Flexible Design Method for Multi-Repeater Wireless Power Transfer System Based on Coupled Resonator Bandpass Filter Model

It has been verified that wireless power transfer (WPT) system with multiple relay resonators (repeaters) inserted properly between the transmitter and the receiver can increase the transmission distance significantly. Based on the coupled resonator bandpass filter model, a flexible design method for wireless power transfer system with arbitrary number of repeaters is proposed in detail. The transmission efficiency and the transferred power of the proposed wireless power transfer system are derived under the design theory of filters. It is illuminated the reason that Butterworth type is preferred type for designing WPT with multi-repeater. Moreover, the relation between transmission distance and bandwidth is examined and a technique is further introduced to increase the transmission distance. An RS=50 Ω WPT system with three repeaters is tested and another RS=0 Ω WPT system with one repeater is simulated, and the effectiveness of the proposed method is confirmed as well.