The Internet of Things (IoT) connects billions of smart devices through wireless sensor networks (WSNs). However, to ensure the power supply for numerous passive devices in a WSN, it is necessary to replace batteries periodically, which will undoubtedly increase maintenance costs. This study proposes a capacitive coupling structure that is different from the previous capacitive power transfer (CPT) structures. The proposed structure can allow the positional variation of the receiver, and multiple receivers to be charged at the same time. Both theoretical and experimental results demonstrate that the power transmission is less affected by the positional variation of the pickup plates in the vertical and horizontal directions. In this study, all coupling capacitors between the plates are considered and the equivalent circuit model is derived. Further output characteristics of the circuit are derived and analysed. The dimensions of the structure are designed and simulated by using the EM full wave simulation. A prototype is designed to verify that a battery can be charged based on capacitive coupling. A 60 mAh rechargeable lithium-ion button battery is fully charged in 250 min, and the output power is ∼36 mW during charging.

中文翻译：

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对位置不敏感的无线充电的电容耦合结构设计

物联网（IoT）通过无线传感器网络（WSN）连接数十亿个智能设备。但是，为了确保WSN中众多无源设备的供电，必须定期更换电池，这无疑会增加维护成本。这项研究提出了一种电容耦合结构，该结构与以前的电容功率传输（CPT）结构不同。所提出的结构可以允许接收器的位置变化，并且可以同时对多个接收器进行充电。理论和实验结果均表明，功率传输受拾取板在垂直和水平方向上位置变化的影响较小。在这项研究中，考虑了极板之间的所有耦合电容器，并推导了等效电路模型。导出并分析电路的其他输出特性。通过使用EM全波模拟设计和模拟结构的尺寸。设计了一个原型，以基于电容耦合来验证电池是否可以充电。60毫安时可充电锂离子纽扣电池在250分钟内充满电，充电时输出功率约为36 mW。