A Dual Circularly Polarized Rectenna with Wide-Beam

In this paper, a novel dual-circularly polarized rectenna, with a wide 3-dB axial-ratio beam-width, operating in the WIFI band(the central frequency is 2.4GHz) is proposed for harvesting the ambient radio frequency (RF) energy. Here, the rectenna with two 50-Omega microstrip-fed ports are designed to realize both right-hand and left-hand circular polarization. Good isolation is achieved by reasonably adjusting the radius of the annular slots and the length of the feed microstrip. A prototype is manufactured and tested. Measured results are in reasonably good agreement with the simulated ones, exhibiting a 3-dB AR beam-width as wide as 120 degrees for both LHCP and RHCP. The measured polarization isolation is better than 20dB at 2.4GHz and reflection coefficient is better than 15 dB within the working band. In addition, the 3-dB ARBW is approximately 6.25% (2.32-2.48 GHz).