KR102505423B1 - Apparatus and method for multiple beamforming using multi-tone signal for wireless power transmission to multiple device - Google Patents

Abstract

Disclosed are a multi-tone based beamforming device and method for wireless power transmission to multiple devices. The multi-tone based beamforming method for wireless power transmission to multiple devices according to an embodiment of the present application may comprise the following: a step (a) of obtaining direction information for each of a plurality of target devices; a step (b) of deriving a phase weight associated with power radiated from each of a plurality of unit antennas toward each of the plurality of target devices based on the direction information and arrangement information of an antenna array including the plurality of unit antennas; a step (c) of defining a weight matrix based on the phase weight; and a step (d) of generating an output signal of the antenna array based on the weight matrix and baseband information.

Description

Multi-tone based beamforming apparatus and method for wireless power transmission to multiple devices

The present disclosure relates to a multi-tone based beamforming apparatus and method for wireless power transmission to multiple devices.

Wireless Power Transfer (WPT) technology has recently been actively researched for application to the Internet of Things and medical devices. Among various wireless power transfer technologies, the microwave power transfer (MPT) method using beamforming has the potential to be used to transmit power over long distances regardless of the location of the receiver. Since transfer efficiency is relatively low compared to other wireless power transmission technologies due to large path loss, various studies are being conducted to overcome the disadvantages of the microwave power transmission (MPT) method.

In this regard, research related to retroreflection beamforming has been mainly studied in the radar application field, and this technology tracks the direction of a receiver through a pilot signal and transfers power by transmitting power in the corresponding direction. In addition, in another study on wireless power transmission, a look-up table (LUT) was used to store the phase of an array antenna capable of optimally transmitting power in a designated receiving antenna direction, and beamforming was performed toward the corresponding receiving antenna. As another example, research on a wireless power transmission method using beam focusing that transfers power to a specific point in order to concentrate power on a location of a receiver has also been conducted.

However, in the above-mentioned conventional studies, there is a limitation that they are mainly designed considering a single beam radiated to a single receiver and do not consider simultaneous power transmission through multiple reception, so the development of a system capable of multiple beamforming is required. do.

The background technology of the present application is disclosed in Korean Patent Registration No. 10-1795097.

The present invention is to solve the above-mentioned problems of the prior art, and multi-tone based beamforming for wireless power transmission to multiple devices generating multi-tone signals based on a multi-antenna array to simultaneously transmit power to a plurality of target devices. It aims to provide an apparatus and method.

However, the technical problem to be achieved by the embodiments of the present application is not limited to the technical problems described above, and other technical problems may exist.

As a technical means for achieving the above technical problem, a multi-tone based beamforming method for wireless power transmission to multiple devices according to an embodiment of the present invention includes (a) obtaining direction information of each of a plurality of target devices (b) deriving a phase weight associated with power radiated from each of the plurality of unit antennas toward each of the plurality of target devices based on the direction information and information on the arrangement of an antenna array including a plurality of unit antennas; (c) defining a weight matrix based on the phase weights; and (d) generating an output signal of the antenna array based on the weight matrix and baseband information.

In the step (d), a multi-tone signal radiated from each of the plurality of unit antennas and divided according to a predetermined tone interval and the number of target devices may be generated as the output signal.

In the step (a), the direction information including azimuth information and altitude information toward each of the plurality of target devices may be obtained from the antenna array.

In addition, the step (b) may include the azimuth information, the elevation information, the horizontal interval between the unit antennas, the vertical interval between the unit antennas, and wavelength information of beams emitted from the antenna array corresponding to each of the target TVs. It is possible to calculate the phase weight based on.

In addition, in the step (b), the phase weight associated with the component of the output signal radiated to the k -th target device by the ( m , n ) element among the plurality of unit antennas constituting the antenna array is based on Equation 1 below. can be computed.

Also, the baseband information may be a baseband vector determined according to the tone interval and the number of the plurality of target devices.

In the step (d), the weight matrix and the baseband vector may be multiplied.

