Design of transmitting coil for wireless charging system to expand charging area for drone applications.

Abstract: This research proposes a transmitting coil structure for wireless charging which has the constant efficiency regardless of the position of the receiving coil. The proposed transmitting coil is designed to operate at 140 kHz, and to improve the uniformity of the magnetic field intensity using a stepped helical coil and ferrite core. The measured results of the charging system with proposed transmitting coil show that it has low difference in rectifying voltage and efficiency within the charging area. Therefore, it has advantages in terms of wide charging area without the charging shadow area. [ABSTRACT FROM AUTHOR]