Low-scattering encoded cloaking superstructure and method of making same

Abstract

The application discloses a low-scattering coding stealth superstructure and a manufacturing method thereof. The low-scattering coding stealth superstructure comprises a bottom plate and a square sheet array arranged above the bottom plate, the square sheet array is a plurality of array-arranged and interval-arranged metal plates, sizes of the metal plates adopt a plurality of size combination modes, the bottom plate is made of metal, and the metal plates and the bottom plate are interval-arranged and fixedly connected through metal columns. The low-scattering coding stealth superstructure inhibits reflectivity of the metal structure, and further improves the concealment of a ship skin structure in a radar detection scene.

Description

Technical Field

[0001] This invention relates to the field of radar detection, and in particular to a low-scattering coded stealth superstructure and its fabrication method. Background Technology

[0002] As a mature detection system, radar operating in the microwave band has become a primary situational awareness technology in applications such as ship situational awareness and offensive and defensive operations. Countering radar detection places an urgent need on the electromagnetic camouflage and stealth capabilities of ship skin structures. However, existing electromagnetic stealth materials are generally non-metallic composite materials that absorb electromagnetic waves based on electromagnetic loss mechanisms, requiring special design for their environmental adaptability.

[0003] In stealth material structures, metallic shell structures are considered to have high reliability, while the reliability, anti-aging properties, and durability of non-metallic materials (such as composite materials) have not yet been fully verified and standardized. The working mechanisms of all-metal stealth structures and composite material stealth structures differ. If an all-metal low-scatter radar camouflage structure with a smooth surface profile can be designed, it will have significant engineering value and can be rapidly applied.

[0004] Metallic materials possess excellent environmental adaptability and reliability, but they typically reflect electromagnetic waves strongly. This situation urgently necessitates the development of an all-metal low-scattering structure to improve the stealth of ship skin structures in radar detection scenarios, thereby enhancing their survivability. Summary of the Invention

[0005] The main objective of this invention is to provide a low-scattering coded stealth superstructure and its fabrication method, which aims to suppress the reflectivity of metal structures and thereby improve the stealth of ship skin structures in radar detection scenarios.

[0006] To achieve the above objectives, the present invention provides a low-scattering coded stealth superstructure, including a base plate and a square array mounted on the base plate. The square array consists of multiple arrays of metal plates arranged at intervals. The metal plates are sized in various combinations. The base plate is made of metal, and the metal plates are spaced apart from the base plate and are fixedly connected by metal columns.

[0007] Preferably, the base plate is a square plate, and the square plate array includes multiple square metal plates.

[0008] Preferably, the metal plate includes multiple first square pieces and multiple second square pieces, which are arranged in a random coding manner. The first square piece is a single-piece structure, and the second square piece includes multiple square pieces arranged at intervals. The number of square pieces that make up the second square piece is the same in both the horizontal and vertical directions.

[0009] Preferably, the outer frame size of the first square piece is the same as the outer frame size of the second square piece.

[0010] Preferably, the distance between the square array and the base plate is 2mm to 4mm.

[0011] Preferably, the thickness of the metal plate of the square array is 0.4mm to 0.6mm.

[0012] Preferably, the thickness of the base plate is 0.5mm to 1.5mm.

[0013] Preferably, the top and bottom surfaces of all the metal plates in the square array are flush.

[0014] Preferably, the metal plate and the base plate are connected to the metal column by welding or bonding.

[0015] This invention further proposes a method for fabricating a low-scattering coded stealth superstructure based on the above, comprising the following steps: Multiple metal plates and a base plate are cut from a metal sheet using a cutting method; Metal plates are installed in an array on the base plate, and the metal plates and the base plate are fixed together by metal columns.

[0016] The low-scattering coded stealth superstructure proposed in this invention realizes a low-scattering structure based on all metal, which can suppress the scattering of metal parts. Therefore, it can be used in ship skin structures to improve the stealth of ship skin structures in radar detection scenarios, thereby improving their survivability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the low-scattering coded stealth superstructure of the present invention; Figure 2 for Figure 1 The diagram shows the structure of the low-scattering coded stealth superstructure after removing the padding. Figure 3 This is a schematic diagram of the scattering principle of Embodiment 1 of the low-scattering coded stealth superstructure of the present invention; Figure 4 This is a simulation diagram of scattering suppression in Embodiment 1 of the low-scattering coded stealth superstructure of the present invention; Figure 5 This is a schematic diagram illustrating the performance verification of a sample of Embodiment 1 of the low-scattering coded stealth superstructure of the present invention. Figure 6 This is a schematic diagram illustrating the scattering principle of the low-scattering coded stealth superstructure of the present invention. Figure 7 This is a simulation diagram of scattering suppression on a scale of the low-scattering coded stealth superstructure of the present invention.

