Metamaterial microwave co-polarization broadband wave absorber
By optimizing the geometric parameters of the resonant unit and the thickness of the dielectric layer, a metamaterial microwave co-polarized broadband absorber was designed, solving the problems of narrow bandwidth and large thickness of microwave absorbers. This design achieves wide bandwidth, high absorption rate and wide incident angle characteristics, making it suitable for microwave radar stealth and electromagnetic compatibility applications.
Patent Information
- Application Number
- CN202511163169.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-19
- Publication Date
- 2025-12-09
AI Technical Summary
Existing microwave absorbers have narrow bandwidth, large thickness, and poor environmental adaptability, making it difficult to meet the requirements of 5G communication and microwave radar stealth. Furthermore, existing metamaterial designs suffer from complex structures and difficult manufacturing processes.
By optimizing the geometric parameters of the resonant unit and the thickness of the dielectric layer, a metamaterial microwave co-polarization broadband absorber is designed. It adopts an all-copper reflective layer, an FR-4 epoxy resin substrate and a periodic metal structure to achieve wide bandwidth, high absorption rate and wide incident angle characteristics. The structure is simple and only requires a single-layer dielectric substrate.
Achieves broadband characteristics with an absorption rate of ≥90% in the 4.64-9.47GHz frequency band, maintains high absorption rate within the incident angle range, has a thickness of less than 5mm, and features simple manufacturing process and low cost.
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Figure CN121097408A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of microwave wave-absorbing materials, and particularly relates to a metamaterial microwave co-polarization wideband wave-absorbing body with wide frequency band, high absorption and wide incidence angle, which is suitable for the fields of microwave radar stealth, electromagnetic compatibility and wireless communication. BACKGROUND
[0002] The development of microwave wave-absorbing bodies is faced with challenges such as narrow bandwidth, large thickness and poor environmental adaptability, and it is difficult to meet the urgent needs of the fields of 5G communication, microwave radar stealth and the like for wideband high-efficiency materials. The technology of metamaterials breaks through the limitations of natural materials through artificial structure design, but the existing design has significant bottlenecks: some wave-absorbing bodies have a narrow absorption bandwidth, and the wideband design leads to a complex structure and difficult process due to multi-layer stacking or composite resonant units. Although FR-4 epoxy resin substrate combined with copper has the potential for synergistic dielectric and ohmic loss, the existing design fails to fully exploit the impedance matching characteristics and multi-mode coupling mechanism thereof. Conventional metamaterial structures are sensitive to the direction of the incidence angle, and symmetric design often sacrifices bandwidth, which restricts the development of wave-absorbing bodies with both wideband absorption and insensitivity to the incidence angle. An ideal wideband wave-absorbing body needs to build a gradient impedance matching layer to achieve low reflection in a wide frequency band, and expand the dissipation frequency band through multi-scale resonant structures, which puts high requirements on the optimization of geometric parameters.
[0003] It has important scientific value to develop a metamaterial wave-absorbing body with simple structure, process compatibility, wideband absorption and stable polarization characteristics, which can provide a key electromagnetic protection solution for new generation electronic systems. SUMMARY
[0004] The present disclosure provides a metamaterial microwave co-polarization wideband wave-absorbing body, which overcomes the defects of narrow bandwidth and low absorption rate of traditional metamaterial wave-absorbing bodies by optimizing the geometric parameters of resonant units and the thickness of dielectric layers, and realizes a wideband characteristic with an absorption rate ≥90% in a frequency band of 4.64-9.47 GHz; and has wide incidence angle adaptability.
[0005] The metamaterial microwave co-polarization wideband wave-absorbing body provided by the present disclosure comprises: a full-copper reflection layer (1) covering the bottom layer of a substrate, a dielectric substrate (2) and a periodic metal structure (3) arranged on the top layer of the substrate, which constitute a two-dimensional array structure, wherein the length and width of the full-copper reflection layer (1) and the dielectric substrate (2) are both greater than that of the periodic metal structure (3); the thickness of the full-copper reflection layer (1) is greater than the skin depth of copper in the microwave frequency band;
[0006] Microwaves are normally incident from above the periodic metal structure (3) on the top layer, pass through the metal structure (3) and the dielectric substrate (2) to the full-copper reflection layer (1) to realize total reflection, and the reflected waves return to the top layer directly above through the dielectric substrate (2) and the metal structure (3).
[0007] Further, the periodic metal structure (3) comprises several square units, wherein each unit comprises:
[0008] two symmetrical "L" type metal arms (31) and a hexagonal copper ring (32), the hexagonal copper ring is not communicated with the two symmetrical "L" metal arms, wherein:
[0009] the hexagonal copper ring (32) is arranged at the center of the unit;
[0010] the two symmetrical "L" type metal arms (31) are arranged at the right upper and left lower positions of the unit respectively, and are symmetrical to the center of the unit, and each arm is away from the edge of the unit by a fixed distance on the periphery of the hexagonal copper ring (32).
