Micro-scale planar-coil transformers including one or more shields are disclosed. The one or more shields can block most common-mode current from crossing from one side to another side of a transformer. Reduction of common-mode current crossing the transformer results in reduction of dipole radiation, which is the main component of electromagnetic interference (EMI) in some transformers.

A transformer according to one embodiment comprises: a core portion having an upper core and a lower core; and a coil portion disposed in the core portion, wherein: the coil portion includes a first coil wound in a first direction, a second coil wound in a second direction opposite to the first direction, and a third coil including a flat panel shape; the lower core includes a body portion, a first leg portion and a second leg portion protruding from the body portion, and a spacing portion formed between the first leg portion and the second leg portion; the first leg portion includes two first outer legs and a first intermediate leg disposed between the two first outer legs; the second leg portion includes two second outer legs and a second intermediate leg disposed between the two second outer legs; the first coil can be disposed to surround the first intermediate leg; and the second coil can be disposed to surround the second intermediate leg.

A magnetic structure for wireless power transfer has a plurality of pieces of magnetically permeable material arranged along a first dimension. Each piece is separated from a neighbouring piece by a gap defining a separation distance which is selected to prevent partial saturation of a region of the structure.

A non-contact power reception apparatus is provided, in which a power reception coil for a charging system and a loop antenna for an electronic settlement system are mounted on a battery pack and a cover case of a portable terminal such that the power reception coil is arranged in the center thereof and the loop antenna is disposed outside the power reception coil, so that a mode of receiving a wireless power signal and a mode of transmitting and receiving data are selectively performed, thereby preventing interference from harmonic components and enabling non-contact charging and electronic settlement using a single portable terminal. A jig for fabricating a core to be mounted to the non-contact power reception apparatus is provided.

A power transmitter comprises a transmitter coil (103) generating an electromagnetic field. A set of balanced detection coils (207, 209) comprises detection coils in series and compensating each other. A foreign object detector (205) performs foreign object detection, by potentially detect a foreign object in response to a property of an output signal from the set of balanced detection coils (207, 209) in response to the electromagnetic test meeting a foreign object detection criterion. A communicator (211) is coupled to a communication antenna (213) communicates with a power receiver (105) via this. The communication antenna (213) comprises a plurality of communication coils (215, 217) coupled in parallel. A first segment of a first communication coil (215) has a first coupling to a first detection coil and a second segment of a second coil (217) has a second coupling to a second detection coil. The couplings are capacitive and/or inductive couplings and the first coupling and the second coupling compensate each other in the output signal.

A wireless charging coil is provided herein. More specifically, provided herein is a wireless charging coil comprising a first stamped coil having a first spiral trace, the first spiral trace defining a first space between windings, and a second stamped coil having a second spiral trace, the second spiral trace defining a second space between windings, the first stamped coil and second stamped coil in co-planar relation, the first stamped coil positioned within the second space of the second stamped coil, and the second stamped coil positioned within the first space of the first stamped coil, the first and second coils electronically connected and an adhesive covering and surrounding the first stamped coil and the second stamped coil to bond the coils together and to insulate the coils.

A wireless power transmission device for a vehicle is provided. A wireless power transmission device for a vehicle includes: a wireless power transmission module including at least one wireless power transmission antenna for transmitting wireless power, and a magnetic field shielding sheet arranged on one surface of the wireless power transmission antenna; a radiation case having one side to which the wireless power transmission module is coupled, having at least one circuit board embedded therein so as to drive the wireless power transmission module, and radiating heat generated by a heat source; a radiation plate arranged between the wireless power transmission module and the radiation case, and dispersing heat generated in the wireless power transmission antenna; an insulating layer arranged on one surface of the radiation plate so as to block thermal transferring between the radiation case and the radiation plate; and a cover detachably coupled to the radiation case.

An apparatus for wirelessly transferring charging power is provided. The apparatus comprises a ferrite structure. The apparatus comprises a first coil comprising 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 is recessed into the ferrite structure. The apparatus comprises a second coil comprising 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.

Disclosed is a litz wire coil that is configured by spirally winding a litz wire on one plane by a predetermined number of turns. The litz wire is configured by twisting together a plurality of enameled wires formed by baking an insulating film on a conducting body. Pressure shaping is performed such that the litz wire has a substantially rectangular shape in cross section, and the flatness ratio of the litz wire in cross section (long side/short side) is controlled at 1.10 to 1.60, preferably 1.20 to 1.40, more preferably 1.25 to 1.35.

The disclosure features systems for wireless power transfer that include a resonator featuring a coil with at least two windings and at least one inductor having an inductance value, where the at least one inductor is connected in series to at least one of the windings, and where the inductance value is selected so that when the coil carries a current during operation of the system, the at least one inductor maintains a distribution of current flows among the at least two windings such that for each of the at least two windings, an actual current flow in the winding differs from a target current flow for the winding by 10% or less.