Sensing and Reconfigurable Reflection of Electromagnetic Waves From a Metasurface With Sparse Sensing Elements
Sensing and Reconfigurable Reflection of Electromagnetic Waves From a Metasurface With Sparse Sensing Elements
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DOI：
10.1109/access.2022.3206831
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发表时间：
2022
期刊：
影响因子：
3.9
通讯作者：
Idban Alamzadeh;M. Imani
中科院分区：
文献类型：
--
作者：
Idban Alamzadeh;M. Imani
给定已知的入射信号，可重构反射表面可以形成规定的辐射模式，这种能力广泛用于雷达和成像系统中的波束形成，或用于改变无线通信网络中的传播环境。反射面要实现智能操作，需要自主获取入射方向和反射方向的相关信息。为了实现这一目标，我们设计了一种超表面，它可以产生可重构的辐射模式，并对事件信号进行压缩感知，使其能够适应其响应，而无需反馈回路或发射器或接收器的专用链接，从而为自主和智能操作铺平了道路。为了实现这样的操作，我们提出了一个由常规和混合两种元素组成的元表面。虽然这两种元件都被设计为反射信号，但混合元件允许将一小部分入射信号耦合到传感层。为了保证低损耗和复杂性，混合元件和相关传感电路的数量需要保持在较小的数量，这可能会降低传感性能。为了规避这个问题，我们开发了一种压缩感知方案，该方案利用元表面衬底内固有的信息多路复用，使用几个传感RF链检索相关信息，从而保证低成本和复杂性。作为一个说明性的例子，我们在数值上证明了使用所提出的结构的全波模拟来检测单个和多个入射光束到达角度的可能性。我们还表明，所提出的超表面可以形成所需的辐射模式，并且传感能力的引入对其主要功能的影响最小。提出的具有传感能力的智能可重构表面可以自主运行，并有利于无线通信、无线电力传输和成像系统。
Reconfigurable reflective surfaces can form prescribed radiation patterns given a known incident signal, a capability with widespread use for beamforming in radar and imaging systems or for altering the propagation environment in wireless communication networks. For reflective surfaces to operate intelligently, they need to acquire the relevant information about the incident and reflection directions autonomously. Toward this goal, we design a metasurface that can generate reconfigurable radiation patterns as well as perform compressive sensing of the incident signals, allowing it to adapt its response without requiring feedback loops or dedicated links to transmitters or receivers—paving the way for autonomous and smart operation. To realize such an operation, we propose a metasurface consisting of two types of elements, conventional and hybrid. While both elements are designed to reflect the signal, the hybrid ones allow coupling of a small portion of the incident signal into a sensing layer. To ensure low loss and complexity, the number of hybrid elements and the associated sensing circuitry need to be kept small, which can degrade sensing performance. To circumvent this issue, we develop a compressive sensing scheme that leverages the inherent multiplexing of information within the metasurface’s substrate to retrieve relevant information using a few sensing RF chains, thus guaranteeing low cost and complexity. As an illustrative example, we numerically demonstrate the possibility to detect angles of arrivals of single and multiple incident beams using full-wave simulations of the proposed structure. We also show that the proposed metasurface can form desired radiation patterns and the introduction of the sensing capabilities has a minimal impact on its main functionality. The proposed smart reconfigurable surface with sensing capabilities may operate autonomously and can benefit wireless communication, wireless power transfer, and imaging systems.