阅读说明：本技术 一种可见光透过的极化不敏感的低rcs超宽带超材料吸波体 (Polarization insensitive low RCS ultra-wideband metamaterial wave absorber with visible light transmission ) 是由 杨磊 闵萍萍 朱嘉琦 宋梓诚 张智博 张昕宇 于 2020-04-29 设计创作，主要内容包括：一种可见光透过的极化不敏感的低RCS超宽带超材料吸波体,它属于电磁波和新型人工电磁材料领域。本发明要解决现有超材料吸波体无法同时兼顾高透过率、超宽频带吸收、低剖面和低雷达散射截面积的问题。它自上而下依次由图案化阻抗膜层、第一透明基体、中间透明介质层、第二透明基体及透明导电薄膜组成；所述的图案化阻抗膜层由阵列的N×M个透明图案化阻抗膜单元组成；所述的透明图案化阻抗膜单元的形状为1个位于中央的大圆和周围均匀分布的4个小圆交叠而成。本发明可以在保持高透过率的同时,在超宽频带内实现电磁波的吸收和RCS的降低,同时具有极化不敏感、低剖面的优异特性以及良好的角度稳定性。(The invention relates to a polarization-insensitive low-RCS ultra-wideband metamaterial wave absorber with visible light transmission, which belongs to the field of electromagnetic waves and novel artificial electromagnetic materials and aims to solve the problem that the existing metamaterial wave absorber cannot simultaneously consider high transmittance, ultra-wideband absorption, low profile and low radar scattering sectional area.)

1. A polarization insensitive low RCS ultra-wideband metamaterial wave absorber which is transparent to visible light is characterized by sequentially consisting of a patterned impedance film layer, a first transparent substrate, a middle transparent dielectric layer, a second transparent substrate and a transparent conductive film from top to bottom;

the thickness of the patterned impedance film layer is 0.01-3 mu m; the thicknesses of the first transparent substrate and the second transparent substrate are both 0.05 mm-2 mm; the thickness of the middle transparent medium layer is 1 mm-8 mm; the thickness of the transparent conductive film is 0.01-3 mu m;

the patterned impedance film layer consists of N × M transparent patterned impedance film units of an array, wherein N is more than or equal to 12 columns, M is more than or equal to 12 rows, and the minimum distance between the adjacent transparent patterned impedance film units is 0.1-5 mm;

the shape of the transparent patterned impedance film unit is formed by overlapping 1 big circle positioned in the center and 4 small circles uniformly distributed on the periphery; the diameter of the large circle is 4 mm-10 mm; the diameter of the small circle is 1 mm-5 mm; the distance between the centers of the large circle and the small circle is 2 mm-8 mm.

2. The visible light-transmitting polarization-insensitive low-RCS ultra-wideband metamaterial wave absorber of claim 1, wherein the middle transparent dielectric layer is made of one or both of a transparent polymer and a transparent inorganic material.

3. The visible light-transmitting polarization-insensitive low-RCS ultra-wideband metamaterial wave absorber of claim 1, wherein the middle transparent dielectric layer is air, specifically, the periphery support frame is made of a transparent composite material, the first transparent substrate is used as the top, the second transparent substrate is used as the bottom, and the interior is filled with air.

4. The visible light-transmitting polarization-insensitive low-RCS ultra-wideband metamaterial absorber of claim 3, wherein the transparent composite material is polymethylmethacrylate.

5. The visible light-transmitting polarization-insensitive low-RCS ultra-wideband metamaterial wave absorber of claim 2 or 3, wherein the relative dielectric constant of the middle transparent dielectric layer is 1-6.

6. The visible light-transmitting polarization-insensitive low-RCS ultra-wideband metamaterial wave absorber of claim 1, wherein the first transparent substrate and the second transparent substrate are made of one or more of quartz glass, polycarbonate, polymethyl methacrylate, common glass, polycarbonate and polyethylene terephthalate.

7. The visible light-transmitting polarization-insensitive low-RCS ultra-wideband metamaterial wave absorber of claim 6, wherein the first transparent substrate and the second transparent substrate have relative dielectric constants of 1-6.

