Intelligent Reflecting and Refracting Surfaces for Swipt-Enabled 6G RF-Based Communications

In this paper, we introduce a novel architecture for simultaneous wireless information and power transfer (SWIPT) featuring a single transmitter, an Intelligent Reflecting and Refracting Surface with multiple elements, and two users respectively receiving the reflected and refracted signals. A time-switching (TS) architecture of SWIPT is employed at the receivers, enabling orthogonal energy harvesting (EH) and information decoding. We formulate an optimization problem to maximize the sum throughput while meeting the EH constraints at both users. The optimal transmit power is determined while ensuring constraint satisfaction. A bisection method is used to find the optimal TS ratio, leveraging the unimodal nature of the throughput and EH functions for computational efficiency and guaranteed convergence. Numerical simulations validate the proposed approach, demonstrating significant performance gains in SWIPT systems.