A retrodirective antenna (RDA) array for wireless power transmission (WPT) is presented. Applications include the wireless charging of mobile phones and other handheld devices. The reported RDA defines an active high-power transmitter module that retrodirects a received beacon tone back to a mobile unit by circularly polarized (CP) free-space radiation. In addition, this RDA architecture uses a network of four subarrays, defined by a total of 16 radiating patch elements, in an effort to boost the transmit gain while also reducing the supporting RF hardware requirements when compared to a more conventional RDA. Measurements and simulations in the reactive near-field of the system are in agreement in terms of the tracking capabilities of the high-power CP-RDA. Power levels in excess of 27 dBm were measured at 2.4 GHz at a receiver module, and when this RF power was rectified, more than 350 mW at dc was observed. To the best knowledge of the authors, this is the first demonstration of a WPT system using a mixer-based analog RDA. Previous low-power demonstrations were more complex computer-controlled systems that did not offer any real-time tracking ability. Other applications for the proposed RDA include target tracking, sensor charging, and other WPT systems.

中文翻译：

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用于无线电力传输的圆极化反向天线阵列

介绍了一种用于无线电力传输 (WPT) 的反向天线 (RDA) 阵列。应用包括手机和其他手持设备的无线充电。报告的 RDA 定义了一个有源高功率发射器模块，该模块通过圆极化 (CP) 自由空间辐射将接收到的信标音调回移动单元。此外，与更传统的 RDA 相比，这种 RDA 架构使用由四个子阵列组成的网络，由总共 16 个辐射贴片元件定义，以努力提高发射增益，同时还降低支持的 RF 硬件要求。系统无功近场中的测量和模拟在高功率 CP-RDA 的跟踪能力方面是一致的。超过 27 dBm 的功率电平是在 2.4 GHz 的接收器模块上测得的，当这个 RF 功率被整流时，在 dc 上观察到超过 350 mW。据作者所知，这是使用基于混频器的模拟 RDA 的 WPT 系统的首次演示。之前的低功耗演示是更复杂的计算机控制系统，不提供任何实时跟踪能力。提议的 RDA 的其他应用包括目标跟踪、传感器充电和其他 WPT 系统。