Abstract: A wireless power transmitter includes a source resonator configured to wirelessly transmit power via magnetic coupling with a target resonator; and an impedance adjusting unit configured to adjust an impedance of the source resonator using a plurality of impedance-matching bars located in the source resonator.

Abstract: An overvoltage protecting unit and an overcurrent protecting unit protect a power device from an overvoltage and an overcurrent using a comparator having hysteresis. An overtemperature protecting unit protects the power device from an overtemperature using a thermistor having a resistance that changes as a temperature of the thermistor changes.

Abstract: A wireless power transmission system and a method for increasing a coupling efficiency by adjusting a resonant frequency are provided. A device of the wireless power transmission system includes a resonator configured to transmit a wireless power, and a communication unit configured to receive information from another device. The device further includes a controller configured to determine a power transmission efficiency based on the information, and adjust a resonant frequency of the device, a resonant frequency of a relay device, and a resonant frequency of the other device, if the power transmission efficiency is less than or equal to a predetermined reference efficiency.

Abstract: A resonance power transmission system for controlling a supply voltage of a power converter based on power transmission efficiency is provided. According to an aspect, a resonance power transmitter configured to transmit resonance power to one or more resonance power receivers may include: a voltage controller configured to receive an input signal and to output voltage of a predetermined level; a source controller configured to control a signal level of the DC voltage based the number of resonance power receivers.

Abstract: An interference control method of a power transmitting unit (PTU) includes determining whether the PTU is in an interference environment in which interference by a neighbor PTU occurs, and controlling a communication parameter of either one or both of the neighbor PTU and a power receiving unit (PRU) in response to a result of the determining being that the PTU is in the interference environment.

Abstract: An electronic device is provided. The electronic device includes a power receiver circuit configured to wirelessly receive power from a wireless power transmitter, a plurality of rectifiers, and a processor configured to detect a magnitude of the received power, select a rectifier to perform rectification from among the plurality of rectifiers based on the magnitude of the received power, and control the selected rectifier to rectify the power.

Abstract: An apparatus and a method for charge control are provided. The apparatus for charge control may include an integrated direct current-to-direct current (DC/DC) converter configured to step up an output voltage level of a load to be greater than or equal to a supply voltage level set in a power amplifier, and the power amplifier configured to convert a direct current (DC) voltage stepped up by the integrated DC/DC converter into an alternating current (AC) voltage based on a resonant frequency, and to amplify the converted AC voltage. The apparatus for charge control may include a rectification unit configured to convert an AC power received wirelessly into a DC power; and a DC/DC converter configured to step down a voltage level of the DC power to a voltage level required by a load in the receiving mode.

Abstract: A resonator has an increased isolation for stable wireless power transmission. A material that reduces resonance coupling may be disposed in a space between each of a plurality of resonators and a resonator adjacent to each of the plurality of resonators. A material that reduces resonance coupling may be disposed on a plane opposite to a direction in which a resonator resonates. Power at an operating frequency set to be equal to or within a predetermined range of a frequency corresponding to a resonant mode may be injected into a plurality of transmission resonators.

Abstract: A resonance power transmission system for controlling a supply voltage of a power converter based on power transmission efficiency is provided. According to an aspect, a resonance power transmitter configured to transmit resonance power to one or more resonance power receivers may include: a voltage controller configured to receive an input signal and to output voltage of a predetermined level; a source controller configured to control a signal level of the DC voltage based the number of resonance power receivers.

Abstract: An electronic device is provided that includes a housing and a power receiver disposed within the housing. The power receiver includes a conductive pattern for receiving power wirelessly. The conductive pattern includes a main coil having a plurality of turns, a first sub-coil formed at an input port of the main coil, and a second sub-coil formed at an output port of the main coil. The electronic device also includes a controller configured to control to receive power using the conductive pattern.

