数字编码超表面:迈向电磁功能的可编程与智能调控

数字编码超表面是超材料与超表面领域的重要研究分支。通过数字编码方法替代等效媒质理论来表征超表面，不仅有效简化了超表面设计，而且建立了数字信息与超材料物理的联系。该文系统梳理数字编码超表面的发展历程，重点介绍其在可编程与智能电磁调控领域的最新研究进展。首先，详细介绍数字编码超表面的基本概念以及基于数字编码超表面的信息论研究；然后，具体介绍可编程超表面的工作原理和实现方式以及可编程超表面的不同研究方向，包括辐射式可编程超表面、多维度可编程超表面、时域数字编码超表面与新体制通信系统；接着，介绍智能超表面的最新研究进展，展示其环境感知与自适应电磁调控能力；最后，对超表面的未来发展进行讨论与展望。 

Digital Coding Metasurfaces: Toward Programmable and Smart Manipulations of Electromagnetic Functions

Digital coding metasurfaces are an important research branch of metamaterials and metasurfaces. The digital coding method replaces the equivalent medium theory to characterize metasurfaces, which not only simplifies the design process of metasurfaces but also builds a bridge between digital information and metasurface physics. The development of digital coding metasurfaces is systematically summarized in this review, and latest research progress of digital coding metasurfaces toward programmable and smart ElectroMagnetic (EM) manipulations is highlighted. First, the basic concept of digital coding metasurfaces and corresponding research in information theory are thoroughly explained. Next, the working principle, realization method, and different research directions of programmable metasurfaces are detailed, including radiation-type programmable metasurfaces, multidimensional programmable metasurfaces, time-domain digital coding metasurfaces, and new wireless communication systems. The recent research on smart metasurfaces is then introduced, and their capabilities of environment sensing and adaptive EM manipulation are demonstrated. Finally, the future development and prospects of metasurfaces are also discussed.