Second-Order Polarization Rotating Frequency-Selective Surface

In the communication, a monopolarized and a dual-polarized polarization-rotating frequency-selective surfaces (PR-FSSs) are designed successively. The two PR-FSSs are both a three-layer aperture-coupled-patch periodic structure. When they are interpreted as an array of antenna-filter-antenna (AFA) modules, because polarization directions of the upper and lower antennas in each AFA module are orthogonal to each other, they can both realize polarization rotation and frequency selection at the same time. The monopolarized PR-FSS is designed first, its relative bandwidth reaches up to 13.58% although there is a maximum insertion loss of 0.8 dB in the band. The final-designed dual-polarized PR-FSS can be regarded as the combination of two orthogonal monopolarized one, so it can work under both x - and y -polarized incidences, its relative bandwidth is still up to 9.81%; moreover, the maximum insertion loss in the passband is very low. The performances of the two PR-FSSs are both verified by simulations and experiments.