Also, the output signal may be a complex envelope signal.

In addition, in the multi-tone beamforming method for wireless power transmission to multiple devices according to an embodiment of the present invention, (e) the antenna array is applied by applying analog signal conversion, up-conversion, and power amplification to the output signal. It may include the step of radiating through.

In addition, if the antenna array has a structure in which M unit antennas are disposed in a horizontal direction and N unit antennas are disposed in a vertical direction, and the number of the plurality of target devices is K , the step (c), (c1) defining a first reference vector that is a 1xK vector having the phase weight as an element, (c2) defining a second reference vector that is an MxK vector having the first reference vector as an element, and ( c3) defining the weight matrix as an MN × K vector having the second reference vector as an element.

Meanwhile, in the multi-tone beamforming apparatus for wireless power transmission to multiple devices according to an embodiment of the present invention, direction information of each of a plurality of target devices is acquired, and an antenna including the direction information and a plurality of unit antennas. A weight calculation unit for deriving phase weights associated with power radiated from each of the plurality of unit antennas toward each of the plurality of target devices based on arrangement information of an array, a matrix calculation unit for defining a weight matrix based on the phase weights, and and a signal generator for generating an output signal of the antenna array based on the weight matrix and baseband information.

In addition, the signal generator may generate a multi-tone signal, which is radiated from each of the plurality of unit antennas and divided according to a predetermined tone interval and the number of target devices, as the output signal.

In addition, the direction information may include azimuth angle information and elevation angle information toward each of the plurality of target devices from the antenna array.

The weight calculation unit may be based on the azimuth angle information, the elevation angle information, the horizontal distance between the unit antennas, the vertical distance between the unit antennas, and wavelength information of beams emitted from the antenna array corresponding to each of the target T-vices. Thus, the phase weight can be calculated.

In addition, the weight calculation unit calculates the phase weight associated with a component of an output signal radiated to a k -th target device by an ( m , n ) element among a plurality of unit antennas constituting the antenna array based on Equation 1 below. can do.

Also, the signal generator may perform a multiplication operation by the weight matrix and the baseband vector.

In addition, the multi-tone based beamforming apparatus for wireless power transmission to multiple devices according to an embodiment of the present invention applies analog signal conversion, up-conversion and power amplification to the output signal and radiates through the antenna array. It may include a signal output unit.

The above-described problem solving means are merely exemplary and should not be construed as intended to limit the present disclosure. In addition to the exemplary embodiments described above, additional embodiments may exist in the drawings and detailed description of the invention.

According to the above-described problem solving means of the present application, a multi-tone based beamforming apparatus and method for wireless power transmission to multiple devices generating multi-tone signals based on a multi-antenna array in order to simultaneously transmit power to a plurality of target devices can provide

However, the effects obtainable herein are not limited to the effects described above, and other effects may exist.

1 is a schematic configuration diagram of a wireless power transmission system including a multi-tone based beamforming device for wireless power transmission to multiple devices according to an embodiment of the present invention.
2 is a conceptual diagram for explaining a process of generating and radiating an output signal of an antenna array based on a weight matrix based on phase weights and baseband information.
3 is a conceptual diagram for explaining an operation process of a multi-tone based beamforming device for wireless power transmission to multiple devices according to an embodiment of the present invention.
FIG. 4 is a diagram illustrating multi-tone signals radiated from each channel of an antenna array and combining multi-tone signals into beams directed to each of a plurality of target devices.
5A and 5B are diagrams showing simulation results associated with a multi-tone based beamforming technique for wireless power transmission to multiple devices according to an embodiment of the present invention.
6 is a diagram showing a plurality of beams generated according to the number of target devices as a result of simulation associated with a multi-tone based beamforming technique for wireless power transmission to multiple devices according to an embodiment of the present invention.
7 is a schematic configuration diagram of a multi-tone based beamforming device for wireless power transmission to multiple devices according to an embodiment of the present invention.
8 is an operation flowchart of a multi-tone based beamforming method for wireless power transmission to multiple devices according to an embodiment of the present invention.

