Patched-Wall Quasistatic Cavity Resonators for 3-D Wireless Power Transfer
This addresses the need for unobstructed, full-volume wireless power transfer in environments like homes or offices, representing an incremental improvement over existing high-coverage systems.
The paper tackled the problem of internal obstructions in room-scale wireless power transfer systems by introducing a patched-wall quasistatic cavity resonator, which achieved a minimum power-transfer efficiency of 48.1% across a 54 m³ charging volume without internal structures.
Traditional wireless power transfer (WPT) systems are largely limited to 1-D charging pads or 2-D charging surfaces and therefore do not support a truly ubiquitous device-powering experience. Although room-scale WPT based on multimode quasistatic cavity resonance (QSCR) has demonstrated full-volume coverage by leveraging multiple resonant modes, existing high-coverage implementations require obstructive internal conductive structures, such as a central pole. This letter presents a new structure, termed the patched-wall QSCR, that eliminates such internal obstructions while preserving full-volume coverage. By using conductive wall segments interconnected by capacitors, the proposed structure supports two complementary resonant modes that cover both the peripheral and central regions without obstructions within the charging volume. Electromagnetic simulations show that, by selectively exciting these two resonant modes, the proposed structure achieves a minimum power-transfer efficiency of 48.1% across the evaluated 54 m^3 charging volume while preserving an unobstructed interior space.