Resonant cavity mode enabled wireless power transfer

This letter proposes using the electromagnetic resonant modes of a hollow metallic structure to provide wireless power to small receivers contained anywhere inside. The coupling between a large chamber (used as a cavity resonator) and a small wire loop (used as a receiver) is studied. An analytic expression for the coupling coefficient between the fields in the cavity and a loop receiver is derived. This model is validated against simulation and experimental results. Finally, wireless power transfer is demonstrated at an efficiency of over 60% for large volumes in the structure, even though the receiver is a small 7.6 cm square shaped loop and the distance to the source probe is greater than 1m. This technique for wireless power transfer has thus far been unexplored, and the results here serve as a starting point for resonant cavity mode wireless power systems with many receivers having arbitrary locations and orientations. (C) 2014 AIP Publishing LLC.