[0018] In the diagram, 10 represents the base plate, 20 represents the square array, and 30 represents the metal column.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0021] It should be noted that in the description of this invention, the terms "lateral," "longitudinal," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] This invention proposes a low-scattering coded stealth superstructure.

[0023] Reference Figure 1 and Figure 2 A low-scattering coded stealth superstructure includes a base plate 10 and a square array 20 mounted on the base plate 10. The square array 20 consists of multiple arrays of metal plates arranged at intervals. The size of the metal plates adopts a variety of size combinations. The base plate 10 is made of metal. The metal plates are spaced apart from the base plate 10 and are fixedly connected by metal columns 30.

[0024] Specifically, the base plate 10 is a square plate, and the square plate array 20 includes multiple square metal plates. The metal plates can be made in various combinations of sizes, meaning that the metal plates are not limited to a single square size, but can be square in multiple sizes. For example, multiple four-piece structures can be combined with multiple nine-piece structures, or single-piece structures can be combined with four-piece or nine-piece structures, etc. There are many implementation methods, and this invention does not limit them, as long as the outer frame dimensions are not all the same.

[0025] Because a metal plate adds a reflection phase when reflecting electromagnetic waves, typically 180 degrees, if the metal plate is divided into array units, and through structural design, the reflection phase of the modulation unit is a random value, a diffuse reflection effect can be achieved, thereby reducing the radar cross-section and achieving a camouflage effect.

[0026] Specifically, the metal plate includes multiple first square pieces and multiple second square pieces. The first and second square pieces are arranged in a randomly coded manner. The first square piece is a single-piece structure, and the second square piece includes multiple spaced square pieces. The number of square pieces in the second square piece is the same both horizontally and vertically. For example, the second square piece may include 2×2 square pieces or 3×3 square pieces. That is to say, the square piece array 20 proposed in this invention includes not only a single size of square piece structure, but also a structure with multiple size combinations. This allows the reflection phase difference to be controlled at around 180 degrees, so that the reflections between adjacent square pieces cancel each other out, and the reflectivity of the mirror surface relative to the metal plane can be significantly reduced to below -10dB.

[0027] Specifically, the outer frame dimensions of the first square are the same as those of the second square. The metal plate and base plate 10 are connected to the metal column 30 by welding or bonding. The metal column 30 should not be excessively clustered (excessive clustering means that the cross-section at the connection between the metal column 30 and the base plate 10 is very small, which easily causes stress concentration and damage), otherwise it is easily damaged under external force. The distance between the square array 20 and the base plate 10 is 2mm~4mm. The thickness of the metal plate of the square array 20 is 0.4mm~0.6mm. The thickness of the base plate 10 is 0.5mm~1.5mm.

[0028] The top and bottom surfaces of all the metal plates in the square array 20 are flush. That is, all the metal plates are of equal thickness and are set at the same height.

[0029] The side length of the base plate 10 should be greater than 5 times the wavelength corresponding to the frequency. For example, 10GHz corresponds to a wavelength of 30mm, so the side length should be greater than 150mm. The base plate 10 is divided into cells after the side length is given. For example, if one cell is 10mm, a 30×30 cell array can be arranged on a base plate 10 with a side length of 300mm.

[0030] This low-scattering coded stealth metastructure can suppress scattering characteristics and thus achieve camouflage functionality through scattering reduction. During implementation, the feasibility of using multiple decoys can be studied based on the phase-modulated diffuse scattering mechanism. Considering that the all-metal radar camouflage structure is located in the middle layer of the ship's skin structure, various functional modules can be embedded during implementation to achieve a multi-functional ship skin shell structure, thus achieving an integrated skin with multiple functions. By utilizing novel metamaterial structures and high-degree-of-freedom design, the contradictions between multiple functions are resolved, while simultaneously achieving weight and volume optimization, adapting to the harsh boundary conditions of marine applications, and obtaining a ship load-bearing shell structure with excellent practical functions.

[0031] This low-scattering coded stealth metastructure typically employs porous structures such as lattices, allowing for the embedding of various functional modules, such as adjustable modules, self-sensing modules, and antenna modules. During the conversion process, this low-scattering coded stealth metastructure can be integrated with a wave load protection structure for unified design, achieving a camouflage and protection integrated structure. All-metal radar camouflage structures can utilize the excellent load-bearing properties of metal; if these properties are combined with stealth capabilities, a load-bearing and stealth integrated structure can be achieved.

[0032] The following is a specific embodiment for illustration.

[0033] Example 1 In this embodiment, the first square of the low-scattering coded stealth superstructure has a side length of 11.5 mm and a thickness of 0.5 mm. The square unit of the second square has a side length of 4 mm and a thickness of 0.5 mm. The distance between the base plate 10 and the square array 2020 is 3 mm. The base plate 1010 has a side length of 300 mm and a thickness of 1 mm.

