Tailored and reconfigurable Huygens' metasurfaces

下一代无线网络将严重依赖带宽丰富的毫米波频段（30 GHz-300 GHz），以支持新兴应用，如物联网（IoT），5G蜂窝，通过卫星的宽带互联网服务和联网的自动驾驶汽车。在这些频率下，电力成为一种珍贵的商品，而波的传播则由视线过程主导。因此，业界正在大力开发相控阵天线，以便软件驱动的专用波束被引导到用户以节省功率，实现先进的频谱管理并保持视线连接。尽管毫米波频率的IC技术取得了惊人的进步，但这种相控阵天线的部署在成本和功耗方面仍然是一个重大挑战。因此，迫切需要进行变革性的研究，研究如何在传统相控阵之外随意操纵电磁波。在这个项目中，我们将使用惠更斯超颖表面的新范例来应对这一挑战：工程电磁表面可以以前所未有的方式控制电磁波。在这个项目中，我们将开发新的开创性研究方向，将这种技术带到一个新的水平。例如，将开发定制的超表面，使得入射波可以以期望的偏转角折射或反射，但具有完全定制的远场图案（例如，受控的旁瓣水平和波束宽度）。这将在不需要传统天线阵列中的功耗馈电网络的情况下实现。这些表面可以从附近的小规模天线阵列馈电，从而为新兴的5G移动的和卫星网络提供低成本和低轮廓的整体强大的天线平台。此外，将追求一个全新的方向，其中这些超颖表面由合适的金属化制成，以使它们光学透明。

The next generation of wireless networks will rely heavily on the millimetre-wave band (30GHz-300 GHz) where bandwidth is abundant in order to support emerging applications such as the Internet-of-things (IoT), 5G cellular , broadband internet service via satellites, and networked autonomous vehicles. At these frequencies, power becomes a precious commodity whereas wave propagation is dominated by line-of-sight processes. Hence industry is fiercely developing phased-array antennas such that, software-driven, dedicated beams are steered to users to save power, achieve advanced spectrum management and maintain line-of-sight connectivity. Despite spectacular advances in IC technologies at mm-wave frequencies, the deployment of such phased array antennas remains a major challenge in terms of cost and power dissipation. Therefore, there is a pressing need for transformative research on how to manipulate electromagnetic waves at will, beyond traditional phased arrays. In this project we will address this challenge using the new paradigm of the Huygens' metasurface: Engineered electromagnetic surfaces that can control electromagnetic waves in unprecedented ways. In this Project we will develop new pioneering research directions to bring this type of technology to the next level. For example, tailored metasurfaces will be developed such that incident waves can be refracted or reflected at a desired deflection angle but with completely tailored far-field patterns (e.g. controlled side-lobe levels and beamwidth). This will be achieved without the need of a power-consuming feeding network as in traditional antenna arrays. These surfaces could be fed from nearby small-scale antenna arrays thus providing an overall powerful antenna platform that is low cost and low profile for emerging 5G mobile and satellite networks. In addition, an entirely new direction will be pursued where these metasurfaces are made out of suitable metallizations to render them optically transparent.