A parabolic spiral coil transmitter with uniform magnetic field for smart devices

Abstract

Wireless power transfer technology is installed in various devices such as smartphones and smart watches. The misalignment of devices and the increase in the number of dedicated chargers pose problems in terms of convenience and the room landscape. In this letter, we propose a parabolic spiral coil transmitter with a uniform magnetic field that is robust against misalignment and can charge multiple devices at the same time with one transmitter coil. The verification results show that the coefficients of variations of the magnetic flux density of the conventional transmitter and the proposed transmitter are 0.380 and 0.245, respectively, indicating that the proposed transmitter has a small magnetic field fluctuation.