We describe efficient four-coil inductive power transfer (IPT) systems that operate at 100 MHz. The magnetically coupled transmitter and receiver were made from electrically small and high- Q loop-gap resonators (LGRs). In contrast to the commonly used helical and spiral resonators, the LGR design has the distinct advantage that electric fields are strongly confined to the capacitive gap of the resonator. With negligible fringing electric fields in the surrounding space, the IPT system is immune to interference from nearby dielectric objects, even when they are in close proximity to the transmitter and/or receiver. We experimented with both cylindrical and split-toroidal LGR (TLGR) geometries. Although both systems performed well under laboratory conditions, the toroidal geometry has the additional advantage that the magnetic flux is weak everywhere except within the bore of the LGR and in the space directly between the transmitter and the receiver. Furthermore, we show that the TLGR system can be operated efficiently at a fixed frequency for a wide range of transmitter-receiver distances. The experimental results are complimented by 3-D finite-element simulations that were used to investigate the electromagnetic field profiles and surface current density distributions. Finally, we demonstrate the use of our IPT system at powers up to 32 W and discuss possible applications.

中文翻译：

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使用磁耦合环隙谐振器以 100 MHz 进行中程无线功率传输


我们描述了工作频率为 100 MHz 的高效四线圈感应电力传输 (IPT) 系统。磁耦合发射器和接收器由电气小型高 Q 环隙谐振器 (LGR) 制成。与常用的螺旋谐振器和螺线谐振器相比，LGR 设计具有明显的优势，即电场被强烈限制在谐振器的电容间隙内。由于周围空间中的边缘电场可以忽略不计，IPT 系统不会受到附近电介质物体的干扰，即使它们非常接近发射器和/或接收器。我们尝试了圆柱形和分裂环形 LGR (TLGR) 几何形状。尽管这两个系统在实验室条件下都表现良好，但环形几何形状还有一个额外的优点，即除了 LGR 的孔内以及发射器和接收器直接之间的空间外，各处的磁通量都很弱。此外，我们还表明 TLGR 系统可以在固定频率下在较宽的发射器-接收器距离范围内有效运行。实验结果得到了用于研究电磁场分布和表面电流密度分布的 3D 有限元模拟的补充。最后，我们演示了 IPT 系统在高达 32 W 功率下的使用，并讨论了可能的应用。