This work introduces a novel design for high efficiency and compact size dual-frequency wireless power transfer (DF-WPT) systems. The proposed design is composed of two identical transmitting (Tx) and receiving (Rx) substrates. Each substrate has a microstrip feed line, a C-shaped coupled resonator on the top layer and a spiral coupled defected ground structure on the bottom layer. The system is analysed using J-inverters for the dual-frequencies (DFs) operation. The measured results show that the proposed DF-WPT system with a compact size of 20 × 20 mm ² is able to provide a stable WPT characteristic with total efficiencies of 91.2 and 79.4% at 0.28 and 0.49 GHz, respectively with a transmission distance of 6 mm. The proposed system achieved good agreements between the analytical design procedure, the circuit model, the electromagnetic simulations, and the measurements.

中文翻译：

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小型双频无线电力传输（DF-WPT）系统的紧凑型耦合谐振器

这项工作为高效率和紧凑型双频无线电力传输（DF-WPT）系统引入了一种新颖的设计。提议的设计由两个相同的发射（Tx）和接收（Rx）基板组成。每个基板都有一个微带馈线，一个在顶层的C形耦合谐振器和在底层的一个螺旋耦合缺陷接地结构。使用J逆变器分析系统的双频（DF）操作。测量结果表明，所建议的DF-WPT系统的紧凑尺寸为20×20 mm ²能够提供稳定的WPT特性，在0.28和0.49 GHz的总效率下，总效率分别为91.2％和79.4％，传输距离为6 mm。拟议的系统在分析设计程序，电路模型，电磁仿真和测量之间达成了良好的协议。