A high linearity, high efficiency pseudomorphic HEMT

The authors report the third-order intermodulation distortion and phase deviation of 1.2-mm periphery double pulsed doped pseudomorphic high-electron-mobility transistors (HEMTs) at high levels of power and efficiency. A device tuned for single-tone power-added efficiency (PAE) of 59% with 0.87-W output power and 10.4 associated gain at 10 GHz could provide two-tone PAE of 50% with -19 dBc IM3/C and 0.30 W/tone. Single-tone phase deviation never exceeded 18 degrees from small signal with a phase deviation slope less than 3 degrees /dB. These measurements compare favorably to those of reported GaAs-based devices with comparable output power. A dry etched double recess structure was incorporated in the device for obtaining high reverse breakdown voltage and therefore high efficiency.<>