A single-layer antenna-filter-antenna array with polarization rotation characteristic

A type of frequency selective surface (FSS) using array of single-layer antenna-filter-antenna (AFA) elements is presented in this paper. The periodic element of the proposed FSS is built up by a square substrate integrated waveguide (SIW) cavity resonator with two stepped-impedance resonators (SIRs) orthogonally etched on the its front and back sides. Coupling scheme of the proposed FSS element has been presented in theoretical analysis and applied in the FSS design. As an example, a prototype of the proposed FSS has been designed, fabricated and measured at 35GHz. Both the simulated and measured results demonstrate that the FSS exhibits polarization rotation characteristic, good frequency selectivity and stable frequency response in the passband with a large variation of the incident angle.