Sub-GHz RF Energy Harvester including a Small Loop Antenna

To achieve the exponential growth needed for a 1-trillion-node Internet of Things (IoT) in the next decade, innovative solutions are required to eliminate recurring battery replacement costs. Radio frequency (RF) energy harvesting allows the IoT node to harvest ambient electromagnetic energy and reduce the dependence on battery power consumption. The performance of the RF energy harvester depends on the power conversion efficiency (PCE), the strength of the incident RF energy, the gain of the harvester antenna, and the power transmission coefficient. It is also imperative to enhance the sensitivity of the RF energy harvester to ensure a startup at ultra-low input power levels [1].