8. The visible light-transmitting polarization-insensitive low-RCS ultra-wideband metamaterial wave absorber of claim 1, wherein the patterned resistive film layer and the transparent conductive film are made of aluminum-doped zinc oxide, fluorine-doped tin dioxide or indium tin oxide.

9. The visible light-transmissive polarization-insensitive low-RCS ultra-wideband metamaterial absorber of claim 8, wherein the sheet resistance of the patterned resistive film layer is between 10 Ω/sq and 400 Ω/sq.

10. The visible light-transmitting polarization-insensitive low-RCS ultra-wideband metamaterial absorber of claim 1, wherein the sheet resistance of the transparent conductive film is between 1 Ω/sq and 50 Ω/sq.

Technical Field

The invention belongs to the field of electromagnetic waves and novel artificial electromagnetic materials.

Background

The microwave absorber can effectively absorb incident electromagnetic waves and enable the incident electromagnetic waves to be scattered and attenuated without generating secondary pollution, is widely applied to the technical fields of national defense, military industry and civil use, such as radar echo intensity attenuation, electromagnetic compatibility, microwave darkroom and the like, and most of applications have strong requirements on broadband absorption.

The typical microwave absorber Salisbury screen has strong absorption but narrow absorption band, and in order to further widen the absorption band, the Jaumann screen is designed by a multilayer structure, but the thickness is increased.

The novel artificial electromagnetic metamaterial wave absorber is generally composed of a sub-wavelength periodic conductive pattern layer, an intermediate medium and a grounding surface, is high in designability, and is easy to realize excellent performances such as low profile and strong absorption under a wide frequency band.

Through the design of a proper dielectric layer material, a proper conductive layer material and an artificial structure, the metamaterial wave absorber with transparent optical wave bands can be obtained, and the requirements of application in an airplane cabin, an automatic toll collection system (ETC) of an expressway, wireless communication and the like can be met.

For example, T.Jang, H.Youn, Y.J.shin, and L. J.Guo in 2014 at page 279 of the first phase 279 of ACS Photonics journal discloses a Transparent metamaterial Absorber using aluminum mesh grid for patterning, which can achieve more than 90% absorption in 5.8 GHz-12.2 GHz but cannot meet the requirement that most applied wave-absorbing bands are larger than 10 GHz.Wuhan marble worker in the patent "a vertical Transparent metamaterial Absorber" (application No. CN201610079121.9, application publication No. CN105552566A) discloses a Transparent metamaterial Absorber using Transparent metamaterial units embedded in a Transparent flat substrate to form a periodic array to achieve Broadband absorption, but the excellent Polarization characteristics of the Absorber are limited to specific Polarization characteristics.

At present, the development of a metamaterial wave absorber which has multiple excellent characteristics of high transmittance, ultra-wide band absorption, low profile, low radar scattering cross section (RCS) and the like at the same time is still a difficult problem which needs to be solved urgently and has practical application significance.

Disclosure of Invention

The invention provides a low RCS ultra-wideband metamaterial wave absorber insensitive to polarization of visible light transmission, and aims to solve the problem that the existing metamaterial wave absorber cannot simultaneously consider high transmittance, ultra-wideband absorption, low profile and low radar scattering sectional area.

A polarization insensitive low RCS ultra-wideband metamaterial wave absorber with visible light transmission consists of a patterned impedance film layer, a first transparent substrate, a middle transparent dielectric layer, a second transparent substrate and a transparent conductive film in sequence from top to bottom;

the thickness of the patterned impedance film layer is 0.01-3 mu m; the thicknesses of the first transparent substrate and the second transparent substrate are both 0.05 mm-2 mm; the thickness of the middle transparent medium layer is 1 mm-8 mm; the thickness of the transparent conductive film is 0.01-3 mu m;

the patterned impedance film layer consists of N × M transparent patterned impedance film units of an array, wherein N is more than or equal to 12 columns, M is more than or equal to 12 rows, and the minimum distance between the adjacent transparent patterned impedance film units is 0.1-5 mm;

the shape of the transparent patterned impedance film unit is formed by overlapping 1 big circle positioned in the center and 4 small circles uniformly distributed on the periphery; the diameter of the large circle is 4 mm-10 mm; the diameter of the small circle is 1 mm-5 mm; the distance between the centers of the large circle and the small circle is 2 mm-8 mm.

