3 V operation L-band power double-doped heterojunction FETs

The microwave power performance of double-doped AlGaAs/InGaAs/GaAs pseudomorphic heterojunction field-effect transistors (HJFETs) operated at a DC drain bias of 3 V is presented. The fabricated 1.1- mu m-gate-length HJFET with an undoped AlGaAs Schottky layer exhibited a maximum drain current of 220 mA/mm, a peak transconductance of 200 mS/mm, and a gate-to-drain breakdown voltage of 21 V. Power performance evaluated at a 3-V drain bias for a 12-mm-gate-periphery device demonstrated a maximum output power of 1.4 W with a 61% power-added efficiency at 950 MHz. The results indicate that the double-doped pseudomorphic HJFETs have a high potential for battery-operated portable power applications.<>