Hosseininejad Seyed Ehsan, Khalily Mohsen, Tafazolli Rahim
Institute for Communication Systems (ICS), Home of the 5G and 6G Innovation Centres, University of Surrey, Guildford, UK.
Sci Rep. 2025 Mar 31;15(1):10964. doi: 10.1038/s41598-025-95415-x.
Two-dimensional (2D) space-encoded metamaterials enable the progressive development of a multitude of functionalities for controlling electromagnetic (EM) waves. Recently, time-modulated phase-coded metasurfaces have been introduced into 2D metamaterials, allowing for EM wave manipulation across both spatial and frequency domains. This approach is naturally suited to microwave frequency range where the compact phase controlling elements, such as diodes and varactors are readily available. However, as future generation communication systems target frequencies above 100 GHz with a much higher speed and more densification, enhanced solutions utilizing the novel concepts will be inevitable because the metasurface integration with the common active elements is challenging. Here, we propose the space-time 1-bit amplitude-coded metasurfaces instead of phase-coded one to support the complex functionality for the intelligent control of the environment in wireless communication systems. The solution is implemented using graphene-based meta-atom, where 1-bit amplitude-coding is reconfigurable via bias voltage. To validate the effectiveness of this approach for beam shaping, we demonstrate beam steering with low sidelobe patterns by achieving the desired effective amplitude and phase distributions. This proposed method is anticipated to broaden the applications of digital coding metasurfaces, particularly in THz wireless communication systems.
二维（2D）空间编码超材料能够逐步开发出多种用于控制电磁波（EM）的功能。最近，时间调制相位编码超表面已被引入二维超材料中，从而实现了跨空间和频域的电磁波操纵。这种方法自然适用于微波频率范围，在该范围内，诸如二极管和变容二极管等紧凑的相位控制元件很容易获得。然而，由于下一代通信系统的目标频率高于100GHz，速度更快且更加密集，利用新颖概念的增强解决方案将不可避免，因为超表面与普通有源元件的集成具有挑战性。在此，我们提出时空1比特幅度编码超表面而非相位编码超表面，以支持无线通信系统中对环境进行智能控制的复杂功能。该解决方案使用基于石墨烯的元原子来实现，其中1比特幅度编码可通过偏置电压进行重构。为了验证这种方法对波束成形的有效性，我们通过实现所需的有效幅度和相位分布，展示了具有低旁瓣方向图的波束转向。预计这种提出的方法将拓宽数字编码超表面的应用，特别是在太赫兹无线通信系统中。
