Ultra-wideband absorber and verification optimization processing method of ultra-wideband absorber

Abstract

The present application provides an ultra-wideband absorber and a verification and optimization processing method for the ultra-wideband absorber, wherein the ultra-wideband absorber comprises: a bottom plate layer and a plurality of composite absorption layers; the bottom plate layer is located at the bottom of the ultra-wideband absorber, and each composite absorption layer is stacked on the bottom plate layer in a preset order; each composite absorption layer comprises: an intermediate dielectric layer and an absorbing layer arranged on the intermediate dielectric layer; each absorbing layer surface is bonded with a resistance film layer; the resistance film layers on the surface of each absorbing layer are not completely the same. The ultra-wideband absorber can achieve a wider working frequency band response and a wider range of multi-angle absorption, improve the frequency band coverage of the ultra-wideband absorber, enhance the applicability and practicality of the ultra-wideband absorber, and at the same time, can quickly achieve the performance optimization of the ultra-wideband absorber.

Description

Technical Field

[0001] The present application relates to the technical field of absorber design, and in particular to an ultra-wideband absorber and a verification and optimization processing method for the ultra-wideband absorber. Background Art

[0002] With the rapid development of electronics, communications, aerospace and other fields, the demand for high-performance electromagnetic wave absorbing materials is increasing. Metamaterial absorbers, as a new type of artificial material, have many excellent electromagnetic wave properties and can achieve precise control and regulation of electromagnetic waves.

[0003] Traditional ultra-wideband absorber design is usually based on electromagnetic field theory and numerical simulation, but this method often requires complex calculations and a large amount of experimental verification, and the design cycle is long.

[0004] Therefore, it is necessary to improve the design method, simplify the design method, and reduce the design complexity in order to achieve a wider operating frequency band response and a wider multi-angle absorption, improve the frequency band coverage of the absorber, and enhance its applicability and practicality. Summary of the invention

[0005] The purpose of the present application is to provide an ultra-wideband absorber and a verification and optimization processing method for the ultra-wideband absorber in view of the deficiencies in the above-mentioned prior art, so as to solve the problems of low frequency band coverage and long design cycle of the absorber in the prior art.

[0006] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0007] In a first aspect, an embodiment of the present application provides an ultra-wideband absorber, the ultra-wideband absorber comprising: a bottom plate layer and a plurality of composite absorption layers;

[0008] The bottom plate layer is located at the bottom of the ultra-wideband absorber, and each of the composite absorption layers is stacked on the bottom plate layer in sequence according to a preset order;

[0009] Each of the composite absorption layers comprises: an intermediate dielectric layer and an absorbing layer arranged on the intermediate dielectric layer;

[0010] A resistance film layer is laminated on the surface of each of the wave absorbing layers;

[0011] The resistance film layers on the surfaces of the various absorbing layers are not completely the same.

[0012] In a possible implementation, the ultra-wideband absorber includes a first composite absorption layer, a second composite absorption layer, and a third composite absorption layer;

[0013] The first composite absorption layer includes: a first intermediate medium layer and a first absorbing layer;

[0014] A first resistance film layer is laminated on the first absorbing layer;

[0015] The second composite absorption layer includes: a second intermediate dielectric layer and a second absorbing layer;

[0016] A second resistance film layer is laminated on the second absorbing layer;

[0017] The third composite absorption layer comprises: a third intermediate medium layer and a third absorbing layer;

[0018] A third resistance film layer is laminated on the third absorbing layer;

[0019] The first resistance film layer, the second resistance film layer and the third resistance film layer are not completely the same.

[0020] In a possible implementation manner, the first resistance film layer and the third resistance film layer are rotated strip resistance film layers;

[0021] The rotated strip-shaped resistor film layer comprises: a first periodic structure unit, a second periodic structure unit, a third periodic structure unit and a fourth periodic structure unit;

[0022] The first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit are periodically extended along the horizontal and vertical directions and are centrally symmetrically arranged;

[0023] The first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit each include three strip-shaped resistor films of equal length and equal spacing.

[0024] In a possible implementation, the resistance of the first resistance film layer is 160 ohms, the resistance of the second resistance film layer is 200 ohms, and the resistance of the third resistance film layer is 400 ohms.

[0025] In a possible implementation, the period of the first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit is 20 mm, the thickness is 0.175 mm, the length of each strip resistor film is 10 mm, the width of each strip resistor film is 2 mm, and the spacing between two adjacent strip resistor films is 1 mm.

[0026] In a possible implementation manner, the second resistance film layer is a square resistance film layer;

[0027] The square resistor film layer is a classic square structure resistor film layer with a side length of w.

[0028] In a possible implementation, the thickness of the first intermediate dielectric layer is 8 mm, the thickness of the second intermediate dielectric layer is 7 mm, and the thickness of the third intermediate dielectric layer is 14 mm.

[0029] In a second aspect, another embodiment of the present application provides a verification and optimization processing method for an ultra-wideband absorber, the verification and optimization processing method for an ultra-wideband absorber comprising:

[0030] According to the structure of the ultra-wideband absorber, an equivalent circuit model is constructed, wherein the equivalent circuit model includes at least one set of initial equivalent circuit parameters, and the ultra-wideband absorber is the ultra-wideband absorber according to any one of claims 1 to 7;

[0031] Correcting each of the initial equivalent circuit parameters to obtain target equivalent circuit parameters;

[0032] Determining the surface impedance of the ultra-wideband absorber according to target equivalent circuit parameters;

[0033] Determining the absorptivity performance of the ultra-wideband absorber according to the surface impedance of the ultra-wideband absorber;

[0034] According to the absorptivity performance of the ultra-wideband absorber, the structure of the ultra-wideband absorber is optimized.

