A light-transmissive ultra-wideband absorbing structure

Abstract

The present invention discloses a light-transmissive ultra-wideband microwave absorbing structure, which includes microwave absorbing units. Each microwave absorbing unit includes a seven-layer stacked structure. The cross-section of the microwave absorbing unit is a square with a side length of p = 10 mm. It has the advantages of simple structure, light transmissibility, ultra-wide microwave absorption bandwidth, high absorption efficiency, bendability, etc., and can effectively achieve broadband microwave stealth for satellite solar panels, fighter plane windows, etc.

Description

Technical Field

[0001] The present invention relates to the field of mobile communications, and particularly to a light-transmissive ultra-wideband absorbing structure. Background Art

[0002] With the development of surveillance and reconnaissance, the security and survivability of satellites are seriously threatened. In recent years, the stealth problem of satellite solar panels has attracted great attention. The working frequencies of existing satellite detection radars and airborne radars are generally in the Ku band. Traditional material-based absorbers and early metamaterial absorbers cannot meet the requirements of high efficiency. There are limitations in opacity, thickness, mass, and manufacturing for the stealth of solar panels of some existing satellites. For the performance of the radar itself, the key issue is how to eliminate clutter interference and improve detection accuracy. The most direct and effective method is to apply absorbing materials to reduce clutter interference. However, the currently used Ku-band absorbing materials have the disadvantages of being non-light-transmissive, having a relatively narrow frequency band, and low absorption efficiency. The light-transmissive absorbing material designed in the present invention achieves full coverage of wave absorption in the X-band, Ku-band, K-band, and Ka-band, and basically achieves more than 95% electromagnetic wave absorption within these bands. At the same time, it can achieve effective light transmission, opening up a new way for the stealth of solar panels. Summary of the Invention

[0003] The purpose of the present invention is to provide a light-transmissive ultra-wideband absorbing structure, which has the advantages of simple structure, light transmissibility, ultra-wide absorbing bandwidth, high absorption efficiency, bendability, etc., and can effectively achieve broadband microwave stealth of satellite solar panels, fighter plane windows, etc.

[0004] A light-transmissive ultra-wideband absorbing structure includes absorbing units, and each absorbing unit includes a seven-layer stacked structure;

[0005] The first layer is processed and etched from ITO material with a dielectric constant of 3, and is composed of a ring with inner and outer radii of r1 = 2.5 mm and r2 = 3.75 mm respectively and a cross in the middle, and its resistance value is 155 ohms;

[0006] The second layer is a thin film layer made of PET material;

[0007] The third layer is made of PMMA material with a dielectric constant of 2.25;

[0008] The fourth layer is etched with a slit groove with a width of 0.1 mm in the middle of the entire ITO film. The inner side length of the slit groove is l1 = 6.8 mm, and the closest distance from the periphery of the slit to the four sides of the unit is 1.5 mm;

[0009] The fifth layer is exactly the same as the second layer, and the sixth layer is exactly the same as the third layer;

[0010] The seventh layer is a whole ITO thin film with a sheet resistance of 5 ohms;

[0011] The above-mentioned wave-absorbing structure is composed of a combination of several wave-absorbing units.

[0012] Preferably, the cross-section of the wave-absorbing unit is a square with a side length of p = 10 mm.

[0013] Preferably, the thickness of the third layer and the sixth layer is d = 2 mm.

[0014] Preferably, the wave-absorbing structure is formed by combining wave-absorbing units through side bonding.

[0015] Preferably, the wave-absorbing structure can be attached to a solar panel.

[0016] The advantages of the present invention are as follows: simple structure, light transmissibility, ultra-wide wave-absorbing bandwidth, high wave-absorbing efficiency, bendability, etc., which can effectively achieve broadband microwave stealth for satellite solar panels, fighter plane portholes, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the wave-absorbing unit of the present invention;

[0018] Figure 2 is an absorption rate curve graph of the light-transmissive wave absorber of the present invention;

[0019] Figure 3 is an overall structural diagram of the first layer of the processed sample of the present invention;

[0020] Figure 4 is a structural diagram of the wave-absorbing unit of the first layer of the present invention;

[0021] Figure 5 is an overall structural diagram of the fourth layer of the processed sample of the present invention;

