Pulse Width Modulation (PWM)-Controlled Wireless Power Transfer using Mu-Negative Metamaterials and Ferrite Shielding on a Four-Coil Layered Double-D (LDD) System

Wireless power transfer (WPT) systems rarely include shielding on their prototypes. The proposal combines ferrite tiles, 3D-printed metamaterials, and circuitry to develop a high- efficiency transfer. Objectives include: (1) to design layered ‘double-D’ (DD) coils and metamaterial slabs for the system with ferrite tiles for shielding; (2) to model a PWM-controlled inductance double capacitance series and parallel capacitance (LCC-SP); (3) to build a working prototype based on the model with the ferrite tile, designed metamaterial slab and layered DD coil; and (4) to determine the efficiency, transfer distance, and coupling coefficient of the prototype. The researchers used a portable oscilloscope to measure the relevant parameters concerning power transfer. An increase in efficiency and coupling coefficient was attained with the proposed WPT system.