When Light Meets RF: Integrating SWIPT, SLIPT, and Backscattering for Localization

This paper introduces a hybrid energy-harvesting and communication system that combines radio frequency and optical power and data transfer to enable battery-free Internet of Things devices with localization capabilities. By designing a dual-band RF circuit at 880MHz and 2480MHz in conjunction with photovoltaic receiver, we integrate Simultaneous Wireless Information and Power Transfer (SWIPT), Simultaneous Light Information and Power Transfer (SLIPT), and RF backscatter. Experimental results demonstrate a 1Mbps downlink data rate and 16.73μW of harvested RF power for SWIPT, along with an uplink backscatter transmission at 880MHz. Moreover, the system achieves a 35kHz optical data transfer rate and 550μW of harvested optical energy under 400 l× illumination using an a-Si PV panel. Although organic photovoltaics perform similarly to a-Si for communication purposes, their energy-harvesting capacity is lower. Localization was conducted with respect to two LEDs placed 1meter apart by comparing the backscattered signal spectrum.These findings highlight the potential of this hybrid approach for real-time tracking, asset management, and pervasive sensing in environments such as warehouses, smart buildings, and healthcare facilities.