Method and apparatus for detecting efficiency of wireless power transmission

A method of detecting an efficiency of a wireless power transmission from a source device to a target device, the method comprising:

• receiving, from the target device, information about power used by the target device;
• determining an output power of a power amplifier (PA) of the source device based on the information about power used by a target device;
• transmitting, to the target device, wireless power corresponding to the output power;
• receiving, from the target device, information about power that is received by the target device, wherein the information about the power that is received by the target device comprises information about a current flowing in a load modulator of the target device, in a state in which a connection to a load of the target device is blocked and the received power inputted to the load modulator of the target device;
• and
• calculating the efficiency of the wireless power transmission, based on the information about the power that is received by the target device and the output power.

A computer-readable storage medium having stored therein program instructions to cause a processor to execute a method of detecting an efficiency of a wireless power transmission from a source device to a target device, the method comprising:

• receiving, from the target device, information about power used by the target device;
• determining a first output power of a power amplifier (PA) of the source device based on the information about power used by the target device;
• transmitting, to the target device, wireless power corresponding to the first power;
• determining a second power of the PA in response to a current of the PA converging to a constant level, wherein the current of the PA is changed until the target device receives wireless power corresponding the information about the power used by the target device;
• and
• calculating the efficiency of the wireless power transmission, based on the second power and the information about the power used by the target device.

A wireless power transmitter, comprising:

• a controller to determine a first power of a power amplifier (PA) of the wireless power transmitter based on information about power used by a target device received from the target device;
• and
• a resonator to transmit, to the target device, wireless power corresponding to the first power,
• wherein the controller
• determines a second power of the PA in response to a current of the PA converging to a constant level, wherein the current of the PA is changed until the target device receives wireless power corresponding the information about the power used by the target device, and
• calculates an efficiency of a wireless power transmission, based on the second power and the information about power used by the target device.

A wireless power transmitter, comprising:

• a controller to determine an output power of a power amplifier (PA) of the wireless power transmitter based on information about power used by a target device;
• and
• a resonator to transmit, to the target device, wireless power corresponding to the output power,
• wherein the controller
• receives, from the target device, information about power that is received by the target device, wherein the information about the power that is received by the target device comprises information about a current flowing in a load modulator of the target device, in a state in which a connection to a load of the target device is blocked and the received power inputted to the load modulator of the target device, and
• calculates an efficiency of a wireless power transmission, based on the information about the power that is received by the target device and the output power.