Metamaterials and Spacecraft

Abstract

A metamaterial and an aircraft are disclosed. The metamaterial includes a plurality of first microstructure units disposed on a carrier substrate. The plurality of first microstructure units are arranged sequentially along a direction from a first end to a second end of the carrier substrate, and the number of petals in the flower-shaped pattern of the plurality of first microstructure units increases sequentially according to the aforementioned sequential arrangement, resulting in a gradual change in the equivalent impedance of the metamaterial. The metamaterial of the present invention has a surface with a gradual change in equivalent impedance. When receiving incident electromagnetic waves, the surface of the metamaterial with a gradual change in equivalent impedance can obtain a gradual surface current. By gradually losing the surface current, scattering from gap defects can be reduced, effectively improving the defect scattering suppression effect. The aircraft provided by the present invention includes the metamaterial of the present invention, which can reduce gap defect scattering of the aircraft, reduce the possibility of the aircraft being detected, and improve the stealth performance of the aircraft.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic detection technology, and more specifically, to metamaterials and aircraft. Background Technology

[0002] In recent years, with the rapid development of various new detectors and radars, electromagnetic detection technology has been greatly improved. Electromagnetic scattering caused by various electromagnetic defects of military targets can be detected, which poses a great threat to the survivability of military targets in modern warfare.

[0003] To reduce the likelihood of a target being detected, the development of electromagnetic defect scattering suppression technology has become of paramount importance. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide a metamaterial and an aircraft, thereby improving the defect scattering suppression effect and enhancing the stealth performance of the aircraft.

[0005] According to one aspect of the present invention, a metamaterial is provided for suppressing electromagnetic defect scattering, characterized in that the metamaterial comprises:

[0006] Carrier substrate;

[0007] Multiple first microstructure units are disposed on the carrier substrate and arranged sequentially from the first end to the second end of the carrier substrate, and the equivalent impedance of the multiple first microstructure units gradually changes.

[0008] in,

[0009] The shapes of the plurality of first microstructure units each include a series of floral patterns that vary according to a preset rule. Each floral pattern includes at least one petal, which is a hollow structure. The preset rule includes that the number of petals in the plurality of floral patterns increases sequentially according to the sequential arrangement of the plurality of first microstructure units.

[0010] Optionally, the hollow structure of the petals is elongated, elliptical, or triangular.

[0011] Optionally, the maximum number of petals in the plurality of said flower patterns is eight, and the included angle between two adjacent petals is 45 degrees.

[0012] Optionally, the multiple petals in the flower pattern are all the same, and the extension direction of the starting petal among the multiple petals is perpendicular to the direction from the first end to the second end of the carrier substrate. The preset rule also includes rotating the starting petal sequentially by 45 degrees with the starting end point of the starting petal as the center to obtain the other multiple petals in sequence.

[0013] Optionally, the metamaterial further includes a second microstructure unit, which is disposed downstream of the sequential arrangement of the plurality of first microstructure units, wherein,

[0014] The second microstructure unit includes a combination pattern of the floral pattern and the square pattern. The combination pattern is a hollow structure. The number of petals in the floral pattern of the second microstructure unit is the maximum number of petals in the floral pattern. The center of the square pattern coincides with the center of the floral pattern.

[0015] Optionally, the metamaterial further includes a third microstructure unit, which is disposed sequentially downstream of the second microstructure unit, wherein...

[0016] The third microstructure unit includes a square pattern with a hollow structure, and the square pattern of the third microstructure unit is the same as the square pattern of the second microstructure unit.

[0017] Optionally, the metamaterial further includes a fourth microstructure unit, which is disposed upstream of the sequential arrangement of the plurality of first microstructure units, wherein,

[0018] The fourth microstructure unit is a material plate without a perforated structure.

[0019] Optionally, the elongated structure of the petals has a length of 4.6 to 5 mm and a width of 1.6 to 2 mm, and each microstructural unit is a square structure with a side length of 8 to 12 mm, wherein the side length of the square pattern is 6 to 8 mm.

[0020] Optionally, the plurality of first microstructure units are arranged in multiple groups and side by side on the carrier substrate.

[0021] The carrier substrate is disposed over the gap in the gap defect structure, and the first end or the second end faces the electromagnetic incident direction of the gap defect structure.

[0022] Optionally, the carrier substrate is a flexible transparent material substrate, and the hollow structure is a hollow structure in a transparent conductive material.

[0023] According to another aspect of the present invention, an aircraft is provided, characterized in that it comprises a metamaterial provided according to the present invention.

