7 mm gate width power heterojunction FETs for Li-ion battery operated personal digital cellular phones

Abstract

This paper describes 950 MHz power performance of a 7.0 mm gate width double-doped AlGaAs-InGaAs-AlGaAs heterojunction FET (HJFET) with a 0.8 /spl mu/m long WSi gate for personal digital cellular phones. The fabricated HJFET exhibited 2.3 /spl Omega/.mm on-resistance, 600 mA/mm maximum drain current, 330 mS/mm transconductance and 12.7 V gate-to-drain breakdown voltage. Operated with a drain bias of 3.4 V, the HJFET demonstrated 1.23 W (30.9 dBm) output power and 56.3% power-added efficiency with -51.5 dBc adjacent channel leakage power at 50 kHz off-center frequency.