The invention has the beneficial effects that:

first, the etched patterned impedance film unit has simple pattern and the wave absorber has simple structure, overcomes the defects of complex structure and poor engineering realizability of wave absorbing materials in the prior art, and has easy processing, low cost and good engineering realizability.

Secondly, the metamaterial wave absorber structure designed by the invention can generate three resonance peaks through a single-layer patterned impedance film, so that the wave absorber has the characteristics of ultra-wideband wave absorption (the relative bandwidth of the absorption rate of more than 90% can reach 125%) while ensuring good light transmittance (the transparency of visible light is not lower than 75%), and also has the excellent characteristics of polarization insensitivity, low profile and good angle stability.

Thirdly, the invention can realize that the radar scattering cross section (RCS) in C, X, K radar wave band is reduced by 10dB, and the absorption frequency band is more than 10GHz, thus having great application potential in military.

The invention is used for a low RCS ultra-wideband metamaterial wave absorber which is insensitive to polarization and is transparent to visible light.

Drawings

Fig. 1 is a schematic structural diagram of a low RCS ultra-wideband metamaterial absorber with low polarization insensitivity for visible light transmission, which only includes a transparent patterned impedance film unit, 1 is the transparent patterned impedance film unit, 2 is a first transparent substrate, 3 is an intermediate transparent dielectric layer, 4 is a second transparent substrate, and 5 is a transparent conductive film;

FIG. 2 is a top view of FIG. 1, 11 is a large circle, 12 is a small circle, U is a large circle diameter, V is a small circle diameter, and Y is a distance between centers of the large circle and the small circle;

FIG. 3 is a graph showing the simulation result of the absorption rate of the visible light-transmitting polarization-insensitive low RCS ultra-wideband metamaterial absorber when the electromagnetic wave is vertically incident;

fig. 4 is a comparison graph of the single-station RCS simulation results of the visible light-transmissive polarization-insensitive low RCS ultra-wideband metamaterial wave absorber and the good conductor PEC prepared in the first example, where a is the good conductor PEC, and b is the visible light-transmissive polarization-insensitive low RCS ultra-wideband metamaterial wave absorber prepared in the first example;

FIG. 5 is a graph showing the absorption rate simulation result of the polarization insensitive low RCS ultra-wideband metamaterial absorber of visible light transmission prepared in the first embodiment when the azimuth angle is 0 °;

FIG. 6 is a graph showing the absorption rate simulation result of the polarization insensitive low RCS ultra-wideband metamaterial absorber of visible light transmission prepared in the first embodiment when the azimuth angle is 15 degrees;

FIG. 7 is a graph showing the absorption rate simulation result of the polarization insensitive low RCS ultra-wideband metamaterial absorber of visible light transmission prepared in the first embodiment when the azimuth angle is 30 degrees;

FIG. 8 is a graph of the absorption rate simulation result of the polarization insensitive low RCS ultra-wideband metamaterial absorber of visible light transmission prepared in the first embodiment when the azimuth angle is 45 degrees;

fig. 9 is a simulation result diagram of the absorption rate of the visible light-transmitting polarization-insensitive low RCS ultra-wideband metamaterial absorber prepared in the first embodiment on TE waves at different pitch angles, where a is a pitch angle of 0 °, b is a pitch angle of 15 °, c is a pitch angle of 30 °, and d is a pitch angle of 45 °;

fig. 10 is a graph of the simulation result of the absorption rate of the visible light-transmitting polarization-insensitive low-RCS ultra-wideband metamaterial absorber prepared in the first embodiment on TM waves under different pitch angles, where a is a pitch angle of 0 °, b is a pitch angle of 15 °, c is a pitch angle of 30 °, and d is a pitch angle of 45 °.

Detailed Description