Flexible broadband metamaterial absorber and design method thereof
By designing a flexible broadband metamaterial absorber, and employing a multi-layer integrated structure and a flexible dielectric substrate, the problems of existing absorbers being too thin and inflexible were solved, achieving high absorption rate and flexible conformal absorption effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG UNIV
- Filing Date
- 2023-04-24
- Publication Date
- 2026-07-21
AI Technical Summary
Existing metamaterial absorbers use rigid substrates, resulting in insufficient lightness and thinness, lack of flexibility, inability to be folded, inability to conform to the protected target, and large mass, which affects the absorption effect.
A flexible broadband metamaterial absorber is designed, which adopts a multi-layer integrated structure composed of a resistive film, a PI film, a flexible dielectric and a copper film, including a resonant structure with a cross-shaped and four circular resistive films. The flexible dielectric is used as the substrate and the fabrication is achieved by screen printing.
It achieves broadband absorption characteristics on flexible substrates with an absorption rate of over 90%, exhibits high absorption performance in the 10-19 GHz range, and can conformally attach to complex and irregular object surfaces, with high flexibility and simple manufacturing process.
Smart Images
Figure CN116526154B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of metamaterial absorbing technology, and more specifically to a flexible broadband metamaterial absorber and its design method. Background Technology
[0002] Metamaterials are artificial composite materials composed of periodically arranged subwavelength unit cells. Their key characteristic lies in the ability to acquire physical properties not found in naturally occurring materials through the rational design of the metamaterial unit cell shape and structure, optimization of cell size parameters, and appropriate arrangement of cells. These physical properties are particularly evident in electromagnetic characteristics, such as negative permeability, negative permittivity, and negative refractive index. Metamaterial absorbers are characterized by high absorption efficiency, thinness, and light weight, and are widely used in electromagnetic shielding, stealth technology, microwave and radio frequency energy harvesting, and solar cells.
[0003] Metamaterial absorbers have become a research hotspot in recent years, with broad application prospects and significant development potential in numerous technological fields. The research and fabrication of metamaterial absorbers are of indispensable importance for enhancing military strength and improving people's living standards.
[0004] At present, most metamaterial absorbers typically use rigid substrates such as FR-4 as the base, which have disadvantages such as not being thin enough, not being flexible enough, not being able to be folded, not being able to conform to the protected target, and having a large mass, which affect the absorption effect.
[0005] Therefore, how to propose a flexible broadband metamaterial absorber and its design method is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0006] In view of this, the present invention provides a flexible broadband metamaterial absorber and its design method to solve the technical problems existing in the prior art.
[0007] To achieve the above objectives, the present invention provides the following technical solution:
[0008] On one hand, the present invention provides a flexible broadband metamaterial absorber, comprising: a resistive film, a PI film, a flexible dielectric, and a copper film arranged vertically from top to bottom;
[0009] The resistive film is composed of a cross-shaped cross resistive film and a circular resistive film;
[0010] The cross-shaped resistive film has four circular resistive films symmetrically arranged in the four quadrants.
[0011] Preferably, the horizontal and vertical lengths of the cross-shaped resistive film are both 12 mm, and the width is 2 mm.
[0012] Preferably, the diameter of the circular resistive film is 5.7 mm.
[0013] Preferably, the distance between the edge point of the circular resistive film and the edge point of the cross-shaped resistive film is ≥0.4mm.
[0014] Preferably, it also includes right-angle resistive films, symmetrically distributed at the four corners of the unit, wherein the horizontal and vertical lengths of the right-angle resistive films are both 5mm, and the width is 2mm.
[0015] Preferably, the overall thickness is 2.11 mm.
[0016] Preferably, the cycle length is 20mm.
[0017] Preferably, the sheet resistance of the resistive film is 80 ohms.
[0018] On the other hand, the present invention provides a design method for a flexible broadband metamaterial absorber, the design method comprising:
[0019] The overall structure constituting the flexible broadband metamaterial absorber is determined, including: a resistive film, a PI film, a flexible dielectric, and a copper film arranged vertically from top to bottom;
[0020] The overall thickness is set to 2.11mm, and the cycle length is set to 20mm.
[0021] The thicknesses of the resistive film, PI film, flexible dielectric substrate, and copper film are set, wherein the thickness of the resistive film is 10 micrometers, the thickness of the PI film is 0.075 mm, the thickness of the flexible dielectric substrate is 2 mm, and the thickness of the copper film is 0.035 mm.
[0022] The structure of the resistive film is configured;
[0023] The sheet resistance of the resistive film is set to 80 ohms.
[0024] Preferably, the structure for setting the resistive film includes:
[0025] S1: The resistive film is configured as a cross-shaped cross resistive film and a circular resistive film, wherein four circular resistive films are symmetrically arranged in the four quadrants of the cross-shaped cross resistive film.
[0026] S2: The horizontal and vertical lengths of the cross-shaped resistive film are both 12mm, and the width is 2mm.
