Beam control method and system applied to microwave wireless energy transmission

Abstract

The invention discloses a beam control method and system applied to microwave wireless energy transmission, and relates to the technical field of wireless transmission. According to the wireless energy transmitter, two one-dimensional linear antenna arrays are adopted to receive guide signals from a wireless energy receiver, and then the transmitting phase of a two-dimensional antenna array is determined through linear operation according to the phase of the guide signals received by each array element of the two one-dimensional linear antenna arrays; therefore, the two-dimensional antenna array is controlled to transmit microwave energy transmission beams to the wireless energy receiver. The method and the device have relatively low complexity. According to the method, the phase value of microwave power emission is directly calculated according to the phase value of the guide signal, the position of a wireless energy receiver does not need to be found, and engineering implementation is easier.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless microwave transmission, and in particular to a beam control method and system applied to microwave wireless energy transmission. Background Art

[0002] Wireless power transmission technology can wirelessly power electronic devices, get rid of the physical size and wiring layout limitations of traditional charging cables, and greatly improve the flexibility of power supply. Due to the characteristics of microwaves such as long propagation distance, less environmental impact, high power carrying capacity, and electronic control (i.e., not mechanical control), microwave-based wireless power transmission can efficiently and flexibly remotely charge multiple mobile electronic devices. When using microwaves for wireless energy transmission, the wireless energy transmitter must generate one or more narrow microwave beams as carriers of wireless energy to improve the efficiency of microwave transmission, and the microwave energy beam must be accurately directed to the wireless energy receiver (i.e., the mobile electronic device to be charged). In microwave wireless energy transmission systems, "reverse beam control" technology is often used to control the direction of the energy beam; that is, the wireless energy receiver first sends a guidance signal, the wireless energy transmitter receives and analyzes the guidance signal, and then, based on the analysis results of the guidance signal, the wireless energy transmitter generates a narrow microwave beam that accurately points to the wireless energy receiver. In other words, the "reverse beam control" technology uses the guidance signal to guide the propagation of microwave energy.

[0003] There are three main common reverse beam control methods. The first is a beamforming scheme based on the estimation of the arrival direction of the incoming wave. The arriving electromagnetic wave meets the far-field conditions and can be approximated as a plane wave. The angle between the plane wave and the array normal is the wave arrival direction, but this method cannot be used in the near field; the second is based on phase conjugation retroreflection beamforming, which uses the conjugate phase of the guidance signal received by the transmitting antenna array to feed the transmitting antenna unit to complete the reverse beam control. This scheme can act on the near field and far field of the antenna array at the same time, but the disadvantage is that it requires a one-to-one corresponding transceiver channel, which is costly; the third is a microwave energy transmission and receiving end positioning method represented by a patent application (application number 202210391846.7) that uses a spatial search strategy to establish a spatial coordinate identification function of the receiving target by measuring the phase difference between the guidance signal receiving units, and determine the spatial coordinates of the receiving target through a spatial search strategy. The disadvantage of this beam control method is that the process is relatively complicated. Summary of the invention

[0004] In view of the shortcomings of the above three common beam control methods, the present invention provides a beam control method and system for microwave wireless energy transmission. The beam control method and system provided by the present invention can act on the far field and near field, while reducing the number of receiving antennas and reducing costs. The beam control method is simple and clear, and easy to implement in engineering. In order to achieve the above invention purpose, the technical solution adopted by the present invention is:

[0005] A beam control method for microwave wireless energy transmission is proposed, which is characterized by comprising the following steps:

[0006] S1. The wireless energy receiver transmits a guidance signal; wherein the wireless energy receiver is a target electronic device to be powered;

[0007] S2. Two one-dimensional linear antenna arrays of the wireless energy transmitter receive the guidance signal; wherein the wireless energy transmitter is a power supply end, including two orthogonally arranged one-dimensional linear antenna arrays and a two-dimensional planar transmitting antenna array; the one-dimensional linear antenna array is a guidance signal receiving antenna; the two-dimensional planar transmitting antenna array is composed of M×N transmitting array elements; all transmitting array elements are arranged into M columns and N rows; (x m ,y n ) represents the rectangular coordinates of the position of the transmitting array element in the mth column and the nth row in the two-dimensional plane, where m=1, 2, ..., M, n=1, 2, ..., N;

