Design method of metal resonant layer and triple-band broadband metasurface energy harvester

Abstract

The present invention relates to the technical field of energy collection devices, and in particular to a design method for a metal resonance layer and a three-band broadband metasurface energy collector. The design method comprises: S1. preset parameters; S2. according to the preset parameters of S1, generating structures other than the metal resonance layer in CST; S3. taking a square coaxial with the intermediate dielectric layer as the basic shape of the metal resonance layer and dividing it into a number of squares, using a 0-1 matrix for description, randomly generating an initial population, and generating a metal resonance layer in CST; S4. constructing an electromagnetic simulation model in CST to obtain the reflection coefficient of the target frequency band; S5. taking the reflection coefficient of the target frequency band as the fitness function and setting a threshold, and using a particle swarm algorithm to calculate the optimal value of the population; S6. generating a metal resonance layer in CST with the optimal value of the population determined in step S5. The design method provided by the present invention saves a lot of manpower and computer resources, and can effectively avoid the local optimal problem existing in the artificial design process.

Description

Technical Field

[0001] The present invention relates to the technical field of energy collection devices, and in particular to a design method of a metal resonance layer and a three-band broadband metasurface energy collector. Background Art

[0002] Metamaterial is a synthetic material with negative magnetic permeability and negative dielectric constant composed of small electric resonators. It has extraordinary physical properties that natural materials do not have, and is characterized by miniaturization and high absorption efficiency per unit area. The energy harvester based on electromagnetic metamaterial is evolved from the metamaterial absorber structure, which is composed of several periodic units. Each periodic unit includes a metal resonance layer, an intermediate dielectric layer and a bottom metal plate arranged in sequence from top to bottom. The metal resonance layer is provided with a circular metal through hole, which penetrates the intermediate dielectric layer to reach the bottom metal plate. The bottom metal plate is coaxially provided with a circular hole with a diameter larger than the metal through hole, and the circular hole is connected to the metal through hole through a resistive load.

[0003] In energy harvesters based on electromagnetic metamaterials, the middle dielectric layer and the bottom metal plate are generally designed to be square, with a relatively simple structure and easy design. However, the metal resonance layer is generally designed to be relatively complex in shape, which is difficult to design. Existing metal resonance layers generally require a lot of manpower and computer resources through steps such as model design, parameter scanning and manual optimization. In addition, the manual design method is also prone to cause the structure to fall into a local optimum, and it cannot have the optimal performance under the limited conditions. Summary of the invention

[0004] In order to overcome the technical defects that the manual design of the existing metal resonance layer consumes a lot of manpower and material resources and is prone to falling into local optimality, the present invention provides a design method for a metal resonance layer and a three-band broadband metasurface energy collector.

[0005] The design method of the metal resonance layer provided by the present invention comprises the following steps:

[0006] S1. Preset: target resonant frequency band of the structure; material and thickness of the intermediate dielectric layer; material and thickness of the bottom metal plate and metal resonant layer; location and radius of metal through holes;

[0007] S2. Generate structures other than the metal resonance layer in CST according to the parameters preset in S1;

[0008] S3. A square coaxial with the intermediate dielectric layer is used as the basic shape of the metal resonance layer and is divided into a number of squares, which are described using a 0-1 matrix, where 0 represents a blank and 1 represents a square covered by metal. The initial population number and the maximum number of iterations of the metal resonance layer are assigned in MATLAB, an initial population is randomly generated, and an initial coding matrix representing the metal resonance layer is generated based on the initial population;

[0009] S4. Combining step S2 and step S3, constructing an electromagnetic simulation model in CST;

[0010] S5. Take the reflection coefficient of the target frequency band as the fitness function and set the threshold, and use the particle swarm algorithm to calculate the optimal value of the population: through CST-MATLAB joint simulation, import the reflection coefficient of the target frequency band into MATLAB, calculate the fitness of the particles, and end the cycle if the fitness function threshold is met. At this time, the corresponding population is the optimal value; if the fitness function threshold is not met, update the speed and position of each particle according to the particle swarm algorithm, perform electromagnetic simulation again, and calculate the particle fitness. Repeat this cycle until the fitness function threshold is met, and the corresponding population is the optimal value;

[0011] S6. Generate a metal resonance layer in CST with the optimal value of the population determined in step S5 to complete the design.