Hereinafter, embodiments of the present application will be described in detail so that those skilled in the art can easily practice with reference to the accompanying drawings. However, the present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. And in order to clearly describe the present application in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the present specification, when a part is said to be “connected” to another part, it is not only “directly connected”, but also “electrically connected” or “indirectly connected” with another element in between. "Including cases where

Throughout the present specification, when a member is referred to as being “on,” “above,” “on top of,” “below,” “below,” or “below” another member, this means that a member is located in relation to another member. This includes not only the case of contact but also the case of another member between the two members.

Throughout the present specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

The present disclosure relates to a multi-tone based beamforming apparatus and method for wireless power transmission to multiple devices.

1 is a schematic configuration diagram of a wireless power transmission system including a multi-tone based beamforming device for wireless power transmission to multiple devices according to an embodiment of the present invention.

Referring to FIG. 1, a wireless power transmission system 10 according to an embodiment of the present invention includes a multi-tone based beamforming device 100 for wireless power transmission to multiple devices (hereinafter referred to as 'beamforming device 100'). ), an antenna array 200 and a target device 300 may be included.

The beamforming apparatus 100, the antenna array 200, and the target device 300 may communicate with each other through a network (not shown). A network (not shown) means a connection structure capable of exchanging information between nodes such as terminals and servers, and an example of such a network (not shown) includes a 3rd Generation Partnership Project (3GPP) network, LTE (Long Term Evolution) network, 5G network, WIMAX (World Interoperability for Microwave Access) network, Internet, LAN (Local Area Network), Wireless LAN (Wireless Local Area Network), WAN (Wide Area Network), PAN( Personal Area Network), wifi network, Bluetooth network, satellite broadcasting network, analog broadcasting network, DMB (Digital Multimedia Broadcasting) network, etc. are included, but are not limited thereto.

In the description of the embodiments of the present application, the target device 300 may refer to a terminal or device that obtains power from a signal (beam) radiated by the antenna array 200 controlled by the beamforming apparatus 100. . In addition, according to an embodiment of the present application, the target device 300 may be a multiple device provided in a plurality of areas around the antenna array 200 .

The target device 300 is, for example, a smartphone (Smartphone), a smart pad (SmartPad), a tablet PC, etc. and PCS (Personal Communication System), GSM (Global System for Mobile communication), PDC (Personal Digital Cellular), PHS ( Personal Handyphone System), PDA (Personal Digital Assistant), IMT (International Mobile Telecommunication)-2000, CDMA (Code Division Multiple Access)-2000, W-CDMA (W-Code Division Multiple Access), Wibro (Wireless Broadband Internet) terminal It may be any kind of wireless communication device, such as

Hereinafter, a detailed structure and function of the beamforming apparatus 100 will be described with reference to FIGS. 2 to 4 .

2 is a conceptual diagram for explaining a process of generating and radiating an output signal of an antenna array based on a weight matrix based on phase weights and baseband information, and FIG. 3 is a wireless power to multiple devices according to an embodiment of the present invention. It is a conceptual diagram for explaining an operation process of a multi-tone based beamforming device for transmission.

Referring to FIGS. 2 and 3 , first, the beamforming apparatus 100 may obtain direction information of each of a plurality of target devices 300 . Here, the direction information may include azimuth angle information and elevation angle information toward each of the plurality of target devices 300 from the antenna array 200 .

In addition, the beamforming apparatus 100 includes a plurality of target devices (from each of a plurality of unit antennas) based on the acquired direction information of each target device 300 and arrangement information of the antenna array 200 including a plurality of unit antennas. 300) A phase weight associated with power radiated toward each may be derived.

Specifically, the beamforming apparatus 100 corresponds to azimuth angle information, elevation angle information, horizontal intervals between unit antennas of the antenna array 200, vertical intervals between unit antennas of each target device 300, and each target device 300. Thus, the phase weight can be calculated based on the wavelength information of the beam emitted from the antenna array 200 .