[0035] In a possible implementation, the correcting each of the initial equivalent circuit parameters to obtain a target equivalent circuit parameter includes:

[0036] Generating an initial absorption rate curve and a reference absorption rate curve according to each of the initial equivalent circuit parameters;

[0037] The initial absorptivity curve and the reference absorptivity curve are fitted by a preset algorithm to determine the target equivalent circuit parameters.

[0038] In a possible implementation, fitting the initial absorption rate curve and the reference absorption rate curve by a preset algorithm to determine the target equivalent circuit parameters includes:

[0039] Obtain preset fitting targets, fitting constraints, and frequency ranges;

[0040] Determine characteristic points on the initial absorption rate curve, segment the initial absorption rate curve, and fit the initial absorption rate curve and the reference absorption rate curve by a preset algorithm to obtain a fitted curve;

[0041] The error between the fitted curve and the reference absorptivity curve is determined, and if a preset error condition is met, target equivalent circuit parameters are determined according to the fitted curve.

[0042] The beneficial effects of the present application are as follows: by arranging a bottom plate layer and a plurality of composite absorption layers in an ultra-wideband absorber, and arranging the bottom plate layer at the bottom of the ultra-wideband absorber, and stacking the composite absorption layers in sequence on the bottom plate layer according to a preset order, and at the same time, arranging an intermediate dielectric layer and an absorbing layer arranged on the intermediate dielectric layer in each composite absorption layer, and laminating and dissimilar resistance film layers on the surface of each absorbing layer, the ultra-wideband absorber overcomes the polarization sensitivity problem of the traditional metamaterial absorber, and enables the ultra-wideband absorber to have a higher absorption rate within different incident angles, thereby improving the absorption bandwidth of the ultra-wideband absorber and realizing ultra-wideband absorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 A schematic diagram of the structure of an ultra-wideband absorber provided in an embodiment of the present application;

[0045] Figure 2 Another schematic diagram of the structure of the ultra-wideband absorber provided in an embodiment of the present application;

[0046] Figure 3 A schematic diagram of another structure of the ultra-wideband absorber provided in an embodiment of the present application;

[0047] Figure 4 A schematic diagram of a structure of a rotated strip resistor film layer in an ultra-wideband absorber provided in an embodiment of the present application;

[0048] Figure 5 A schematic diagram of the structure of a square resistor film layer in an ultra-wideband absorber provided in an embodiment of the present application;

[0049] Figure 6 A schematic diagram of an absorption rate parameter curve of an ultra-wideband absorber provided in an embodiment of the present application;

[0050] Figure 7 A schematic diagram of the absorption rate of the ultra-wideband absorber provided in an embodiment of the present application at different angles when the incident wave is a TE wave;

[0051] Figure 8 A schematic diagram of the absorption rate of the ultra-wideband absorber provided in an embodiment of the present application at different angles when the incident wave is a TM wave;

[0052] Fig. 9A schematic flow chart of a verification and optimization processing method for an ultra-wideband absorber provided in an embodiment of the present application;

[0053] Fig.10 A schematic diagram of a flow chart for obtaining target equivalent circuit parameters in the verification and optimization processing method for an ultra-wideband absorber provided in an embodiment of the present application;

[0054] Fig.11 A schematic flow chart of determining target equivalent circuit parameters in the verification and optimization processing method for an ultra-wideband absorber provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

[0056] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0057] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0058] Traditional ultra-wideband absorber design is usually based on electromagnetic field theory and numerical simulation, but this method often requires complex calculations and a large number of experimental verifications, and the design cycle is long. To address this problem, MI Hossain et al. proposed a design method based on an efficient equivalent circuit model in the "Equivalent Circuit Design Method for Wideband Nonmagnetic Absorbers at Low Microwave Frequencies" published in IEEE Transactions on Antennas and Propagation. It is used for non-magnetic absorbers, using single-layer and multi-layer FSS, and achieved absorption bandwidths of 121% and 161%, respectively. Compared with traditional methods, the ultra-wideband multi-angle absorber design based on the equivalent circuit model is simpler and more efficient, and can quickly achieve performance regulation and optimization of the absorber.

[0059] However, the current technical problems of metamaterial absorbers are: while keeping the thickness of metamaterial absorbers relatively thin, their absorption bandwidth needs to be further improved; and the multi-angle absorption range needs to be expanded. Therefore, it is necessary to improve the design method, simplify the design method, and reduce the design complexity to achieve a wider working frequency band response and a wider multi-angle absorption, improve the frequency band coverage of the absorber, and enhance its applicability and practicality.

[0060] Based on the above problems, the embodiment of the present application proposes an ultra-wideband absorber and a verification and optimization processing method for the ultra-wideband absorber. By designing the structure of the metamaterial absorber, an ultra-wideband absorber with different resistance film layers on the surface of each absorbing layer is obtained, so that the absorption bandwidth of the metamaterial absorber is further improved, and an equivalent circuit model including multiple groups of initial equivalent circuit parameters is constructed through the structure of the ultra-wideband absorber, and the initial equivalent circuit parameters are corrected to obtain the target equivalent circuit parameters, and further according to the target equivalent circuit parameters, the absorption rate performance of the ultra-wideband absorber is determined to achieve structural optimization of the ultra-wideband absorber. The ultra-wideband absorber is enabled to achieve a wider working frequency band response and a wider range of multi-angle absorption, improve the frequency band coverage of the ultra-wideband absorber, enhance the applicability and practicality of the ultra-wideband absorber, and at the same time, the performance optimization of the ultra-wideband absorber can be quickly achieved.

