A Dual-Source Energy Harvesting Architecture for Smart Sensors: PV and 5.8 GHz Rectenna Integration

This paper presents a hybrid energy harvesting system combining photovoltaic (PV) and 5.8 GHz RF rectenna sources to provide continuous power for low-energy smart sensors. A 4×4 microstrip patch antenna array is developed and integrated with a voltage doubler rectifier using Schottky diodes, achieving a peak power conversion efficiency of 81.75% at 10 dBm input power. In parallel, a PV module modeled in Simulink delivers up to 6 W, with a maximum power point at 17.1 V and 3.5 A. To resolve the voltage mismatch between the PV and RF sources whose rectifier output reaches approximately 3.5 V individual DC-DC converters are used for each source, and their outputs are unified via a power management unit (PMU). The integrated system ensures a stable and efficient supply of energy, harvesting up to 30–35 Wh. This dual-source architecture enhances energy reliability and supports autonomous sensor operation under variable lighting and RF exposure conditions. It offers a robust solution for sustainable IoT deployments, especially in remote environments, paving the way for long-life, self-powered smart electronics.