According to an embodiment of the present invention, the beamforming apparatus 100 has a phase associated with a component of an output signal radiated to a k -th target device by an ( m , n ) element among a plurality of unit antennas constituting the antenna array 200. Each weight can be calculated based on Equation 1 below.

[Equation 1]

는 (m, n, k) 번째 위상 가중치이고,

는 k번째 타겟 디바이스(300)에 대하여 안테나 어레이(200)로부터 방사되는 빔의 파장 정보이고,

는 단위 안테나 간의 수평 간격이고,

는 단위 안테나 간의 수직 간격이고,

는 k번째 타겟 디바이스(300)에 대한 고도각 정보이고,

는 k번째 타겟 디바이스(300)에 대한 방위각 정보일 수 있다.In Equation 1 above

is the ( m , n , k )th phase weight,

Is wavelength information of a beam emitted from the antenna array 200 for the k -th target device 300,

is the horizontal spacing between unit antennas,

is the vertical spacing between unit antennas,

Is elevation angle information for the k -th target device 300,

may be azimuth information about the k -th target device 300 .

Also, the beamforming apparatus 100 may define a weight matrix based on the calculated phase weights.

Specifically, the antenna array 200 has a structure in which M unit antennas are disposed in a horizontal direction and N unit antennas are disposed in a vertical direction (in other words, an antenna array 200 structure including MN unit channels). and if the number of the plurality of target devices 300 is K , the beamforming apparatus 100 converts the first reference vector, which is a 1xK vector, with elements of each of the previously calculated phase weights as shown in Equation 2-1 below. can be defined

[Equation 2-1]

)를 이루는 각각의 원소인

는 앞서 연산된 위상 가중치(

)에 대하여

와 같이 연산될 수 있다.Here, the first reference vector (

), each element of

is the previously calculated phase weight (

)about

can be computed as

In addition, the beamforming apparatus 100 may define a second reference vector, which is an M x K vector having the first reference vector defined through Equation 2-1 as an element, as shown in Equation 2-2 below.

[Equation 2-2]

은 제2기준 벡터이고,

는 안테나 어레이(200)의 각각의 행에 위치하는 단위 안테나들에 대응하는 제1기준 벡터일 수 있다.here,

is the second reference vector,

may be a first reference vector corresponding to unit antennas located in each row of the antenna array 200.

In addition, the beamforming apparatus 100 may define a weight matrix that is an MN × K vector having the second reference vector defined through Equation 2-2 as an element. Here, the weight matrix may be finally derived as shown in Equation 2-3 below.

[Equation 2-3]

In addition, the beamforming apparatus 100 may generate an output signal of the antenna array 200 based on a weight matrix and baseband information obtained by vector (matrix) calculation through Equations 2-1 to 2-3 described above. . According to an embodiment of the present application, the beamforming apparatus 100 may perform a multiplication (matrix multiplication) operation between the generated weight matrix and a baseband vector corresponding to the baseband information.

In this regard, the baseband information may be a vector (baseband vector) defined by Equation 3 below.

[Equation 3]

)의 각각의 원소(

)는 하기 식 4에 기초하여 톤 간격 및 각각의 타겟 디바이스(300)에 대응하는 식별자(k)에 기초하여 연산될 수 있다.Here, the baseband vector (

) of each element (

) may be calculated based on the tone interval and an identifier ( k ) corresponding to each target device 300 based on Equation 4 below.

[Equation 4]

는 기 설정된 톤 간격일 수 있다.here,

may be a preset tone interval.

In other words, referring to Equations 3 and 4 above, baseband information for generating an output signal may be a baseband vector determined according to a tone interval and the number of target devices 300 .

)는 하기 식 5와 같이 도출될 수 있다.In addition, the output signal according to the matrix multiplication operation of the weight matrix and the baseband vector (

) can be derived as in Equation 5 below.