[0008] The two orthogonally arranged one-dimensional linear receiving antenna arrays include a longitudinal linear receiving antenna array and a transverse linear receiving antenna array; each transverse linear receiving antenna array includes M array elements, and the position abscissa of the mth receiving array element of the transverse linear receiving antenna array is (x m , y0), where y0 is the y coordinate of the horizontal linear receiving antenna array, m = 1, 2, ..., M; the vertical linear receiving antenna array includes N array elements, and the vertical coordinate of the position of the nth receiving array element of the vertical linear receiving antenna array is (x0, y n ), where x0 is the x coordinate of the longitudinal linear receiving antenna array, n=1, 2, ..., N;

[0009] S3, the wireless energy transmitter performs phase assignment on the feeding signal of the two-dimensional planar transmitting antenna array according to the phase value of the received guidance signal, so as to form a microwave beam to transmit the wireless energy to the wireless energy receiver;

[0010] The frequency of the feed signal is the same as the frequency of the guidance signal; the feed phase value Ψ of the transmitting array element in the mth column and the nth row is mn The calculation formula is:

[0011] Ψ mn =Ψ0-β n -γm ;

[0012] Among them, β n is the phase value of the pilot signal received by the nth receiving element of the longitudinal linear receiving antenna array, γ m is the phase value of the guidance signal received by the mth receiving element of the horizontal linear receiving antenna array; Ψ0 is an arbitrary constant phase.

[0013] Furthermore, the one-dimensional linear antenna array is placed outside the two-dimensional antenna array or embedded in the two-dimensional antenna array.

[0014] A beam control system for microwave wireless energy transmission includes a wireless energy transmission machine and a wireless energy receiver; the wireless energy transmission machine includes a wireless energy transmission module and a guidance signal receiving module connected in series; wherein the wireless energy transmission machine is a wireless energy transmission device, and the wireless energy receiver is a target electronic device to be powered;

[0015] The wireless energy transmitting module includes a transmitting circuit module and a two-dimensional planar antenna array, and the two-dimensional antenna array is composed of planar antenna units;

[0016] The transmitting circuit module includes a pilot signal phase analysis circuit and a microwave power transmitting circuit; the pilot signal circuit is connected to a one-dimensional linear antenna array; the microwave power transmitting circuit is connected to a two-dimensional planar antenna array;

[0017] The guidance signal receiving module includes at least two one-dimensional linear antenna arrays, each of which is composed of planar antenna units;

[0018] The one-dimensional linear antenna array is placed outside the two-dimensional antenna array or embedded in the two-dimensional antenna array;

[0019] The wireless energy receiver includes a guide signal transmitting circuit and a microwave power receiving circuit;

[0020] in:

[0021] A guidance signal transmitting circuit, used for transmitting a guidance signal;

[0022] A microwave power receiving circuit for receiving wireless energy;

[0023] A one-dimensional linear antenna array for receiving a guidance signal;

[0024] A pilot signal phase analysis circuit is used to process the pilot signal received by the one-dimensional linear antenna array to obtain a phase value of the pilot signal; wherein the pilot signal phase analysis circuit includes but is not limited to a detector, a phase detector, an FPGA or other programmable digital processing circuit;

[0025] A microwave power transmitting circuit is used to perform phase assignment and beamforming on a feed signal of a two-dimensional planar antenna array through a wireless energy transmitter according to the phase value of the guidance signal, and control and transmit a narrow microwave beam to transmit energy to a wireless energy receiver;

[0026] A two-dimensional planar antenna array is used to transmit a narrow microwave beam to a microwave power receiving circuit.

[0027] The beneficial effects of the present invention are:

[0028] The beam control method of the present invention has low complexity. The present invention directly calculates the phase value of microwave power transmission from the phase value of the guidance signal, does not need to find the position of the wireless energy receiver, and is easier to implement in engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of the method of the present invention;

[0030] Figure 2 It is a schematic diagram of the method process of the present invention;

[0031] Figure 3 The antenna arrangement diagrams under different arrangement structures of the present invention;

[0032] Figure 4 Schematic diagram of free space positions of two one-dimensional linear antenna arrays and two two-dimensional antenna arrays;

[0033] Figure 5 It is a schematic diagram of a specific simulation example of the present invention;

[0034] Figure 6 This is a specific simulation example result diagram of the present invention. DETAILED DESCRIPTION

[0035] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0036] like Figure 1 As shown, a beam control method applied to microwave wireless energy transmission includes the following steps:

