Low-cost high-efficiency wireless energy transfer emission array irregular tiling method

Abstract

The invention discloses a low-cost high-efficiency wireless energy transmission emission array irregular tiling method, which belongs to the technical field of antenna design, and comprises the following steps: constructing a candidate matrix so as to construct an aperture coverage problem of an emission antenna array in a microwave wireless energy transmission system into an accurate coverage problem; based on an accurate coverage problem, obtaining a first excitation coefficient of each antenna unit in the transmitting antenna array, and constructing a candidate matrix containing excitation information; extracting a second excitation coefficient from the candidate matrix containing the excitation information, and constructing a calculation model of beam collection efficiency (BCE) according to the second excitation coefficient; and solving the calculation model by taking maximization of the BCE as a target to obtain an antenna unit tiling scheme. By optimizing the splicing layout, the actual BCE approaches the theoretical limit, and the high-energy transmission efficiency of the system is ensured.

Description

Technical Field

[0001] This invention belongs to the field of antenna design technology, specifically relating to a low-cost, high-efficiency method for irregularly tiling wireless power transmission arrays. Background Technology

[0002] Microwave Wireless Power Transfer (MWPT) technology has broad application prospects. In MWPT systems, the transmitting antenna and the rectifier antenna are the core components, and the system performance is usually evaluated by the beam collection efficiency (BCE), which is defined as the ratio of the energy radiated to the rectifier antenna to the total energy transmitted by the transmitting antenna.

[0003] Studies have shown that the optimal taper for achieving a BCE exhibits a quasi-Gaussian shape. To improve the BCE, existing techniques have proposed methods such as edge tapering and stepped distribution, as well as clustered planar array design methods based on clustering algorithms. However, achieving such illumination distributions typically requires a power amplifier for each array element, leading to high system costs.

[0004] To further reduce costs, those skilled in the art have explored subarray architectures. For spliced ​​arrays, optimization methods and exhaustive search methods have been proposed to determine the optimal layout and amplitude excitation, as well as a convex optimization method based on generalized BCE. However, subarray-based spliced ​​arrays require various types of power amplifiers, which complicates the manufacturing process and increases the difficulty and cost of subsequent maintenance.

[0005] Equal-amplitude array technology has emerged, in which all array elements are driven by the same power amplifier operating at maximum efficiency, reducing the number of power amplifier types while improving power amplifier efficiency. In the radar and communications fields, methods have been developed to design equal-amplitude spliced ​​arrays using combinations of two different sized square spliced ​​subarrays. For MWPT applications, non-uniformly spaced equal-amplitude planar arrays have also been proposed to improve BCE (Block Array Component Interchange). However, while non-uniformly spaced equal-amplitude arrays require only a single type of power amplifier, the irregular placement of array elements leads to complex manufacturing processes, high processing difficulty, and challenges in mass production.

[0006] It is evident that existing technologies have the following problems: First, high BCE designs require a large number of different types of power amplifiers, resulting in high costs and maintenance difficulties; second, although non-equal-pitch equal-amplitude arrays reduce costs, they are difficult to manufacture and cannot be mass-produced. Summary of the Invention

[0007] To address the aforementioned problems in the existing technology, this invention provides a low-cost, high-efficiency method for irregularly tiling wireless power transmission arrays. This invention provides a low-cost, high-efficiency method for irregularly tiling a wireless power transmission array, comprising: Constructing candidate matrices This allows us to construct the aperture coverage problem of the transmitting antenna array in a microwave wireless power transmission system as a precise coverage problem. Based on the aforementioned precise coverage problem, the first excitation coefficients of each antenna element in the transmit antenna array are obtained, and a candidate matrix containing excitation information is constructed. ; From the candidate matrix containing incentive information Extract the second excitation coefficient and construct a calculation model for beam collection efficiency (BCE) based on the second excitation coefficient; With the goal of maximizing BCE, the computational model is solved to obtain the antenna element tiling scheme.

