GA optimized reconfigurable frequency selective surfaces for passive standoff detection of chemical agents

In this paper we present a new class of reconfigurable frequency selective surfaces (FSS) for the remote passive detection of chemical agents. The frequency selective surface is composed of a periodic tiled pixelized pattern on a thin dielectric substrate. The pixelized pattern consists of squares of either metallic patches or chemoresistive patches. In the absence of an analyte, the chemoresistive patches have a high impedance and in the presence of an analyte they have a low impedance. The FSS is designed to provide a sharp narrowband reflection resonance that shifts down in frequency with exposure to the analyte. The geometry of the FSS is selected via a Genetic Algorithm (GA) [1].