Parallel connected transmitting coil for achieving uniform magnetic field distribution in WPT

Transmitting coil with uniform magnetic field distribution allows the received coil to be positioned freely and keeps the coupling coefficient, the received power, and the power transfer efficiency stable. Traditionally, the transmitting coil is realized by connecting the coil turns in series and each turn has the same current. In this paper, a new transmitting coil is proposed, in which all the coil turns are connected in parallel. The current in each turn is not necessarily the same, instead, determined by a series connected capacitor. It is shown that this new transmitting coil improves the uniformity of the magnetic field.