MIMO WiFi Imaging Based on Reconfigurable Passive EM Skins

The integration of Reconfigurable Passive Electro-magnetic (EM) skins in WiFi-based Imaging systems offers a smart and cost-effective improvement of achievable resolution. The research about smart displacement of properly designed RISs has already proved the capability to overcome the spatial resolution limitations given by off-the-shelf WiFi systems. This article looks into a RIS-aided WIFi imaging system based on MIMO antennas for achieving high-resolution results. After drafting a valuable beamforming model to account for RIS presence, we discuss about the performance carried out by a MIMO based RX-TX compared to single-antenna case. This investigation takes also into account the modeling of different phase contributions provided by the $M$ × $N$ single cells displaced over the passive surface. Particular attention will be given to the finite phase quantization, negatively impacting over imaging resolution.