[0012] Optionally, in step S3, the metal resonance layer is firstly taken as a basic shape of a square, and the two center lines of the square are used as baselines to divide it into four target units, and a single target unit is divided into several grids for design; after the optimal value of the population is determined through steps S4 and S5, the entire metal resonance layer is obtained by performing two symmetrical designs with the two center lines as symmetry axes.

[0013] The three-band broadband metasurface energy collector provided by the present invention is composed of a plurality of periodic units, wherein the periodic units include:

[0014] The metal resonance layer comprises a frame and four L-shaped strips, wherein the frame forms a square, the four L-shaped strips respectively form square gaps with the four corners of the frame, a cross gap located at the center of the metal resonance layer is formed between the four L-shaped strips, and metal through holes are provided at the four corners of the frame;

[0015] an intermediate dielectric layer, which is located below the metal resonance layer, wherein a cross section of the intermediate dielectric layer parallel to the metal resonance layer is a square, the cross section is coaxial with the metal resonance layer, sides of the cross section are respectively parallel to sides of the metal resonance layer, and the side length of the cross section is greater than the side length of the metal resonance layer;

[0016] A bottom metal plate is located below the intermediate dielectric layer, the plate surface shape and plate surface size of the bottom metal plate are the same as the cross section, the plate surface of the bottom metal plate is coaxial with the cross section, the sides of the bottom metal plate are parallel to the sides of the cross section, four corners of the bottom metal plate are provided with circular holes, the circular holes are coaxial with the metal through holes, the diameter of the circular holes is larger than the diameter of the metal through holes, the metal through holes penetrate the intermediate dielectric layer and extend into the circular holes, and the hole walls of the metal through holes are connected to the hole walls of the circular holes through a resistive load.

[0017] Optionally, the single side length of the frame is 19.2mm and the width is 0.6mm, the width of the L-shaped strip is 1.2mm, the width of the cross gap is 1.2mm, the material of the intermediate dielectric layer is F4B and the thickness is 5.5mm, the material of the bottom metal plate and the metal resonance layer is copper and the thickness is 0.035mm; the center of the metal through hole is 9.1mm away from the center of the metal resonance layer, and the radius of the metal through hole is 0.12mm.

[0018] The technical solution provided by the present invention has the following advantages compared with the prior art:

[0019] The design method of the metal resonance layer provided by the present invention adopts a particle swarm algorithm and realizes the automatic design of the metal resonance layer through CST-MATLAB joint simulation. Compared with the manual design method, the steps of model design, parameter scanning and manual optimization are omitted, thereby saving a large amount of manpower and computer resources. Moreover, the particle swarm algorithm adopted in the design method has a strong global search capability in the early stage of iteration, which can effectively avoid the occurrence of local optimal problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 It is an overall schematic diagram of the three-band broadband metasurface energy harvester of the present invention;

[0023] Figure 2 is a schematic structural diagram of the metal resonance layer of the present invention;

[0024] Figure 3 This is a schematic diagram of the structure of the bottom metal plate of the present invention.

[0025] Figure 4 is the reflection coefficient curve S of the present invention 11 Schematic diagram;

[0026] Figure 5 is the energy collection efficiency curve of the present invention under the conditions of transverse electric wave and transverse magnetic wave;

[0027] Figure 6is a schematic diagram comparing the absorption efficiency and the load collection efficiency of the present invention;

[0028] Figures 7 to 9 It is a schematic diagram of normalization of the equivalent impedance of the metasurface relative to the free space impedance in three frequency bands of the present invention;

[0029] Figures 10 to 13 It is the energy collection efficiency curve of transverse electric wave and transverse magnetic wave of the present invention when the electromagnetic wave is incident at an oblique angle of 15°-60°.

