Double-d base pad magnetics for reduced emissions in flush mounted and buried wireless power transfer applications

A method for wirelessly transferring charging power, comprising:

• driving each of a first coil and a second coil with a current to generate an alternating magnetic field;
• and
• wirelessly transferring charging power to at least one vehicle pad via the alternating magnetic field, wherein:
• the first coil comprises a first conductor wound in a first layer at an outer side of the first coil and wound in a first plurality of stacked layers on an inner side of the first coil, at least one layer of the first plurality of stacked layers on the inner side of the first coil recessed into a ferrite structure, and
• the second coil comprises a second conductor wound in a second layer at an outer side of the second coil and wound in a second plurality of stacked layers on an inner side of the second coil, at least one layer of the second plurality of stacked layers on the inner side of the second coil recessed into the ferrite structure.

An apparatus for wirelessly transferring charging power, comprising:

• a first coil comprising a first plurality of conductive windings wound about a first opening, wherein the first plurality of conductive windings are wound in a first plurality of stacked layers on a first side of the first coil wherein the number of layers on the first side of the first coil is greater than the number of layers on a second side of the first coil;
• and
• a second coil positioned substantially co-planar with the first coil and comprising a second plurality of conductive windings wound about a second opening, wherein the second plurality of conductive windings are wound in a second plurality of stacked layers on a third side of the second coil wherein the number of layers on the third side of the second coil is greater than the number of layers on a fourth side of the second coil, wherein the first side of the first coil is positioned closer to the third side of the second coil than to the fourth side of the second coil;
• and
• a ferrite structure overlapping at least a portion of the first coil and the second coil.