A wireless charging system and method are provided, that are capable of simultaneously charging multiple mobile devices, providing high power transfer efficiency for multiple mobile devices located at any position and orientation, and minimizing electromagnetic radiation from a transmitting (TX) coil and a receiving (RX) coil. The method and structure reduce electromagnetic interference (EMI) radiation by shunting in-phase currents flowing in a wireless power transmitting unit (TX unit) and a wireless power receiving unit (RX unit) of a wireless charging system.