Ultra-wideband flexible transparent ultra-thin metamaterial wave absorber

Abstract

The invention relates to an ultra-wideband flexible transparent ultra-thin metamaterial wave absorber, which solves the problems of low profile, wide bandwidth and insensitive polarization and angle of the wave absorber, and belongs to the field of electromagnetic metamaterials. The antenna comprises a first dielectric layer, a second dielectric layer and a third dielectric layer which are sequentially arranged from bottom to top, the first dielectric layer and the third dielectric layer are PET substrates; the second dielectric layer is a PVC layer; the upper surface of the third dielectric layer is provided with conductive film units which are arranged periodically, and the lower surface of the first dielectric layer is covered with a conductive film. The upper surface of the third dielectric layer is provided with four conductive thin film units which are periodically arranged, and each conductive thin film unit is an ITO resistive thin film with a cross-shaped pattern. According to the invention, the flexible PVC is used as the dielectric substrate, the PET is used as the reflection bottom plate and the resonance layer, and the conductive film pattern of the resonance layer is optimally designed, so that the absorption performance of which the absorption rate is greater than 90% is realized within the frequency range of 12.02-102.91 GHz, and the relative absorption bandwidth can reach 158.1%.

Description

Technical Field

[0001] The invention relates to an ultra-wideband flexible transparent ultra-thin metamaterial absorber, and belongs to the field of electromagnetic metamaterials. Background Art

[0002] With the rapid development of high-precision military technology, the detection and tracking technologies of various countries are becoming increasingly advanced, which poses a serious threat to the survivability of weapons such as missiles and fighter jets, and also puts forward more stringent requirements on the concealment of important military equipment. Therefore, how to effectively ensure the safety of sensitive telepathic equipment and military equipment has become an important issue in maintaining national security. In order to meet this challenge, electromagnetic stealth technology has emerged and has become the focus of many research teams. Satellite stealth technology occupies a unique position in space attack and defense systems. It has certain similarities with the stealth technology used in ground armored vehicles, ships, and aircraft. However, due to the different satellite development conditions and the space environment in which it is located, the research and application of satellite stealth technology is more challenging. In order to effectively expand the spectrum coverage of absorbing materials, researchers have tried a variety of methods, including incorporating active components, carefully constructing resonant units, or adopting multi-layer stacking designs, and combining high dielectric loss materials to create ultra-wideband absorbers. However, these strategies often lead to increased material thickness and increased manufacturing complexity. Considering that special application scenarios such as small mobile communication devices, satellite communication antennas, and military aircraft have more stringent requirements on the size and thickness of absorbing materials, the current research focus has shifted to the development of a new type of absorbing material. This material must combine high absorption efficiency, extremely thin thickness, small size, light weight, and broadband absorption, while also being flexible and transparent. Such innovative designs are expected to bring disruptive progress to future communication technologies and electronic devices, and are of great significance to the promotion of practical application fields.

[0003] The emergence of artificial electromagnetic metamaterials has made a major breakthrough in electromagnetic stealth technology. Artificial electromagnetic metamaterials (Metamaterial), referred to as "metamaterials", are a new type of artificial composite material composed of periodic or non-periodic arrangement of artificial "atomic-like" materials at the sub-wavelength level. Artificial electromagnetic metasurfaces (Metasurface) can be regarded as the two-dimensional planar form of metamaterials, referred to as "metasurfaces". Electromagnetic metasurfaces have the advantages of ultra-thin profiles, low losses, and easy design, processing and integration. They have shown broad application prospects in popular fields of microwave frequency bands such as electromagnetic stealth, electromagnetic isolation and radar detection. Its development has promoted the miniaturization, integration, conformality, digitization and intelligence of microwave devices.

[0004] Solar panels absorb sunlight and convert solar radiation energy directly or indirectly into electrical energy through the photoelectric effect or photochemical effect. They are indispensable energy devices on satellites. However, their strong metal-like backscattering characteristics pose a serious threat to the safety and survivability of satellites. Therefore, the microwave stealth design of solar panels has attracted great attention in recent years. The conventional method is to achieve microwave stealth by coating microwave absorbing materials, but traditional coated absorbing materials cannot guarantee efficient optical transmittance when solar panels are working. The emergence of optically transparent metamaterial absorbers has opened up a new path for the microwave stealth design of solar panels. However, it is still a challenge to design an absorber with low profile, wide bandwidth, polarization and angle insensitivity, while ensuring good working efficiency and microwave stealth when applied to solar panels. Summary of the invention

[0005] In order to solve the problem of how an absorber can have low profile, wide bandwidth, polarization and angle insensitivity, the present invention provides an ultra-wideband flexible transparent ultra-thin metamaterial absorber.