[0030] in:

[0031] 1. Metal resonant layer; 11. Frame; 12. L-shaped strip; 13. Square gap; 14. Cross gap; 2. Metal through hole; 3. Intermediate dielectric layer; 4. Bottom metal plate; 41. Round hole; 5. Resistive load. DETAILED DESCRIPTION

[0032] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0034] In one embodiment, a design method of a metal resonance layer 1 is provided, comprising the following steps:

[0035] S1. Preset: target resonant frequency band of the structure; material and thickness of the intermediate dielectric layer 3; material and thickness of the bottom metal plate 4 and the metal resonant layer 1; position and radius of the metal through hole 2;

[0036] S2. Generate a structure other than the metal resonance layer 1 in CST according to the parameters preset in S1;

[0037] S3. A square coaxial with the intermediate dielectric layer 3 is used as the basic shape of the metal resonance layer 1 and is divided into a number of squares, which are described using a 0-1 matrix, where 0 represents a blank and 1 represents a square covered by metal. The metal resonance layer 1 is given an initial population number and a maximum number of iterations in MATLAB, an initial population is randomly generated, and an initial coding matrix representing the metal resonance layer 1 is generated based on the initial population;

[0038] S4. Combining step S2 and step S3, constructing an electromagnetic simulation model in CST;

[0039] S5. Take the reflection coefficient of the target frequency band as the fitness function and set the threshold, and use the particle swarm algorithm to calculate the optimal value of the population: through CST-MATLAB joint simulation, import the reflection coefficient of the target frequency band into MATLAB, calculate the fitness of the particles, and end the cycle if the fitness function threshold is met. At this time, the corresponding population is the optimal value; if the fitness function threshold is not met, update the speed and position of each particle according to the particle swarm algorithm, perform electromagnetic simulation again, and calculate the particle fitness. Repeat this cycle until the fitness function threshold is met, and the corresponding population is the optimal value;

[0040] S6. Generate the metal resonance layer 1 in CST with the optimal value of the population determined in step S5 to complete the design.

[0041] It should be noted that the particle swarm algorithm is a type of swarm intelligence algorithm. It uses a fitness function to evaluate particles and updates the particle code in the iterative process by changing the particle speed to find the optimal solution. The design of the metal resonance layer 1 of the metasurface energy harvester based on the particle swarm algorithm in this paper is a process of finding the optimal matrix. The speed and position changes of the classical particle swarm algorithm are jointly determined by the inertial speed of the particle, the historical optimal position of the particle, and the historical optimal position of all particles, that is,

[0042] v i =ω (t) ×v i +c 1 ×rand()×(pbest i -x i )+c 2 ×rand()×(gbest i -x i )

[0043] Among them, pbest is the best historical position of the particle, gbest is the best historical position of all particles, c 1 、c 2 denote individual learning factor and social learning factor, respectively, (t) is the inertia factor, whose size determines the global and local search capabilities of the algorithm. The inertia factor ω (t) It decreases with the increase of the number of iterations. In the early stage of iteration, it can have a higher global search ability, and in the later stage of iteration, it can have a stronger local search ability, which effectively prevents the local optimal problem and reduces the experimental time.

[0044] ω (t) =(ω ini -ω end )(G k -g) / G k +ω end

[0045] where ω (t) is the inertia factor that changes linearly with the number of iterations, G k is the maximum number of iterations, g is the current number of iterations, ω ini is the initial inertia weight, ω end is the final inertia weight.

[0046] The structure designed in this paper should achieve perfect absorption of the incident wave, and the absorption efficiency expression is:

[0047] A=1-|S 11 | 2 -|S 21 | 2

[0048] S 11 is the reflection coefficient, S 21 is the transmission coefficient. When the reflection coefficient and the projection coefficient are both minimum, the absorption efficiency is maximum. Since the material used for the bottom metal plate 4 is metal, S 21 is 0. When S 11 At its smallest, it allows for perfect absorption.

[0049] The collection efficiency of the metasurface energy collector is theoretically calculated by the following formula:

[0050]

[0051] Where P LOAD represents the load collection power, P INC represents the total incident power received by the cross section of the metasurface structure. In the simulation, P LOAD , P INC All can be expressed by S parameters.

[0052] This scheme uses the frequency domain solver of CST electromagnetic simulation software to simulate and optimize the proposed electromagnetic wave energy harvester. The boundary condition is set to unit cell to simulate an infinite array; to simulate the plane wave incidence, the port is set to Floquet, the excitation is set to 1W, and the electromagnetic wave is incident vertically along the axis. During the simulation, two mutually orthogonal polarized electromagnetic waves are set to simulate transverse electric waves and transverse magnetic waves. Transverse electric waves indicate that the direction of the electric field is parallel to the surface, and transverse magnetic waves indicate that the direction of the magnetic field is parallel to the surface.

