A Novel Optically-Controlled Microwave Switch On Semiconductor Substrates For an ON/OFF Ratio Enhancement

A new structure of optically-controlled microwave switches is studied. By analyzing the equivalent schematic representation, the ON/OFF ratio of photoswitching systems is enhanced. A 15.4 dB ON/OFF ratio at a microwave frequency of 20 GHz was measured on Si samples with this new configuration, top-excited by a continuous laser diode at a 671 nm wavelength. Such efficient devices can be directly incorporated in passive and active microwave circuits to be switched with the advantages of optics.