RFID-Based Reconfigurable Intelligent Surfaces: Towards Wireless and Ultra-Low-Power Reconfigurability

Reconfigurable Intelligent Surfaces (RISs) are in-novative smart surfaces, composed by several tunable sub-wavelength scatterers, which provide the capability to control the wireless propagation environment. However, RIS widespread adoption faces obstacles such as high-power requirements for the driving hardware and the need for physical wires for reprogramming. In this study, we propose an architecture that leverages Radio Frequency Identification (RFID) antennas as wireless controllers for RIS unit cells. The rationale is that modern RFID Integrated Circuits (ICs) are programmable and can act as DC power sources using a coin battery. The proposed architecture could significantly reduce costs compared to traditional reprogramming hardware, eliminating the need for physical wiring. As a preliminary proof of concept, we developed a Yagi-Uda antenna with pattern reconfiguration capabilities. Our results demonstrated the feasibility of this approach, with a close match between simulations and measurements. Future research will explore the potential of battery-less ICs for this application.