[0053] In the specific implementation, the design method adopts the particle swarm algorithm to realize the automatic design of the metal resonance layer 1 through CST-MATLAB joint simulation. Compared with the manual design method, it omits the steps of model design, parameter scanning and manual optimization, saving a lot of manpower and computer resources; and the particle swarm algorithm adopted by the design method has a strong global search capability in the early stage of iteration, which can effectively avoid the occurrence of local optimal problems.

[0054] In some embodiments, in step S3, the metal resonance layer 1 is firstly divided into four target units with a square as the basic shape and two center lines of the square as the baseline, and a single target unit is divided into several grids for design; after the optimal value of the population is determined in steps S4 and S5, the entire metal resonance layer 1 is obtained by two symmetrical designs with the two center lines as the symmetry axes. The structure designed in this way is of central symmetry type, the polarization direction of the incident electromagnetic wave will not significantly affect the energy collection efficiency, and it shows good angle and polarization stability.

[0055] In another embodiment, the present invention provides a three-band broadband metasurface energy collector, which is composed of a plurality of periodic units, wherein the periodic units include a metal resonance layer 1, an intermediate dielectric layer 3 and a bottom metal plate 4; the metal resonance layer 1 includes a frame 11 and four L-shaped strips 12, the frame 11 is surrounded by a square, the four L-shaped strips 12 and the four corners of the frame 11 respectively form a square gap 13, a cross gap 14 located at the center of the metal resonance layer 1 is formed between the four L-shaped strips 12, and metal through holes 2 are provided at the four corners of the frame 11; the intermediate dielectric layer 3 is located below the metal resonance layer 1, and the cross section of the intermediate dielectric layer 3 parallel to the metal resonance layer 1 is a square, and the cross section The bottom metal plate 4 is coaxial with the metal resonance layer 1, and the sides of the cross section are parallel to the sides of the metal resonance layer 1, and the side length of the cross section is greater than the side length of the metal resonance layer 1; the bottom metal plate 4 is located below the intermediate dielectric layer 3, and the plate surface shape and plate surface size of the bottom metal plate 4 are the same as the cross section, the plate surface of the bottom metal plate 4 is coaxial with the cross section, and the sides of the bottom metal plate 4 are parallel to the sides of the cross section, and circular holes 41 are opened at the four corners of the bottom metal plate 4, the circular hole 41 is coaxial with the metal through hole 2, and the diameter of the circular hole 41 is greater than the diameter of the metal through hole 2, the metal through hole 2 penetrates the intermediate dielectric layer 3 and extends into the circular hole 41, and the hole wall of the metal through hole 2 is connected to the hole wall of the circular hole 41 through the resistor load 5.

[0056] It should be noted that the metal through hole 2 is a mature structure in the art, such as described in the patent publication number CN113809543A, and can be specifically realized by using a metal tube or by plating metal on the hole wall after opening a hole.

[0057] It should be noted that the size of the metal resonance layer 1 needs to be smaller than that of the intermediate dielectric layer 3 so as to reserve a certain area around it. This is a mature design in the art, such as described in the patent publication number CN113809543A.

[0058] This structure is designed based on the aforementioned design method. The specific design process of this structure is described in detail below.

[0059] Three target frequency bands: The first frequency band is located at 1.8GHz, which is the most commonly used frequency band in global mobile communication systems; the second frequency band is located at 6.0GHz, which is a common frequency band for WIFI; the third frequency band is located at 7.0GHz, which is a common frequency band for satellite communications. Since the electromagnetic wave frequency bands distributed in the environment are not unique, this structure has more practical value and application space compared to traditional single-band energy harvesters. The reflection coefficients of the above three target frequency bands are selected as the fitness function and the threshold is set to -15dB.

[0060] Design parameters: The material of the intermediate dielectric layer 3 is F4B, with a thickness of 5.5 mm; the material of the bottom metal plate 4 and the metal resonance layer 1 is copper, with a thickness of 0.035 mm; the center of the metal through hole 2 is 9.1 mm away from the center of the metal resonance layer 1, and the radius of the metal through hole 2 is 0.12 mm.

