An Analytical Framework of Multisector Rectenna Array Design for Angular Misalignment Tolerant RF Power Transfer Systems

Abstract

A design procedure is presented for an angular misalignment-tolerant multisector rectenna array used as a wireless energy harvesting (WEH) system. The proposed analytical framework derives constraints on the synthesized harvested dc power pattern of the rectenna element as a solution to completely mitigate the angular misalignment. The derived constraints determine the optimal number of sectors required to ensure uniform harvesting capability across the entire azimuth plane. This is analytically verified for a conventional patch antenna used in the rectenna element of the multisector WEH system. The design constraints give <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N=8$ </tex-math></inline-formula> and 12 sectors the optimal solution for single patch and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2 \times 1$ </tex-math></inline-formula> patch array rectenna. Furthermore, a new multilayer wide-beam rectenna is proposed at 5.8 GHz requiring <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N=6$ </tex-math></inline-formula> sectors to mitigate the angular misalignment with 36.5% size reduction when compared with the conventional patch WEH system. The prototype of the WEH systems using the conventional patch rectenna and the proposed rectenna is fabricated and measured. The measurement results corroborate the analytical and simulation results validating the capability of the proposed framework to achieve uniform energy harvesting in the entire azimuth plane.