Abstract Wireless sensor networks are increasingly deployed in Internet of Things (IoT) applications, demanding self‐powered solutions to overcome the limitations of conventional batteries. Radio frequency energy harvesting (RFEH) offers a practical means to scavenge ambient RF power from ubiquitous sources such as mobile base stations, enabling sustainable operation of remote or inaccessible devices. This work presents a complete RFEH system integrating a microstrip patch antenna array, impedance matching network, and rectifier circuit, optimized for the 2.1 GHz 3G downlink band. Full‐wave simulations predict a resonance at 2.1 GHz, realized gain of 5.1 dBi, 60 MHz bandwidth, and half‐power beamwidth of . Circuit‐level simulations indicate a rectifier DC output of 3.575 V under nominal excitation. Experimental measurements in an anechoic chamber confirm the predicted antenna performance and demonstrate a 706 m output under ambient 3G exposure, sufficient to illuminate an LED load. The discrepancy between simulation and measurement is attributed to lower ambient power levels, propagation losses, and rectifier nonlinearity. In contrast to prior RFEH studies centered on single‐element rectennas, multi‐band harvesting circuits, or controlled‐source demonstrations, the present work emphasizes a complete 2.1 GHz UMTS harvesting prototype based on a compact patch array. The measured antenna performance and the ambient 3G experiment, which produced 706 m and illuminated an LED, confirm the feasibility of system‐level RFEH for low‐power IoT nodes without a dedicated RF power transmitter.
Saleem et al. (Wed,) studied this question.