[Equation 5]

) 및 타겟 디바이스(300)의 수에 따라 분할되는 다중 톤 신호를 출력 신호로 생성할 수 있으며, 이렇게 생성되는 출력 신호는 복소 포락선 신호(Complex envelope signal)일 수 있다.That is, the beamforming apparatus 100 radiates from each of a plurality of unit antennas of the antenna array 200, and a preset tone spacing (tone spacing,

) and a multi-tone signal divided according to the number of target devices 300 may be generated as an output signal, and the output signal thus generated may be a complex envelope signal.

In addition, the output signal may be an MN × 1 block matrix having a 1x M vector transposed matrix according to Equation 6 below as a sub-matrix (sub-matrix). In addition, Equation 7 below is a phase-modulated K-tone signal, and a bandpass signal corresponding thereto may be expressed by Equation 8 below.

[Equation 6]

[Equation 7]

[Equation 8]

는 반송 주파수(carrier frequency)이고, 상기 식 8은 안테나 어레이(200)의 (m, n) 번째 채널에서 출력(방사)되는 대역통과(bandpass) 신호를 나타낸 것일 수 있다.here,

Is a carrier frequency, and Equation 8 above may represent a bandpass signal output (radiated) from the ( m , n ) th channel of the antenna array 200.

FIG. 4 is a diagram illustrating multi-tone signals radiated from each channel of an antenna array and combining multi-tone signals into beams directed to each of a plurality of target devices.

Referring to FIG. 4 , K-tone signals generated by the beamforming apparatus 100 disclosed in the present application are K (in other words, the number of target devices 300 to receive power) according to preset tone intervals. It can be expressed as a sum of independent frequency signals. In addition, referring to FIG. 4, K-tone signals generated for each channel may be overlapped and radiated to each channel (in other words, MN channels) constituting the antenna array 200, and the signal for each channel may be radiated. Combining in the air present in the output direction of the antenna array 200 can form K beams radiated individually toward K target devices 200, and each target device 300 It may be that power is delivered to .

For reference, the tone interval for forming such a K-tone signal may be, for example, 500 Hz, but is not limited thereto, and the tone interval is the number of unit antennas of the antenna array 200, the target device 300 The value may be set in consideration of system performance including an average separation distance between the target device 300 and the antenna array 200 in a space in which .

)에 대하여 DAC(Digital to Analog Converter) 회로에 의한 아날로그 신호 변환, 상향 변환(Up-conversion) 및 전력 증폭기(Power Amplifier)에 의한 전력 증폭을 적용하여 출력 신호에 대응하는 밴드패스 신호(

)가 안테나 어레이(200)를 통해 방사되도록 할 수 있다.In addition, referring to FIG. 2 described above, the beamforming apparatus 100 generates an output signal (

), analog signal conversion by DAC (Digital to Analog Converter) circuit, up-conversion and power amplification by power amplifier are applied to the band pass signal corresponding to the output signal (

) can be radiated through the antenna array 200.

Hereinafter, simulation results associated with a multi-tone based beamforming technique for wireless power transmission to multiple devices according to an embodiment of the present invention will be described with reference to FIGS. 5A to 6 .

5A and 5B are diagrams showing simulation results associated with a multi-tone based beamforming technique for wireless power transmission to multiple devices according to an embodiment of the present invention, and FIG. 6 is a diagram showing multiple devices according to an embodiment of the present invention. It is a diagram showing a plurality of beams generated according to the number of target devices as a result of simulation associated with a multi-tone based beamforming technique for wireless power transmission to .

Referring to FIG. 6, the simulation associated with the multi-tone based beamforming technique for wireless power transmission to multiple devices according to an embodiment of the present invention is two, corresponding to 2, 3, and 4 target devices 300, respectively. to 4 beams, and accordingly, 2-tone, 3-tone and 4-tone signals were generated as output signals in each simulation.

