OPTICALLY CONTROLLED MICROWAVE SWITCHING AND PHASE-SHIFTING USING GAAS-FETS

Theoretical and experimental results relating to a novel method for achieving direct optical control of a microwave phase shifter are presented, based upon a microwave reflective switch in which on- and off-states are controlled by direct optical illumination of a GaAs FET. Results, hitherto unavailable in the literature, verify previously published models for the GaAs FET as a microwave switch while under electrical control and establish the use of this model to predict the response of the switch under direct optical control over the frequency range 8 to 12 GHz.