Analysis and Design of Wireless Bidirectional Power and Data Transfer With Decoupled DD-R Coil Geometry

This article proposes and implements a novel wireless bidirectional power and data transfer system using decoupled double-D and rectangular (DD-R) coil geometry. Double-D power coils are placed in overlap with rectangular data coils at both the primary side and secondary side, respectively, to form a compact structure. The slight power-data coupling under displacement and parasitic effect is neglected in previous decoupling structure studies, which may cause a significant decrease in signal-to-noise ratio (SNR), especially in high-power applications. A fully analytical design method of the data channel is proposed aiming to minimize the number of turns and maximize SNR considering parasitic parameters and displacements, which can give an optimal region quickly and is applicable to double-D power coils of different sizes. The coupling characteristics of the power and data coils are first presented. Then, the data channel performance is analyzed, and the corresponding design objectives, limits, and principles are obtained. An optimal design method is further developed, and a detailed design example is given based on the above analysis. Finally, a 5 kW hardware prototype is constructed. The data transfer rate is 200 kbps, and the bit error rate (BER) is 1.9e-5. The experimental results verified the feasibility of the proposed system and the validity of the design method.