Absorption and scattering integrated metasurface based on magnetic material and ABS

Abstract

The invention discloses an absorption and scattering integrated metasurface based on a magnetic material and ABS, the metasurface structure sequentially comprises an ABS cover plate and a magnetic patch from top to bottom, the magnetic patch is a combination of a flat plate structure and a step structure, the ABS cover plate is a combination of a flat plate solid structure and a hollow structure, and the cover plate is prepared by using an FDM 3D printing process. By changing the change of the structural parameters of the magnetic patches or the ABS cover plates in the metasurface units, the coding units can be effectively formed, and then the genetic algorithm is utilized to select the optimal arrangement array. The metasurface is designed by integrating two principles of energy absorption and scattering control, and compared with a traditional single-mechanism wave absorber or diffuse reflection metasurface, the metasurface has the advantages of low cost, low profile, low broadband scattering, polarization insensitivity and the like.

Description

Technical Field

[0001] This invention belongs to the field of metasurface technology, specifically a metasurface based on magnetic materials and ABS that integrates absorption and scattering. Background Technology

[0002] With the rapid development of modern technology, the application scope of electromagnetic waves is constantly expanding, from communication technology and radar systems to consumer electronic devices; electromagnetic waves are ubiquitous. However, the widespread use of electromagnetic waves has also brought many challenges, such as increased electromagnetic pollution and the risk of exposure to personal privacy. Reducing the radar cross section (RCS) has become one of the key technologies for solving these problems.

[0003] Traditional methods for reducing RCS mainly rely on absorbing materials or structural design to reduce reflection by absorbing electromagnetic waves, thereby lowering the RCS. However, this method has certain limitations in practical applications. For example, the performance of absorbing materials is limited by the frequency band, making it difficult to achieve a low RCS effect over a wide frequency band. Reference 1 (Zhao YT, Chen B, Wu B. Miniaturized Periodicity Broadband Absorber With Via-Based Hybrid Metal-Graphene Structure for Large-Angle RCS Reduction[J].IEEE Transactions on Antennas and Propagation, 2022, 70(4): 2832-2840.) proposes an absorber using graphene as the loss material, but its operating frequency band is narrow, and it can only achieve an absorption rate greater than 90% in the range of 2.73~7.54 GHz.

[0004] In recent years, the rise of artificial electromagnetic materials technology has provided new solutions for reducing RCS. Phase has also become a new degree of design freedom for achieving RCS reduction. Reference 2 (Sang D, Chen Q, Ding L, et al. Design of Checkerboard AMC Structure for Wideband RCS Reduction[J].IEEE Transactions on Antennas and Propagation, 2019, 67(4): 2604-2612.) proposes a checkerboard distributed artificial magnetic conductor structure, which achieves an RCS reduction of more than 10 dB in the range of 3.77~10.14 GHz.

[0005] Furthermore, many studies combine absorption and scattering mechanisms, and the designed metasurfaces can effectively reduce RCS over a wider frequency band. Reference 3 (Wu Z, Zhang Z, Chen X, et al. Microwave scattering-absorption properties of a lightweight all-dielectric coding metamaterial based on TiO2 / CNTs[J]. Optics Letters, 2020, 45(2): 555-558.) proposes a coding metasurface based on dielectric loss material, achieving a RCS of 0.106λ. L (λ) L The thickness (at the wavelength of the lowest operating frequency) achieved an RCS reduction of better than 10 dB in the range of 5.3 to 18 GHz.

[0006] However, in the work on achieving RCS reduction through a combination of absorption and scattering mechanisms, there are few works using magnetic materials, and even fewer that combine magnetic materials with lossless materials to create metasurfaces that integrate absorption and scattering. Summary of the Invention

[0007] The purpose of this invention is to propose an absorption and scattering metasurface based on magnetic materials and ABS, which can achieve RCS reduction over a wide bandwidth by designing an encoding array through the size parameters of the tuned unit structure.

[0008] The technical solution to achieve the purpose of this invention is as follows: a metasurface integrating absorption and scattering based on magnetic materials and ABS, comprising a magnetic patch and an ABS cover plate. The magnetic patch is placed at the bottom of the ABS cover plate, which is a combination of a flat solid cover plate and a hollow cover plate. The magnetic patch is a two-dimensional planar combination of a flat patch and a stepped patch with gradually changing size along the electromagnetic wave propagation direction. The units of the metasurface form coding units by tuning the structural parameters of the magnetic patch and the ABS cover plate. The coding units are arranged by optimizing the arrangement through a genetic algorithm to achieve a broadband 10dB radar cross section reduction.

