Abstract: Provided is a reflective intelligent reflecting surface (IRS) flexible board, which includes: a flexible film; and a plurality of unit cells formed on the flexible film, in which each of the plurality of unit cells includes an IC for adjusting a reflection phase, a line pattern for driving the IC, and first and second antenna patterns formed symmetrically to each other based on the IC or the line pattern.

Abstract: Provided is a method for transmitting power in wireless communication using reconfigurable intelligent reflecting surfaces (RIS) of an electronic device, which includes: determining a value of a reflection coefficient of each unit cell or tile by scanning each tile of a reconfigurable intelligent reflecting surface (RIS) by a signal radiated through a transmitter; sending a beam to the reconfigurable intelligent reflecting surface (RIS) by controlling the transmitter; and multi-focusing an electromagnetic wave signal incident on the reconfigurable intelligent reflecting surface (RIS) on a plurality of receivers by setting an on/off state in each unit cell of the reconfigurable intelligent reflecting surface (RIS) based on the determined control parameter value, in which the tile is a partial array of the RIS having the same size, and supports far-field communication for the plurality of receivers.

Abstract: Provided is a reflective intelligent reflecting surface (IRS) flexible board, which includes: a flexible film; and a plurality of unit cells formed on the flexible film, in which each of the plurality of unit cells includes an IC for adjusting a reflection phase, a line pattern for driving the IC, and first and second antenna patterns formed symmetrically to each other based on the IC or the line pattern.

Abstract: A power transmitting method of a wireless communication system includes a metasurface. The method includes transmitting power of a power supply device to a target device through the metasurface comprising N cells, where N is an integer; estimating, by the metasurface, a channel between the metasurface and the target device based on the power received by the target device and a property matrix with a magnitude of (N+1)×(N+1); adjusting, by the metasurface, a phase of each cell of the N cells based on the estimated channel; and reflecting, by the metasurface, the power transmitted from the power supply device to the target device using the adjusted phase of each cell of the N cells. The property matrix includes information indicating whether each cell of the N cells is turned on and information about a bias value of the wireless communication system.

Abstract: A power transmitting method of a wireless communication system includes a metasurface. The method includes transmitting power of a power supply device to a target device through the metasurface comprising N cells, where N is an integer; estimating, by the metasurface, a channel between the metasurface and the target device based on the power received by the target device and a property matrix with a magnitude of (N+1)×(N+1); adjusting, by the metasurface, a phase of each cell of the N cells based on the estimated channel; and reflecting, by the metasurface, the power transmitted from the power supply device to the target device using the adjusted phase of each cell of the N cells. The property matrix includes information indicating whether each cell of the N cells is turned on and information about a bias value of the wireless communication system.

Abstract: A method for transmitting energy to a plurality of receiving nodes using a plurality of antennas includes: acquiring residual energy information of the receiving nodes and channel information between the antennas and the receiving nodes; determining a beamforming weight indicating a ratio between signals transmitted from the antennas and an awake ratio indicating a probability that the receiving nodes are in an active state to receive signals, based on the residual energy information and the channel information of each of the receiving nodes; generating beacon signals corresponding to the antennas based on either one or both of the beamforming weight and the awake ratio; and transmitting the beacon signals through the antennas.

Abstract: A method for transmitting energy to a plurality of receiving nodes using a plurality of antennas includes: acquiring residual energy information of the receiving nodes and channel information between the antennas and the receiving nodes; determining a beamforming weight indicating a ratio between signals transmitted from the antennas and an awake ratio indicating a probability that the receiving nodes are in an active state to receive signals, based on the residual energy information and the channel information of each of the receiving nodes; generating beacon signals corresponding to the antennas based on either one or both of the beamforming weight and the awake ratio; and transmitting the beacon signals through the antennas.

Abstract: Disclosed is a beamforming method for microwave power transmission. The beamforming method includes sending, by a transmitter, microwaves to each training slot based on a random phase through antennas, receiving from a receiver, by the transmitter, a power measurement value for each of the training slots, estimating, by the transmitter, a channel using the received power measurement value, and determining, by the transmitter, beamforming weight based on information about the estimated channel.

Abstract: Disclosed is a beamforming method for microwave power transmission. The beamforming method includes sending, by a transmitter, microwaves to each training slot based on a random phase through antennas, receiving from a receiver, by the transmitter, a power measurement value for each of the training slots, estimating, by the transmitter, a channel using the received power measurement value, and determining, by the transmitter, beamforming weight based on information about the estimated channel.