Dual-Band Frequency Selective Surface on Aperture-Coupled Patch Resonators With Different Polarization Rotation

In this letter, a dual-band frequency selective surface (FSS) based on aperture-coupled patch resonators is proposed to achieve different angles of polarization rotation, that is, 90° and 0°. The dual-band response is achieved by periodically arranging two independent subelements consisting of back-to-back patch resonators with coupling apertures etched on the middle metallic layer. Herein, the first passband is realized by the crossed patch resonators with a pair of rectangular apertures etched beneath the edges of the crossed patches. It can produce 180° phase difference between the two orthogonal components of a linearly polarized incident wave oriented to the diagonal of the FSS elements, thus rotating the incident polarization to its orthogonal one in this first passband. The second passband is caused by the square patch resonators with crossed apertures etched beneath the center of the square patches, thereby maintaining the incident polarization unchanged in this second passband. The operation principle is, then, extensively analyzed and discussed. To validate the design concept, the proposed FSS is designed, fabricated, and measured. A good agreement between the measured and simulated results is achieved to reveal the attractive dual-band and dual-polarization features of the proposed FSS.