Simultaneous Wireless Power and Data Transfer System with Reduced Common Mode Noises Based on Symmetric Filter Inductor Configuration

Noises from power interference deteriorates the communication quality in simultaneous wireless power and data transfer (SWPDT) system. Previous researches only pay attention to noises originating from power carrier, neglecting that from common-mode (CM) currents. To solve this problem, the model of CM noises of the simultaneous wireless power and data transfer system based on split filter inductor configuration is established. Then the effects of split filter inductor on reduction of CM noises are analysed. It is shown that a symmetric filter inductor can minimize the CM noises caused by switching of MOSFETS. Finally, a 120W LCL based SWPDT prototype is built to validate the finding. Compared with traditional configuration, CM noises are reduced significantly using symmetric filter inductor configuration.