Qi Standard Wireless Power Transfer Technology Development Toward Spatial Freedom

´Qi´, the wireless power transfer interface specification published by the Wireless Power Consortium (WPC), has been regarded as the wireless charging standard and widely adopted in industry since its first release in August 2010. Larger spatial freedom between the power transmitter and power receiver provides significant convenience for users and device manufacturers, and is one of the critical factors for the success of wireless charging. In this paper, the recent progress of Qi technology development towards spatial freedom is reported. The achieved larger X/Y/Z placement shows that Qi standard is also capable to fulfill the spatial freedom requirement.