Electromagnetic Radiated Emissions from a Repeating-Coil Wireless Power Transfer System using a Resonant Magnetic Field Coupling

Wireless power transfer technologies have been studied steadily and reached the stage of practical use in recent years. As the commercialized research on the wireless power transfer have been performed, the wireless power transfer system utilizing the repeating-coil have been attempted. Then, the electromagnetic radiated emissions have become an important issue. In this paper, we report the measurement and analysis of the electromagnetic radiated emissions from the repeating-coil wireless power transfer system using a resonant magnetic field. A relationship between the resonance and the transferred power are analyzed with respect to the impedance profile obtained from analytical expressions, simulations and measurements. The results show that the electromagnetic radiated emissions are enhanced at the series resonance peaks of the impedance profile in the repeating-coil wireless power transfer system using a resonant magnetic field coupling in the case of a constant-voltage AC source.