[0008] In one embodiment of the present invention, a candidate matrix is ​​constructed. The steps for transforming the aperture coverage problem of a transmitting antenna array in a microwave wireless power transfer system into an exact coverage problem include: Constructing candidate matrices :

[0009] In the formula, the candidate matrix The dimension is , Indicates the number of candidate subarrays. This indicates the number of antenna elements in the transmitting antenna array. , ; Based on the candidate matrix The aperture coverage problem of the transmitting antenna array in a microwave wireless power transfer system is mathematically represented as follows: ; In the formula, Indicates transpose. Represents the identity matrix. Indicates the selection of vectors, if , indicating the first If one candidate subarray is selected, otherwise, if , indicating the first No candidate subarrays were selected.

[0010] In one embodiment of the present invention, the number of antenna elements included in each candidate subarray satisfies , It is a natural number.

[0011] In one embodiment of the present invention, based on the precise coverage problem, the first excitation coefficients of each antenna element in the transmit antenna array are obtained, and a candidate matrix containing excitation information is constructed. The steps include: Feeding the candidate subarray with the same power, the calculated number of... The first excitation coefficient of the antenna elements in the candidate subarray , Indicates the first The number of antenna elements in each candidate subarray; Based on the first incentive coefficient, a candidate matrix containing incentive information is constructed. : .

[0012] In one embodiment of the present invention, from the candidate matrix containing incentive information The steps of extracting the second excitation coefficient and constructing a calculation model for beam collection efficiency (BCE) based on the second excitation coefficient include: Using the selection vector From the candidate matrix containing incentive information Extract the second excitation coefficient: ; In the formula, vector , Indicates the first The second excitation coefficient of each antenna element; Calculate the array factor pattern of the transmitting antenna array based on the second excitation coefficient: ; In the formula, Indicates the matrix factor, , , Indicates pitch angle, Indicates azimuth. The imaginary unit, Indicates the first The location of each antenna element; Based on the array factor pattern, a calculation model for beam collection efficiency (BCE) is constructed: ; In the formula, , , , This indicates the conjugate transpose.

[0013] In one embodiment of the present invention, the step of solving the computational model to obtain the antenna element tiling scheme with the objective of maximizing BCE includes: With the goal of maximizing BCE, the computational model is transformed as follows: ; In the formula, , This is the theoretical upper limit of BCE calculated using the generalized eigenvalue algorithm. express The smallest eigenvalue, , This indicates the maximum number of antenna elements in the candidate subarray. As a preset constant, satisfying ; The transformed computational model is solved using the GUROBI solver to obtain the antenna element tiling scheme.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention mathematically represents the aperture coverage problem of the transmitting antenna array in a microwave wireless power transmission system as an exact coverage problem. Based on the exact coverage problem, the first excitation coefficient of each antenna element in the transmitting antenna array is obtained, and a candidate matrix containing excitation information is constructed. From the candidate matrix containing incentive information The second excitation coefficient is extracted, and a calculation model for beam collection efficiency (BCE) is constructed based on the second excitation coefficient. By optimizing the splicing layout, the actual BCE is brought close to the theoretical limit, thus ensuring the high energy transmission efficiency of the system. (2) Since all candidate subarrays use the same type of power amplifier, only one type of PA needs to be purchased and stocked, which greatly reduces hardware and inventory costs, and allows all PAs to operate at maximum efficiency, thus reducing energy consumption costs.

[0015] (3) Rectangular subarray splicing is adopted, and the positions of all antenna elements are arranged in a regular manner, avoiding the processing difficulties of non-equal spacing arrays. Rectangular subarrays are easy to standardize production, thereby realizing large-scale manufacturing and reducing production costs.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a flowchart of a low-cost, high-efficiency wireless power transmission array irregular tiling method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a planar phased array with a completely flat rectangular subarray provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of amplitude excitation for candidate subarrays of different sizes provided in an embodiment of the present invention; Figure 4 This is a flowchart of the nested double-layer optimization provided in the embodiments of the present invention; Figure 5 This is a schematic diagram of the subarray tiling obtained from the simulation; Figure 6 It is the array factor pattern obtained from simulation. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto.

