In this contribution, we present a metasurface-based dome to be placed above a bidimensional antenna array able to synthesize a radiation beam pointing towards the specific direction in elevation and azimuth defined by the antenna that is radiating. The metasurface is designed for acting similarly to the beamforming network, allowing controlling the beam direction by switching power to the desired beam port. The metasurface consists of a dense array of Huygens unit-cells, each of which exhibits an extremely low insertion loss and the desired phase shift. The profile of the transmission coefficient across the surface is engineered to transform the spherical phase fronts radiated by the antennas into a plane wave propagating towards a specific direction. Here, the operativity of the proposed metasurface is verified by illuminating it with a set of antennas arranged into a 6×6 array, enabling its capability to radiate towards 36 possible different directions. The metasurface dome reduces the complexity of the antenna system, avoiding the need for a beamforming network, and enables the activation of more than one beam, or even all of them, simultaneously.
Stefanini, L., Ramaccia, D., Bilotti, F., Toscano, A. (2021). Gradient metasurface dome implements a matrix beamforming network for 2D antenna arrays. In 2021 IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting, APS/URSI 2021 - Proceedings (pp.775-776). Institute of Electrical and Electronics Engineers Inc. [10.1109/APS/URSI47566.2021.9703914].