INDIUM GALLIUM-ARSENIDE MICROWAVE-POWER TRANSISTORS

Depletion-mode InGaAs microwave power MISFET's with 1-mu-m gate lengths and up to 1 mm gate widths have been fabricated using an ion-implanted process. The devices employed a plasma-deposited silicon/silicon dioxide gate insulator. The dc current-voltage (I-V) characteristics and RF power performance at 9.7 GHz are presented. The output power, power-added efficiency, and power gain as a function of input power are reported. An output power of 1.07 W at 9.7 GHz with a corresponding power gain and power-added efficiency of 4.3 dB and 38%, respectively, was obtained. The large-gate-width devices provided over twice the previously reported output power for InGaAs MISFET's at X band. In addition, the first report of RF output power stability of InGaAs MISFET's over a 24 h period is also presented. An output power stability within 1.2% over 24 h of continuous operation was achieved. In addition, a drain current drift of 4% over 10(4) s was obtained.