A High-Performance Circularly-Polarized Rectenna for WirelessEnergy Harvesting at 1.85 and 2.45 GHz Frequency Band

Abstract : This paper deals with the design and experiments of a dual-band circularly polarized rectenna at 1.85 and 2.45 GHz. It uses a single antenna and a single RF-to-dc rectifier. The circuit contains a dual-band circularly polarized antenna and a dual-band RF-to-dc rectifier based on a miniaturized 180 • hybrid ring junction. The ring junction is used to independently match the sub-rectifiers at each frequency. The proposed rectenna was experimented with single-tone and multi-tone incident waves. It achieves more than 300 mV and 40% efficiency, across a 4-kΩ resistive load, at very low power density of 1.13 µW/cm 2 at 1.85 GHz and 1.87 µW/cm 2 at 2.45 GHz. It also achieves more than 150 mV under the same load condition and in the critical case when receiving only one of the two frequency bands. It is dedicated to harvest RF energy in the GSM 1800 and the 2.45-GHz ISM bands, regardless the polarization angle of the incident waves.