Radio-frequency (RF) energy harvesting (RFEH) and radiative wireless power transfer (WPT) have attracted significant interest as methods of enabling battery-free sustainable wireless networks. Rectifying antennas (rectennas) are the cornerstone of WPT and RFEH systems and critically affect the amount of dc power delivered to the load. The antenna element of the rectenna directly impacts the radiation-to-ac harvesting efficiency, which can vary the harvested power by orders of magnitude. In this article, antenna designs employed in WPT and ambient RFEH applications are reviewed. Reported rectennas are categorized based on two main criteria: the antenna-rectifier impedance bandwidth and the antenna's radiation properties. For each criterion, the figure of merit (FoM) is identified for different applications and reviewed comparatively.

中文翻译：

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用于射频能量收集和无线电力传输的整流天线：天线设计回顾 [天线应用专区]

射频 (RF) 能量收集 (RFEH) 和辐射无线电力传输 (WPT) 作为实现无电池可持续无线网络的方法引起了极大的兴趣。整流天线 (rectennas) 是 WPT 和 RFEH 系统的基石，它严重影响输送到负载的直流功率量。整流天线的天线元件直接影响辐射到交流的收集效率，这可能会在数量级上改变收集的功率。在本文中，回顾了 WPT 和环境 RFEH 应用中采用的天线设计。报告的整流天线根据两个主要标准进行分类：天线-整流器阻抗带宽和天线的辐射特性。对于每个标准，品质因数 (FoM) 被确定为不同的应用程序并进行比较审查。