[0061] The ultra-wideband absorber and the verification and optimization processing method of the ultra-wideband absorber provided in the embodiments of the present application are described in detail below in combination with multiple embodiments.

[0062] Figure 1 A schematic diagram of the structure of an ultra-wideband absorber provided in an embodiment of the present application, referring to Figure 1As shown, the ultra-wideband absorber includes: a bottom plate layer 100 and a plurality of composite absorption layers 200 .

[0063] The bottom plate layer 100 is located at the bottom of the ultra-wideband absorber, and each composite absorption layer 200 is stacked on the bottom plate layer 100 in sequence according to a preset order.

[0064] Optionally, continue to refer to Figure 1 As shown, the bottom plate layer 100 is arranged at the bottom of the ultra-wideband absorber. The bottom plate layer can be made of a metal material with high electrical conductivity. The bottom plate layer 100 can reflect the incident electromagnetic waves, which helps to enhance the absorption effect of the ultra-wideband absorber.

[0065] Optionally, the bottom plate layer is a metal copper layer with an electrical conductivity of σ=5.8×10 7 S / m, the thickness of the metal copper layer is 0.018mm.

[0066] Optionally, continue to refer to Figure 1 As shown, the bottom plate layer serves as the basis and support structure of each composite absorption layer 200, and a plurality of composite absorption layers 200 may be stacked in sequence on the bottom plate layer 100 in a preset order. The preset order may be related to the electromagnetic parameters of each composite absorption layer 200, and the stacking arrangement in the preset order is to achieve a specific wave absorbing effect and frequency response, so that the composite absorption layers 200 and the bottom plate layer 100 can achieve efficient absorption of electromagnetic waves.

[0067] Each composite absorption layer 200 includes: an intermediate dielectric layer 201 and an absorbing layer 202 disposed on the intermediate dielectric layer 201 ; a resistance film layer 203 is bonded to the surface of each absorbing layer 202 ; and the resistance film layers 203 on the surface of each absorbing layer 202 are not completely the same.

[0068] Optionally, continue to refer to Figure 1 As shown, each composite absorption layer 200 is used to absorb electromagnetic waves in different frequency ranges, and each composite absorption layer 200 includes an intermediate dielectric layer 201 and an absorbing layer 202 disposed on the intermediate dielectric layer 201. Each absorbing layer 202 is disposed above the corresponding intermediate dielectric layer 201, and a resistance film layer 203 is laminated on the surface of each absorbing layer 202, thereby optimizing the absorption performance of the ultra-wideband absorber.

[0069] Optionally, each resistor film layer 203 is respectively disposed on the corresponding wave absorbing layer 202, and each resistor film layer 203 may be respectively composed of different resistor film patterns, and the resistor film patterns in each resistor film layer 203 may not be completely the same. Exemplarily, taking three resistor film layers as an example, the resistor film patterns of the first resistor film layer and the second resistor film layer in each resistor film layer 203 may be the same, and the patterns of the first resistor film layer and the second resistor film layer are different from the pattern of the third resistor film layer.

[0070] By setting different resistor film patterns in each resistor film layer, the ultra-wideband absorber can overcome the polarization sensitivity problem of the traditional metamaterial absorber, and make the ultra-wideband absorber have a higher absorption rate at different incident angles, thereby improving the absorption bandwidth of the ultra-wideband absorber and realizing ultra-wideband absorption.

[0071] The intermediate dielectric layer 201 is used to promote energy loss and absorption when absorbing electromagnetic waves. The absorbing layer 202 is used to convert the incident electromagnetic wave energy into heat energy or other forms of energy through the electromagnetic loss mechanism, thereby reducing the target echo intensity. The resistor film layer 203 is used to provide resistance and dissipate the absorbed electromagnetic waves in the form of heat energy, thereby achieving high absorption efficiency. At the same time, the resistance value of the resistor film can be changed to achieve the best absorbing effect in a specific frequency band.

[0072] Optionally, the intermediate dielectric layer 201 can be made of polymethacrylimide foam (PMI for short), which has the advantages of low dielectric constant and low magnetic permeability. The absorbing layer 202 can be made of polyethylene terephthalate (PET for short), which has excellent electrical insulation. Using PET as the substrate of the resistor film layer can fix the stability of the resistor film. The resistor film layer 203 can be made of polyethylene terephthalate (PET for short).

[0073] Exemplarily, each absorbing layer 202 may have a thickness of 0.175 mm, a dielectric constant ε=3.0, and a loss tangent tanδ=0.061.

[0074] In this embodiment, a bottom plate layer and a plurality of composite absorption layers are provided in an ultra-wideband absorber, and the bottom plate layer is provided at the bottom of the ultra-wideband absorber, and each composite absorption layer is stacked on the bottom plate layer in a preset order. At the same time, an intermediate dielectric layer and an absorbing layer provided on the intermediate dielectric layer are provided in each composite absorption layer, and a non-completely identical resistance film layer is provided on the surface of each absorbing layer. The ultra-wideband absorber overcomes the polarization sensitivity problem of the traditional metamaterial absorber, and the ultra-wideband absorber has a higher absorption rate within different incident angles, thereby improving the absorption bandwidth of the ultra-wideband absorber and realizing ultra-wideband absorption.

[0075] Illustratively, the following embodiments are described by taking the ultra-wideband absorber including three composite absorption layers as an example.

[0076] Figure 2 Another schematic diagram of the structure of the ultra-wideband absorber provided in an embodiment of the present application.

[0077] As a possible implementation, refer to Figure 2As shown, the ultra-wideband absorber includes a first composite absorption layer 200 , a second composite absorption layer 300 and a third composite absorption layer 400 .