In addition, referring to FIG. 5A, the direction and order of the main beam were determined as (20°, 0°) and (30°, 180°) in Case 1 (two beams), and in Case 2 (three beams) Cases (20°, 90°), (30°, 225°), (30°, 315°) were determined, and in the case of Case 3 (4 beams), (20°, 0°), (20°, 90°) °), (20°, 180°), and (20°, 270°) were determined based on the spherical coordinate system.

Referring to FIGS. 5A and 5B , unlike conventional beamforming-based power transmission schemes, since the beamforming apparatus 100 disclosed herein performs multi-beamforming, multi-tone signals are analyzed in consideration of the main beam direction. In the above analysis, the instantaneous power of the complex envelope signal, which is the output signal, can be calculated as shown in Equation 9 below.

[Equation 9]

In this regard, referring to FIG. 5B , the conventional beamforming method uses a continuous signal (CW) having a constant envelope, whereas an output signal generated by the beamforming apparatus 100 disclosed in the present application is suitable for multi-beamforming. It can be confirmed that the change of the envelope of the multi-tone signal over time occurs in each channel of the antenna array 200.

7 is a schematic configuration diagram of a multi-tone based beamforming device for wireless power transmission to multiple devices according to an embodiment of the present invention.

Referring to FIG. 7 , the beamforming apparatus 100 may include a weight calculation unit 110 , a matrix calculation unit 120 , a signal generator 130 and a signal output unit 140 .

The weight calculator 110 may obtain direction information of each of the plurality of target devices 300 . Here, the direction information may include azimuth angle information and elevation angle information toward each of the plurality of target devices 300 from the antenna array 200 .

In addition, the weight calculator 110 radiates power from each of the plurality of unit antennas toward each of the plurality of target devices 300 based on the obtained direction information and the arrangement information of the antenna array 200 including the plurality of unit antennas. A phase weight associated with can be derived.

Specifically, the weight calculation unit 110 corresponds to azimuth angle information, altitude angle information, horizontal intervals between unit antennas of the antenna array 200, vertical intervals between unit antennas of each target device 300, and target devices 300, respectively. A phase weight may be calculated based on wavelength information of a beam emitted from the antenna array 200 .

That is, the weight calculation unit 110 calculates each of the phase weights associated with components of the output signal radiated to the k -th target device by the ( m , n ) element among the plurality of unit antennas constituting the antenna array 200 according to Equation 1 described above. can be calculated based on

The matrix operator 120 may define a weight matrix based on the calculated phase weights.

Specifically, if the antenna array 200 has a structure in which M unit antennas are disposed in the horizontal direction and N unit antennas are disposed in the vertical direction, and the number of the plurality of target devices 300 is K , the matrix operation unit 120 may first define a first reference vector that is a 1xK vector having each phase weight calculated by the weight calculation unit 110 as an element.

In addition, the matrix operation unit 120 defines a second reference vector that is an MxK vector having the defined first reference vector as an element, and defines a weight matrix that is an MNxK vector having the defined second reference vector as an element. In this way, sequential matrix (vector) operations can be performed.

The signal generator 130 may generate an output signal of the antenna array 200 based on the weight matrix and baseband information. According to an embodiment of the present application, the signal generator 130 may perform a multiplication (matrix multiplication) operation between the generated weight matrix and the baseband vector.

) 및 타겟 디바이스(300)의 수에 따라 분할되는 다중 톤 신호를 출력 신호로 생성할 수 있다.Specifically, the signal generator 130 is radiated from each of a plurality of unit antennas of the antenna array 200, and a preset tone spacing (tone spacing,

) and a multi-tone signal divided according to the number of target devices 300 may be generated as an output signal.

The signal output unit 140 may apply analog signal conversion, up-conversion, and power amplification to the generated output signal so that a bandpass signal corresponding to the output signal is radiated through the antenna array 200. there is.

Hereinafter, based on the details described above, the operation flow of the present application will be briefly reviewed.

8 is an operation flowchart of a multi-tone based beamforming method for wireless power transmission to multiple devices according to an embodiment of the present invention.

