Metasurfaces 3.0: A New Paradigm for Enabling Smart Electromagnetic Environments

So far, the environment has been considered as a source of fading, clutter, and blockage, with detrimental consequences for efficiency and robustness of communication systems. However, the intense research developed toward beyond-5G communications is leading to a paradigm change, in which the environment is exploited as a new degree of freedom and plays an active role in achieving unprecedented system performances. For implementing this challenging paradigm, the use of intelligent surfaces able to control the propagation of electromagnetic (EM) waves has been recently proposed. In this framework, metasurfaces have emerged as a promising solution, thanks to their field manipulation capabilities achieved through low-cost, lightweight, and planar structures. The aim of this article is to review some recent applications of metasurfaces and cast them in the scenario of next-generation wireless systems. In particular, we show their potentialities in overcoming some detrimental effects presented by the environment in wireless communications and discuss their crucial role toward practical implementation of a smart EM environment.