In this article, a triband highly selective widely‐spaced bandpass frequency‐selective surface (FSS) is presented. The proposed FSS is consisted of five metal layers that are separated from each other by four dielectric substrates. Using coupled resonance between layers, three passbands operating at 11.0, 17.4, and 31.9 GHz are achieved. Meanwhile, the dimension of the unit cell of the FSS can be achieved in 0.139λ₀ × 0.139λ₀ (λ₀ is the wavelength of the first resonant frequency in the free‐space), and the overall thickness can be 0.057λ₀, exhibiting miniaturization and low profile characteristics. Due to the proposed FSS can provide multitransmission zeros between two adjacent passbands, the relative bandwidth of the spacing between the second passband and the third passband can reach 58.8% from 17.4 to 31.9 GHz. Thus, a widely spaced response is achieved. In practical, the proposed FSS has an important role in the radio cross‐sectional reduction of some military systems, such as homing head, which can simultaneously detecting mid‐range and long‐range targets. Furthermore, the FSS shows the stable response of angles for both TE and TM polarizations. The equivalent circuit model (ECM) is provided to analysis its operating principle. Finally, a prototype of the proposed FSS is simulated, fabricated and measured. The measured results are in good agreement with the simulation ones.

中文翻译：

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使用耦合谐振的薄型小型化宽间隔三频带带通FSS

本文介绍了一种三频高选择性宽间隔带通频率选择表面（FSS）。提议的FSS由五个金属层组成，这些金属层被四个介电基板彼此隔开。使用层之间的耦合谐振，可以实现在11.0、17.4和31.9 GHz下工作的三个通带。同时，FSS的单位单元的尺寸可以在0.139实现λ ₀ ×0.139 λ ₀（λ ₀是在自由空间中的第一谐振频率的波长），和整体厚度可以是0.057 λ ₀，具有小型化和低调特性。由于提出的FSS可以在两个相邻通带之间提供多传输零点，因此第二通带和第三通带之间的间隔的相对带宽可以从17.4 GHz到31.9 GHz达到58.8％。因此，实现了宽间隔的响应。在实践中，拟议的FSS在某些军用系统（例如导航头）的无线电横截面缩小中具有重要作用，可以同时检测中距离和远距离目标。此外，FSS对TE和TM偏振均显示角度的稳定响应。提供等效电路模型（ECM）来分析其工作原理。最后，对所提出的FSS的原型进行了仿真，制造和测量。测量结果与仿真结果吻合良好。