Quantitative Evaluation of Ambient RF Energy Contribution in Hybrid LED Micro-Illumination Systems

This work provides a rigorous feasibility analysis of ambient RF energy harvesting for ultra-low-power LED illumination. Using conservative power density estimates, rectifier efficiency limits, and storage losses, we demonstrate that typical residential RF environments provide only μW-level harvested power—insufficient for continuous lighting. Practical operation is limited to pulsed modes or deployment near high-power transmitters. Optical water-bottle diffusion is treated as angular redistribution, not amplification. The study establishes realistic engineering boundaries for RF-assisted micro-illumination systems.