Dual-Band Dual-Polarized Stacked Rectenna for RF Energy Harvesting at 1.85 and 2.45 GHz

International audienceIn this paper, a 1.85 and 2.45 GHz dual-band dual-polarized rectenna for RF energy harvesting is designed and experimentally validated. The proposed rectenna consists of stacked circuits for both antenna and rectifier. The antenna is a dual-polarized array consisting of 4 single elements. Each polarization is associated with one frequency band of operation. The rectifier is built around a diplexer for the two input frequencies 1850 and 2450 MHz and a series-mounted Schottky diode. The insertion losses of the diplexer are significantly reduced which improves the conversion efficiency. The proposed rectenna is fabricated and measured, the experiments are in good agreement with the simulations. More than 500 and 400 mV dc voltage were measured across an optimal 2 k-Ohms load, with −8 dBm input power, at 1.85 and 2.45 GHz, respectively

RF Energy harvesting in urban environment using transparent rectenna arrays

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Compact and efficient 2.45 GHz circularly polarised shorted ring-slot rectenna

International audienceA compact and efficient rectenna based on a printed shorted annular ring-slot antenna with circular polarisation properties has been designed and evaluated at 2.45 GHz. The rectifier part is localised at the back side and centred inside the radiating element, resulting in a more compact structure in comparison with most conventional devices where rectifying circuit and antenna parts are geometrically clearly separated. In addition, the printed annular ring antenna is mismatched at the 4.9 GHz second and 7.35 GHz third harmonics, thus avoiding the use of an input lowpass filter. The proposed antenna and rectifier circuit have been first simulated and optimised separately using electromagnetic and circuit analyses, and then connected together. A maximum efficiency of 69% and an output DC voltage of 1.1 V have been measured over an optimised 2500 Omega resistive load at a power density of 20 mu W/cm(2). This rectenna is particularly suitable for powering wireless sensors or sensor networks by recycling ambient RF energy because it exhibits a global efficiency of more than 50% for power densities more than 10 mu W/cm(2.