Mobile phone mid-range wireless charger development via coupled magnetic resonance

In this paper, wireless power transfer for mobile phones via coupled magnetic resonance with multiple transmitters (Txs) and / or receivers (Rxs) are investigated and tested. The system is able to charge cellphones with more than 3 W in a distance between 5 and 15 cm and also in different angles. The resonant frequency is 6MHz. For lower charging powers the distance between the Tx and Rx can go up to 20 cm. Additionally, the three-dimensional movement of the Rx and its effect to the charging power is tested, as self-rotation and rotation around the Tx coil. This achievement is significant to improve user experience of wireless charging for portable electronic devices.