A high gain wideband circularly polarized rectenna with wide ranges of input power and output load

This paper introduces a wideband circularly polarized rectenna that can harvest efficiently ambient wireless power with bandwidth from 1.7 to 2.6 GHz in both wide operating power and output load ranges. The rectenna is based on a high gain wideband slot microstip receiving antenna array and a wideband rectifier with a branch-line coupler that appropriately improve the RF-dc conversion efficiency at ambient wireless power level in a wide input power range, working frequency and a wide load impedance range. The circular polarization is obtained using by corner perturbation on a square radiation patch and has a bandwidth for axial ratio < 6 dB from 1.65 to 2.76 GHz. An example of the antenna and rectifier circuit have been designed, fabricated and tested. In the proposed rectifier, a peak efficiency of 69% with 12 dBm input power and 64% with 10 dBm input is obtained for a load of 1 KΩ at 1.85 and 2.45 GHz, respectively. The efficiency and dc output of the proposed rectenna is also measured at different frequencies and received power levels with a load resistance of 1 kΩ. The rectenna depicts well performance for the real applications with a much-easy configuration and decreased cost.