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 $50-\mathbf{\Omega}$ 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° 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).