Very high power-added efficiency and low-noise 0.15- mu m gate-length pseudomorphic HEMTs

0.15- mu m-gate-length double-heterojunction pseudomorphic high electron mobility transistors (HEMTs) for which excellent millimeter-wave power and noise performance were achieved simultaneously are reported. The 50- mu m-wide HEMTs yielded record maximum power-added efficiencies of 51, 41, and 23% at 35, 60, and 94 GHz, respectively. Maximum output powers of 139 mW at 60 GHz and 57 mW at 94 GHz were also measured for 150- mu m-gate-width devices. Finally, minimum noise figures as low as 0.55 and 1.8 dB were measured at 18 and 60 GHz respectively. This is the best power and noise performance yet reported for passivated transistors at millimeter-wave frequencies. >