Holographic Smart EM Skins for Advanced Beam Power Shaping in Next Generation Wireless Environments

Abstract

An innovative approach for the synthesis of inexpensive holographic smart electromagnetic (EM) skins with advanced beamforming features is proposed. The complex multiscale smart skin design is formulated within the Generalized Sheet Transition Condition (GSTC) framework as a combination of a mask-constrained isophoric inverse source problem and a micro-scale susceptibility dyadic optimization. The solution strategy integrates a local search procedure based on the iterative projection technique (IPT) and a Systemby-Design (SbD)-based optimization loop for the identification of optimal metasurface descriptors matching the desired surface currents. The performance and the efficiency of the proposed approach are assessed in a set of representative test cases concerned with different smart skin apertures and target pattern masks.

Conformal Metasurfaces: a Novel Solution for Vehicular Communications

“…Although (18) contains three differential equations, only two equations are mutually independent, i.e., Φ(x, y, z) = Φ(x, f (x, z), z). Therefore, the phase increment along any tangential direction on the surface can be expressed as…”

“…These surfaces are made by nearly passive arrays of sub-wavelength sized elements whose complex reflection coefficient can be tuned (either amplitude and phase, or phase only) to manipulate the impinging wavefront and control the reflection angle [16]. Herein, we refer to reconfigurable intelligent surfaces (RIS) when the amplitude and phase of each element can be set in real-time [17] and to intelligent reflecting surfaces (IRS) when it is pre-configured and not tunable after manufacturing [18]. Although the RIS and IRS terminologies are often used interchangeably in literature, we herein stress this distinction to distinguish between fully passive surfaces (IRS) and nearly passive ones (RIS).…”

“…By contrast, IRS can offer a fully passive alternative to RIS when either the deployment cost is excessive or the incidence/reflection angles are not a-priori known and cannot be properly estimated. For instance, IRS can be deployed on buildings to enrich the environment scattering, improving the coverage and the average communication performance over different users in different positions in space [18], [29]. However, the density of building-deployed metasurfaces required for coverage might be critical in highly urbanized areas, especially to support V2V communications at the road level.…”

Planning of EM Skins for Improved Quality-of-Service in Urban Areas

“…The smart electromagnetic environment (SEME) is without any doubt a promising and revolutionizing concept for the design of future wireless communications systems [1]- [4]. It is based on the idea that the environment should be no more regarded as an uncontrollable impairment to the overall quality-of-service (QoS).…”

“…It is based on the idea that the environment should be no more regarded as an uncontrollable impairment to the overall quality-of-service (QoS). Conversely, it should be exploited as a powerful "tool" to enable unprecedented manipulations of the complex electromagnetic (EM) phenomena for enhancing the overall coverage, the data throughput, and the QoS [3] [4]. As a matter of fact, fitting ever-growing needs for ubiquitous connectivity and low latency/resiliency of forthcoming communication standards, also beyond the fifth-generation (5G) [5]- [9], will be possible only if the propagation scenario will play a fundamental role in counteracting the distortions, the delays, the losses, and the fading of the EM waves radiated by the base-stations (BTSs).…”