Enhancement of wireless power transfer efficiency using flat conductor with ferrite wall

ABSTRACT In this letter, a flat conductor with ferrite wall of spiral resonator is presented to reduce ohmic loss and improve wireless power transmission (WPT) efficiency. The ferrite walls are configured along both side edges of the flat conductor and make more uniformed current distribution on the conductor, so that the conductor resistance is reduced and the efficiency is improved. In the measurement, it is confirmed that the resistance of the spiral resonator with the ferrite wall is reduced by 25% (0.020–0.015 Ω) and the WPT efficiency is improved by 10% (25–35%) at 70‐cm distance when the size of the resonator and the resonance frequency are 35 × 35 × 6 cm3 and 128 kHz, respectively. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2371–2373, 2015