[0022] Figure 6 is a structural diagram of the wave-absorbing unit of the fourth layer of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0023] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0024] As Figures 1 to 6 shown, the present invention includes wave-absorbing units, and the wave-absorbing units include a seven-layer stacked structure; as above Figure 1(As shown in (b), the first layer is an electromagnetic wave absorbing structure processed by etching ITO. The dielectric constant of the ITO material is 3, and the unit perimeter is p = 10 mm. It consists of a ring with inner and outer radii of r1 = 2.5 mm and r2 = 3.75 mm respectively and a cross in the middle. Its sheet resistance is 155 ohms; the second layer is PET, and its thickness is negligible; the third layer is PMMA material with a thickness of d = 2 mm and a dielectric constant of 2.25; the fourth layer is a slit groove with a width of 0.1 mm etched in the middle of the entire ITO thin film. The inner side length of the slit groove is l1 = 6.8 mm, and the closest distance from the periphery of the slit to the four sides of the unit is 1.5 mm. The fifth layer is exactly the same as the second layer, which is PET material, and the sixth layer is exactly the same as the third layer, which is PMMA material with a thickness of d = 2 mm. The seventh layer is a whole ITO thin film with a sheet resistance of 5 ohms. The seven-layer structure together constitutes an overall electromagnetic wave absorbing unit.)

[0025] The above electromagnetic wave absorbing structure is composed of a combination of several electromagnetic wave absorbing units. The cross-section of the electromagnetic wave absorbing unit is a square with a side length of p = 10 mm. The electromagnetic wave absorbing structure is formed by combining electromagnetic wave absorbing units through side bonding. The electromagnetic wave absorbing structure can be attached to a solar panel.)

[0026] Specific implementation methods and principles:

[0027] Figure 1 (a) describes the designed ultra-thin optically transparent metamaterial absorber covering a solar panel. The absorption rate A(ω) of incident visible light in the transmissive metamaterial absorber can be calculated by the following formula. The reflection coefficient and transmission coefficient are expressed as R(ω) and T(ω), and A(ω) - T(ω) = 1 - |S11| 2 - |S21| 2 . The bottom ITO layer is approximately an ideal conductor (PEC), and the transmission of the incident wave is almost at the bottom ITO layer. The absorption rate can be simply defined as A(ω) = 1 - |S11| 2 .

[0028] Under normal incidence of electromagnetic waves, the transmissive metamaterial absorber exhibits an absorption rate of more than 90% under any polarization in the frequency band of 8.7 GHz - 38.9 GHz, as follows Figure 2 shown. When the electromagnetic wave is obliquely incident, when manufacturing a sample of the transmissive metamaterial absorber with a thickness of 4 mm, CST simulation shows that the designed transmissive metamaterial absorber realizes full electromagnetic wave absorption coverage in the X-band, Ku-band, K-band, and Ka-band, and basically realizes electromagnetic wave absorption of more than 95% in these frequency bands, and at the same time can achieve effective light transmission.)

[0029] Based on the above, the structure of the present invention has the advantages of simple structure, light transmissibility, ultra-wide electromagnetic wave absorption bandwidth, high electromagnetic wave absorption efficiency, bendability, etc., and can effectively realize broadband microwave stealth for satellite solar panels, fighter plane windows, etc.)

[0030] As is known to those skilled in the art, the present invention can be implemented by other embodiments that do not depart from its spirit or essential features. Therefore, the above-disclosed embodiments are illustrative in all respects and not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are encompassed by the present invention.

Claims

1. A light-transmissive ultra-wideband absorbing structure, characterized in that, It includes an electromagnetic wave absorbing unit. The cross-section of the electromagnetic wave absorbing unit is a square with a side length of p = 10 mm. The electromagnetic wave absorbing unit includes a seven-layer stacked structure; The first layer is processed and etched from ITO material with a dielectric constant of 3. It consists of a ring with inner and outer radii of r1 = 2.5 mm and r2 = 3.75 mm respectively and a cross in the middle, and its resistance value is 155 ohms; The second layer is a thin film layer made of PET material; The third layer is made of PMMA material with a dielectric constant of 2.25; The fourth layer is etched with a slit groove with a width of 0.1 mm in the middle of the entire ITO thin film. The inner side length of the slit groove is l1 = 6.8 mm, and the closest distance from the periphery of the slit groove to the four sides of the unit is 1.5 mm; The fifth layer is exactly the same as the second layer, and the sixth layer is exactly the same as the third layer. The thickness of the third layer and the sixth layer is d = 2 mm; The seventh layer is a whole ITO thin film with a sheet resistance of 5 ohms; the above electromagnetic wave absorbing structure is composed of a plurality of electromagnetic wave absorbing units combined; 2. The transparent ultra-wideband absorbing structure according to claim 1, wherein: The electromagnetic wave absorbing structure is combined by side bonding of electromagnetic wave absorbing units; 3. The light-transmissive ultra-wideband absorbing structure according to claim 1, wherein: The electromagnetic wave absorbing structure can be attached to a solar panel.

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