[0009] Furthermore, there are five types of encoding units.

[0010] Furthermore, the thickness of the flat magnetic patch, the thickness of the ABS cover air layer, and the thickness of the ABS solid layer of E1 in the five coding units are 2 mm, 0 mm, and 5 mm, respectively.

[0011] Furthermore, the thickness of the flat magnetic patch, the thickness of the ABS cover air layer, and the thickness of the ABS solid layer of E2 in the five coding units are 2 mm, 1 mm, and 1 mm, respectively.

[0012] Furthermore, the thickness of the flat magnetic patch, the thickness of the ABS cover air layer, and the thickness of the ABS solid layer of E3 among the five coding units are 1 mm, 3 mm, and 3 mm, respectively.

[0013] Furthermore, the thickness of the stepped magnetic patch, the thickness of the ABS cover air layer, and the thickness of the ABS solid layer of E4 among the five coding units are 3 mm, 2 mm, and 3 mm, respectively.

[0014] Furthermore, the thickness of the stepped magnetic patch, the thickness of the ABS cover air layer, and the thickness of the ABS solid layer of E5 among the five coding units are 2 mm, 1 mm, and 3 mm, respectively.

[0015] Furthermore, 4*4 coding units form a superunit.

[0016] Furthermore, the dielectric constant of the ABS cover is 2.96, and the loss tangent is 0.01.

[0017] Furthermore, the ABS cover plate is a two-dimensional planar combination of a solid flat cover plate with an air layer thickness of 0 mm and a hollow cover plate with an air layer thickness of no more than 3 mm.

[0018] Compared with the prior art, the significant advantages of this invention are: (1) This invention utilizes both absorption and scattering scattering mechanisms to reduce the design complexity of the structure; (2) Compared with other reported scattering reduction devices, this invention has the advantages of a wider operating bandwidth, lower profile and lower fabrication cost; (3) While satisfying the low profile design of the metasurface, this invention also takes into account the broadband design of RCS reduction, and proposes a metasurface that integrates absorption and scattering, which can achieve 10 dB RCS reduction in the range of 2~18 GHz with only 7 mm.

[0019] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a three-dimensional exploded view of the integrated absorption and dissipation metasurface of the present invention.

[0021] Figure 2 This is a diagram showing the dielectric constant and permeability of the magnetic patch of the integrated absorber metasurface of the present invention.

[0022] Figure 3 The diagram shows the different coding unit structures of the integrated absorption and dissipation metasurface of the present invention, (a) unit 1-3, (b) unit 4-5.

[0023] Figure 4 The amplitude and phase responses of the encoding units of the absorbing and dissipating metasurface of the present invention are shown in (a) amplitude and (b) phase.

[0024] Figure 5 This is a schematic diagram of the encoding array optimization process of the integrated absorption and dissipation metasurface of the present invention.

[0025] Figure 6 This is the final optimized result of the coding array of the integrated absorber-dissipator metasurface of the present invention.

[0026] Figure 7 This is a comparison chart of theoretical calculations and full-wave simulations of the integrated absorption and dissipation metasurface of this invention. Detailed Implementation

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and modifications without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0028] Combination Figure 1 A metasurface integrating absorption and scattering based on magnetic materials and ABS (acrylonitrile-butadiene-styrene) is disclosed. The metasurface structure consists of a stacked ABS cover plate 1 and a magnetic patch 2 from top to bottom. The magnetic patch is a combination of flat and stepped structures, and the ABS cover plate is a combination of solid and hollow flat structures. The cover plate is fabricated using FDM (Fused Deposition Modeling) 3D printing technology. By changing the thickness, side length, and other structural parameters of the magnetic patch or ABS cover plate in the metasurface unit, the required amplitude and phase response can be obtained to form encoding units. Then, a genetic algorithm is used to select the optimal array arrangement.

[0029] In a further embodiment, there are five types of coding units, including units E1 to E3 which are combinations of flat magnetic patches and ABS cover plates, and units E4 to E5 which are combinations of stepped magnetic patches and ABS cover plate lines. Then, a genetic algorithm is used to arrange the optimal metasurface array to achieve a broadband RCS reduction of 10 dB.

