High-Efficiency 2-D Multibeam Rectenna Based on Gain Enhanced Patch Array

Abstract

Wireless power transfer (WPT) is a promising technique used in many applications, like smart terminals, IoT equipment, etc. For WPT systems based on RF rectifying, working in very low power density situation, high-gain rectenna system is of great essential. According to the antenna theory, for the same physical size, higher gain means higher aperture efficiency, which means more power will be received by the antenna instead of being scattered. However, high-gain rectenna usually means narrow beam width and high directivity, which is contradictory to a power harvesting system that need to have wide spatial coverage. In order to realize high aperture efficiency and wide spatial coverage at the same time, a two-dimensional (2-D) multibeam rectenna based on gain enhanced patches and hybrid coupler is proposed, which can improve the 2-D spatial coverage and achieve the maximum 81.5% power receiving efficiency. Simulation and experimental results indicate that the power receiving efficiency is more than 50% with 100° coverage in main beam cutting plane, 70° in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> -plane, and 90° in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</i> -plane. The practicality of this letter is fully verified, which can help to provide a guidance for the design of rectenna.