Devices and systems of inductive-capacitive (LC) coil-resonators that can be embedded easily inside high-voltage insulation discs are provided. Each LC coil-resonator comprises spiral conductive tracks fabricated or printed in the form of at least two layers of planar spiral windings on electrically non-conductive materials. The planar conductive windings on at least two parallel layers may be connected to form a closed winding. The distributed inductance associated with the planar spiral windings and the distributed capacitance between the layers of the conductive tracks form an equivalent LC coil-resonator. When these LC coil-resonators are embedded in some or all of the insulation discs in a high-voltage insulation rod, they form the relay coil-resonators for wireless power transfer.

Devices and systems of inductive-capacitive (LC) coil-resonators that can be embedded easily inside high-voltage insulation discs are provided. Each LC coil-resonator comprises spiral conductive tracks fabricated or printed in the form of at least two layers of planar spiral windings on electrically non-conductive materials. The planar conductive windings on at least two parallel layers may be connected to form a closed winding. The distributed inductance associated with the planar spiral windings and the distributed capacitance between the layers of the conductive tracks form an equivalent LC coil-resonator. When these LC coil-resonators are embedded in some or all of the insulation discs in a high-voltage insulation rod, they form the relay coil-resonators for wireless power transfer.

Disclosed herein is a wireless charging apparatus for preventing cancelation of magnetic fields generated between a plurality of adjacent transmission coils by placing a repeater on the plurality of transmission coils, the wireless charging apparatus including a plurality of transmission coils spaced the same distance apart from a reference point, and a repeater placed on the plurality of transmission coils to be overlapped with each of the plurality of transmission coils with respect to the reference point that is a center, wherein a coupling coefficient between each of the plurality of transmission coils and the repeater is higher than a coupling coefficient between the plurality of transmission coils.

Disclosed herein is a wireless charging apparatus for preventing cancelation of magnetic fields generated between a plurality of adjacent transmission coils by placing a repeater on the plurality of transmission coils, the wireless charging apparatus including a plurality of transmission coils spaced the same distance apart from a reference point, and a repeater placed on the plurality of transmission coils to be overlapped with each of the plurality of transmission coils with respect to the reference point that is a center, wherein a coupling coefficient between each of the plurality of transmission coils and the repeater is higher than a coupling coefficient between the plurality of transmission coils.

One example discloses a near-field communications device, including: an energy harvesting circuit configured to be coupled to a near-field antenna that is responsive to non-propagating quasi-static near-field energy; wherein the harvesting circuit is configured to harvest energy from the non-propagating quasi-static near-field energy; and wherein the harvesting circuit includes a harvesting filter configured to input a first set of near-field energy and output a second set of near-field energy; and wherein the second set of near-field energy is a sub-set of the first set of near-field energy.

One example discloses a near-field communications device, including: an energy harvesting circuit configured to be coupled to a near-field antenna that is responsive to non-propagating quasi-static near-field energy; wherein the harvesting circuit is configured to harvest energy from the non-propagating quasi-static near-field energy; and wherein the harvesting circuit includes a harvesting filter configured to input a first set of near-field energy and output a second set of near-field energy; and wherein the second set of near-field energy is a sub-set of the first set of near-field energy.

A power transmitting unit (PTU) for wireless power transmission (WPT) includes a communication transceiver and a power controller. The communication transceiver connects a communication link with at least one power receiving unit (PRU) through legacy communication and exchanges parameters necessary for the WPT through the connected communication link. The power controller is configured to transmit, to the PRU, a PTU beacon containing information about a dedicated power slot (DPS) allocated to the PRU in a super frame including a plurality of DPSs, to receive a PRU beacon from the PRU, to extract a phase difference between a plurality of antennas by analyzing a continuous wave (CW) of the PRU beacon, and to transmit power to the PRU in the allocated DPS in consideration of the phase difference.

A power transmitting unit (PTU) for wireless power transmission (WPT) includes a communication transceiver and a power controller. The communication transceiver connects a communication link with at least one power receiving unit (PRU) through legacy communication and exchanges parameters necessary for the WPT through the connected communication link. The power controller is configured to transmit, to the PRU, a PTU beacon containing information about a dedicated power slot (DPS) allocated to the PRU in a super frame including a plurality of DPSs, to receive a PRU beacon from the PRU, to extract a phase difference between a plurality of antennas by analyzing a continuous wave (CW) of the PRU beacon, and to transmit power to the PRU in the allocated DPS in consideration of the phase difference.

A wireless power transmission system includes: a wireless power transmission apparatus including: a transmission coil configured to form mutual coupling with an auxiliary coil disposed outside of a living body; and a controller configured to control a supply of power by a power source to the transmission coil to wirelessly transmit the power from the transmission coil, using the auxiliary coil, to a wireless power reception apparatus disposed inside the living body through the mutual coupling, wherein a distance between the transmission coil and the auxiliary coil is adjustable.

A wireless power transmission system includes: a wireless power transmission apparatus including: a transmission coil configured to form mutual coupling with an auxiliary coil disposed outside of a living body; and a controller configured to control a supply of power by a power source to the transmission coil to wirelessly transmit the power from the transmission coil, using the auxiliary coil, to a wireless power reception apparatus disposed inside the living body through the mutual coupling, wherein a distance between the transmission coil and the auxiliary coil is adjustable.