Transmission-type frequency selective surface with polarization modulation

In this work, a transmission-type frequency selective surface (FSS) with polarization modulation is proposed. This design achieves cross-polarized transmission under both x- and y-polarized normal incidences, while supporting co-polarized transmission at a 45 degrees incidence polarization angle. Consequently, the structure can serve as a polarization rotating FSS (PR-FSS) or a conventional bandpass FSS. The design consists of two fundamental units, corresponding to x- and y-polarized PR-FSS, arranged according to a specific group array paradigm. This arrangement preserves the cross-polarization transmission functionality of each unit. In addition, at a 45 degrees polarization angle, the symmetry of the paradigm with respect to the electric field enables it to support co-polarized transmission. A prototype containing a 12 x 12 element array is constructed and tested. The measured results demonstrate good agreement with the simulation results.