Generalized reflection and transmission analysis and applications of impedance loaded straight wire frequency selective surfaces

Arrays of impedance loaded thin wire antennas have been used for decades in a variety of practical applications, including FSS for spatial microwave filters. We describe a means of analysing a doubly periodic array of thin wires loaded with any type of lumped linear impedance element. We give generic closed form expressions for the scattering properties of a generally impedance-loaded wire FSS. The resulting expressions can be evaluated rapidly and thus provide the means for synthesis by repeated analysis. Some examples of the application of such impedance surfaces, for example as a switchable FSS EM shutter or dual band filter and as a means of enhancing angle of incidence properties, are given. These results have been confirmed experimentally and a qualitative explanation for the behavioral response of the loaded FSS in each of the applications cited has been derived.