[0019] Figure 1 This is a flowchart of a low-cost, high-efficiency irregular tiling method for wireless power transmission arrays provided in an embodiment of the present invention. Figure 1 As shown, this embodiment of the invention provides a low-cost, high-efficiency method for irregularly tiling a wireless power transmission array, comprising: S1. Constructing the candidate matrix This allows us to construct the aperture coverage problem of the transmitting antenna array in a microwave wireless power transmission system as a precise coverage problem.

[0020] It should be understood that in a microwave wireless power transmission system, the antenna element is the basic radiating element in the transmitting antenna array, and the subarray is a rectangular sub-region formed by combining multiple antenna elements. The aperture coverage problem of the transmitting antenna array refers to how to cover the entire aperture of the transmitting antenna by splicing rectangular subarrays of different sizes.

[0021] In step S1, in order to transform the physical aperture coverage problem into a computable mathematical problem, candidate matrices are first constructed. :

[0022] In the formula, the candidate matrix The dimension is , Indicates the number of candidate subarrays. This indicates the number of antenna elements in the transmitting antenna array. , Clearly, the candidate matrix It is used to store all possible subarray coverage methods.

[0023] Based on candidate matrix The aperture coverage problem of the transmitting antenna array in a microwave wireless power transfer system is mathematically represented as follows: ; In the formula, Indicates transpose. Represents the identity matrix. Indicates the selection of vectors, if , indicating the first If one candidate subarray is selected, otherwise, if , indicating the first No candidate subarrays were selected. This mathematical representation simplifies the complex physical stitching problem into a mathematical one, ensuring that each antenna element is covered by only one subarray.

[0024] In this embodiment, the number of antenna elements contained in each candidate subarray all satisfy the following: , It is a natural number. Figure 2 This is a schematic diagram of a planar phased array with completely tiled rectangular subarrays provided in an embodiment of the present invention. For example... Figure 2 As shown, x The axis extends horizontally. y The axis extends vertically, with each square representing an antenna element. The entire phased array includes... Each antenna element is composed of... , , , , , , These seven candidate subarrays of different sizes provide precise coverage.

[0025] S2. Based on the precise coverage problem, obtain the first excitation coefficient of each antenna element in the transmit antenna array, and construct a candidate matrix containing excitation information. .

[0026] Feeding the candidate subarrays the same power, for example, each candidate subarray can be driven by the same type of power amplifier, the calculation yields the... The first excitation coefficient of the antenna elements in the candidate subarray , Indicates the first The number of antenna elements in each candidate subarray; Based on the first incentive coefficient, construct a candidate matrix containing incentive information. : .

[0027] Figure 3 This is a schematic diagram of amplitude excitation for candidate subarrays of different sizes provided in embodiments of the present invention. For example... Figure 3 As shown, when the candidate subarrays are fed with the same power, the calculated value is... The first excitation coefficient of each antenna element in the candidate subarray ,For example, Figure 3 medium size is In the candidate subarray, the first excitation coefficient of the antenna element is 1, and the size is... In the candidate subarray, the first excitation coefficient of each antenna element is The size is In the candidate subarray, the first excitation coefficient of each antenna element is The size is In the candidate subarray, the first excitation coefficient of each antenna element is The size is In the candidate subarray, the first excitation coefficient of each antenna element is .

[0028] S3. From the candidate matrix containing incentive information The second excitation coefficient is extracted, and a calculation model for beam collection efficiency (BCE) is constructed based on the second excitation coefficient.

[0029] Specifically, using selection vectors From the candidate matrix containing incentive information Extract the second excitation coefficient: ; In the formula, vector , Indicates the first The second excitation coefficient of each antenna element.

[0030] Next, based on the second excitation coefficient, the array factor pattern of the transmitting antenna array is calculated: ; In the formula, Indicates the matrix factor, , , Indicates pitch angle, Indicates azimuth. The imaginary unit, Indicates the first The location of each antenna element.