[0027] S3: Set the diameter of the circular resistive film to 5.7 mm;
[0028] S4: The distance between the edge point of the circular resistive film and the edge point of the cross-shaped resistive film is ≥0.4mm;
[0029] Preferably, the resistive film further includes: setting the right-angle resistive film, which is symmetrically distributed at the four corners of the resistive film, wherein the horizontal length and vertical length of the right-angle resistive film are both 5mm, and the width is 2mm.
[0030] As can be seen from the above technical solution, compared with the prior art, this invention discloses a flexible broadband metamaterial absorber and its design method, obtaining a metamaterial absorber that can exhibit certain broadband absorption characteristics on a flexible substrate. It addresses the problems of low absorption rate, narrow absorption bandwidth, and inability to conform to curved surfaces in existing metamaterial absorbers, achieving flexible broadband absorption. This method starts from the absorption mechanism of metamaterial absorbers and designs a multi-layer integrated metamaterial absorber composed of a resonant structure layer combining a cross-shaped structure and four circular resistive films, a polymer interlayer, and more. The designed multi-layer integrated metamaterial absorber achieves an absorption rate exceeding 90% in a wide frequency range of 10-19 GHz, exhibiting high absorption performance under different polarization angles and incident angles, achieving optimal absorption effect. Furthermore, this invention uses a flexible medium as the substrate, allowing it to conformally attach to complex and irregular object surfaces. Compared with traditional electromagnetic metamaterial absorbers based on rigid substrates, flexible metamaterial absorbers offer high flexibility, simple fabrication processes, and strong practicality, making them suitable for the future demand for broadband and flexible metamaterial absorbers. Attached Figure Description
[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0032] Figure 1 This is a schematic diagram of different layers of the flexible broadband metamaterial absorber of the present invention.
[0033] Figure 2 This is a schematic diagram of the overall structure of the flexible broadband metamaterial absorber of the present invention.
[0034] Figure 3 This is a schematic diagram illustrating the absorption effect of the present invention at different frequencies.
[0035] Figure 4 This is a schematic diagram of the absorption effect of the present invention at different polarization angles.
[0036] Figure 5This is a schematic diagram of the absorption effect of the present invention at different incident angles. Detailed Implementation
[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0038] See appendix Figure 1 As shown, an embodiment of the present invention discloses a flexible broadband metamaterial absorber, comprising: a resistive film, a PI film, a flexible dielectric, and a copper film arranged vertically from top to bottom;
[0039] The resistive film consists of a cross-shaped resistive film, a circular resistive film, and a right-angle resistive film. The right-angle resistive film has a horizontal and vertical length of 5mm and a width of 2mm.
[0040] Among them, four circular resistor films are symmetrically arranged in the four quadrants of the cross-shaped cross resistor film, and four right-angle resistor films are symmetrically distributed in the four corners of the unit, with the closest distance between the right-angle resistor film and the edge of the unit structure being 0.5mm.
[0041] Specifically, the flexible broadband metamaterial absorber of the present invention consists of a total of 4 layers: a high-resistivity carbon paste resistive film, a PI film, a flexible dielectric substrate, and a back reflective metal plate (copper), which are arranged vertically from top to bottom.
[0042] More specifically, the cross-shaped cross-resistive film is centered relative to the PI film, the flexible dielectric substrate, and the copper film. Four circular resistive films are symmetrically distributed in the four quadrants of the cross-shaped cross-resistive film, and four right-angle resistive films are symmetrically distributed in the four corners of the unit.
[0043] In one specific embodiment, the horizontal and vertical lengths of the cross-shaped resistive film are both l = 12 mm, and the width is d = 2 mm.
[0044] In one specific embodiment, the diameter of the four circular resistive films is r = 5.7 mm.
[0045] In one specific embodiment, the distance between the edge point of the circular resistive film and the edge point of the cross-shaped resistive film is ≥0.4mm, that is, the four circular resistive films are symmetrically distributed in the four quadrants of the cross-shaped resistive film and the closest distance between the point on the circular edge and the cross-shaped resistive film is 0.4mm.
[0046] See appendix Figure 2As shown, in one specific embodiment, the overall thickness of the flexible broadband metamaterial absorber is h = 2.11 mm, and the period length is p = 20 mm.
[0047] In one specific embodiment, the sheet resistance of the resistive film is 80 ohms.
[0048] Specifically, this invention uses a flexible medium as the substrate of the metamaterial absorber, allowing it to conformally attach to complex and irregular object surfaces. Compared to traditional electromagnetic metamaterial absorbers based on rigid substrates, flexible metamaterial absorbers offer significantly greater flexibility. The design of flexible metamaterial absorbers often boasts advantages such as a smaller radar cross-section (RCS) and a larger incident angle.
[0049] More specifically, the absorption effect of a flexible broadband metamaterial absorber provided by this invention is as follows: Figures 3-5 As shown, this absorber can achieve an absorption rate of over 90% in a wide frequency range of 10-19 GHz, and exhibits high absorption performance under different polarization angles and incident angles.
