contact was obtained with an R-c of 0.62 Omega . mm. The maximum extrinsic transconductance was 354 mS/mm with an I-DSS of 1197 mA/mm at a V-GS of 0 V, an f(t) of 79 GHz, and an f(max) of 113.8 GHz.