A Patch Rectenna Fed with L-probe to Harvest Solar and RF Energy

In this paper, a hybrid energy harvester consisting of a solar panel and a broadband loop rectenna is designed as a part of power management unit for IoT devices. The harvester comprises of a solar panel mounted on top of circular patch fed with an L-probe rectenna for RF energy harvesting. The rectenna achieves a monopole like radiation pattern in azimuth plane. The measured results demonstrate that at 630 μ W/cm2 power density for 858 MHz to 1.175 GHz, a DC output voltage of 0.647 V has been produced via a 10 KΩ resistor. The presented energy harvester is useful in mountainous or elevated areas where the majority of cellular towers are located at the same altitude as the sensor node of IoT device.