The multi-tone based beamforming method for wireless power transmission to multiple devices shown in FIG. 8 may be performed by the beamforming device 100 described above. Therefore, even if omitted below, the description of the beamforming device 100 can be equally applied to a description of a multi-tone based beamforming method for wireless power transmission to multiple devices.

Referring to FIG. 8 , in step S11 , the weight calculator 110 may (a) obtain direction information of each of the plurality of target devices 300 .

Specifically, in step S11 , the weight calculator 110 may obtain direction information including azimuth angle information and elevation angle information toward each of the plurality of target devices 300 from the antenna array 200 .

Next, in step S12, the weight calculator 110 performs (b) each of a plurality of unit antennas based on the direction information of each of the plurality of target devices 300 and the arrangement information of the antenna array 200 including the plurality of unit antennas. A phase weight associated with power radiated toward each of the plurality of target devices 300 may be derived.

Specifically, in step S12, the weight calculation unit 120 corresponds to the azimuth angle information and elevation angle information of each target device 300, the horizontal interval and vertical interval between unit antennas of the antenna array 200, and each target device 300. A phase weight may be calculated based on wavelength information of a beam emitted from the antenna array 200 .

More specifically, in step S12, the weight calculation unit 120 is associated with a component of an output signal radiated to the k -th target device 300 by an ( m , n ) element among a plurality of unit antennas constituting the antenna array 200. The phase weight can be calculated based on Equation 1 above.

Next, in step S13, the matrix operator 120 may define a weight matrix by using (c) the derived phase weights.

Next, in step S14, the signal generator 130 may generate an output signal of the antenna array 200 based on (d) the defined weight matrix and baseband information.

) 및 타겟 디바이스(300)의 수에 따라 분할되는 다중 톤 신호를 출력 신호로 생성할 수 있다.Specifically, in step S14, the signal generator 130 radiates from each of a plurality of unit antennas, and a preset tone interval (

) and a multi-tone signal divided according to the number of target devices 300 may be generated as an output signal.

Next, in step S15, the signal output unit 140 transmits power to the target device 300 through the antenna array 200 by applying analog signal conversion, up-conversion, and power amplification to (e) the generated output signal. It is possible to radiate multiple beams based on multi-tone signals for

In the foregoing description, steps S11 to S15 may be further divided into additional steps or combined into fewer steps, depending on the implementation of the present application. Also, some steps may be omitted if necessary, and the order of steps may be changed.

A multi-tone based beamforming method for wireless power transmission to multiple devices according to an embodiment of the present application may be implemented in the form of program instructions that can be executed by various computer means and recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the medium may be those specially designed and configured for the present invention or those known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. - includes hardware devices specially configured to store and execute program instructions, such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler. The hardware devices described above may be configured to act as one or more software modules to perform the operations of the present invention, and vice versa.

In addition, the above-described multi-tone beamforming method for wireless power transmission to multiple devices may be implemented in the form of a computer program or application stored in a recording medium and executed by a computer.

The above description of the present application is for illustrative purposes, and those skilled in the art will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present application. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present application is indicated by the following claims rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts thereof should be construed as being included in the scope of the present application.

10: wireless power transmission system
100: Multi-tone based beamforming device for wireless power transmission to multiple devices
110: weight calculation unit
120: matrix operation unit
130: signal generator
140: signal output unit
200: antenna array
300: target device

Claims (15)

