A novel compact broadband rectenna for ambient RF energy harvesting

In this paper, a novel compact broadband rectifying antenna (rectenna) is presented for ambient radio frequency (RF) energy harvesting. Slot antennas with excellent bandwidth and matching characteristic are designed by etching fractal geometries with different iteration order on a radiation patch. A rectifier with a single stub matching network is investigated for impedance matching and the RF to DC conversion efficiency is improved at low input power. Simulation and the experiments have been carried out to evaluate the performance of antenna and rectifier respectively. A good match is observed between the simulated and measured results. The experimental results show that antenna features a broad bandwidth from 2.15 GHz to 2.9 GHz and the maximum conversion efficiency of rectifier is up to 64% at 0 dBm. The highest conversion efficiency of rectenna is 62% and the maximum output voltage is 1.5 V at the input power of 0 dBm.