Curved Electromagnetic Skins for Smart Electromagnetic Environments

Recently, the definition and use of a Smart Electromagnetic Environment (SEE) has been emerging as a key concept for the development of the next generation communication systems [1, 2], able to provide huge data rates with very low latency, ubiquitous mobile, ultra-broadband connectivity, seamless coverage, guaranteeing at the same time a reduced power consumption. The idea is that of considering the environment in which the propagation occurs as a further degree of freedom of the wireless network. Its use is possible only thanks to the use of Smart Electromagnetic Skins (SES), that are (planar) surfaces, consisting in many resonant or sub-wavelength elements, arranged is such a way that they provide an anomalous reflection, according to which the incident field covers a desired area. Depending on their operating principle and mode, SESs can be divided in static (passive) surface, designed to provide a desired coverage for a given direction of arrival of the incident field, and dynamic surfaces, able to furnish some reconfigurability. While in a SEE both the solutions are present, here the focus is on the static one. Even if SES are originally supposed to be planar, for its possible integration in the wall of building, in some cases, as for instance in historical city centers or when there is not enough room for their placement on the building facades, this solution is not feasible. An alternative consists in using a curved surface, that can be mounted on structures as street light or stop light poles.