[0037] S1. The wireless energy receiver transmits a guidance signal; wherein the wireless energy receiver is a target electronic device to be powered;

[0038] S2. Two one-dimensional linear antenna arrays of the wireless energy transmitter receive the guidance signal; wherein the wireless energy transmitter is a power supply end, including two orthogonally arranged one-dimensional linear antenna arrays and a two-dimensional planar transmitting antenna array; the one-dimensional linear antenna array is a guidance signal receiving antenna; the two-dimensional planar transmitting antenna array is composed of M×N transmitting array elements; all transmitting array elements are arranged into M columns and N rows; the rectangular coordinates of the position of the transmitting array element in the mth column and the nth row in the two-dimensional plane are (x m ,y n ), where m=1, 2, ..., M, =1, 2, ..., N;

[0039] The two orthogonally arranged one-dimensional linear receiving antenna arrays include a longitudinal linear receiving antenna array and a transverse linear receiving antenna array; each transverse linear receiving antenna array includes M array elements, and the position abscissa of the mth receiving array element of the transverse linear receiving antenna array is (x m , y0), where y0 is the y coordinate of the horizontal linear receiving antenna array, m = 1, 2, ..., M; the vertical linear receiving antenna array includes N array elements, and the vertical coordinate of the position of the nth receiving array element of the vertical linear receiving antenna array is (x0, y n ), where x0 is the x coordinate of the longitudinal linear receiving antenna array, n=1, 2, ..., N;

[0040] S3, the wireless energy transmitter performs phase assignment on the feeding signal of the two-dimensional planar transmitting antenna array according to the phase value of the received guidance signal, so as to form a microwave beam to transmit the wireless energy to the wireless energy receiver;

[0041] The frequency of the feed signal is the same as the frequency of the guidance signal; the feed phase value Ψ of the transmitting array element in the mth column and the nth row is mn The calculation formula is:

[0042] Ψ mn =Ψ0-β n -γ m ;

[0043] Among them, β n is the phase value of the pilot signal received by the nth receiving element of the longitudinal linear receiving antenna array, γ m is the phase value of the guidance signal received by the mth receiving element of the horizontal linear receiving antenna array; Ψ0 is an arbitrary constant phase.

[0044] The one-dimensional linear antenna array is placed outside the two-dimensional antenna array or embedded in the two-dimensional antenna array.

[0045] A beam control system for microwave wireless energy transmission includes a wireless energy transmission machine and a wireless energy receiver; the wireless energy transmission machine includes a wireless energy transmission module and a guidance signal receiving module connected in series; wherein the wireless energy transmission machine is a wireless energy transmission device, and the wireless energy receiver is a target electronic device to be powered;

[0046] The wireless energy transmitting module includes a transmitting circuit module and a two-dimensional planar antenna array, and the two-dimensional antenna array is composed of planar antenna units;

[0047] The transmitting circuit module includes a pilot signal phase analysis circuit and a microwave power transmitting circuit; the pilot signal circuit is connected to a one-dimensional linear antenna array; the microwave power transmitting circuit is connected to a two-dimensional planar antenna array;

[0048] The guidance signal receiving module includes at least two one-dimensional linear antenna arrays, each of which is composed of planar antenna units;

[0049] The one-dimensional linear antenna array is placed outside the two-dimensional antenna array or embedded in the two-dimensional antenna array;

[0050] The wireless energy receiver includes a guide signal transmitting circuit and a microwave power receiving circuit;

[0051] in:

[0052] A guidance signal transmitting circuit, used for transmitting a guidance signal;

[0053] A microwave power receiving circuit for receiving wireless energy;

[0054] A one-dimensional linear antenna array for receiving a guidance signal;

[0055] A pilot signal phase analysis circuit is used to process the pilot signal received by the one-dimensional linear antenna array to obtain a phase value of the pilot signal; wherein the pilot signal phase analysis circuit includes but is not limited to a detector, a phase detector, an FPGA or other programmable digital processing circuit;

[0056] A microwave power transmitting circuit is used to perform phase assignment and beamforming on a feed signal of a two-dimensional planar antenna array through a wireless energy transmitter according to the phase value of the guidance signal, and control and transmit a narrow microwave beam to transmit energy to a wireless energy receiver;

[0057] A two-dimensional planar antenna array is used to transmit a narrow microwave beam to a microwave power receiving circuit.