[0034] In this embodiment, the scattering suppression simulation diagram is as follows: Figure 4 As shown, the scattering intensity of the low-scattering encoded stealth superstructure at various angles under normally incident electromagnetic wave illumination (incident from above to below, with the structure at the bottom). From Figure 4 As can be seen, after setting up the square array 20, the electromagnetic waves are dispersed to multiple directions, and the specular scattering is significantly suppressed, which means that a diffuse reflection effect can be formed, and the scattering reduction effect can reach -14dB (11GHz).

[0035] To investigate the broadband camouflage mechanism within the 8-18 GHz frequency band, a low-scattering structure was designed and preliminarily experimentally verified. 3D-printed prototypes of the all-metal low-scattering structure at the unit level were fabricated. Reflectivity testing experiments were conducted, and the comparison between simulation and test results is as follows: Figure 5 As shown, where, Figure 5 The curve with a dot represents the reflectivity reduction value obtained from the simulation design of the low-scattering coded stealth superstructure, while the curve without a dot represents the reflectivity reduction value obtained from the experimental measurement of the low-scattering coded stealth superstructure sample. Experimental results show that the designed and fabricated metallic sample achieved a scattering cross-section reduction of better than or equal to -10 dB in the 8-18 GHz frequency range. However, the test results for the metallic sample show frequency drift compared to the simulation results. Frequency drift is a relatively common phenomenon in electromagnetic camouflage structures. Figure 5 The reflection test curve and the simulation design curve are consistent in terms of reduction effect, which proves the correctness and effectiveness of the design method and design process, and verifies the rationality of the design method of all-metal low-scattering coded stealth superstructure.

[0036] Comparative Example 1 In this comparative example, only a base plate 10 is provided, with dimensions of 300mm × 300mm. The square array 20 is not provided above the base plate 10. When only the metal base plate 10 is provided, it is a strong scatterer and has no scattering suppression function. Figure 3 contrast Figure 6 Its scattering is significantly lower, and it has scattering suppression function.

[0037] In this comparative example, the simulation diagram of scattering suppression is as follows: Figure 7 As shown, from Figure 7 It can be seen that when only the light base plate 10 is set, the vertical specular scattering is very concentrated and the magnitude is very large, that is, strong scattering is formed in the specular direction.

[0038] The low-scattering coded stealth superstructure proposed in this invention realizes a low-scattering structure based on all metal, which can reduce the scattering performance of metal parts. Therefore, it can be used in ship skin structures to improve the stealth of ship skin structures in radar detection scenarios, thereby improving their survivability.

[0039] This invention proposes a method for fabricating a low-scattering coded stealth superstructure.

[0040] In this preferred embodiment, a method for fabricating a low-scattering coded stealth superstructure as described above includes the following steps: Step S10: Cut multiple metal plates and base plate 10 from the metal sheet using a cutting method; In step S20, the metal plates are installed on the base plate 10 in an array, and the metal plates and the base plate 10 are fixed together by metal columns 30.

[0041] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A low-scattering coded stealth superstructure, characterized in that, The system includes a base plate and a square array mounted on top of the base plate. The square array consists of multiple arrays of metal plates arranged at intervals. The metal plates are available in various size combinations. The base plate is made of metal, and the metal plates are spaced apart from the base plate and fixedly connected by metal columns. Each metal plate includes multiple first squares and multiple second squares, which are arranged in a random coding manner. The first squares are single-piece structures, and the second squares include multiple spaced square units. The number of square units in the second square is the same both horizontally and vertically. The outer frame dimensions of the first squares are the same as those of the second squares.

2. The low-scattering coded stealth superstructure as described in claim 1, characterized in that, The base plate is a square plate, and the square plate array includes multiple square metal plates.

3. The low-scattering coded stealth superstructure as described in claim 1, characterized in that, The distance between the square array and the base plate is 2mm~4mm.

4. The low-scattering coded stealth superstructure as described in claim 1, characterized in that, The thickness of the metal plate in the square array is 0.4mm to 0.6mm.

5. The low-scattering coded stealth superstructure as described in claim 1, characterized in that, The thickness of the base plate is 0.5mm to 1.5mm.

6. The low-scattering coded stealth superstructure as described in claim 1, characterized in that, The top and bottom surfaces of all the metal plates in the square array are flush.

7. The low-scattering coded stealth superstructure as described in any one of claims 1 to 6, characterized in that, The metal plate and base plate are connected to the metal column by welding or bonding.

8. A method for fabricating a low-scattering coded stealth superstructure according to any one of claims 1 to 7, characterized in that, Includes the following steps: Multiple metal plates and a base plate are cut from a metal sheet using a cutting method; Metal plates are installed in an array on the base plate, and the metal plates and the base plate are fixed together by metal columns.

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