Al/sub 0.3/Ga/sub 0.7/As/GaAs HEMT's under optical illumination

Theoretical and experimental work for the DC and RF performance of depletion mode Al/sub 0.3/Ga/sub 0.7/As/GaAs HEMTs under optical illumination is presented. The photoconductive effect increasing the 2-DEG channel electron concentration and photovoltaic effect in the gate junction are considered. Optical tuning of a 2 GHz HEMT oscillator and optical control of the gain of a 2 to 6 GHz HEMT amplifier are presented and potential applications are described. >