Enhanced efficiency of wireless power transfer using slotting in the metals

Wireless power transfer (WPT) is greatly affected when the transmission channel is surrounded by nonferromagnetic metallic objects. In order to minimize the influence of metals, a method of etching on the metal plate is proposed in this paper. The effects of various lengths, shapes, thicknesses of slots and thicknesses of metal plate are studied. The results show that effective slots should meet four key requirements, namely, reaching the edge of the metal plate, passing through the inner area of the coil projection, etching through the metal in the thickness direction, and the thickness of the metal plate is much smaller than the skin depth. The H-shaped branch structure is considered to be the best branch, and the composite slot shape formed by the H-shaped branch and the cross has the best system improvement. In addition, this kind of graphics is uncomplicated and could be easily realized by existing cutting methods. The conclusions of this paper provide references for the design and optimization of WPT system.