[0031] Beam collection efficiency (BCE) is a key performance indicator for transmit antenna arrays, defined as: ; In the formula, and Indicates receiving area Radiated power and visible space Total power of internal radiation.

[0032] Furthermore, the above equation is rewritten, and a calculation model for the beam collection efficiency (BCE) is constructed based on the array factor pattern: ; In the formula, , , , This indicates the conjugate transpose.

[0033] S4. Solve the calculation model with the goal of maximizing BCE to obtain the antenna element tiling scheme.

[0034] With the goal of maximizing BCE, the computational model is written as the following minimization model. :

[0035]

[0036] For a given array and receiving area, the theoretical maximum upper limit of BCE can be calculated using the generalized eigenvalue method. Therefore, the following constraints need to be met: ; By performing a simple transformation on the above equation, we can obtain: ; It can also be written as: ; when , As a preset constant, The smaller, The closer to . Therefore, minimize the model It can be transformed into the model shown below. :

[0037] In the formula, , It represents the 2-norm.

[0038] because It is a positive definite matrix that satisfies: ; In the formula, express The smallest eigenvalue. According to the Cauchy-Schwarz inequality. have:

[0039] Therefore, the model It can be further transformed into a model : ; In the formula, , This is the theoretical upper limit of BCE calculated using the generalized eigenvalue algorithm. express The smallest eigenvalue, , This indicates the maximum number of antenna elements in the candidate subarray. As a preset constant, satisfying ; The computational model established by the above process is a typical integer convex optimization model. Solving the transformed computational model using the GUROBI solver yields the selection vector. The optimal value is obtained to obtain the antenna element tiling scheme (i.e. which candidate subarrays are selected to cover the aperture) and maximize BCE.

[0040] In fact, the model The solution will be as It varies depending on the individual. By choosing the appropriate The optimal solution to this problem can be obtained by considering the value. .therefore, Can be regarded as The function. Clearly, this is a nested, two-level optimization problem. Figure 4 This is a flowchart of the nested two-layer optimization provided in an embodiment of the present invention. Please refer to [link / reference]. Figure 4 Outer layer optimization is to find suitable The value is determined by the inner layer optimization, which targets the model. The outer layer optimization is a simple one-dimensional search problem. Therefore, the GWO algorithm, which has global optimization capabilities, is used for the outer layer optimization design.

[0041] The following simulation experiment further illustrates the low-cost, high-efficiency irregular tiling method for wireless power transmission arrays provided by this invention.

[0042] Specifically, this embodiment adopts Square-aperture transmitting antenna If the wavelength is given, then the size of the transmitting antenna array is 10×10, the spacing between the antenna elements is half a wavelength, and the receiving area is... The maximum number of antenna elements in the candidate subarray is set to 8, the number of GWO populations is set to 3, and the maximum number of iterations is set to 10.

[0043] Figure 5 This is a schematic diagram of the subarray tiling obtained from simulation. Figure 6This is the array factor pattern obtained from simulation. For example... Figures 5-6 As shown, the beam collection efficiency of the obtained subarray tiling method is 92.6%. Clearly, the subarray tiling scheme obtained using this invention has superior performance.

[0044] As can be seen from the above embodiments, the beneficial effects of the present invention are as follows: (1) This invention mathematically represents the aperture coverage problem of the transmitting antenna array in a microwave wireless power transmission system as an exact coverage problem. Based on the exact coverage problem, the first excitation coefficient of each antenna element in the transmitting antenna array is obtained, and a candidate matrix containing excitation information is constructed. From the candidate matrix containing incentive information The second excitation coefficient is extracted, and a calculation model for beam collection efficiency (BCE) is constructed based on the second excitation coefficient. By optimizing the splicing layout, the actual BCE is brought close to the theoretical limit, thus ensuring the high energy transmission efficiency of the system. (2) Since all candidate subarrays use the same type of power amplifier, only one type of PA needs to be purchased and stocked, which greatly reduces hardware and inventory costs, and allows all PAs to operate at maximum efficiency, thus reducing energy consumption costs.