[0061] During the design, in order to achieve the characteristics of polarization stability and angle stability, the metal resonance layer 1 is designed as a rotationally symmetrical structure, that is, the two center lines of the square are used as the baseline to divide it into four target units, and a single target unit is divided into several grids for design; after the optimal value of the population is determined through steps S4 and S5, the entire metal resonance layer 1 is obtained by two symmetrical designs with the two center lines as the symmetry axes. Specifically, a width of 0.35mm is left between the edge of the metal resonance layer 1 and the edge of the intermediate dielectric layer 3. The grid is a small metal grid of 0.6×0.6mm, and a 16×16 0-1 matrix is ​​used to describe one of the target units. The initial population size is 20, and the maximum number of iterations is 100.

[0062] After the design is completed, the specific parameters of the metal resonance layer 1 are as follows: the single side length of the frame 11 is 19.2 mm, the width is 0.6 mm, the width of the L-shaped strip 12 is 1.2 mm, and the width of the cross gap 14 is 1.2 mm.

[0063] The performance of this structure is demonstrated below.

[0064] Reference Figure 4 , is the reflection coefficient S 11 Curve diagram, reflection coefficient S of three frequency bands obtained by simulation 11 All are below -15dB, so the incident energy on the surface is collected by the metasurface energy collector.

[0065] Reference Figure 5 , which is the energy collection efficiency curve under the conditions of transverse electric wave and transverse magnetic wave. From the simulation results, it can be obtained that no matter what polarization mode the electromagnetic wave is incident in, the energy collection efficiency of the structure remains consistent, proving that the structure has polarization stability.

[0066] Reference Figure 6 , which is a comparison chart of the absorption efficiency and load collection efficiency of the structure, the energy collection efficiencies at 1.8 GHz, 6 GHz and 7 GHz are 97%, 98% and 97% respectively, accounting for 98% of the absorption efficiency, indicating that the electromagnetic waves incident on the structure are almost completely collected by the load.

[0067] Reference Figures 7 to 9 , which is a schematic diagram of the normalization of the equivalent impedance of the metasurface relative to the free space impedance in the three target frequency bands of this structure. After determining that the resistance value of the resistive load 5 is 700Ω, the equivalent impedance of the metasurface is calculated and normalized relative to the free space impedance (377Ω): at 1.8GHz, the normalized impedance of the metasurface is (0.89-j0.09)Ω; at 6GHz, the normalized impedance of the metasurface is (0.82+j0.13)Ω; at 7GHz, the normalized impedance of the metasurface is (0.93-j0.19)Ω. This shows that most of the electromagnetic wave energy can be collected by the metasurface.

[0068] Reference Figures 10 to 13 , the performance of the device is analyzed under the conditions of oblique incidence of transverse electric wave and transverse magnetic wave. As the incident angle increases, the structure can still maintain a high energy collection efficiency. Under transverse magnetic wave polarization, when the incident angle reaches 60°, the energy collection efficiency of the three frequency bands remains above 95%, but due to the influence of the position of the metal through hole 2, as the angle of the incident electromagnetic wave increases, the energy collection efficiency will produce a certain frequency deviation, which can be improved by adaptive tuning circuit frequency calibration. When the incident angle increases to 15°, a resonance peak appears after 7.5GHz, which is due to the high-frequency resonance peak shifting to a low frequency as the incident angle increases. Under transverse electric wave polarization, when the resonant frequency is 1.8GHz, as the incident angle increases, the energy collection efficiency decreases by 1%, 3%, 10% and 27% respectively. When the resonant frequency is 6GHz, as the incident angle increases, the energy collection efficiency decreases by 1%, 2%, 7% and 22% respectively. When the resonant frequency is 7 GHz, the energy collection efficiency decreases by 2%, 4%, 5%, and 10% with the increase of the incident angle. Since the proposed structure is centrosymmetric, the polarization direction of the incident electromagnetic wave does not significantly affect the energy collection efficiency, showing good angular stability.

[0069] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments described herein, but should conform to the widest scope consistent with the principles and novel features invented herein.

