A 2.5D high stability dual bandstop frequency selective surface based on the square screw patch

In this paper, a novel dual bandstop frequency selective surface with excellent angle stability and polarization stability is proposed. The FSS structure is based on parallel LC-resonators, the metal vias are used to connect both top layer and bottom layer so that the equivalent element in the circuit can be enlarged or minished, the metal vias minimize the unit size greatly, which achieves 0.052λ×0.052λ. The thickness of the proposed FSS is 0.254mm. Simulation calculation and analysis through CST simulation software, the FSS forms two obvious bandstops near 1.24GHz and 2.78GHz. At different incident angles of electromagnetic wave, the stability of the two resonant points and the relative bandwidth of the bandstops of the FSS cell is exceedingly high. The measured results show that the proposed FSS has better polarization and incident angle stabilities compared with other FSSs.