[0024] The metamaterial provided by the present invention includes a plurality of first microstructure units disposed on a carrier substrate. The plurality of first microstructure units are arranged sequentially along the direction from the first end to the second end of the carrier substrate, and the number of petals of the flower pattern of the plurality of first microstructure units increases sequentially according to a preset rule as they are arranged, so that the equivalent impedance of the plurality of first microstructure units gradually changes. When receiving electromagnetic wave incident, the surface of the metamaterial with gradually changing equivalent impedance can obtain a gradually changing surface current. By gradually losing the surface current, the scattering of gap defects is reduced, and the defect scattering suppression effect is effectively improved.

[0025] The carrier substrate is a flexible transparent material substrate, and the hollow structure of the flower pattern of the microstructure unit is a hollow structure in a transparent conductive material, which can improve the environmental adaptability of the metamaterial of the present invention and improve the scattering effect of gap defects in complex environments with requirements such as transparency and conformality.

[0026] The aircraft provided by this invention includes the metamaterial provided by this invention, which can reduce electromagnetic scattering on its surface and improve the stealth performance of the aircraft. Attached Figure Description

[0027] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0028] Figure 1 A schematic diagram of the structure of a metamaterial according to an embodiment of the present invention is shown;

[0029] Figure 2 A schematic diagram of the structure of a metamaterial according to another embodiment of the present invention is shown;

[0030] Figure 3 and Figure 4 A schematic diagram of a gap defect structure according to an embodiment of the present invention is shown;

[0031] Figure 5 It shows that according to Figure 3 The curves showing the scattering suppression performance of the slit defect structure are illustrated. Detailed Implementation

[0032] Various embodiments of the invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0033] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0034] Figure 1 A schematic diagram of the structure of a metamaterial according to an embodiment of the present invention is shown.

[0035] like Figure 1 As shown, the metamaterial 10 of this embodiment includes a carrier substrate 11 and a plurality of microstructure units 12 (first microstructure units) disposed on the carrier substrate 11, so as to... Figure 1 For reference, the left end is the first end and the right end is the second end. Multiple microstructure units 12 are arranged sequentially from the first end to the second end, and their equivalent impedances gradually change.

[0036] In this embodiment, the carrier substrate 11 is a flexible transparent material substrate, such as PET (polyethylene terephthalate). The microstructure unit 12 is a transparent conductive material, such as indium tin oxide (ITO). The microstructure pattern 13 in the microstructure unit 12 is the outline of a hollow structure. In an optional embodiment, the hollow structure is filled with a flexible transparent material, such as PVC (polyvinyl chloride).

[0037] Among them, the surface current J of metamaterials x The relationship between (x) and surface impedance η is as follows:

[0038]

[0039]

[0040] Wherein, equation (1) represents horizontal transmission and horizontal reception polarization (HH polarization), and equation (2) represents vertical transmission and vertical reception polarization (VV polarization), Φ0 is the incident angle, and k is the wave number. After normalizing the incident field amplitude, the impedance expression is solved by the above two equations. When Φ0 = 90°, the above equations (1) and (2) can be unified as follows:

[0041]

[0042] That is, the metamaterial 10 of the present invention has a surface impedance that is a gradually changing impedance, and a gradually changing surface current can be obtained. By gradually losing the surface current, electromagnetic scattering caused by electrical discontinuity can be reduced. Loading the metamaterial 10 at the gap can effectively reduce backscattering caused by gap defects.

[0043] In this embodiment, each microstructure unit 12 is a square structure, and the outline of its hollow structure forms a microstructure pattern 13. The microstructure pattern 13 is a series of flower patterns that change according to a preset rule. Each flower pattern includes at least one petal. The number of petals in the flower patterns of each microstructure unit 12 increases sequentially with the sequential arrangement of the microstructure units 12, increasing from one petal to eight petals from the first end to the second end. The starting petals of each flower pattern are in the same position, that is, directly above (with... Figure 1 Starting with one petal (for orientation reference), each petal is rotated 45 degrees clockwise and then superimposed on the petal before rotation to form a series of microstructure patterns with an increasing number of petals.

[0044] In this embodiment, the petal structure is elongated, with a length a of 4.6 to 5 mm and a width b of 1.6 to 2 mm. The microstructure unit 12 is a square structure with a side length p of 8 to 12 mm.

