In this letter, high-order mode dispersion of a novel spoof surface plasmon polariton (SSPP) unit cell is reported, which has excellent bandpass propagation feature. Its asymptotic frequency and intersection frequency with light line can be independently manipulated by changing the geometric parameters of the slot in proposed SSPP unit cell. In order to validate the feasibility of high-order mode of SSPPs applied in the design of bandpass filters, two SSPP waveguides based on the method with different bandwidths are fabricated and measured. No mode-conversion transition part is introduced in the procedure of waveguide design which avoids extra addition of layout area and reduces complexity of devices. The measurements show that the proposed SSPP waveguide based on high-order mode characteristics can achieve bandpass signal propagation smoothly with controllable bandwidth.

中文翻译：

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伪表面等离激元极化子在带通滤波器设计中的高阶模式应用

在这封信中，报道了一种新型的欺骗性表面等离子体激元极化子（SSPP）晶胞的高阶模色散，它具有出色的带通传播特性。可以通过更改建议的SSPP单元中缝隙的几何参数来独立地控制其渐近频率和与光线的相交频率。为了验证在带通滤波器设计中应用高阶模式的SSPPs的可行性，制造并测量了两种基于带宽不同的方法的SSPP波导。在波导设计过程中没有引入模式转换过渡部分，从而避免了额外增加布局面积并降低了设备的复杂性。