Transmitting Coil Arrays for Improvement of Wireless Power Transmission Efficiency

Wireless power transfer (WPT) offers the promise of cutting the last cord, marking users to recharge portable electronic devices easily through the air. In the conventional transmitting coil array for wireless power transmission, an opposite magnetic field will create at the gap between the unit. Consequently, the power transfer efficiency is decreased at gap of resonator unit. To alleviate this problem, adding a coil to a conventional array to form a five-coil array structure is proposed in this article. The results show that the transmission efficiency at these locations will reach above 70%. In comparisons with the conventional system, the proposed transmitting system provides a higher wireless power transmission efficiency.