[0045] In the metamaterial 10 of this embodiment, the microstructure units 12 are a group, wherein the number of continuous petals of the flower pattern of the microstructure pattern gradually changes. At the first end of the group of microstructure units 12 (the first end of the carrier substrate 11, upstream of the sequential arrangement of multiple microstructure units 12), a fourth microstructure unit 121 without microstructure pattern (a material plate without a hollow structure, which in an optional embodiment is a transparent conductive material plate, wherein the material plate of the non-hollow part of each microstructure unit is an integral structure or a discrete combination structure) is also provided to improve the continuity of the surface impedance between the microstructure unit at the first end of the metamaterial 10 and the microstructure unit behind it.

[0046] In this embodiment, the microstructure pattern of the flower-shaped pattern of the microstructure unit 122 at the tail end of the group of microstructure units 12 has a maximum of eight petals. Following the microstructure unit 122 (downstream of the sequential arrangement of multiple microstructure units 12), a second microstructure unit 123 and a third microstructure unit 124 are sequentially arranged. The microstructure pattern in the second microstructure unit 123 is a combination of an eight-petal flower pattern and a square pattern, with the center of the square pattern coinciding with the center of the eight-petal flower pattern, and the sides of the square pattern being parallel to the corresponding sides of the second microstructure unit 123. The microstructure pattern of the third microstructure unit 124 is a square pattern, and its structure is identical to the square pattern in the second microstructure unit 123. In this embodiment, the side length c of the square pattern is 6 to 8 millimeters.

[0047] In this embodiment, the orientation of the starting petal of the floral pattern is perpendicular to the direction from the first end to the second end of the carrier substrate 11. In an optional embodiment, the angle between the orientation of the starting petal and the direction from the first end to the second end of the carrier substrate 11 is arbitrary.

[0048] In this embodiment, the maximum number of petals in the flower pattern of the microstructure pattern in the microstructure unit 12 is eight, and they are evenly distributed in the circumferential direction. In optional embodiments, the maximum number of petals in the flower pattern is four, five, etc., and the shape of the petals is not limited to regular square strips. For example, they can also be elliptical, triangular, etc. The number of a set of microstructure units 12 can be set according to actual needs.

[0049] Figure 2 A schematic diagram of the structure of a metamaterial according to another embodiment of the present invention is shown.

[0050] Reference Figure 2 and Figure 1 In this embodiment, the metamaterial 20 is a multi-group parallel arrangement of a set of microstructural units 12 in the metamaterial 10, with the head and tail ends of each group of microstructural units corresponding to each other, forming a structure corresponding to the upper to lower ends of the metamaterial 20 (within). Figure 2 The surface with gradually varying impedance (for orientation reference) is wherein the width W1 of the metamaterial 20 in this embodiment is 168 to 252 mm and the length d is 88 to 131 mm.

[0051] Figure 3 and Figure 4 A schematic diagram of a gap defect structure according to an embodiment of the present invention is shown, wherein, Figure 3 This is a top view of the gap defect structure 100. Figure 4 This is a side view of the gap defect structure 100.

[0052] Reference Figure 3 and Figure 4 The slit defect structure 100 includes a slit defect plate 102, with a slit 101 formed at the middle position of the slit defect plate 102. A metamaterial 20 of the present invention is disposed above the slit defect plate 102. The length L of the slit defect plate 102 of the slit defect structure 100 is 600 mm, the width W2 is 210 mm, the width S of the slit 101 is 2 mm, and its scattering angle θ is 80 degrees, which can reduce the scattering of the leading and trailing edge corners. The length a of the petal of the flower-shaped microstructure pattern in the corresponding metamaterial 20 is 4.9 mm, the width b is 1.8 mm, the side length p of the microstructure unit 12 is 10 mm, the side length c of the square pattern of the third microstructure unit 124 at the end is 7 mm, the width W1 of the metamaterial 20 is 210 mm, the length d is 110 mm, and the metamaterial 20 is laid above the gap 101 of the gap defect plate 102, with a distance h (ignoring thickness) of 1 mm between it and the gap defect plate 102.

[0053] Among them, with Figure 4 For azimuth reference, the right end is the electromagnetic wave incident direction, with a certain incident angle Phi, and the upper end of metamaterial 20 (with...) Figure 2 (For orientation reference) The gap defect plate 102 is oriented to the right end and its center is biased towards the right end of the gap 101.

[0054] Figure 5 It shows that according to Figure 3 The curves showing the scattering suppression performance of the slit defect structure are illustrated. The horizontal axis represents the electromagnetic wave incident angle Phi, and the middle axis represents the radar cross section (RCS). Curves L11 and L12 represent the VV and HH polarization performance curves of the slit defect plate 102 without metamaterial 20, respectively. Curves L21 and L22 represent the VV and HH polarization performance curves of the slit defect structure 100 with metamaterial 20, respectively.