[0006] An ultra-wideband flexible transparent ultra-thin metamaterial absorber of the present invention comprises a first dielectric layer, a second dielectric layer and a third dielectric layer arranged in sequence from bottom to top;

[0007] The first medium layer and the third medium layer are both PET substrates;

[0008] The second medium layer is a PVC layer;

[0009] The upper surface of the third dielectric layer is provided with periodically arranged conductive film units, and the lower surface of the first dielectric layer is covered with a conductive film.

[0010] Preferably, four periodically arranged conductive film units are provided on the upper surface of the third dielectric layer, and each conductive film unit is an ITO resistance film in a cross pattern.

[0011] Preferably, the sheet resistance Rs of the conductive film unit is 260Ω / sq.

[0012] Preferably, the period of the conductive film unit is p=8 mm;

[0013] Each cross pattern has a length of a=3.3 mm and a width of b=0.9 mm.

[0014] Preferably, the sheet resistance Rs of the conductive film covering the lower surface of the first dielectric layer is 150Ω / sq.

[0015] Preferably, the second dielectric layer is a PVC layer with a relative dielectric constant of 3, a loss tangent value of 0.014, and a thickness of h=0.5 mm.

[0016] Preferably, the first dielectric layer and the third dielectric layer both adopt a PET substrate with a relative dielectric constant of 3, a loss tangent value of 0.06, and a thickness of d=0.125 mm.

[0017] The beneficial effects of the present invention are as follows: the absorber designed by the present invention achieves an absorption performance with an absorption rate greater than 90% in the frequency range of 12.02 to 102.91 GHz, and the relative absorption bandwidth can reach 158.1%. The overall thickness of the absorber designed by the present invention is only 0.75 mm, showing the remarkable characteristics of lightness and thinness. On the premise of ensuring ultra-wideband absorption performance and high absorption rate, the thickness and quality of the device are effectively reduced, and its practical value is significantly improved, and it is conducive to the integrated application with the microwave system; the PVC, PET, and ITO used in the present invention have good optical transmittance and flexibility. Compared with the prior art, while ensuring the absorption bandwidth and absorption rate, the good light transmittance of the electromagnetic absorber is achieved, and the application range is expanded. In addition to the excellent optical properties of the material itself, it has a certain conformal ability. The absorber of the present invention has optical transparency, and the wave absorption characteristics of this transparent absorber are verified by simulation. It has the advantages of low profile, wide bandwidth, polarization and angle insensitivity, and has broad application prospects in the field of stealth. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the wave absorber of the present invention;

[0019] Figure 2 is a side view of the absorber structure of the present invention;

[0020] Figure 3 is a top view of the absorber structure of the present invention;

[0021] Figure 4 is the reflection coefficient curve of the absorber of the present invention;

[0022] Figure 5 It is the wave absorption rate curve of the wave absorber of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0026] like Figure 1 and Figure 2 As shown, the ultra-wideband flexible transparent ultra-thin metamaterial absorber of this embodiment includes a first dielectric layer, a second dielectric layer and a third dielectric layer arranged in sequence from bottom to top, a conductive film is arranged on the upper surface of the first dielectric layer, and a conductive film is arranged on the lower surface of the third dielectric layer. The first dielectric layer and the third dielectric layer are made of the same material, PET, and the material of the second dielectric layer is PVC. The specific method is as follows:

[0027] The second dielectric layer is made of PVC with a relative dielectric constant of 3, a loss tangent value of 0.014, and a thickness of h=0.5 mm.

[0028] The first dielectric layer and the third dielectric layer are both made of PET with a relative dielectric constant of 3, a loss tangent value of 0.06, and a thickness of d=0.125 mm.

[0029] The lower surface of the first dielectric layer is covered with a conductive film, specifically, an ITO resistor film with a sheet resistance Rs of 150Ω / sq is used to completely cover the PET substrate.

