Frequency splitting elimination in wireless power transfer using nonidentical resonant coils

We propose an approach to eliminate frequency splitting in wireless power transfer (WPT). Two nonidentical resonant coils (NIRCs) are used in this method as power transmitter and receiver, respectively. According to the elliptic integral term in the analytical expression, the pole of the mutual inductance function with respect to transfer distance can be eliminated by using NIRCs. Therefore, frequency splitting caused by over-coupling can be eliminated. Experimental measurement of the NIRCs shows that frequency splitting is completely eliminated and uniform voltage across the load is achieved.