Active metasurfaces pave a way for manipulating electromagnetic (EM) waves in real-time by incorporating with tunable materials or components, emerging as an attractive solution to achieve versatile EM functionalities in dynamic fashions. However, most of the active metasurfaces demonstrated so far only support tunable responses for a certain single frequency band, or have obvious frequency cross-talks that cannot provide dual-band independent operations, limiting their further uses in practical applications. Here, we propose a 1-bit high-efficiency programmable metasurface to achieve completely independent functions with real-time reconfigurability controlled by FPGA hardware system in both C-band and X-band. Specifically, the metasurface is designed with abilities of generating multi-beams or twin-beam scanning in the low frequency band while dynamic beam-scanning in high frequency band. As the experimental verifications, a double-layered metasurface has been fabricated and tested, and the measured results agree well with the simulations, demonstrating its abilities of independent, high-efficiency, real-time, and programmable manipulation of EM waves in two discrete frequency bands. The proposed concept may largely enhance the information capacity of the metasurface, bringing new degrees of freedom in achieving versatile tunable functionalities and offering useful applications in the radar and wireless communication systems.

中文翻译：

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用于双波段独立实时光束控制的可编程编码超表面

有源超表面通过结合可调材料或组件为实时操纵电磁 (EM) 波铺平了道路，成为以动态方式实现多功能 EM 功能的有吸引力的解决方案。然而，迄今为止所展示的大多数有源超表面仅支持某个单一频段的可调响应，或者具有明显的频率串扰，无法提供双频段独立操作，限制了它们在实际应用中的进一步应用。在这里，我们提出了一种 1 位高效可编程超表面，以在 C 波段和 X 波段由 FPGA 硬件系统控制的实时可重构性实现完全独立的功能。具体来说，超表面设计具有在低频段产生多光束或双光束扫描而在高频段产生动态光束扫描的能力。作为实验验证，已经制作并测试了双层超表面，测量结果与模拟结果吻合良好，证明了其在两个离散频率下独立、高效、实时和可编程操纵电磁波的能力乐队。所提出的概念可以在很大程度上增强超表面的信息容量，为实现多功能可调功能带来新的自由度，并在雷达和无线通信系统中提供有用的应用。实测结果与仿真结果吻合较好，证明了其在两个离散频段内独立、高效、实时、可编程操纵电磁波的能力。所提出的概念可以在很大程度上增强超表面的信息容量，为实现多功能可调功能带来新的自由度，并在雷达和无线通信系统中提供有用的应用。实测结果与仿真结果吻合较好，证明了其在两个离散频段内独立、高效、实时、可编程操纵电磁波的能力。所提出的概念可以在很大程度上增强超表面的信息容量，为实现多功能可调功能带来新的自由度，并在雷达和无线通信系统中提供有用的应用。