Optically transparent frequency selective surface based on nested ring metallic mesh

An optically transparent frequency selective surface (FSS) based on a nested ring metallic mesh is proposed, whose diffraction distribution is uniform and normalized higher-order diffraction intensity is lower than that of an existing transparent FSS based on metallic meshes. Compared with non-meshed FSSs, the proposed FSS has a remarkably higher optical transmittance, lower -3 dB bandwidth, and higher maximum transmittance in the microwave band. Experimental results indicate that the FSS sample achieved a normalized visible transmittance of 94.84%, uniform diffraction distribution, and stable filtering passband around 31.00 GHz simultaneously, which are attractive properties for transparent FSS applications.