[0030] Preferably, the dielectric constant of the ABS cover plate of units E1 to E5 is 2.96 and the loss tangent is 0.01.

[0031] Preferably, the units E1 to E3 include a flat magnetic patch and an ABS cover plate, with the magnetic patch placed under the ABS cover plate.

[0032] Preferably, units E4 to E5 include stepped magnetic patches and ABS cover plates, with the magnetic patches placed under the ABS cover plates.

[0033] Preferably, the thicknesses of the flat magnetic patches of units E1 to E3 are 2 mm, 2 mm and 1 mm, respectively, and the thicknesses of the ABS cover plates are 5 mm, 2 mm and 6 mm, respectively.

[0034] Preferably, the thicknesses of the stepped magnetic patches of unit E4 and unit E5 are 3 mm and 2 mm, respectively, and the thicknesses of the ABS cover plates are 5 mm and 4 mm, respectively.

[0035] Preferably, the unit achieves an amplitude of less than -2.5 dB and a significant phase difference in the coding unit range of 2~18 GHz by tuning the thickness of the flat magnetic patch, the size and thickness of the stepped magnetic material, the thickness of the air layer of the ABS cover plate, and the thickness of the top layer of the ABS cover plate.

[0036] Preferably, the thickness of the magnetic patch in the encoding unit does not exceed 3 mm, and the thickness of the overall unit does not exceed 7 mm.

[0037] The magnetic patch is a mixture of carbonyl iron powder and resin, and the ABS cover has a dielectric constant of 2.96 and a loss tangent of 0.01.

[0038] Preferably, the coding unit performs rapid optimization of the optimal array arrangement using a genetic algorithm, achieving a scattering reduction of more than 10 dB in the 2~18 GHz range.

[0039] Example

[0040] This embodiment presents an absorption and scattering integrated metasurface based on magnetic materials and ABS. The metasurface structure includes an ABS cover plate and magnetic patches stacked sequentially from top to bottom. The magnetic patches are a combination of flat and stepped structures, and the ABS cover plate is a combination of solid and hollow flat structures. The cover plate is fabricated using FDM (Fused Deposition Modeling) 3D printing technology. By changing the structural parameters of the magnetic patches or ABS cover plate in the metasurface unit, coding units can be effectively formed, and then a genetic algorithm can be used to select the optimal arrangement array.

[0041] like Figure 2 As shown, in this embodiment, the imaginary part of the dielectric constant of the magnetic patch used is... With the imaginary part of permeability Compared to the real part of the dielectric constant With the real part of permeability It has a relatively large capacity and good electromagnetic loss characteristics.

[0042] like Figure 3 As shown in Figure (a), units E1 to E3 in this embodiment are composed of flat magnetic patches and ABS cover plates. Their structural parameters include the thickness t of the magnetic patch.m ABS cover plate air layer thickness t a and the thickness t of the solid ABS layer h The specific structural parameters are shown in Table 1.

[0043] Table 1 Structural parameters of units E1 to E3 (unit: mm)

[0044] <![CDATA[t m ]]> <![CDATA[t a ]]> <![CDATA[t h ]]> E 1 2 0 5 E 2 2 1 1 E 3 1 3 3

[0045] like Figure 3 As shown in Figure (b), units E4 and E5 in this embodiment are composed of stepped magnetic patches and ABS cover plates. Their structural parameters include the thickness t of the bottom magnetic patch. m1 The thickness of the top magnetic patch (t) m2 The side length of the top magnetic patch is P1, and the thickness of the air layer in the ABS cover plate is t. a and the thickness t of the solid ABS layer h The specific structural parameters are shown in Table 2.

[0046] Table 2 Structural parameters of units E4 to E5 (unit: mm)

[0047] <![CDATA[t m1 ]]> <![CDATA[t m2 ]]> <![CDATA[P1]]> <![CDATA[t a ]]> <![CDATA[t h ]]> E 4 1 2 18 2 3 E 5 1 1 10 1 3

[0048] like Figure 4 As shown, in this embodiment, the reflection coefficients of units E1 to E5 are all less than -2.5dB in the range of 2~18 GHz, and the reflection phase differences of the units are obvious.

[0049] like Figure 5 As shown in this embodiment, the process of optimizing the array arrangement using a genetic algorithm includes steps such as population initialization, fitness calculation, selection, crossover, and mutation. The specific process of fitness calculation involves discretizing the 2-18 GHz frequency band. The encoding matrix of each discrete frequency point corresponds to the corresponding amplitude and phase matrices. The RCS reduction value is calculated using an array synthesis algorithm. If the RCS reduction value of a frequency point is greater than 10 dB, the fitness function value is incremented by 1.

