Nanomagnetic structures for inductive coupling and shielding in wireless charging applications

This paper presents materials modeling, design, processing, integration and characterization of a new class of nanomagnetic structures for coupling and shielding in wireless charging and power conversion applications. Wireless power transfer applications such as wireless charging, operating at 6.78 MHz, require high-performance magnetic materials for enhancing the coupling between transceiver and receiver coils as well as for suppressing electromagnetic interference (EMI) shielding. This research describes two novel magnetic structures for coupling inductors and ultra-thin EMI shields. A novel vertically aligned magnetic composite structure was demonstrated for the coupling inductor. This structure is shown to result in permeabilities of above 500 and loss tangent of 0.01, which enhances the coupling inductance by 3-5x at 6.78 MHz, and also enhances the power-transfer efficiency by 2x. The second part of this paper presents the modeling, design and fabrication of nanomagnetic structures for ultra-thin EMI shields in wireless power transfer applications. The ultra-thin EMI shields for wireless power transfer described in this research can achieve greater than 20dB attenuation at 6.78 MHz even for 3-5μm shield thickness.