Different from previous phase gradient metasurfaces, in this letter we show that the spoof plasmon polariton conversion is dominated by the high-order surface wave modes rather than the pre-defined linear phase distribution. The latter becomes invalid due to the coupling between different metallic unit cells of the metasurface. To demonstrate this point, a metasurface, which includes six different H-shaped structures in a super cell, is designed based on the high-order surface wave modes with a nonlinear reflective phase distribution. The simulated and measured results support the proposed theory, that is, the designed metasurface can convert x- and y-polarized incident waves into spoof plasmon polariton at 8.9, 10.6, and 11.9 GHz. The metasurface not only verifies the mechanism of spoof plasmon polariton conversion, but also shows great potential in realizing cloaks, flat antennas, and so on.

中文翻译：

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基于反射超表面高阶模式的欺骗等离子体激元耦合器

与之前的相位梯度超表面不同，在这封信中，我们展示了欺骗等离子体激元转换由高阶表面波模式而不是预定义的线性相位分布主导。由于超表面的不同金属晶胞之间的耦合，后者变得无效。为了证明这一点，基于具有非线性反射相位分布的高阶表面波模式设计了一个超表面，在超级单元中包括六个不同的 H 形结构。模拟和测量结果支持提出的理论，即设计的超表面可以将 x 和 y 极化的入射波转换为 8.9、10.6 和 11.9 GHz 的欺骗等离子体激元。超表面不仅验证了欺骗等离子体激元转换的机制，