Metamaterial wireless power transfer system (MWPT)

Abstract

Wireless power transfer (WPT) is becoming more prevalent with a number of wireless charging devices now available in the consumer market for charging consumer electronics. The principle of wireless power transfer is based on the coupling of inductor coils to transfer energy between coils. In the past, two coils geometries were used to inductively transfer power. More recently, resonant power transfer has emerged as a power transfer method with higher transfer efficiency. Resonant power transfer tunes the receiver and transmitter coils with capacitors to the desired frequency of operation. Additional modalities include 4-coil resonant power transfer and telescoped coil power transfer. But, all of these modalities basically utilize the same principle of the two-coil resonant power transfer method. It is also important to point out that all these modalities utilize a lumped capacitor to tune the inductive coil to a desired resonant frequency. Also, most of these methods utilize planar geometrics for packaging their coils, which makes it simpler to charge devices by stacking them.