In the multi-tone based beamforming method for wireless power transmission to multiple devices,
(a) acquiring direction information of each of a plurality of target devices;
(b) deriving a phase weight associated with power radiated from each of the plurality of unit antennas toward each of the plurality of target devices based on the direction information and information on an arrangement of an antenna array including a plurality of unit antennas;
(c) defining a weight matrix based on the phase weights; and
(d) generating an output signal of the antenna array based on the weight matrix and baseband information;
Including,
If the antenna array has a structure in which M unit antennas are disposed in a horizontal direction and N unit antennas are disposed in a vertical direction, and the number of the plurality of target devices is K,
In step (c),
(c1) defining a first reference vector that is a 1xK vector having the phase weight as an element;
(c2) defining a second reference vector that is an MxK vector having the first reference vector as an element; and
(c3) defining the weight matrix as an MNxK vector having the second reference vector as an element;
To include, a beamforming method. According to claim 1,
In step (d),
The beamforming method of generating a multi-tone signal radiated from each of the plurality of unit antennas and divided according to a predetermined tone interval and the number of target devices as the output signal. According to claim 1,
In step (a),
Obtaining the direction information including azimuth angle information and elevation angle information toward each of the plurality of target devices from the antenna array. According to claim 3,
In step (b),
Calculating the phase weight based on the azimuth information, the elevation information, the horizontal distance between the unit antennas, the vertical distance between the unit antennas, and wavelength information of beams radiated from the antenna array corresponding to each of the target devices In, beamforming method. According to claim 4,
In step (b),
The phase weight associated with the component of the output signal radiated to the k -th target device by the ( m , n ) element among the plurality of unit antennas constituting the antenna array is calculated based on Equation 1 below,
[Equation 1]

here,

is the phase weight,

is the wavelength information,

is the horizontal spacing,

is the vertical spacing,

Is the altitude angle information,

Is the azimuth information, the beamforming method. According to claim 2,
The baseband information,
A baseband vector determined according to the tone interval and the number of the plurality of target devices;
In step (d),
and multiplying the weight matrix and the baseband vector. According to claim 1,
The output signal is a complex envelope signal,
(e) radiating through the antenna array by applying analog signal conversion, up-conversion, and power amplification to the output signal;
To further include, the beamforming method. delete In a multi-tone based beamforming device for wireless power transmission to multiple devices,
direction information of each of a plurality of target devices is acquired, and power radiated from each of the plurality of unit antennas toward each of the plurality of target devices based on the direction information and arrangement information of an antenna array including a plurality of unit antennas; a weight calculator for deriving associated phase weights;
a matrix operator defining a weight matrix based on the phase weights; and
a signal generator for generating an output signal of the antenna array based on the weight matrix and baseband information;
Including,
If the antenna array has a structure in which M unit antennas are disposed in a horizontal direction and N unit antennas are disposed in a vertical direction, and the number of the plurality of target devices is K,
The matrix operation unit,
A first reference vector that is a 1xK vector having the phase weight as an element is defined, a second reference vector that is an MxK vector having the first reference vector as an element is defined, and an MNxK vector having the second reference vector as an element. To define the weight matrix, the beamforming apparatus. According to claim 9,
The signal generator,
And generating a multi-tone signal radiated from each of the plurality of unit antennas and divided according to a predetermined tone interval and the number of target devices as the output signal. According to claim 9,
The beamforming apparatus of claim 1, wherein the direction information includes azimuth information and elevation information from the antenna array toward each of the plurality of target devices. According to claim 11,
The weight calculator,
Calculating the phase weight based on the azimuth information, the elevation information, the horizontal distance between the unit antennas, the vertical distance between the unit antennas, and wavelength information of beams radiated from the antenna array corresponding to each of the target devices Phosphorus, a beamforming device. According to claim 12,
The weight calculator,
The phase weight associated with the component of the output signal radiated to the k -th target device by the ( m , n ) element among the plurality of unit antennas constituting the antenna array is calculated based on Equation 1 below,
[Equation 1]

here,

is the phase weight,

is the wavelength information,

is the horizontal spacing,

is the vertical spacing,

Is the altitude angle information,

Is the azimuth information, the beamforming device. According to claim 10,
The baseband information,
A baseband vector determined according to the tone interval and the number of the plurality of target devices;
The signal generator,
and performing a multiplication operation by the weight matrix and the baseband vector. According to claim 9,
The output signal is a complex envelope signal,
A signal output unit that applies analog signal conversion, up-conversion, and power amplification to the output signal and radiates it through the antenna array;
To further include, the beamforming device.

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