Third-order frequency selective surface based on inverter interlayers

A third-order Frequency Selective Surface based on inverter interlayers is presented. Second order FSS filter design method using coupling interlayer has been previously proposed [1]. Coupling interlayers are essentially spatial inverters that can be simply adjusted to control the transfer function of the filters. To demonstrate the design flexibility in realizing multi-pole FSS filter based on spatial inverters, this paper validates a higher order (third-order) high performance bandpass FSS adapting the same technique presented in [1]. The main advantage of this technique is its versatile implementation capability that can be adapted for various filter types and for dielectric spacers with arbitrary thicknesses. The simulation results of the third-order bandpass FSSs show a highly selective and stable filter response for oblique angle of incidence and polarizations.