The broad spectrum available at millimeter-wave (mmWave) bands has attracted significant interest for a breadth of applications, with 5G communications being the main commercial drive for mmWave networks. Wireless power transmission and harvesting at mmWave bands have attracted significant attention due to the potential for minimizing the harvesting antenna size, allowing for more compact rectennas. For a fixed antenna size, the received power increases with frequency. Nevertheless, several challenges lie in realizing high efficiency antennas and rectifiers at mmWave bands. This article reviews the recent advances in mmWave rectenna design at a component- and system-level. Low-cost antennas and components for mmWave power harvesting, such as high efficiency scalable rectifiers on polymers and high radiation efficiency antennas on textiles, are reviewed. Both the antenna and rectifier can be realized using low-cost fabrication methods such as additively-manufactured circuits and packages, in addition to digital integrated circuits (ICs) for the rectifiers. Finally, this article provides an overview of future antenna design challenges and research directions for mmWave power harvesting.

中文翻译：

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毫米波功率收集：回顾

在毫米波（mmWave）频段上可用的广谱引起了广泛应用的广泛兴趣，其中5G通信是mmWave网络的主要商业驱动力。毫米波频段的无线电力传输和采集已经引起了极大的关注，因为它有可能使采集天线的尺寸最小化，从而使更紧凑的整流天线成为可能。对于固定的天线尺寸，接收功率随频率增加。然而，在毫米波频段上实现高效天线和整流器仍存在一些挑战。本文回顾了组件级和系统级mmWave整流天线设计的最新进展。用于毫米波功率收集的低成本天线和组件，例如聚合物上的高效可扩展整流器和纺织品上的高辐射效率天线，被审查。除了用于整流器的数字集成电路（IC）之外，还可以使用低成本制造方法（例如，增材制造的电路和封装）来实现天线和整流器。最后，本文概述了未来天线设计面临的挑战以及mmWave功率收集的研究方向。