A novel low-profile tri-band bandpass frequency-selective surface (FSS) is proposed in this paper. The structure is designed by the two-dimensional repetition of a unit cell consisting of four apertures. Each aperture is a combination of T-shaped, U-shaped and a rectangular-shaped aperture aligned horizontally or vertically. The performance of the designed FSS structure is independent of the angle of incidence of the incident wave due to the orientation of the apertures in the unit cell. The designed FSS structure operates at the desired frequency bands close to 8-14 GHz. The insertion loss is close to 3.26, 2.68 and 1.12 dB at the respective frequencies of 8.1, 9.8 and 11 GHz. The advantage of this design is that it exhibits tri-band characteristics for various angles of incidence of the incident wave even though it is a low-profile single layer structure. The total dimensions of the unit cell are approximately 0.55 λ₀ × 0.55 λ₀ at 8 GHz.

本文提出了一种新颖的低调三频带通频率选择表面（FSS）。通过由四个孔组成的晶胞的二维重复来设计该结构。每个孔是水平或垂直排列的T形，U形和矩形孔的组合。设计的FSS结构的性能与入射光的入射角无关，这归因于晶胞中孔的方向。设计的FSS结构在接近8-14 GHz的所需频段上运行。在8.1、9.8和11 GHz的相应频率下，插入损耗接近3.26、2.68和1.12 dB。这种设计的优点是，即使它是低矮的单层结构，它对于入射波的各种入射角仍表现出三波段特性。晶胞的总尺寸约为0.55λ₀ ×0.55λ ₀在8GHz。