On the Design of Modular Reflecting EM Skins for Enhanced Urban Wireless Coverage

The design of modular, passive, and static artificial metasurfaces to be used as electromagnetic skins (EMSs) of buildings for improving the coverage in urban millimeter-wave communication scenarios is addressed. Toward this end, an ad hoc design strategy is presented to determine optimal tradeoff implementation solutions that assure a suitable coverage of the areas of interest, where the signal from the base station is too weak, with the minimum complexity. More specifically, the admissible surface in the building facade is first partitioned into tiles that are the minimum-size elements of the artificial coating (i.e., the building block of an EMS). Then, the search for the optimal EMS layout (i.e., the minimum number and the positions of the tiles to be installed) is carried out with a binary multiobjective optimization method. Representative numerical results are reported and discussed to point out the features and the potentialities of the EMS solution in the smart electromagnetic environment (SEME) and the effectiveness of the proposed design method.