[0045] (3) Rectangular subarray splicing is adopted, and the positions of all antenna elements are arranged in a regular manner, avoiding the processing difficulties of non-equal spacing arrays. Rectangular subarrays are easy to standardize production, thereby realizing large-scale manufacturing and reducing production costs.

[0046] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0047] The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples" indicates that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0048] Although this application has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, the disclosure, and the appended claims in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce a good effect.

[0049] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A low-cost, high-efficiency method for irregularly tiling a wireless power transmission array, characterized in that, include: Constructing candidate matrices This allows us to construct the aperture coverage problem of the transmitting antenna array in a microwave wireless power transmission system as a precise coverage problem. Based on the aforementioned precise coverage problem, the first excitation coefficients of each antenna element in the transmit antenna array are obtained, and a candidate matrix containing excitation information is constructed. ; From the candidate matrix containing incentive information Extract the second excitation coefficient and construct a calculation model for beam collection efficiency (BCE) based on the second excitation coefficient; With the goal of maximizing BCE, the computational model is solved to obtain the antenna element tiling scheme.

2. The low-cost, high-efficiency non-irregular tiling method for wireless power transmission arrays according to claim 1, characterized in that, Constructing candidate matrices The steps for transforming the aperture coverage problem of a transmitting antenna array in a microwave wireless power transfer system into an exact coverage problem include: Constructing candidate matrices : In the formula, the candidate matrix The dimension is , Indicates the number of candidate subarrays. This indicates the number of antenna elements in the transmitting antenna array. , ; Based on the candidate matrix The aperture coverage problem of the transmitting antenna array in a microwave wireless power transfer system is mathematically represented as follows: ； In the formula, Indicates transpose. Represents the identity matrix. Indicates the selection of vectors, if , indicating the first If one candidate subarray is selected, otherwise, if , indicating the first No candidate subarrays were selected.

3. The low-cost, high-efficiency non-irregular tiling method for wireless power transmission arrays according to claim 2, characterized in that, The number of antenna elements contained in each candidate subarray all satisfy , It is a natural number.

4. The low-cost, high-efficiency wireless power transmission array irregular tiling method according to claim 3, characterized in that, Based on the aforementioned precise coverage problem, the first excitation coefficients of each antenna element in the transmit antenna array are obtained, and a candidate matrix containing excitation information is constructed. The steps include: Feeding the candidate subarray with the same power, the calculated number of... The first excitation coefficient of the antenna elements in the candidate subarray , Indicates the first The number of antenna elements in each candidate subarray; Based on the first incentive coefficient, a candidate matrix containing incentive information is constructed. : 。 5. The low-cost, high-efficiency non-irregular tiling method for wireless power transmission arrays according to claim 4, characterized in that, From the candidate matrix containing incentive information The steps of extracting the second excitation coefficient and constructing a calculation model for beam collection efficiency (BCE) based on the second excitation coefficient include: Using the selection vector From the candidate matrix containing incentive information Extract the second excitation coefficient: ； In the formula, vector , Indicates the first The second excitation coefficient of each antenna element; Calculate the array factor pattern of the transmitting antenna array based on the second excitation coefficient: ； In the formula, Indicates the matrix factor, , , Indicates pitch angle, Indicates azimuth. The imaginary unit, Indicates the first The location of each antenna element; Based on the array factor pattern, a calculation model for beam collection efficiency (BCE) is constructed: ； In the formula, , , , This indicates the conjugate transpose.

6. The low-cost, high-efficiency non-irregular tiling method for wireless power transmission arrays according to claim 5, characterized in that, The steps for solving the computational model to obtain the antenna element tiling scheme with the goal of maximizing BCE include: With the goal of maximizing BCE, the computational model is transformed as follows: ； In the formula, , This is the theoretical upper limit of BCE calculated using the generalized eigenvalue algorithm. express The smallest eigenvalue, , This indicates the maximum number of antenna elements in the candidate subarray. As a preset constant, satisfying ; The transformed computational model is solved using the GUROBI solver to obtain the antenna element tiling scheme.

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