Bias free optical control of microwave circuits and antennas using improved optically variable capacitors

Monolithic optically variable capacitors (OVC´s) consisting of photovoltaic arrays integrated with varactor diodes are used in bias free optical control of microwave circuits and antennas. The improved OVC´s presented here required only 450 /spl mu/W of optical power for a 2.2:1 change in capacitance, a threefold reduction in optical power compared to previous results. Using these improved OVC´s, bias free optical control of phase shifters and slot antennas has been demonstrated with the lowest reported optical power.