102-GHz AlInN/GaN HEMTs on Silicon With 2.5-W/mm Output Power at 10 GHz
Grown on a (111) high-resistivity silicon substrate, 0.1-mu m gate AlInN/GaN high-electron mobility transistors (HEMTs) achieve a maximum current density of 1.3 A/mm, an extrinsic transconductance of 330 mS/mm, and a peak current gain cutoff frequency as high as f(T) = 102 GHz, which is the highest value reported so far for nitride-based devices on silicon substrates, as well as for any AlInN/GaN-based HEMT regardless of substrate type. Continuous-wave power measurements in class-A operation at 10 GHz with V-DS = 15 V revealed a 19-dB linear gain, a maximum output power density of 2.5 W/mm with an similar to 23% power-added efficiency (PAE), and a 9-dB large-signal gain. At VDS = 8 V, the output power is 1 W/mm, and the peak PAE reaches 50%. Results demonstrate the interest of AlInN/GaN on silicon HEMT technology for low-cost millimeter-wave and high-power applications.