Design of 2.5-dimensional miniaturized frequency selective surface

In this paper a novel 2.5-dimensional miniaturized frequency selective surface (FSS) is designed based on closed loop. The proposed miniaturized FSS consists of two main parts: the planar meandering lines and the vertical metallic via-holes. Compared with the previous miniaturized FSSs, the proposed FSS element has promising miniaturization characteristics with the dimension of a unit cell only 0.039λ×0.039λ, where λ is the wavelength of the resonant frequency. Moreover, the structure exhibits a high resonance stability with respect to different polarization and incidence angles.