Abstract: Provided are a method and apparatus for detecting an efficiency of a wireless power transmission. An output power of a source device may be adjusted based on current that is flowing in a power converter of the source device. The efficiency of wireless power transmission may be calculated based on the adjusted output power, and an amount of power used by a target device.

Abstract: A method of operating a wireless power transmission apparatus includes receiving information on rectifier output voltages from at least one wireless power reception apparatus; determining whether the rectifier output voltages are within a predetermined operating range, and controlling an impedance of the wireless power transmission apparatus based on a result of the determining.

Abstract: An apparatus that transmits and receives wireless power, includes a controller configured to determine whether the apparatus is to operate in a power reception mode or a power transmission mode based on a capacity of a battery of the apparatus, and a capacity of a battery of another apparatus. The apparatus further includes a resonator configured to receive power from the other apparatus in response to the apparatus being determined to operate in the power reception mode, and transmit power to the other apparatus in response to the apparatus being determined to operate in the power transmission mode.

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: Disclosed is a method for controlling a wireless power transmitter for transmitting charging power to a wireless power receiver. The control method of the present invention comprises the steps of: adjusting the internal impedance of the wireless power transmitter such that the impedance variation occurring when the wireless power receiver is positioned is set to a second impedance variation different from the first impedance variation; applying detection power for detecting the wireless power receiver; detecting the second impedance variation during the application of the detection power so as to detect the wireless power receiver; and changing the impedance variation occurring when the wireless power receiver is positioned from the second impedance variation to the first impedance variation.

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: A method and apparatus for controlling a wireless power transmitter configured to transmit power to a wireless power receiver is provided. The method includes receiving a first signal from the wireless power receiver, wherein the first signal comprises load detection indication bits, detecting a change in load of the wireless power transmitter caused by placement of the wireless power receiver in a charging area of the wireless power transmitter, based on the load detection indication bits, and determining whether to transmit a second signal to the wireless power receiver based on detecting the change in load of the wireless power transmitter.

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: 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 method of configuring a network of a power transmitting unit (PTU) includes determining whether a neighboring PTU is operating in a master mode; determining an operation mode of a PTU based on a result of the determining; and setting a network between the PTU and the neighboring PTU based on the operation mode of the PTU.

Abstract: A wireless power transmitter configured to transmit power to a wireless power receiver and a method for controlling the wireless power transmitted are provided. The method includes applying a detection power for detecting a change in a load impedance of the wireless power transmitter caused by a placement of the wireless power receiver, detecting the change in the load impedance of the wireless power transmitter, receiving a first signal from the wireless power receiver, determining whether a reception intensity of the first signal is greater than a threshold, and transmitting a second signal to the wireless power receiver based on detecting the change in the load impedance and determining whether the reception intensity of the first signal is greater than the threshold.

Abstract: A wireless power transmission system, and a method for controlling wireless power transmission and wireless power reception are provided. According to an aspect, a method for controlling a wireless power transmission may include: detecting a plurality of target devices used to wirelessly receive power; selecting a source resonating unit from among a plurality of source resonating units, based on the amount of power to be transmitted to one or more of the plurality of target devices, a coupling factor associated with one or more of the plurality of target devices, or both; and wirelessly transmitting power to a target device using the selected source resonating unit.

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: 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 wireless power transmission system, and a method of controlling power in the wireless power transmission system based on a detection parameter are provided. The method includes transmitting a request signal to a device. The method further includes receiving, from the device, a response signal corresponding to the request signal, the response signal including a parameter of the device. The method further includes generating an operation power based on the parameter of the device, the operation power being used for an operation of the device.

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 portable device is provided. The portable device includes a power receiving unit configured to receive a first energy or a second energy from a wireless power transmitter, the first energy being used to perform a communication function and a control function, the second energy being used to charge a battery, and the wireless power transmitter being configured to wirelessly transmit a power, a voltage generator configured to generate a wake-up voltage from the first energy, or to generate a voltage for charging the battery from the second energy, a controller configured to perform the communication function and the control function, the controller being activated by the wake-up voltage, and a communication unit configured to perform a communication with the wireless power transmitter based on a control of the controller.

Abstract: A communication apparatus in a wireless power transmission system includes an operating mode converter configured to switch an operating mode of the communication apparatus between a transmitting mode and a receiving mode according to a predetermined timing; and a transmitting unit configured to transmit state information of a channel occupied by a source including the communication apparatus using a continuous wave signal while the communication apparatus is operating in the transmitting mode irrespective of whether the communication apparatus is performing communication via the occupied channel. The source including the communication apparatus is configured to transmit wireless power. The occupied channel has been assigned to the source including the communication apparatus from a plurality of channels available in a communication cell for assignment to a plurality of sources each configured to transmit wireless power.