[0011] Further, the unit period of the array is 15mm;
[0012] the hexagonal copper ring (32) is arranged at the center of each unit, the side length is 3.0mm, and the line width is 1.0mm;
[0013] the two symmetrical "L" type metal arms (31) are arranged at the right upper and left lower positions of each unit respectively, and are away from the edge by 1.5mm, the length of each arm is 8mm, and the width is 1mm.
[0014] Further, the material of the metal structure (3) is copper, and the thickness of the copper reflection layer (1) is 0.035mm, and the conductivity is 5.96*10S / m.
[0015] Further, the material of the medium substrate (2) is FR-4 epoxy resin glass fiber reinforced laminated board, the thickness is 4.2mm, the dielectric constant is 4.3, the tangent loss angle is 0.025, and the length and width are both 15mm.
[0016] Further, the total thickness of the wave absorber is <5mm.
[0017] The present disclosure realizes efficient absorption of incident electromagnetic waves in a wide frequency range by optimizing the resonance unit geometric parameters and the medium layer thickness, and still realizes high absorption in a wide incident angle range. Compared with the prior art, the beneficial effects of the present disclosure are: ① the coupling design of the hexagonal copper ring and the "L" type metal arm realizes wideband high absorption characteristics, and the absorption bandwidth reaches 4.83GHz; ② the co-polarization design maintains stable absorption performance for TE / TM polarized waves; ③ the structure is simple, only a single medium substrate is needed, the total thickness is less than 5mm, and the lightweight advantage is achieved; ④ high absorption rate is still maintained in a wide incident angle range, and the angle stability is good; ⑤ mature FR-4 substrate and copper material are adopted, the preparation process is simple, and the cost is low. BRIEF DESCRIPTION OF DRAWINGS
[0018] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the figures, exemplary embodiments of the present disclosure are shown.
[0019] Figure 1 A top view of a microwave co-polarization metamaterial broadband absorber according to an embodiment of the present disclosure;
[0020] Figure 2 A top view of a microwave co-polarization metamaterial broadband absorber according to an embodiment of the present disclosure; Figure 1 A cross-sectional view along A-A in FIG. 1;
[0021] Figure 3 A top view of a microwave co-polarization metamaterial broadband absorber according to an embodiment of the present disclosure; Figure 1 A schematic diagram of an array unit structure in FIG. 1;
[0022] Figure 4 A graph of absorption rate under TE and TM polarization when electromagnetic wave is normally incident in a microwave co-polarization metamaterial broadband absorber in an exemplary embodiment;
[0023] Figure 5 A graph of frequency response of real and imaginary parts of effective input impedance when electromagnetic wave is normally incident in a microwave co-polarization metamaterial broadband absorber in an exemplary embodiment;
[0024] Figure 6 A graph of absorption rate under TE polarization at different incident angles in a microwave co-polarization metamaterial broadband absorber in an exemplary embodiment;
[0025] Figure 7 A graph of absorption rate under TM polarization at different incident angles in a microwave co-polarization metamaterial broadband absorber in an exemplary embodiment.
[0026] Reference numerals in the drawings: 1, metal copper reflection layer, 2, FR-4 dielectric substrate, 3, two-dimensional array, 31, symmetric "L" type metal arm, 32, hexagonal copper ring. DETAILED DESCRIPTION
[0027] Preferred embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. While preferred embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.
[0028] The present disclosure provides a microwave co-polarization metamaterial broadband absorber, comprising: a dielectric substrate layer, a periodic metal structure on the top layer of the substrate, and a full copper reflection layer on the bottom layer of the substrate. The full copper reflection layer (1) and the dielectric substrate (2) are both longer and wider than the periodic metal structure (3).
[0029] Microwave is normally incident from above the periodic metal structure (3) of the top layer, passes through the metal structure (3), and passes through the dielectric substrate (2) to the full copper reflection layer (1). Since the thickness of the full copper reflection layer (1) is greater than the skin depth of copper at the microwave frequency band, full reflection is achieved, the transmittance is 0, and the absorption is 1 minus the reflectance. The reflected wave returns to the top layer directly above the point, and the intensity of the reflected wave is measured at this point. The reflectance is calculated, and finally the absorption is obtained.
[0030] Preferably, each unit of the periodic metal structure comprises two symmetrical "L" type metal arms (31) and a hexagonal copper ring (32).
