一种宽带带通三维频率选择表面设计及分析

基于方形波导结构提出了一种宽带带通三维频率选择表面(3D FSS).所提出的FSS的单元结构由上下端面刻蚀两个相同正方形金属贴片的介质方块和空气方形波导组成,此时每个端面形成了方形槽谐振单元.在电磁耦合作用下,方形槽谐振单元原有单一的谐振模式耦合分裂为奇模和偶模两种谐振模式,由此产生了两个传输极点,从而形成了一个平坦的二阶通带,且通带3 dB相对带宽为25.12%.通过等效电路模型,阐明了该FSS的工作原理.仿真结果显示:在TE和TM两种极化方式下,以0°到45°角度入射时所提出的FSS具有稳定的频率响应.此外,该3D FSS还具有相对较小的单元结构.

Design and analysis of wideband bandpass three-dimensional frequency selective surface

A wideband bandpass three-dimensional frequency selective surface (3D FSS) is proposed based on the square waveguide structure. The unit cell of the proposed FSS consists of a cuboid dielectric block with two identically-sized metallic square patches on the top and bottom surfaces and an air-filled square waveguide, in which each surface provides a square slot resonant structure.Theoriginal single resonant mode of the square slot resonance will split into even- or odd- resonant modes by the electromagnetic coupling. Thus, two transmission poles are introduced for obtaining a flat passband with second-order response, and its 3 dB fractional bandwidth of the passband is 25.12%.The operating principle of the proposed FSS is explained by the equivalent circuit model. The simulated results show that the proposed FSS exhibits a stable response to variations of incident angle from 0° to 45° under both TE and TM polarizations. In addition, this 3D FSS has a relatively small unit cell.