Single layer Ultra-Thin FSS structure with Quad Band characteristics used for Multi Band Applications

In this paper, a novel single layered frequency selective surface (FSS) design is proposed resulting in quad band characteristics. The proposed FSS design is made using FR-4 substrate as the base for the patch elements. The structure thus proposed is composed of inter connected octagonal loops encompassed in a rectangular loop. The unit cell size is very compact and is of dimensions
$0.230)\lambda^{*}0.230\lambda^{\star}0.002\lambda$
and the thickness of the patch is
$0.00031\lambda$
. The novel proposed structure thus resonates at frequencies 2.65 GHz, 7.7 GHz, 9.9 GHz, and 11.58 GHz. The resonance frequencies achieved makes it possible for this structure to be used for upcoming 5G applications which falls in the Sub Gigahertz range along with various other C and X band applications. This proposed novel FSS structure can also be used for multiband antenna systems as well.