[0031] Preferably, the period of each array unit is 15 mm; two symmetrical "L" type metal arms (31) are respectively arranged at positions 1.5 mm away from the edges in the right upper and left lower positions of the array, each arm has a length of 8 mm and a width of 1 mm; the hexagonal copper ring (32) is arranged at the center position of the array unit, has a side length of 3.0 mm and a line width of 1.0 mm.
[0032] The dielectric layer is preferably an FR-4 epoxy resin glass fiber reinforced laminated board, has a dielectric constant of 4.3, a tangent loss angle of 0.025, a thickness of 4.2 mm, and a length and width of 15 mm.
[0033] The bottom layer is a full copper reflection layer, and the thickness is preferably 0.035 mm.
[0034] The material of the metal structure is copper, and the thickness is also preferably 0.035 mm, and the electrical conductivity is 5.96×10 S / m.
[0035] The total thickness of the wave absorber is less than 5 mm.
[0036] The absorption of the microwave co-polarization metamaterial wideband wave absorber is A(ω)=1-R(ω); wherein A(ω) is the absorption, and R(ω) is the reflectance.
[0037] The wave absorber has the same absorption characteristics under TE and TM polarization, and can achieve a wideband characteristic with an absorption rate ≥90% in the frequency band of 4.64-9.47 GHz; in the TE polarization mode, the absorption rate ≥60% in the range of 0-40° incident angle, and in the TM polarization mode, the absorption rate ≥80% in the range of 0-30° incident angle. The real part of the effective input impedance is close to 1 and the absolute value of the imaginary part is close to 0 when vertically incident in the working frequency band.
[0038] In an exemplary embodiment, a microwave co-polarization metamaterial wideband wave absorber according to the present disclosure is shown in a top view Figure 1 and a cross-sectional view Figure 2As shown, the all-copper metal plate 1, the dielectric substrate 2, and the periodic metal structure 3 constitute a two-dimensional array structure.
[0039] The dielectric substrate 2 is disposed between the metal plate 1 and the metal structure 3. For example... Figure 1 and Figure 2 The metamaterial microwave absorber has a cubic structure. The contact surfaces of the metal plate 1 and the dielectric substrate 2 are both squares of the same size, with a side length of 15 mm.
[0040] The bottom metal plate 1 and the top metal structure 3 are made of copper, with an electrical conductivity of 5.96×10 S / m and a thickness of 0.035 mm.
[0041] In a preferred embodiment, the dielectric substrate 2 is made of FR-4 material, with a dielectric constant of 4.3, a tangent loss angle of 0.025, and a thickness of 4.2 mm. Since FR-4 material has low cost and low loss in high-frequency substrates, processing costs are reduced.
[0042] Figure 3 for Figure 1 A schematic diagram of the top metal structure 3 of one unit in the two-dimensional array shown. Figure 3 As shown, in this embodiment, the metal structure 3 is provided with a hexagonal copper ring and two symmetrical "L"-shaped metal arms. The hexagonal copper ring is located at the center of the unit, with a side length of 3.0 mm, a line width of 1.0 mm, and a thickness of 0.035 mm. The two symmetrical "L"-shaped metal arms are located at the upper right and lower left of the unit, respectively, 1.5 mm from the edge of the unit. They are symmetrical about the center of the unit, and each arm has the same length and width: 8 mm, 1 mm, and 0.035 mm.
[0043] Figure 4 The absorption curves of the microwave copolarized metamaterial broadband absorber provided in this embodiment in TE mode and TM mode are shown in the figure. In the wide frequency range of 4.64 GHz to 9.47 GHz, the absorber maintains an absorptivity of above 0.9 in both TE and TM modes, and the absorption bandwidth reaches 4.83 GHz.
[0044] The microwave common polarization metamaterial broadband absorber provided in this embodiment has the characteristics of simple structure and easy fabrication. It adopts a simple "sandwich" structure, which effectively enhances the impedance matching between the metamaterial microwave absorber and free space, thereby further increasing the absorption rate of the microwave absorber and expanding the bandwidth.
[0045] The absorption rate expression of the metamaterial microwave wave absorber is A(ω) = 1-R(ω)-T(ω). Wherein, A(ω) is the absorption rate, R(ω) is the reflectivity, T(ω) is the transmissivity. R(ω) = S11 2 , T(ω) = S21 2 . S11 is the reflection coefficient, the value depends on the matching degree of the impedance value of the metamaterial microwave wave absorber and the impedance of free space, the higher the matching degree, the smaller the value of S11, the incident electromagnetic wave can enter the absorber. S21 is the transmission coefficient, because the bottom layer of the metamaterial microwave wave absorber of the embodiment is a metal plate 5, so for the metamaterial microwave wave absorber of the embodiment, the value of S21 is zero, so the absorption rate expression of the metamaterial microwave wave absorber of the embodiment is A(ω) = 1-R(ω).