Claims

1. A method for designing a metal resonance layer, characterized in that: The steps include: S1. Preset: target resonant frequency band of the structure; material and thickness of the intermediate dielectric layer (3); material and thickness of the bottom metal plate (4) and the metal resonant layer (1); position and radius of the metal through hole (2); S2. According to the parameters preset in S1, a structure other than the metal resonance layer (1) is generated in CST; S3. A square coaxial with the intermediate dielectric layer (3) is used as the basic shape of the metal resonance layer (1) and is divided into a plurality of squares, which are described using a 0-1 matrix, where 0 represents a blank and 1 represents a square covered by metal. An initial population number and a maximum number of iterations are assigned to the metal resonance layer (1) in MATLAB, an initial population is randomly generated, and an initial coding matrix representing the metal resonance layer (1) is generated based on the initial population; S4. Combining step S2 and step S3, constructing an electromagnetic simulation model in CST to obtain the reflection coefficient of the target frequency band; S5. Take the reflection coefficient of the target frequency band as the fitness function and set the threshold, and use the particle swarm algorithm to calculate the optimal value of the population: through CST-MATLAB joint simulation, import the reflection coefficient of the target frequency band into MATLAB, calculate the fitness of the particles, and end the cycle if the fitness function threshold is met. At this time, the corresponding population is the optimal value; if the fitness function threshold is not met, update the speed and position of each particle according to the particle swarm algorithm, perform electromagnetic simulation again, and calculate the particle fitness. Repeat this cycle until the fitness function threshold is met, and the corresponding population is the optimal value; S6. Generate a metal resonance layer (1) in CST with the optimal value of the population determined in step S5 to complete the design.

2. The method for designing a metal resonance layer according to claim 1, characterized in that: In step S3, the metal resonance layer (1) is firstly formed with a square as a basic shape, and the two center lines of the square are used as the baseline to divide it into four target units, and a single target unit is divided into a number of squares for design; after the optimal value of the population is determined through steps S4 and S5, the entire metal resonance layer (1) is obtained by performing two symmetrical designs with the two center lines as the symmetry axes.

3. A three-band broadband metasurface energy harvester, composed of a number of periodic units, characterized in that: The periodic unit comprises: A metal resonance layer (1), comprising a frame (11) and four L-shaped strips (12), wherein the frame (11) forms a square, the four L-shaped strips (12) respectively form square gaps (13) with the four corners of the frame (11), a cross gap (14) located at the center of the metal resonance layer (1) is formed between the four L-shaped strips (12), and metal through holes (2) are provided at the four corners of the frame (11); an intermediate dielectric layer (3) located below the metal resonance layer (1); a cross section of the intermediate dielectric layer (3) parallel to the metal resonance layer (1) is a square; the cross section is coaxial with the metal resonance layer (1); sides of the cross section are respectively parallel to sides of the metal resonance layer (1); and the side length of the cross section is greater than the side length of the metal resonance layer (1); A bottom metal plate (4) is located below the intermediate dielectric layer (3); the plate surface shape and plate surface size of the bottom metal plate (4) are the same as the cross section; the plate surface of the bottom metal plate (4) is coaxial with the cross section; the sides of the bottom metal plate (4) are respectively parallel to the sides of the cross section; four corners of the bottom metal plate (4) are provided with circular holes (41); the circular holes (41) are coaxial with the metal through holes (2); the diameter of the circular holes (41) is larger than the diameter of the metal through holes (2); the metal through holes (2) penetrate the intermediate dielectric layer (3) and extend into the circular holes (41); the hole wall of the metal through holes (2) is connected to the hole wall of the circular holes (41) via a resistance load (5).

4. The triple-band broadband metasurface energy harvester according to claim 3, characterized in that: The single side length of the frame (11) is 19.2 mm and the width is 0.6 mm; the width of the L-shaped strip (12) is 1.2 mm; the width of the cross gap (14) is 1.2 mm; the material of the intermediate dielectric layer (3) is F4B and the thickness is 5.5 mm; the material of the bottom metal plate (4) and the metal resonance layer (1) is copper and the thickness is 0.035 mm; the center of the metal through hole (2) is 9.1 mm away from the center of the metal resonance layer (1); and the radius of the metal through hole (2) is 0.12 mm.

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