[0078] The first composite absorption layer 200 includes: a first intermediate dielectric layer 201 and a first wave absorbing layer 202 ; a first resistance film layer 203 is laminated on the first wave absorbing layer 202 .

[0079] The second composite absorption layer 300 includes: a second intermediate dielectric layer 301 and a second absorbing layer 302; a second resistive film layer 303 ( Figure 2 not shown).

[0080] The third composite absorption layer 400 includes: a third intermediate dielectric layer 401 and a third absorbing layer 402; a third resistance film layer 403 ( Figure 2 not shown).

[0081] Optionally, the first composite absorption layer 200 , the second composite absorption layer 300 , and the third composite absorption layer 400 are all used to absorb electromagnetic waves in different frequency ranges.

[0082] Optionally, the first intermediate dielectric layer 201, the second intermediate dielectric layer 301, and the third intermediate dielectric layer 401 are all used to promote energy loss and absorption when absorbing electromagnetic waves. The first intermediate dielectric layer 201, the second intermediate dielectric layer 301, and the third intermediate dielectric layer 401 have different thicknesses, and the first intermediate dielectric layer 201, the second intermediate dielectric layer 301, and the third intermediate dielectric layer 401 have their own specific absorption frequency bands or efficiencies.

[0083] The first resistance film layer 203 , the second resistance film layer 303 and the third resistance film layer 403 are not completely the same.

[0084] Optionally, continue to refer to Figure 2 As shown, the first resistance film layer 203, the second resistance film layer 303 and the third resistance film layer 403 are respectively composed of different resistance film patterns, and the resistance film patterns in the first resistance film layer 203, the second resistance film layer 303 and the third resistance film layer 403 may not be completely the same. Exemplarily, the resistance film patterns in the first resistance film layer 203 and the third resistance film layer 403 may be the same, and the resistance film patterns in the first resistance film layer 203 and the third resistance film layer 403 are different from the pattern of the second resistance film layer 303.

[0085] By arranging three composite absorption layers in an ultra-wideband absorber and arranging three non-completely identical resistance film layers in the three composite absorption layers, the ultra-wideband absorber overcomes the polarization sensitivity problem of traditional metamaterial absorbers, and enables the ultra-wideband absorber to have a higher absorption rate within different incident angles, thereby improving the absorption bandwidth of the ultra-wideband absorber and realizing ultra-wideband absorption.

[0086] Figure 3 A schematic diagram of another structure of the ultra-wideband absorber provided in an embodiment of the present application.

[0087] As a possible implementation, refer to Figure 3 As shown, the first resistance film layer 203 and the third resistance film layer 403 are rotated strip resistance film layers.

[0088] The rotated strip resistor film layer includes: a first periodic structure unit, a second periodic structure unit, a third periodic structure unit and a fourth periodic structure unit.

[0089] It can be understood that the generation process of the rotated strip resistor film layer is explained as follows: the resistor film layer can be understood as a square plane figure. With the center of the plane figure as the origin, a rectangular coordinate system is established, and the plane figure can be divided to obtain plane figures of the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant. On this basis, a specific pattern is filled into the first quadrant to obtain a first periodic structure unit, and with the origin of the coordinate system as the rotation center, the first periodic structure unit is rotated counterclockwise by 90°, 180°, and 270° in turn, and the obtained pattern is filled into each quadrant to obtain a second periodic structure unit, a third periodic structure unit, and a fourth periodic structure unit, and the first periodic structure unit, the second periodic structure unit, the third periodic structure unit, and the fourth periodic structure unit together constitute a rotated resistor film layer. Among them, the specific pattern can be a stripe pattern, and the obtained resistor film layer is a rotated strip resistor film layer.

[0090] The first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit are extended periodically along the horizontal and vertical directions and are centrally symmetrically arranged.

[0091] Optionally, the first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit are periodically extended along the X-axis and Y-axis directions in the plane figure, and the first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit are centrally symmetrically arranged.

[0092] Figure 4 A schematic diagram of the structure of a rotated strip resistor film layer in an ultra-wideband absorber provided in an embodiment of the present application.

[0093] The first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit each include three strip-shaped resistor films with equal length and equal spacing.

[0094] Optionally, refer to Figure 4 As shown, the specific pattern can be a strip pattern, specifically a strip pattern of equal length and equal spacing, and the first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit respectively include three strip-shaped resistor films with a length of d1, a width of d2 and a spacing of d3. Wherein, P is the size of the periodic unit of the absorber provided in the embodiment of the present application, and exemplarily, P=20mm.

[0095] By setting the first resistor film layer and the third resistor film layer as rotated strip resistor film layers, and setting the first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit in the rotated strip resistor film layer, and setting three strip resistor films with equal length and equal spacing in the first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit, respectively, so that the first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit are not only axisymmetric about the x-axis and the y-axis but also centrally symmetric, the resistor film layer in the ultra-wideband absorber provided by the embodiment of the present application can have a high degree of symmetry, and further the ultra-wideband multi-angle absorber provided by the embodiment of the present application has good polarization insensitivity, overcomes the polarization sensitivity problem of the traditional metamaterial absorber, and makes the ultra-wideband absorber have a higher absorption rate within different incident angles, and can achieve a higher absorption rate for both transverse electric waves (TE waves) and transverse magnetic waves (TM waves), thereby improving the absorption bandwidth of the ultra-wideband absorber and realizing ultra-wideband absorption.

[0096] As a possible implementation, continue to refer to Figure 4 As shown, the period of the first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit is 20mm, the thickness is 0.175mm, the length of each strip resistor film is 10mm, the width of each strip resistor film is 2mm, and the spacing between two adjacent strip resistor films is 1mm.

