A Self-Powered Reconfigurable Intelligent Metasurface

In recent years, reconfigurable intelligent metasurface (RIS) has gained much attention due to its flexibility in modulating the phase, amplitude, and polarization of electromagnetic waves. It is widely used for wireless power and information transmission. However, RIS requires an external wired power supply or batteries to activate their modulation capabilities, as they do not generate the required energy themselves. This paper presents a self-powered RIS that does not require an external wired power supply or batteries. The modulation capability is activated by harvesting radio frequency (RF) energy. The self-powered RIS consists of an energy-metatom, which is loaded with a PIN diode for flexible phase modulation. The inclusion of an absorber/energy port on the energy-metatom allows for independent RF energy harvesting. The RIS consisting of energy-metatoms can cut out all wired power supplies and batteries so that it can dynamically regulate electromagnetic waves by self-powered means. As a proof-of-concept, a prototype composed of 10 x 10 energy-metatoms is fabricated. The measured results are in good agreement with the simulated. This self-powered RIS can be used as an "infinite-lifetime" power supply for dynamic electromagnetic modulation in the RIS. The proposed self-powered RIS that does not require an external wired power supply or batteries, i.e. tail-less. The reflection phase responses are determined by PIN diodes in the x-direction. The EM energy is harvested by the absorption/energy port in the y-direction, which can be used to bias PIN diodes. By arranging specific reflection coding sequences, the x-polarization reflection beams can be modulated without manual battery replacement or wired charging.image