[0050] like Figure 6 As shown in this embodiment, in the optimal coding arrangement, 4*4 units form superunits, and the number of superunits composed of units E1 to E5 are 1, 1, 5, 8 and 1, respectively.

[0051] like Figure 7 As shown, in this embodiment, the designed metasurface is simulated using the CST microwave software in a full-wave simulation. The results are consistent with the calculation results based on array synthesis theory, achieving a 10 dB RCS reduction in the 2~18 GHz range.

[0052] In summary, this invention proposes an integrated absorption and scattering metasurface based on magnetic materials and ABS. The metasurface structure, from top to bottom, consists of an ABS (acrylonitrile-butadiene-styrene) cover plate and magnetic patches. The magnetic patches are a combination of flat and stepped structures, while the ABS cover plate is a combination of solid and hollow flat structures. The cover plate is fabricated using FDM (Fused Deposition Modeling) 3D printing. By changing the structural parameters of the magnetic patches or ABS cover plate within the metasurface unit, coding units can be effectively formed, and a genetic algorithm can be used to select the optimal array arrangement. This invention integrates the principles of energy absorption and scattering control in metasurface design, offering advantages such as low cost, low profile, and broadband low scattering compared to traditional single-mechanism absorbers or diffuse reflection metasurfaces.

Claims

1. An absorption-scattering integrated metasurface based on magnetic material and ABS, characterized in that, It comprises a magnetic patch (2) and an ABS cover plate (1), the magnetic patch (2) is placed at the bottom of the ABS cover plate (1), the ABS cover plate (1) is a combination of a solid cover plate and a hollow cover plate, the magnetic patch (2) is a two-dimensional plane combination of a flat patch and a stepped patch with gradually changing size along the electromagnetic wave propagation direction, the unit of the super surface is formed by tuning the structural parameters of the magnetic patch (2) and the ABS cover plate (1) to form a coding unit, and the coding unit is arranged by genetic algorithm optimization to realize the reduction of the 10dB radar scattering cross section of the wideband.

2. The absorption-scattering integrated metasurface based on magnetic material and ABS of claim 1, wherein, The coding unit is of five types.

3. The absorption-scattering integrated metasurface based on magnetic material and ABS of claim 2, wherein, The thickness of the flat magnetic patch, the thickness of the air layer of the ABS cover plate and the thickness of the ABS solid layer of E1 in the five coding units are 2mm, 0mm and 5mm respectively.

4. The absorption-scattering integrated metasurface based on magnetic material and ABS of claim 2, wherein, The thickness of the flat magnetic patch, the thickness of the air layer of the ABS cover plate and the thickness of the ABS solid layer of E2 in the five coding units are 2mm, 1mm and 1mm respectively.

5. The absorption-scattering integrated metasurface based on magnetic material and ABS of claim 2, wherein, The thickness of the flat magnetic patch, the thickness of the air layer of the ABS cover plate and the thickness of the ABS solid layer of E3 in the five coding units are 1mm, 3mm and 3mm respectively.

6. The magnetic material and ABS based absorption-scattering integrated metasurface according to claim 2, wherein, The thickness of the stepped magnetic patch, the thickness of the air layer of the ABS cover plate and the thickness of the ABS solid layer of E4 in the five coding units are 3mm, 2mm and 3mm respectively.

7. The absorption-scattering integrated metasurface based on magnetic material and ABS of claim 2, wherein, The thickness of the stepped magnetic patch, the thickness of the air layer of the ABS cover plate and the thickness of the ABS solid layer of E5 in the five coding units are 2mm, 1mm and 3mm respectively.

8. The magnetic material and ABS based absorption-scattering integrated metasurface according to claim 1, wherein, The 4*4 number of coding units form a super unit.

9. The magnetic material and ABS based absorption-scattering integrated metasurface according to claim 1, wherein, The dielectric constant of the ABS cover plate (1) is 2.96, and the loss tangent is 0.

01.

10. The magnetic material and ABS based absorption-scattering integrated metasurface according to claim 1, wherein, The ABS cover plate (1) is a two-dimensional plane combination of a flat solid cover plate with an air layer thickness of 0mm and a hollow cover plate with an air layer thickness of not more than 3mm.

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