RF energy harvesting using high impedance asymmetric antenna array without impedance matching network

This manuscript presents a rectenna with a high impedance asymmetric antenna array for ambient wireless energy harvesting at the 2.45 GHz frequency band. It is fulfilled without using any impedance matching networks, which demonstrations significant benefits over available rectennas as a function of the layout and cost with a wide range of input power level and load impedance. A rectenna prototype has been designed, fabricated, and tested. The rectenna configuration is etched on a single layer, commercial, low-cost FR4 substrate. Simulation and experiments have been carried out. The results show that the proposed rectenna features a good characteristic of RF to DC conversion efficiency. Over 60% (up to 67%) RF-DC conversion efficiency is realized for the input power levels from 12 to 21 dBm and load impedance between 1,200 and 8,100 Ω. The proposed rectenna can be suitable for powering many low-power electronic devices, because of simple structure and low cost.