A wireless power receiving device, according to the disclosure, comprises: at least one power receiving antenna for sequentially receiving a plurality of different RF waves formed by a wireless power transmitting device; a communication circuit; and at least one processor, wherein the at least one processor is configured to confirm a plurality of pieces of strength information that indicates the strength of each of the plurality of different RF waves, confirm a plurality of pieces of phase information corresponding to each of the plurality of different RF waves, confirm, on the basis of the plurality of pieces of strength information and the plurality of pieces of phase information, an optimum phase value such that a received RF wave has a maximum strength, and transmit a communication signal including information about the optimum phase value to the wireless power transmitting device through the communication circuit. Additional various embodiments are possible.