[0097] Optionally, the period p of the first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit is 20 mm, the thickness is 0.175 mm, the length d1 of each strip resistor film is 10 mm, the width d2 of each strip resistor film is 2 mm, and the spacing d3 between two adjacent strip resistor films is 1 mm.

[0098] The period of the first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit is set to 20 mm, the thickness is set to 0.175 mm, the length of each strip resistor film is set to 10 mm, the width of each strip resistor film is set to 2 mm, and the spacing between two adjacent strip resistor films is set to 1 mm, which can enable the ultra-wideband absorber to have the highest absorption rate within different incident angles, and can achieve the highest absorption rate for both TE waves and TM waves, thereby ensuring the absorption broadband of the ultra-wideband absorber and realizing ultra-wideband absorption.

[0099] As a possible implementation, the resistance of the first resistance film layer 203 is 160 ohms, the resistance of the second resistance film layer 303 is 200 ohms, and the resistance of the third resistance film layer 403 is 400 ohms.

[0100] Optionally, the resistance of the first resistance film layer 203 is r1 =160Ω / sq, the resistance of the second resistance film layer 303 is r2 =200Ω / sq, and the resistance of the third resistance film layer 403 is r1 =400Ω / sq.

[0101] When the resistance of the first resistor film layer is 160 ohms, the resistance of the second resistor film layer is 200 ohms, and the resistance of the third resistor film layer is 400 ohms, the ultra-wideband absorber can have the highest absorption rate within different incident angles, and can achieve the highest absorption rate for both TE waves and TM waves, thereby ensuring the absorption bandwidth of the ultra-wideband absorber and realizing ultra-wideband absorption.

[0102] Figure 5 A schematic diagram of the structure of a square resistor film layer in an ultra-wideband absorber provided in an embodiment of the present application.

[0103] As a possible implementation, refer to Figure 5 As shown, the second resistance film layer 303 is a square resistance film layer; the square resistance film layer is a classic square structure resistance film layer with a side length of w.

[0104] The side length of the square resistor film layer is w=19.4 mm.

[0105] As a possible implementation, continue to refer to Figure 3 As shown, the thickness of the first intermediate dielectric layer 201 is 8 mm, the thickness of the second intermediate dielectric layer 301 is 7 mm, and the thickness of the third intermediate dielectric layer 401 is 14 mm.

[0106] Optionally, the thickness of the first intermediate dielectric layer 201 is h1=8 mm, the thickness of the second intermediate dielectric layer 301 is h2=7 mm, the thickness of the third intermediate dielectric layer 401 is h3=14 mm, the dielectric constant is ε=1.05, and the loss tangent is tanδ=0.001.

[0107] It is worth noting that the parameter design provided in the above embodiment is only the optimal parameter design scheme of the ultra-wideband absorber provided in the embodiment of the present application. Under the parameter setting, the ultra-wideband absorber provided in the embodiment of the present application has an absorptivity greater than 90%, and a relative bandwidth of 166%. At the same time, the total thickness is only 0.105λL, where λL is the maximum operating wavelength. It can achieve the characteristics of low profile while ensuring ultra-wideband absorption, overcome the polarization sensitivity problem of traditional metamaterial absorbers, and can meet the absorption rate of more than 75% in the incident angle range of 0° to 60°.

[0108] For example, Figure 6 A schematic diagram of an absorption rate parameter curve of an ultra-wideband absorber provided in an embodiment of the present application, referring to Figure 6 As shown, the ultra-wideband absorber provided in the embodiment of the present application is simulated using electromagnetic field simulation software (such as CST), and an absorption rate curve can be obtained, wherein the horizontal axis Frequency is the frequency in GHz, the vertical axis |S11| is the absorption rate parameter in dB, and when the absorption frequency band is 1.07-11.84 GHz, the absorption rate of the ultra-wideband absorber provided in the embodiment of the present application is greater than 90%, and the working frequency band involves L, S, C and X bands. On this basis, the frequency band with an absorption rate higher than 90% (i.e., 1.07-11.84 GHz) is calculated, and the relative bandwidth is 166%, that is, the ultra-wideband absorber provided in the embodiment of the present application achieves ultra-wideband absorption.

[0109] For example, Figure 7 A schematic diagram of the absorption rate of the ultra-wideband absorber at different angles when the incident wave is a TE wave provided in an embodiment of the present application, referring to Figure 7 As shown, it can be seen that when the incident angle is within 0° to 60°, the absorption bandwidth has an obvious blue shift phenomenon as the incident angle increases. This is because as the angle of the incident electromagnetic wave increases, the surface current excited by the incident magnetic field becomes smaller, and the current path becomes shorter, causing the resonance point to move toward high frequency, which is macroscopically manifested as a blue shift. That is, the ultra-wideband absorber provided in the embodiment of the present application has a good absorption effect for electromagnetic waves within an angle of 0 to 60° when the incident wave mode is a TE wave.

[0110] For example, Figure 8 A schematic diagram of the absorption rate of the ultra-wideband absorber provided in the embodiment of the present application at different angles when the incident wave is a TM wave, referring to Figure 8 As shown, it can be seen that when the incident angle is 60°, the absorption rate is still maintained at a level of about 90%. Therefore, the ultra-wideband absorber provided in the embodiment of the present application has a good absorbing effect of electromagnetic waves within an angle of 0 to 60° when the incident wave mode is TM wave, that is, the ultra-wideband absorber provided in the embodiment of the present application has a polarization-insensitive characteristic.