[0046] Figure 5 The frequency response of the effective input impedance (Z) of the microwave co-polarization metamaterial broadband wave absorber provided in the embodiment when the electromagnetic wave is vertically incident. When the real part (Real.(Z)) of the effective input impedance is closer to the wave impedance of free space (the normalized value is 1), and the imaginary part (Imag.(Z)) is closer to zero, it indicates that the metamaterial structure and the free space have achieved good impedance matching.
[0047] Figure 6 The absorption rate curve of the microwave co-polarization metamaterial broadband wave absorber provided in the embodiment under different incident angles θ of the electromagnetic wave in the TE mode. It can be seen from Figure 6 that for the incident electromagnetic wave in the TE mode, when the incident angle increases from 0° to 40°, the absorber can still maintain an absorption efficiency of more than 60%.
[0048] Figure 7 The absorption rate curve of the microwave co-polarization metamaterial broadband wave absorber provided in the embodiment under different incident angles θ of the electromagnetic wave in the TM mode. It can be seen from Figure 7 that for the incident electromagnetic wave in the TE mode, when the incident angle increases from 0° to 30°, the absorption rate of the absorber can be maintained at more than 80%.
[0049] It can be seen that the metamaterial microwave wave absorber provided in the embodiment has a high absorption rate for electromagnetic waves with a wide incident angle, and also has the advantages of high absorption and wide band.
[0050] The microwave co-polarization metamaterial broadband wave absorber provided in the disclosure widens the electromagnetic wave absorption bandwidth by resonating the metal structure 3, the dielectric substrate 2 plays a role in consuming the incident electromagnetic wave, and the metal plate 1 plays a role in fully reflecting the incident wave to achieve zero transmission, thereby realizing wideband absorption. The microwave co-polarization metamaterial broadband wave absorber provided in the disclosure has the advantages of high efficiency, wide band and wide incident angle for absorbing incident waves.
[0051] The above technical solutions are only exemplary embodiments of the present application. Those skilled in the art can easily make various types of improvements or modifications on the basis of the disclosed application methods and principles, and the above-described methods are only preferred and not limited.
Claims
1. A metamaterial microwave co-polarized broadband absorber, characterized in that, include: A two-dimensional array structure is formed by a full copper reflective layer (1) covering the bottom layer of the substrate, a dielectric substrate (2) and a periodic metal structure (3) disposed on the top layer of the substrate. The length and width of the full copper reflective layer (1) and the dielectric substrate (2) are both greater than those of the periodic metal structure (3); the thickness of the full copper reflective layer (1) is greater than the skin depth of copper in the microwave frequency band. Microwaves are incident directly above the periodic metal structure (3) on the top layer, pass through the metal structure (3), and pass through the dielectric substrate (2) to the all-copper reflective layer (1) to achieve total reflection. The reflected wave passes through the dielectric substrate (2) and the metal structure (3) and returns to the top layer directly above.
2. The absorber according to claim 1, characterized in that, The periodic metal structure (3) comprises a plurality of square units, wherein each unit comprises: Two symmetrical "L"-shaped metal arms (31) and a hexagonal copper ring (32) are located in the same plane. The hexagonal copper ring is not connected to the two symmetrical "L"-shaped metal arms. A hexagonal copper ring (32) is positioned at the very center of the unit; The two symmetrical "L"-shaped metal arms (31) are respectively located at the upper right and lower left of the unit, symmetrical with respect to the center of the unit, and on the periphery of the hexagonal copper ring (32), with each arm at a fixed distance from the edge of the unit.
3. The absorber according to claim 2, characterized in that: The array has a cell period of 15mm; The hexagonal copper ring (32) is located at the center of each unit, with a side length of 3.0 mm and a line width of 1.0 mm; The two symmetrical "L"-shaped metal arms (31) are respectively positioned at the upper right and lower left of each unit, 1.5 mm away from the edge in length and width. Each arm is 8 mm long and 1 mm wide.
4. The absorber according to any one of claims 1-3, characterized in that: The metal structure (3) is made of copper, and both the copper reflective layer (1) and the copper reflective layer (3) have a thickness of 0.035 mm and an electrical conductivity of 5.96 × 10 S / m.
5. The absorber according to claim 4, characterized in that: The dielectric substrate (2) is made of FR-4 epoxy resin-based glass fiber reinforced laminate with a thickness of 4.2 mm, a dielectric constant of 4.3, a tangent loss angle of 0.025, and a length and width of 15 mm.
6. The absorber according to claim 1, characterized in that, The total thickness of the absorber is <5mm.