Abstract: An apparatus and method of using near field communication (NFC) and wireless power transmission (WPT) are provided. A power receiving apparatus includes a resonator configured to receive a power and to output the power. The power receiving apparatus further includes a near field communication (NFC) receiver configured to perform wireless communication using the power output by the resonator. The power receiving apparatus further includes a wireless power transmission (WPT) receiver configured to supply a voltage using the power output by the resonator. The power receiving apparatus further includes a connecting unit configured to selectively connect the resonator to either the NFC receiver or the WPT receiver. The power receiving apparatus further includes a mode selector configured to control the connecting unit to selectively connect the resonator to either the NFC receiver or the WPT receiver based on the power output by the resonator.

Abstract: A wireless power receiving device and a wireless power transmission apparatus are provided. The wireless power receiver may include a resonator configured to emit an electromagnetic field, a blocker configured to surround a portion of an exterior of the resonator, and a spacer disposed between the resonator and the blocker.

Abstract: Disclosed are a wireless power transmission device and a control method thereof. The wireless power transmission device includes a communication circuit that receives information transmitted by an electronic device that receives wireless power; an array antenna including multiple cells that radiate wireless power; and a controller that receives the information transmitted by the electronic device through the communication circuit, combines cells of the multiple cells included in the array antenna based on the information and creates a group of cells corresponding to the electronic device, and controls the cells included in the group to radiate the wireless power towards the electronic device.

Abstract: An interference control method of a power transmitting unit (PTU) includes determining whether the PTU is in an interference environment in which interference by a neighbor PTU occurs, and controlling a communication parameter of either one or both of the neighbor PTU and a power receiving unit (PRU) in response to a result of the determining being that the PTU is in the interference environment.

Abstract: A system and a device for wirelessly transferring power without a cable are provided. A wireless electromagnetic receiver includes a first device configured to be magnetized based on an electromagnetic field. The wireless electromagnetic receiver further includes a second device configured to transform the magnetization of the first device into a power, the second device being not in contact with the first device.

Abstract: A wireless power transmission apparatus includes a plurality of transmission (TX) resonators configured to resonate with at least one reception (RX) resonator, and wirelessly transmit power to the at least one RX resonator; and a frequency controller configured to control the input frequency so that power is stably supplied to the at least one RX resonator.

Abstract: A method of a charging apparatus for controlling wireless charging is provided. The method includes detecting an electronic device, determining a charging method corresponding to the detected electronic device, and wirelessly charging the electronic device by selecting a coil corresponding to the determined charging method.

Abstract: An apparatus and a method for charge control are provided. The apparatus for charge control may include an integrated direct current-to-direct current (DC/DC) converter configured to step up an output voltage level of a load to be greater than or equal to a supply voltage level set in a power amplifier, and the power amplifier configured to convert a direct current (DC) voltage stepped up by the integrated DC/DC converter into an alternating current (AC) voltage based on a resonant frequency, and to amplify the converted AC voltage. The apparatus for charge control may include a rectification unit configured to convert an AC power received wirelessly into a DC power; and a DC/DC converter configured to step down a voltage level of the DC power to a voltage level required by a load in the receiving mode.

Abstract: A high efficiency variable power transmitting apparatus outputs a variable power by modulating, with respect to a time axis, a high frequency signal having a constant amplitude by turning the high frequency signal ON and OFF, amplifying the variable power to satisfy a requested power level of a target device based on a supply voltage having a predetermined level, converting an alternating current (AC) voltage received from a power source to a direct current (DC) voltage, generating the supply voltage having the predetermined level based on the DC voltage, and providing the supply voltage having the predetermined level to the PA.

Abstract: A semiconductor light emitting device includes a semiconductor stack including a first conductive semiconductor layer including a first surface, a second conductive semiconductor layer including a second surface opposite to the first surface, an active layer disposed between the first conductive semiconductor layer and the second conductive semiconductor layer, and a through hole disposed through the semiconductor stack. The semiconductor light emitting device further includes a contact layer connected to the first conductive semiconductor layer, disposed in the through hole, and disposed through the semiconductor stack, a first electrode layer connected to the contact layer, and a second electrode layer disposed on the second surface, and including a pad forming portion on which the semiconductor stack is not disposed.