[0111] Based on the same inventive concept, an embodiment of the present application also provides a verification and optimization method for an ultra-wideband absorber for verifying and optimizing the ultra-wideband absorber, which is described in detail below.

[0112] Fig. 9 A flow chart of a verification and optimization processing method for an ultra-wideband absorber provided in an embodiment of the present application, referring to Fig. 9 As shown, the execution subject of the method can be any electronic device with processing capability, and the method includes:

[0113] S901. Construct an equivalent circuit model according to the structure of an ultra-wideband absorber, wherein the equivalent circuit model includes at least one set of initial equivalent circuit parameters. The ultra-wideband absorber is the ultra-wideband absorber in the above embodiment.

[0114] It can be understood that, taking the ultra-wideband absorber provided in the above-mentioned embodiment of the present application as an example, in the aforementioned ultra-wideband absorber, in order to analyze the electromagnetic behavior of the ultra-wideband absorber, the ultra-wideband absorber can be modeled as an equivalent circuit transmission line model, thereby realizing verification and optimization processing of the ultra-wideband absorber by analyzing the equivalent circuit transmission line model.

[0115] It is worth noting that, taking the ultra-wideband absorber provided in the above embodiment of the present application as an example, in the rotated strip resistor film layer, when the strip resistor film is perpendicular to the direction of the electric field, its equivalent circuit characteristic is capacitance, and when it is parallel to the direction of the electric field, it is equivalent to inductance. Therefore, an equivalent circuit transmission line model can be established for each of the rotated strip resistor film layers, and simplified to make each resistor film layer equivalent to a series circuit of R, L, and C.

[0116] Optionally, an equivalent circuit model may be constructed based on the first resistance film layer, the second resistance film layer and the third resistance film layer to obtain multiple groups of initial equivalent circuit parameters, namely resistance R, inductance L and capacitance C.

[0117] Exemplarily, a first equivalent circuit model and a third equivalent circuit model can be established for the first resistance film layer and the third resistance film layer, respectively, and the second resistance film layer can be directly equivalent to an RLC series circuit to obtain a second equivalent circuit model, and the first equivalent circuit model, the second equivalent circuit model and the third equivalent circuit model can be used as equivalent circuit models.

[0118] Exemplarily, based on the parameters of the first resistance film layer, the second resistance film layer and the third resistance film layer, the first initial equivalent circuit parameters in the first equivalent circuit model, the second initial equivalent circuit parameters in the second equivalent circuit model and the third initial equivalent circuit parameters in the third equivalent circuit model can be obtained by calculation, and the first initial equivalent circuit parameters, the second initial equivalent circuit parameters and the third initial equivalent circuit parameters are used as the initial equivalent circuit parameters in the equivalent circuit model.

[0119] For example, the initial equivalent circuit parameters can be calculated by the following formulas (1)-(4):

[0120] For example, the equivalent resistance R of each layer of the multilayer composite electromagnetic wave absorption layer can be calculated according to the resistance film structure size parameters by the following formula (1): i , i = 1, ..., n:

[0121]

[0122] Where, is the surface resistance of the resistor film, S is the area of ​​a periodic unit cell, and A is the area of ​​the lossy element within a periodic unit cell.

[0123] For example, for a square structure resistive film, the capacitance C can be approximately expressed by the following formula (2):

[0124]

[0125] Where p is the unit period and g is the gap between each unit period.

[0126] For example, for a strip structure resistor film, when considering the equivalent capacitance and equivalent inductance of the resistor film, it can be abstracted as an ideal capacitor and an ideal inductor to better understand the circuit characteristics of the resistor film. The capacitance C is related to the length of the line where the charge accumulates at the edge of the resistor film, and can be expressed by the static capacitance expression of an ideal parallel plate capacitor, that is, the following formula (3):

[0127]

[0128] Among them, is the dielectric constant of vacuum, is the relative dielectric constant of the material, S is the plate area of ​​the capacitor, and d is the plate spacing.

[0129] Exemplarily, the equivalent inductance L is related to the length of the line of current flowing through the surface of the resistor film, and can be calculated by the following formula (4):

[0130]

[0131] Among them, is the magnetic permeability of vacuum, is the relative magnetic permeability of the material, r is the effective radius, is the distance between two parallel wires, and l is the length of the wire.

[0132] S902: Correct each initial equivalent circuit parameter to obtain a target equivalent circuit parameter.

[0133] It can be understood that after obtaining the initial equivalent circuit parameters, since the initial equivalent circuit parameters are calculated, there may be errors in the initial equivalent circuit parameters. Therefore, the initial equivalent circuit parameters can be corrected to obtain the target equivalent circuit parameters. In other words, both the initial equivalent circuit parameters and the target equivalent circuit parameters are used to characterize the performance of the ultra-wideband absorber, but the target equivalent circuit parameters have a higher accuracy.

[0134] Optionally, when correcting the initial equivalent circuit parameters, the initial absorption rate curve, the reference absorption rate curve and a preset algorithm may be combined to correct the initial equivalent circuit parameters to obtain target equivalent circuit parameters.

[0135] Exemplarily, in one embodiment, the target equivalent circuit parameters are: R1=112.06Ω, R2=680.07Ω, R3=510.98Ω, L1=1.37nH, L3=13.33nH, C1=656.56fF, C2=585.85fF, C3=179.81fF.

[0136] S903: Determine the surface impedance of the ultra-wideband absorber according to the target equivalent circuit parameters.

[0137] Optionally, after obtaining the target equivalent circuit parameters, impedance analysis may be performed on the ultra-wideband absorber to determine the surface impedance of the ultra-wideband absorber.

