US Patent 9126490 Wireless energy transfer via coupled parasitic resonators

This disclosure provides systems, methods and apparatus for wirelessly transferring power using parasitic resonators. In one aspect a wireless power receiver apparatus for powering or charging an electric vehicle is provided. The wireless power receiver apparatus includes a receive circuit including a first coil. The receive circuit is configured to wirelessly receive power so as to power or charge or power the electric vehicle. The wireless power receiver apparatus further includes a passive circuit including a second coil. The passive circuit is configured to wirelessly receive power from a transmit circuit including a third coil. The passive circuit is further configured to wirelessly retransmit power received from the transmit circuit to the receive circuit. The wireless power receiver apparatus further includes a controller configured to displace the second coil from the first coil is provided.