Communication and Power Transfer Analysis of Interfering Magnetically Resonant Coupled Systems

This work presents, for the first time, a communication and power transfer analysis of interfering wireless power transfer (WPT) and near-field communication (NFC) systems. The communication analysis is conducted by investigating the NFC tag-to-reader communication quality in the digital baseband while being interfered with by WPT. The power transfer analysis is conducted by investigating the maximum power transferred and WPT efficiency η while being affected by the passive loading effects of the NFC prototype system. Inductive decoupling techniques are applied to improve the communication quality and WPT performance. Good communication quality was achieved with at least 60% inductive decoupling. A system-level adjustment of the communication signal demodulation achieved further communication quality improvements, requiring only 15% inductive decoupling. The WPT performance was improved by inductive decoupling, shown by an improved maximum power transfer of up to 27% and an improved WPT efficiency η from 0.42 to 0.67. Additionally, inductive decoupling reduced the chance of the WPT system damaging the NFC system due to too much energy being delivered. These investigations were conducted using time-efficient broadband circuit-level simulations and measurement-verified broadband equivalent circuit coil models.