Optically Controlled Reconfigurable Band-Notched UWB Antenna for Cognitive Radio Applications

By utilizing two optically controlled microwave switches (OCMSs) to control two independent narrow-band complementary split ring resonators, an optically controlled aperture ultrawideband antenna capable of generating reconfigurable multiband notches is proposed. Four reconfigurable states are achieved in the 3.1–10.6-GHz band: 1) a full FCC-allowed band; 2) a WiMax-notched band; 3) a WLAN-notched band; and 4) a WiMax-WLAN-notched band. These bands are useful to detect the available spectra or block the harmful interference from WiMax and/or WLAN systems by simply changing the ON/OFF states of the OCMSs with no more than 100-mW optical powers for each switch. A prototype of the proposed antenna is fabricated and measured. Both simulations and experiments demonstrate the proposed design.