[0030] The upper surface of the third dielectric layer is provided with periodically arranged conductive film units, specifically including four conductive film units, each of which is etched on a PET substrate using a cross-patterned ITO resistor film with a sheet resistance Rs of 260Ω / sq.

[0031] like Figure 3 As shown, the ITO resistance film of the third dielectric layer is four cross patterns, the period of the conductive film unit is p=8mm, the length of each cross pattern is a=3.3mm, and the width is b=0.9mm. The distance between the center of the cross pattern and the absorber boundary is one quarter of the period of the conductive film unit, that is, 2mm.

[0032] like Figure 4 As shown, it is the use of Figure 1 The reflection coefficient of the periodic structure in the range of 5 to 110 GHz is obtained by simulating with the commercial electromagnetic simulation software CST Studio Suite. The horizontal axis represents the frequency and the vertical axis represents the magnitude of the reflected electromagnetic energy. It can be seen that the reflection coefficient in the range of 12.02-102.91 GHz is less than -10 dB.

[0033] like Figure 5The figure shows the absorption rate of the absorber proposed in this embodiment, the horizontal axis is the frequency, and the vertical axis is the absorption rate of electromagnetic energy. In the frequency range of 12.02 to 102.91 GHz, the absorption performance with an absorption rate greater than 90% is achieved, and the relative absorption bandwidth can reach 158.1%. The thickness of the absorber is only 0.75 mm. Compared with the prior art, while ensuring the absorption rate and absorption bandwidth, it also reflects higher light transmittance and smaller weight.

[0034] The absorber of this embodiment uses flexible PVC as the dielectric substrate, and PET covered with ITO conductive film as the reflective bottom plate and the resonance layer. Through the optimization design of the ITO conductive film pattern of the resonance layer, an absorption performance with an absorption rate greater than 90% is achieved in the frequency range of 12.02 to 102.91 GHz, and the relative absorption bandwidth can reach 158.1%. Since the pattern of the resonance unit of the absorber adopts a centrally symmetrical cross structure, it has polarization insensitivity. For specific application scenarios such as small mobile communication devices, satellite communication antennas and military aircraft, the requirements for the size and thickness of absorbing materials are becoming increasingly stringent. Therefore, the flexible transparent absorbing material designed by the present invention, which has the characteristics of high-efficiency absorption, ultra-thin thickness, small size, light weight and broadband absorption, is of vital practical significance for promoting the innovative development of future communication technology and electronic equipment, and can provide breakthrough solutions for related applications.

[0035] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. Ultra-broadband flexible transparent ultra-thin metamaterial absorber, characterized in that: It includes a first dielectric layer, a second dielectric layer and a third dielectric layer arranged in sequence from bottom to top; The first medium layer and the third medium layer are both PET substrates; The second medium layer is a PVC layer; The upper surface of the third dielectric layer is provided with periodically arranged conductive film units, and the lower surface of the first dielectric layer is covered with a conductive film.

2. The ultra-wideband flexible transparent ultra-thin metamaterial absorber according to claim 1, characterized in that: Four periodically arranged conductive film units are disposed on the upper surface of the third dielectric layer, and each conductive film unit is an ITO resistance film with a cross pattern.

3. The ultra-wideband flexible transparent ultra-thin metamaterial absorber according to claim 2, characterized in that: The sheet resistance Rs of the conductive film unit is 260Ω / sq.

4. The ultra-wideband flexible transparent ultra-thin metamaterial absorber according to claim 2, characterized in that: The period of the conductive film unit p = 8 mm; Each cross pattern has a length of a=3.3 mm and a width of b=0.9 mm.

5. The ultra-wideband flexible transparent ultra-thin metamaterial absorber according to claim 1, characterized in that: The sheet resistance Rs of the conductive film covering the lower surface of the first dielectric layer is 150Ω / sq.

6. The ultra-wideband flexible transparent ultra-thin metamaterial absorber according to claim 1, characterized in that: The second dielectric layer is a PVC layer with a relative dielectric constant of 3, a loss tangent value of 0.014, and a thickness of h=0.5 mm.

7. The ultra-wideband flexible transparent ultra-thin metamaterial absorber according to claim 1, characterized in that: The first dielectric layer and the third dielectric layer both adopt a PET substrate with a relative dielectric constant of 3, a loss tangent value of 0.06, and a thickness of d=0.125 mm.

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