Compact Fully Integrated Rectenna System with a Reconfigurable Power Management System for Energy Harvesting at 2.45 GHz

This paper presents a fully integrated and compact rectenna system designed for radio frequency energy harvesting at 2.45 GHz, aimed at powering low-power applications such as semi-passive and active radio frequency identification systems. The rectenna system co-optimizes the antenna and rectifier, eliminating the need for an impedance matching network, thereby reducing transfer losses and its size. A reconfigurable central power management system and a supercapacitor are incorporated, featuring maximum power point tracking, enabling efficient power harvesting and delivery. The antenna design is based on a meandered-line planar inverted-F antenna, which provides compactness, ease of integration on a low-cost FR4 substrate, and an omnidirectional radiation pattern. Over-the-air power conversion efficiency measurements were conducted, demonstrating high efficiency at low input power levels, ranging from −13 dBm to −1 dBm. The system's functionality was further validated by powering a wireless body temperature sensor application, featuring a packet update rate of 14m24s for an input power level of −100 dBm.