Band notched polarization insensitive simple FSS for electromagnetic shielding

A band reject frequency selective surface (FSS) is presented in this paper. The given structure band stops the sub 6 GHz 5G frequency band for the electromagnetic shielding. Modified square loop (MSL) is imprinted over an FR-4 substrate. Modification is done in such a way that metallic patches are attached at all four sides of traditional SL. The proposed design band rejects the 5.05 to 6 GHz frequency band with resonant frequency at 5.55 GHz. The design presents polarization independent characteristics with good angular stability up to 60° for both the incident polarized waves (TE and TM). The −20dB fractional impedance bandwidth is 17.19 % in both the polarization cases. The structure is designed over a cost effective FR-4 substrate. The dimensions of the proposed design are $8 \times 8\text{m}\text{m}^{2}$. The effective dimensions of the given unit cell is $0.14\lambda \times 0.14\lambda. \lambda$ here corresponds to the resonant wavelength.