LOW-VOLTAGE OPERATION GAAS SPIKE-GATE POWER FET WITH HIGH POWER-ADDEDEFFICIENCY

A GaAs power FET with a spike-gate has been developed for the high-eff iciency operation under the extremely low supply voltage less than 1.5 V. The spike-gate provides both the low on-resistance of 2.2 Omega/mm and the high transconductance of 180 mS/mm without reducing the outpu t impedance nor increasing the gate resistance. The implemented device achieved the output power of 31.5 dBm with 70% power-added efficiency at the frequency of 900 MHz. It should be noted that the present devi ce kept PAE of 60% even at the bias of 0.5 V, which is the lowest volt age ever attained.