[0058] like Figure 2 As shown, a specific embodiment is used to describe a beam control method for controlling a two-dimensional antenna array using a one-dimensional antenna array, that is, a beam control method applied to microwave wireless energy transmission. Figure 2 In the figure, a two-dimensional wireless energy transmitting antenna array is represented by brown, and two one-dimensional guided signal receiving antenna arrays are represented by blue. The two-dimensional wireless energy transmitting antenna array includes M×N antenna elements placed along the x direction and the y direction, where M and N are integers greater than 1. A one-dimensional linear antenna array includes N antenna elements placed along the x direction, and another one-dimensional linear antenna array includes M antenna elements placed along the y direction. Figure 2 The structure in is only one embodiment and is not the only possible physical structure; Figure 3 Some other applicable antenna arrangement structures are given.

[0059] Figure 2 The wireless energy receiver (electronic device to be charged) obtains wireless energy from the wireless energy transmitter through two steps. Step (i): The wireless energy receiver broadcasts a guidance signal with a frequency of f, and the wireless energy transmitter receives and analyzes the guidance signal. Step (ii): Based on the result of analyzing the guidance signal, the wireless energy transmitter generates a time-harmonic microwave power beam with a frequency of f directed to the wireless energy receiver. In step (i), the guidance signal emitted by the wireless energy receiver is received by M+N blue antenna units, and the guidance signal phase analysis circuit of the wireless energy transmitter obtains the phase value of the received guidance signal. The phase value of the guidance signal received by the N blue antenna units placed along the x direction is:

[0060] β1,β2,…,β n ,…,β N n=1,2,…,N;

[0061] Wherein, the subscript n=1,2,...,N increases sequentially along the +x direction. The phase value of the guidance signal received by the M blue antenna units placed along the y direction is:

[0062] γ1,γ2,…,γ m ,…,γ M m=1,2,…,M;

[0063] Wherein, the subscript m=1, 2, ..., M increases sequentially along the +y direction. In step (ii), the microwave power transmitting circuit of the wireless energy transmitter feeds M×N brown antenna units with equal amplitude; the feeding amplitude is determined by the wireless energy transmitter according to its own capability and has nothing to do with the guidance signal; the feeding phase value of the M×N brown antenna units is expressed as Ψ mn . Among them, the subscript n=1,2,...,N and the subscript m=1,2,...,M are consistent with the subscript notation of the blue guidance signal receiving antenna, that is, the subscript n=1,2,...,N increases in sequence along the +x direction, and the subscript m=1,2,...,M increases in sequence along the +y direction. The phase value Ψ of the feedmn By the phase value β of the pilot signal n and γ m The calculation formula is a simple linear combination:

[0064]

[0065] The above formula provides a beam control method for controlling a two-dimensional wireless energy transmitting antenna array using a one-dimensional guidance signal receiving antenna array. Compared with several common beam control methods currently used, such as beam forming based on DOA estimation, back reflection based on phase conjugation, and receiving end positioning method based on phase conjugation spatial search strategy, the beam control method in the present invention has lower complexity. The present invention directly calculates the phase value of microwave power transmission from the phase value of the guidance signal, and does not need to find the location of the wireless energy receiver, which is easier to implement in engineering.

[0066] As a specific example, when M=N=4, the wireless energy transmitter includes 4×4=16 wireless energy transmitting antenna units and 4+4=8 guidance signal receiving antenna units, such as Figure 4 As shown. Figure 4 In the specific example, the calculation formula for controlling the two-dimensional wireless energy transmitting antenna array using the one-dimensional guidance signal receiving antenna array is shown in Table 1.

[0067] Table 1

[0068]

[0069] Figure 5 A simulation example of wireless energy transmission using the present invention is given, and the transmission frequency of the system is f = 5.8 GHz. Figure 5 In the example, the two-dimensional planar antenna array consists of 8×8=64 transmitting antenna units. The distance between the receiving area and the two-dimensional planar transmitting antenna array is 100m, and the receiving area is S=400×400=160000m 2 The area. With the normal center of the two-dimensional transmitting antenna array as the origin, a rectangular coordinate system is established in the receiving area. The target device transmits a guidance signal at any position in the receiving area to guide the two-dimensional planar transmitting array to focus the beam. The energy focusing effects of the two sets of simulation examples are shown in Figure 2. Figure 6 As shown, the normalized field strength in the receiving area reflects the focusing effect of the beam. Figure 6 The simulation results shown show that the beam focusing area is concentrated around the guidance signal transmission position, which can explain that the present invention can achieve better reverse beam focusing performance.