[0138] For example, the surface impedance Z of the ultra-wideband absorber can be calculated using the following formula (5):

[0139]

[0140] Wherein, is the angular frequency, R is the equivalent resistance in the target equivalent circuit parameters, L is the equivalent inductance in the target equivalent circuit parameters, and C is the equivalent capacitance in the target equivalent circuit parameters.

[0141] S904: Determine the absorptivity performance of the ultra-wideband absorber according to the surface impedance of the ultra-wideband absorber.

[0142] It can be understood that because impedance matching can maximize the transmission and absorption of energy, so that electromagnetic waves are less reflected at the boundary, more energy will be absorbed instead of reflected back into the air. When the surface impedance of the ultra-wideband absorber is slightly different from the impedance of the surrounding medium, it can be determined that the ultra-wideband absorber has a good absorption performance.

[0143] Optionally, the surface impedance of the ultra-wideband absorber is compared with the impedance of the surrounding medium. When the difference between the surface impedance of the ultra-wideband absorber and the impedance of the surrounding medium is less than a preset threshold, the absorptivity performance of the ultra-wideband absorber can be rated to determine that the absorptivity performance of the ultra-wideband absorber is good. When the difference between the surface impedance of the ultra-wideband absorber and the impedance of the surrounding medium is greater than a preset threshold, the absorptivity performance of the ultra-wideband absorber can be rated to determine that the absorptivity performance of the ultra-wideband absorber is poor.

[0144] S905. Optimize the structure of the ultra-wideband absorber according to the absorptivity performance of the ultra-wideband absorber.

[0145] Optionally, after the absorptivity performance of the ultra-wideband absorber is determined, the structural design of the ultra-wideband absorber may be optimized according to the absorptivity performance of the ultra-wideband absorber.

[0146] For example, the material selection and stacking structure of the ultra-wideband absorber can be optimized according to the absorptivity performance of the ultra-wideband absorber, thereby optimizing the surface impedance of the ultra-wideband absorber.

[0147] In this embodiment, an equivalent circuit model including multiple sets of initial equivalent circuit parameters is constructed through the structure of the ultra-wideband absorber, and the initial equivalent circuit parameters are corrected to obtain target equivalent circuit parameters. The absorptivity performance of the ultra-wideband absorber is further determined based on the target equivalent circuit parameters, so that the structural optimization of the ultra-wideband absorber can be quickly achieved.

[0148] Fig.10 A schematic flow chart of obtaining target equivalent circuit parameters in the verification and optimization processing method for an ultra-wideband absorber provided in an embodiment of the present application.

[0149] As a possible implementation, refer to Fig.10 As shown, in the above step S902, each initial equivalent circuit parameter is corrected to obtain the target equivalent circuit parameter, including:

[0150] S1001. Generate an initial absorption rate curve and a reference absorption rate curve according to each initial equivalent circuit parameter.

[0151] Optionally, an initial absorptivity curve may be generated according to each initial equivalent circuit parameter by using preset software, and each initial equivalent circuit parameter may be used as an initial value to plot a reference absorptivity curve.

[0152] The preset software may be electronic design automation (EDA) software (Agilent Advanced Design System, referred to as ADS software).

[0153] S1002: Fit the initial absorption rate curve and the reference absorption rate curve using a preset algorithm to determine target equivalent circuit parameters.

[0154] Optionally, after obtaining the initial absorptivity curve and the reference absorptivity curve, the initial absorptivity curve and the reference absorptivity curve can be fitted by a preset algorithm, so that the initial absorptivity curve can be more closely aligned with the reference absorptivity curve, and the target equivalent circuit parameters can be determined by the fitted initial absorptivity curve. The preset algorithm may include a gradient descent method, a genetic algorithm, a simulated annealing algorithm, etc.

[0155] An initial absorption rate curve and a reference absorption rate curve are generated through various initial equivalent circuit parameters, and the initial absorption rate curve and the reference absorption rate curve are fitted through a preset algorithm to determine the target equivalent circuit parameters, so that the target equivalent circuit parameters can be accurately generated.

[0156] Fig.11 A schematic flow chart of determining target equivalent circuit parameters in the verification and optimization processing method for an ultra-wideband absorber provided in an embodiment of the present application.

[0157] As a possible implementation, refer to Fig.11 As shown, in the above step S1002, the initial absorption rate curve and the reference absorption rate curve are fitted by a preset algorithm to determine the target equivalent circuit parameters, including:

[0158] S1101, obtaining a preset fitting target, fitting restriction condition, and frequency range.

[0159] Optionally, before fitting, a preset fitting target, fitting restriction condition and frequency range are obtained.

[0160] Exemplarily, the fitting target may be the frequency of the resonance point and the parameter value of the absorption rate, and the restriction condition may be limiting the absorption rate parameter to between -10 dB and -15 dB and setting the corresponding frequency range.

[0161] S1102, determining characteristic points on the initial absorption rate curve, and segmenting the initial absorption rate curve, and fitting the initial absorption rate curve and the reference absorption rate curve through a preset algorithm to obtain a fitted curve.

[0162] Optionally, characteristic points on the initial absorption rate curve, such as peak points, trough points and trend points, can be determined first, and the initial absorption rate curve can be segmented to obtain initial absorption rate curves of multiple intervals. Then, the points on the initial absorption rate curve can be fitted with the reference absorption rate curve through a preset algorithm, that is, the R, L, and C parameters can be gradually adjusted to move the points on the initial absorption rate curve to obtain the fitted curve.

[0163] S1103, determining the error between the fitted curve and the reference absorptivity curve, and if the preset error condition is met, determining the target equivalent circuit parameters according to the fitted curve.

