Reconfigurable Intelligent Surface Assisted Wireless Energy Transfer: Concept and Experimental Validation

This talk introduces a proof-of-concept study on wireless power transfer technology leveraging a 1-bit beam-steering Reconfigurable Intelligent Surface (RIS). The proposed design utilizes a phase-shifting surface as the reflective unit cell, capable of both reflecting waves and providing precise reflection phase shifts. Each unit cell comprises a patch-ground-patch structure: the upper patch serves as the radiating element operating at 2.44 GHz, the middle layer functions as a ground patch to isolate the electric field, and the lower patch acts as a phase delay line, connected to the upper patch via a metal column. For reconfigurable functionality, the reflective unit cell is transformed into a 1-bit unit cell by integrating a PIN diode into the phase shift line. By toggling the PIN diode between on and off states, the unit cell achieves two phase states (0◦ and 180◦). A RIS composed of these 1-bit unit cells is designed, offering a beam-scanning range from −30◦ to +30◦. The proposed 1-bit beam-steering RIS can dynamically transmit electrical energy in various directions, making it suitable for wireless charging applications targeting devices with different orientations.