Claims

1. A beam control method for microwave wireless energy transmission, characterized in that: The following steps are involved: S1. The wireless energy receiver transmits a guidance signal; wherein the wireless energy receiver is a target electronic device to be powered; S2. Two one-dimensional linear antenna arrays of the wireless energy transmitter receive the guidance signal; wherein the wireless energy transmitter is a power supply end, comprising two orthogonally arranged one-dimensional linear antenna arrays and a two-dimensional planar transmitting antenna array; the one-dimensional linear antenna array is a guidance signal receiving antenna; the two-dimensional planar transmitting antenna array is composed of M×N transmitting array elements; all transmitting array elements are arranged into M columns and N rows; (x m ,y n ) represents the rectangular coordinates of the position of the transmitting array element in the mth column and the nth row in the two-dimensional plane, where m=1, 2, ..., M, n=1, 2, ..., N; The two orthogonally arranged one-dimensional linear receiving antenna arrays include a longitudinal linear receiving antenna array and a transverse linear receiving antenna array; each transverse linear receiving antenna array includes M array elements, and the position abscissa of the mth receiving array element of the transverse linear receiving antenna array is (x m , y0), where y0 is the y coordinate of the horizontal linear receiving antenna array, m = 1, 2, ..., M; the vertical linear receiving antenna array includes N array elements, and the vertical coordinate of the position of the nth receiving array element of the vertical linear receiving antenna array is (x0, y n ), where x0 is the x coordinate of the longitudinal linear receiving antenna array, n=1, 2, ..., N; S3, the wireless energy transmitter performs phase assignment on the feeding signal of the two-dimensional planar transmitting antenna array according to the phase value of the received guidance signal, so as to form a microwave beam to transmit the wireless energy to the wireless energy receiver; The frequency of the feed signal is the same as the frequency of the guidance signal; the feed phase value Ψ of the transmitting array element in the mth column and the nth row is mn The calculation formula is: P mn =Ψ0-β n -c m ; Among them, β n is the phase value of the pilot signal received by the nth receiving element of the longitudinal linear receiving antenna array, γ m is the phase value of the guidance signal received by the mth receiving element of the horizontal linear receiving antenna array; Ψ0 is an arbitrary constant phase.

2. The beam control method for microwave wireless energy transmission according to claim 1, characterized in that: The one-dimensional linear antenna array is placed on the periphery of the two-dimensional antenna array or embedded in the two-dimensional antenna array.

3. A beam control system for microwave wireless energy transmission, characterized in that: It includes a wireless energy transmission machine and a wireless energy receiver; the wireless energy transmission machine includes a wireless energy transmission module and a guidance signal receiving module connected in series; wherein the wireless energy transmission machine is a wireless energy transmission device, and the wireless energy receiver is a target electronic device to be powered; The wireless energy transmission module includes a transmission circuit module and a two-dimensional planar antenna array, and the two-dimensional antenna array is composed of planar antenna units; The transmitting circuit module includes a pilot signal phase analysis circuit and a microwave power transmitting circuit; the pilot signal circuit is connected to a one-dimensional linear antenna array; the microwave power transmitting circuit is connected to a two-dimensional planar antenna array; The guidance signal receiving module includes at least two one-dimensional linear antenna arrays, each of which is composed of planar antenna units; The one-dimensional linear antenna array is placed on the periphery of the two-dimensional antenna array or embedded in the two-dimensional antenna array; The wireless energy receiver includes a guide signal transmitting circuit and a microwave power receiving circuit; in: A guidance signal transmitting circuit, used for transmitting a guidance signal; A microwave power receiving circuit for receiving wireless energy; A one-dimensional linear antenna array for receiving a guidance signal; A pilot signal phase analysis circuit is used to process the pilot signal received by the one-dimensional linear antenna array to obtain a phase value of the pilot signal; wherein the pilot signal phase analysis circuit includes but is not limited to a detector, a phase detector, an FPGA or other programmable digital processing circuit; A microwave power transmitting circuit is used to perform phase assignment and beamforming on a feed signal of a two-dimensional planar antenna array through a wireless energy transmitter according to the phase value of the guidance signal, and control and transmit a narrow microwave beam to transmit energy to a wireless energy receiver; A two-dimensional planar antenna array is used to transmit a narrow microwave beam to a microwave power receiving circuit.

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