Wireless power transmitter, wireless power receiver, and method for wireless power transfer using them

A wireless power transmitter, comprising:

• a power generation unit configured to receive an alternating current power and generate a high frequency direct current power;
• a frequency modulation unit configured to determine and modulate a transmission frequency of the high frequency direct current power based on a feedback signal received from at least one wireless power receiver;
• and
• a transmission coil unit configured to transmit the high frequency direct current power as a non-radiative electromagnetic wave.

A wireless power receiver, comprising:

• a reception coil unit configured to receive a high frequency signal;
• a power generation unit configured to generate a direct current power by using an alternating current power received by the reception coil unit;
• a load unit configured to be driven by the generated direct current power;
• and a feedback signal generation unit configured to generate a feedback signal which corresponds to a power value of the received high frequency signal,
• wherein the high frequency signal has a transmission frequency modulated according to the feedback signal.