[0050] On the other hand, this invention discloses a design method for a flexible broadband metamaterial absorber, which includes:
[0051] The overall structure constituting the flexible broadband metamaterial absorber is determined, including: a resistive film, a PI film, a flexible dielectric, and a copper film arranged vertically from top to bottom;
[0052] The overall thickness is set to 2.11mm, and the cycle length is set to 20mm.
[0053] The thicknesses of the resistive film, PI film, flexible dielectric substrate, and copper film are set, wherein the thickness of the resistive film is 10 micrometers, the thickness of the PI film is 0.075 mm, the thickness of the flexible dielectric substrate is 2 mm, and the thickness of the copper film is 0.035 mm.
[0054] The structure of the resistive film is configured;
[0055] The sheet resistance of the resistive film is set to 80 ohms.
[0056] In one specific embodiment, the structure for setting the resistive film includes:
[0057] S1: The resistive film is set as a cross-shaped cross resistive film and a circular resistive film, wherein four circular resistive films are symmetrically arranged in the four quadrants of the cross-shaped cross resistive film.
[0058] S2: The horizontal and vertical lengths of the cross-shaped resistive film are both 12mm, and the width is 2mm.
[0059] S3: Set the diameter of the circular resistive film to 5.7mm;
[0060] S4: The distance between the edge point of the circular resistive film and the edge point of the cross-shaped resistive film is ≥0.4mm.
[0061] Specifically, in one embodiment, the design method defines a unit structure consisting of a cross-shaped and four circular resistive films, a PI film, a flexible dielectric substrate, and a bottom copper film, arranged vertically from top to bottom for impedance matching. It also determines various physical parameters related to the absorption effect, including the period length of the unit structure, the thickness of each layer, the sheet resistance of the resistive films, and the size of the resistive film pattern. Based on the designed metasurface unit structure, an absorption rate exceeding 90% can be achieved in a wide frequency range of 10-19 GHz, exhibiting high absorption performance under different polarization and incident angles. The flexible absorber achieved by this method can be directly processed using screen printing, printing high-resistivity carbon paste onto the surface of the flexible substrate. This processing method is simple, inexpensive, and widely applicable.
[0062] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0063] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily 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 invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A flexible broadband metamaterial absorber, characterized in that, include: The resistive film, PI film, flexible dielectric, and copper film are arranged vertically from top to bottom; The resistive film is composed of a cross-shaped cross resistive film and a circular resistive film; Among them, four circular resistor films are symmetrically arranged in the four quadrants of the cross-shaped cross resistor film; The resistive film also includes right-angle resistive films, which are symmetrically distributed at the four corners of the resistive film. The horizontal and vertical lengths of the right-angle resistive films are both 5 mm, and the width is 2 mm.
2. The flexible broadband metamaterial absorber according to claim 1, characterized in that, The horizontal and vertical lengths of the cross-shaped resistive film are both 12 mm, and the width is 2 mm.
3. The flexible broadband metamaterial absorber according to claim 1, characterized in that, The diameter of the circular resistive film is 5.7 mm.
4. The flexible broadband metamaterial absorber according to claim 1, characterized in that, The distance between the edge point of the circular resistive film and the edge point of the cross-shaped resistive film is ≥0.4mm.
5. A flexible broadband metamaterial absorber according to claim 1, characterized in that, The overall thickness is 2mm.
6. The flexible broadband metamaterial absorber according to claim 1, characterized in that, The cycle length is 20mm.
7. A flexible broadband metamaterial absorber according to claim 1, characterized in that, The sheet resistance of the resistive film is 80 ohms.
8. A design method for a flexible broadband metamaterial absorber as described in any one of claims 1-7, characterized in that, The design method includes: The overall structure constituting the flexible broadband metamaterial absorber is determined, including: a resistive film, a PI film, a flexible dielectric, and a copper film arranged vertically from top to bottom; The overall thickness is set to 2.11mm, and the cycle length is set to 20mm. The thicknesses of the resistive film, PI film, flexible dielectric substrate, and copper film are set, wherein the thickness of the resistive film is 10 micrometers, the thickness of the PI film is 0.075 mm, the thickness of the flexible dielectric substrate is 2 mm, and the thickness of the copper film is 0.035 mm. The structure of the resistive film is configured; The sheet resistance of the resistive film is set to 80 ohms.
9. The design method of a flexible broadband metamaterial absorber according to claim 8, characterized in that, The structure for setting the resistive film includes: S1: The resistive film is configured as a cross-shaped cross resistive film and a circular resistive film, wherein four circular resistive films are symmetrically arranged in the four quadrants of the cross-shaped cross resistive film. S2: The horizontal and vertical lengths of the cross-shaped resistive film are both 12mm, and the width is 2mm. S3: Set the diameter of the circular resistive film to 5.7 mm; S4: The distance between the edge point of the circular resistive film and the edge point of the cross-shaped resistive film is ≥0.4mm.