Design of dual-band coil for wireless power transfer system via magnetic resonant coupling

Abstract

For wireless power transfer (WPT) systems, communication between the two terminals of power transfer system is also an important problem to be solved. This paper proposes a design method of multi-turn dual-band coil for implementing synchronous transfer of power and data in WPT system with one set of WPT coils. An extra compensation circuit is inserted into the multi-turn spiral coil, so the new coil has two resonant frequencies that lie on both sides of the original resonant frequency of the multi-turn coil. Just one set of dual-band coils is used to provide the data and power transfer via two different resonant frequencies, so the undesirable interference in multi-coil WPT system is avoided. The equivalent circuit model is built to analyze the characteristic of the dual-band WPT system. The data pickup circuit is analyzed and designed for the receiver of WPT system. Finally, a dual-band WPT prototype with data pickup circuit is built to demonstrate the effectiveness of the proposed dual-band WPT system.