Wireless power transfer (WPT) plays critical roles in powering deep-tissue implants, which also contributes to several emerging advances for biomedical engineering. To enable a high-power density region in implants, this article presents a method, termed the self-phasing technology, to focus electromagnetic fields from various paths at a deep-tissue spot. By performing the phase-conjugated operation on the incident signal and then retransfer back to the source, coherent RF power can be achieved without learning the precise or even dynamic locations of sources and concerning inhomogeneous medium perturbations. An external slot antenna array placed above skin surface 4 mm is considered as a transmitter and an implanted rectenna consisting of a magnetic resonant coil and an RF-to-dc rectifier circuit is treated as a receiver. The conversion efficiency of the rectifier circuit is optimized within the received power range and the measured efficiency of 50% can be achieved at 0 dBm. To visualize the transceiver effects of the integrated system under safety thresholds, a light-emitting diode (LED) is soldered at the terminal of the rectenna and measurements show that smooth drive can be achieved. Certain brightness of LED can demonstrate that the self-phasing technology can support WPT for biomedical applications.

中文翻译：

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近场无线电力传输到用于生物医学应用的深层组织植入物

无线电力传输 (WPT) 在为深部组织植入物供电方面发挥着关键作用，这也有助于生物医学工程的多项新兴进展。为了在植入物中实现高功率密度区域，本文提出了一种称为自定相技术的方法，将来自不同路径的电磁场聚焦在深部组织点。通过对入射信号执行相位共轭运算，然后再传输回源，可以在不了解源的精确甚至动态位置以及不均匀介质扰动的情况下实现相干射频功率。放置在皮肤表面上方 4 mm 的外部缝隙天线阵列被视为发射器，由磁共振线圈和 RF-to-dc 整流器电路组成的植入式整流天线被视为接收器。在接收功率范围内优化整流电路的转换效率，在 0 dBm 时可实现 50% 的实测效率。为了在安全阈值下可视化集成系统的收发器效果，在整流天线的端子处焊接了一个发光二极管 (LED)，测量表明可以实现平稳驱动。LED 的一定亮度可以证明自定相技术可以支持生物医学应用的 WPT。