[0055] like Figure 5 As shown, the gap defect structure 100 loaded with the metamaterial 20 provided in this embodiment of the invention can effectively suppress the gap defect scattering of electromagnetic waves incident within the incident angle range of 0 to 35 degrees, thereby improving the wave absorption performance of the gap defect structure 100.

[0056] The metamaterial provided by this invention has multiple microstructure units with sequentially varying equivalent impedances arranged on the carrier substrate from the first end to the second end. When receiving electromagnetic wave incident, the surface of the metamaterial with gradually varying equivalent impedances can obtain a gradually varying surface current. By gradually losing the surface current, the scattering of gap defects is reduced, effectively improving the defect scattering suppression effect.

[0057] The carrier substrate is a flexible transparent material substrate, and the microstructure pattern is the outline pattern of the hollow structure in the transparent conductive material, which can improve the environmental adaptability of the metamaterial of the present invention and improve the scattering effect of gap defects in complex environments with requirements such as transparency and conformality.

[0058] The present invention also provides an aircraft comprising the metamaterial provided by the present invention, which can reduce scattering from surface gap defects and improve the stealth performance of the aircraft.

[0059] As described above, these embodiments of the present invention do not exhaustively cover all details, nor do they limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A metamaterial for suppressing electromagnetic defect scattering, characterized in that, The metamaterial includes: Carrier substrate; Multiple first microstructure units are disposed on the carrier substrate and arranged sequentially from the first end to the second end of the carrier substrate, and the equivalent impedance of the multiple first microstructure units gradually changes. in, The shapes of the plurality of first microstructure units each include a series of floral patterns that vary according to a preset rule. Each floral pattern includes at least one petal, which is a hollow structure. The preset rule includes that the number of petals in the plurality of floral patterns increases sequentially according to the sequential arrangement of the plurality of first microstructure units.

2. The metamaterial according to claim 1, characterized in that, The openwork structure of the petals is elongated, elliptical, or triangular.

3. The metamaterial according to claim 2, characterized in that, The maximum number of petals in the multiple flower patterns is eight, and the angle between two adjacent petals is 45 degrees.

4. The metamaterial according to claim 3, characterized in that, The multiple petals in the flower pattern are all the same. The extension direction of the starting petal among the multiple petals is perpendicular to the direction from the first end to the second end of the carrier substrate. The preset rule also includes rotating the starting petal sequentially by 45 degrees with the starting point of the starting petal as the center to obtain the other multiple petals in turn.

5. The metamaterial according to claim 3, characterized in that, The metamaterial further includes a second microstructure unit, which is disposed downstream of the sequential arrangement of the plurality of first microstructure units, wherein... The second microstructure unit includes a combination pattern of the floral pattern and the square pattern. The combination pattern is a hollow structure. The number of petals in the floral pattern of the second microstructure unit is the maximum number of petals in the floral pattern. The center of the square pattern coincides with the center of the floral pattern.

6. The metamaterial according to claim 5, characterized in that, The metamaterial further includes a third microstructure unit, which is disposed downstream of the second microstructure unit, wherein... The third microstructure unit includes a square pattern with a hollow structure, and the square pattern of the third microstructure unit is the same as the square pattern of the second microstructure unit.

7. The metamaterial according to claim 1, characterized in that, The metamaterial further includes a fourth microstructure unit, which is disposed upstream of the sequential arrangement of the plurality of first microstructure units, wherein... The fourth microstructure unit is a material plate without a perforated structure.

8. The metamaterial according to claim 6, characterized in that, The petal-shaped elongated structure is 4.6 to 5 mm long and 1.6 to 2 mm wide. Each microstructural unit is a square structure with a side length of 8 to 12 mm, and the square pattern has a side length of 6 to 8 mm.

9. The metamaterial according to claim 1, characterized in that, The plurality of first microstructure units are arranged in multiple groups and are disposed side by side on the carrier substrate. The carrier substrate is disposed over the gap with the gap defect structure, and the first end or the second end faces the incident direction of the electromagnetic wave.

10. The metamaterial according to claim 2, characterized in that, The carrier substrate is a flexible transparent material substrate, and the plurality of first microstructure units are transparent conductive materials with hollow structures.

11. An aircraft, characterized in that, Including the metamaterials according to any one of claims 1 to 10.

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