Wide-Passband Dual-Polarized Elliptic Frequency Selective Surface

The design of wide-passband dual-polarized elliptic frequency selective structures (FSSs) is proposed in this paper. The unit cell of the proposed structure is comprised of an array of cascaded square-patch resonators with a coupling layer consisting of two types of modified C-type and all-through slots. The designed FSS provides a third-order wide-passband elliptic filtering response, with three transmission poles in the passband and two transmission zeros at below and above the passband, respectively. The designed FSS is fabricated and its performance is measured. The measured results confirm that the proposed design achieves the desired wide-passband filtering performance with a fractional 3-dB bandwidth of up to 63% even for oblique incident angles up to 40°, for both TE- and TM- polarizations.