Simulation results for a novel optically controlled photonic bandgap structure for microstrip lines

A novel optically controlled one dimensional (1D) photonic bandgap (PBG) microstrip structure is proposed. This device consists of a 50 /spl Omega/ microstrip transmission line and a PBG ground plane both deposited onto a photoconductive substrate. With no optical illumination the structure exhibits a well-defined stopband. When light is focused through the holes in the ground plane and onto the substrate, electron-hole pairs are generated to form a photoinduced plasma. This increases the conductivity of the exposed region of the substrate and forms a complete ground plane. The structure then acts as a conventional microstrip line and the bandstop characteristics are switched off. S-parameter simulation results are presented.