[0164] Optionally, after obtaining the fitted curve, the error between the fitted curve and the reference absorptivity curve can be calculated to optimize the R, L, and C parameters. If the error reaches a preset convergence condition or a minimum error condition, the target equivalent circuit parameters are determined according to the fitted curve, that is, the R, L, and C parameters corresponding to the fitted curve are used as the target equivalent circuit parameters.

[0165] Optionally, if it is not satisfied, the initial absorbance curve and the reference absorbance curve are refitted using a preset algorithm.

[0166] By obtaining the preset fitting target, fitting constraints and frequency range, the characteristic points on the initial absorption rate curve are determined, and the initial absorption rate curve is segmented. The initial absorption rate curve and the reference absorption rate curve are fitted through a preset algorithm to obtain a fitted curve, and the error between the fitted curve and the reference absorption rate curve is determined. If the preset error conditions are met, the target equivalent circuit parameters are determined according to the fitted curve, and the target equivalent circuit parameters can be accurately generated.

[0167] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the method embodiment, and will not be repeated in this application. In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0168] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or part of the technical solution that contributes to the prior art or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, RandomAccess Memory), disk or optical disk and other media that can store program code.

[0169] The above are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. An ultra-wideband absorber, characterized in that: include: A bottom plate layer and a plurality of composite absorbent layers; The bottom plate layer is located at the bottom of the ultra-wideband absorber, and each of the composite absorption layers is stacked on the bottom plate layer in sequence according to a preset order, wherein the preset order is related to the electromagnetic parameters of each of the composite absorption layers; Each of the composite absorption layers comprises: an intermediate dielectric layer and an absorbing layer arranged on the intermediate dielectric layer; A resistance film layer is laminated on the surface of each of the wave absorbing layers; The resistance film layers on the surfaces of the various absorbing layers are not exactly the same; The ultra-wideband absorber comprises a first composite absorption layer, a second composite absorption layer and a third composite absorption layer; The first composite absorption layer includes: a first intermediate medium layer and a first absorbing layer; A first resistance film layer is laminated on the first absorbing layer; The second composite absorption layer includes: a second intermediate dielectric layer and a second absorbing layer; A second resistance film layer is laminated on the second absorbing layer; The third composite absorption layer comprises: a third intermediate medium layer and a third absorbing layer; A third resistance film layer is laminated on the third absorbing layer; The first resistance film layer, the second resistance film layer and the third resistance film layer are not completely the same; The first resistance film layer and the third resistance film layer are rotated strip resistance film layers; The rotated strip-shaped resistor film layer comprises: a first periodic structure unit, a second periodic structure unit, a third periodic structure unit and a fourth periodic structure unit; The first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit are periodically extended along the horizontal and vertical directions and are centrally symmetrically arranged; The first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit each include three strip-shaped resistance films of equal length and equal spacing; The first resistance film layer, the second resistance film layer and the third resistance film layer are all made of polyethylene terephthalate; The first periodic structure unit, the second periodic structure unit, the third periodic structure unit and the fourth periodic structure unit have a period of 20 mm and a thickness of 0.175 mm, a length of each strip-shaped resistor film is 10 mm, a width of each strip-shaped resistor film is 2 mm, and a distance between two adjacent strip-shaped resistor films is 1 mm; The second resistor film layer is a square resistor film layer; the square resistor film layer is a classic square structure resistor film layer with a side length of w.

2. The ultra-wideband absorber according to claim 1, characterized in that: The resistance value of the first resistance film layer is 160 ohms, the resistance value of the second resistance film layer is 200 ohms, and the resistance value of the third resistance film layer is 400 ohms.

3. The ultra-wideband absorber according to claim 1, characterized in that: The thickness of the first intermediate dielectric layer is 8 mm, the thickness of the second intermediate dielectric layer is 7 mm, and the thickness of the third intermediate dielectric layer is 14 mm.

4. A verification and optimization processing method for an ultra-wideband absorber, characterized in that: include: According to the structure of the ultra-wideband absorber, an equivalent circuit model is constructed, wherein the equivalent circuit model includes at least one set of initial equivalent circuit parameters, and the ultra-wideband absorber is the ultra-wideband absorber according to any one of claims 1 to 3; Correcting each of the initial equivalent circuit parameters to obtain target equivalent circuit parameters; Determining the surface impedance of the ultra-wideband absorber according to target equivalent circuit parameters; Determining the absorptivity performance of the ultra-wideband absorber according to the surface impedance of the ultra-wideband absorber; According to the absorptivity performance of the ultra-wideband absorber, the structure of the ultra-wideband absorber is optimized.

5. The verification and optimization processing method for an ultra-wideband absorber according to claim 4, characterized in that: The correcting each of the initial equivalent circuit parameters to obtain target equivalent circuit parameters includes: Generating an initial absorption rate curve and a reference absorption rate curve according to each of the initial equivalent circuit parameters; The initial absorptivity curve and the reference absorptivity curve are fitted by a preset algorithm to determine the target equivalent circuit parameters.

6. The verification and optimization processing method for an ultra-wideband absorber according to claim 5, characterized in that: The method of fitting the initial absorption rate curve and the reference absorption rate curve by a preset algorithm to determine the target equivalent circuit parameters includes: Obtain preset fitting targets, fitting constraints, and frequency ranges; Determine characteristic points on the initial absorption rate curve, segment the initial absorption rate curve, and fit the initial absorption rate curve and the reference absorption rate curve by a preset algorithm to obtain a fitted curve; The error between the fitted curve and the reference absorptivity curve is determined, and if a preset error condition is met, target equivalent circuit parameters are determined according to the fitted curve.

Images