A Comparison of Various Double Loops Frequency Selective Surfaces in terms of Angular Stability

This paper presents the comparison of Frequency Selective Surfaces (FSS) structure performance based on three different double loops: square, circular and hexagonal structures. The simulation process of the double loops FFS structures are carried out by using the Computer Simulation Technology (CST) Microwave Studio software. The dielectric substrate used in the simulation is the FR-4 lossy substrate (ε
_r
=4.3). The simulation results show that the frequency resonated at 11.13 GHz (BW = 2.37 GHz), 11.06 GHz (BW = 2.29 GHz) and 11.07 GHz (BW = 2.25 GHz) for the double square loops, double circular loops, and double hexagonal loops FSS structures, respectively. Although the square loop structure is known to have the best filtering performance; however, based on this study, it is proven that the hexagonal and circular structures have better performance in terms of angular stability. The resonant frequency deviation for both the double hexagonal loops and double circular loops is approximately 5 % for TE mode and 1 % for TM mode.