Ultra-wideband radar cross section reduction structure and equipment

Abstract

The invention discloses an ultra-wideband radar cross section reduction structure and equipment. The ultra-wideband radar cross section reduction structure comprises a metal floor and a metal surface layer formed on the metal floor, wherein the metal surface layer comprises a plurality of sub-surfaces which are sequentially stacked in the direction away from the metal floor, each layer of sub-surface is formed by alternately arranging a plurality of metal sheets and a plurality of gaps, the number of the metal sheets in the sub-surface is increased layer by layer according to a preset increasing mode in the direction away from the metal floor, and the number of the metal sheets in the sub-surface is increased layer by layer in the direction away from the metal floor. The area of each metal sheet in the sub-surface is reduced layer by layer according to a preset area reduction mode; the distance between each metal sheet in each layer of sub-surface and the metal sheet or the metal floor of the next layer is the same, and the height between each metal sheet in each layer of sub-surface and the metal sheet or the metal floor of the next layer is reduced layer by layer according to a preset height reduction mode in the direction deviating from the metal floor. The structure is insensitive to the polarization direction, and the transportability of the working frequency band is good.

Description

Technical Field

[0001] The present invention relates to the technical field of radar cross section reduction, and in particular to an ultra-wideband radar cross section reduction structure and equipment. Background Art

[0002] Since the advent of radar detection technology, radar cross-sectional (RCS) reduction technology has also developed. As the operating bandwidth of radar antennas increases, broadband RCS reduction technology becomes increasingly important.

[0003] At present, there are many methods to achieve broadband RCS reduction, such as methods based on absorbing materials, methods based on shape technology, and methods based on electromagnetic metasurface technology. The method based on absorbing materials has the advantages of wide working bandwidth and good reduction effect, but its volume is large, its strength is small, and it is difficult to conform to airborne equipment, so it is often used to build microwave darkrooms, and its application in the defense field is relatively limited. The method based on shape technology mainly controls the direction and path of the induced current to achieve RCS reduction, mainly including grooving, using various special structures represented by bionics and fractals, etc. The main disadvantage of this method is that the working bandwidth is narrow and the reduction range is small. The main methods for achieving broadband RCS reduction based on electromagnetic metasurface technology can be divided into three categories: converting the polarization direction of the incident wave through the polarization conversion metasurface; absorbing the energy of the incident wave through the absorber; and achieving phase cancellation through the chessboard metasurface.

[0004] The method based on electromagnetic metasurface technology has a wide working bandwidth and is easy to integrate with other devices, and is currently attracting widespread attention. However, compared with the high requirements, the working bandwidth of RCS reduction currently obtained still needs to be further improved to reduce the probability of radar detection of targets using RCS reduction structures. Summary of the invention

[0005] In order to solve the above technical problems, the embodiments of the present invention provide an ultra-wideband radar cross section reduction structure and device to solve the technical problem of insufficient bandwidth of the existing radar cross section reduction technology in the prior art.

[0006] An embodiment of the present invention provides an ultra-wideband radar cross-section reduction structure, the structure comprising:

[0007] Metal flooring;

[0008] The metal surface layer formed on the metal floor;

[0009] The metal surface layer includes a plurality of sub-surfaces stacked in sequence in a direction away from the metal floor, each layer of the sub-surface is composed of a plurality of metal sheets and a plurality of gaps arranged alternately, and along the direction away from the metal floor, the number of metal sheets in the sub-surface increases layer by layer according to a preset increasing method, and along the direction away from the metal floor, the area of ​​each metal sheet in the sub-surface decreases layer by layer according to a preset area decreasing method;

[0010] The distance between each metal sheet in each layer of sub-surface and the metal sheet or metal floor of the next layer is the same. Along the direction away from the metal floor, the height between each metal sheet in each layer of sub-surface and the metal sheet or metal floor of the next layer decreases layer by layer according to a preset height reduction method.

[0011] In a possible implementation manner of the first aspect, a dielectric layer is further included, and the dielectric layer is arranged between the metal sheet on each layer of the sub-surface and the metal sheet or metal floor of the next layer;

[0012] The dielectric layer is formed by stacking a number of dielectric plates arranged in sequence away from the metal floor, or is composed of foam plates.

[0013] In a possible implementation manner of the first aspect, the method further includes:

[0014] If the surface of the dielectric plate is connected to the metal sheet, it is not covered with metal. If the surface of the dielectric plate is not connected to the metal sheet, it is covered with a layer of metal.

[0015] If the bottom surface of the dielectric plate is connected to the surface of the dielectric plate of the next layer, no metal is applied. If the bottom surface of the dielectric plate is connected to the surface of the metal floor, a layer of metal is applied to serve as the metal floor.

[0016] In a possible implementation manner of the first aspect, the method further includes:

[0017] The metal sheets and gaps in each layer of sub-surface are squares with equal areas, and the number of metal sheets and gaps in each layer of sub-surface is equal.

[0018] In a possible implementation manner of the first aspect, the preset increasing manner is that the number of metal sheets in each layer of sub-surface is calculated according to the number of layers of the sub-surface, wherein the calculation formula for the number of metal sheets in the sub-surface is:

[0019] n=2 (2p-1)

[0020] Where n is the number of metal sheets in the p-th sub-surface, and p is the number of layers where the sub-surface is located.

[0021] In a possible implementation manner of the first aspect, the preset area reduction manner is that the area of ​​each metal sheet in the sub-surface is calculated according to the side length of the metal sheet, wherein the side length of each metal sheet in the sub-surface is:

[0022]

[0023] Where L is the side length of the metal floor, and p is the number of layers where the metal sheet is located.

[0024] In a possible implementation of the first aspect, the preset height reduction method is that along the direction away from the metal floor, the height of each metal sheet in each layer of sub-surface relative to the metal sheet of the previous layer is half the height of the sub-surface relative to the metal sheet of the next layer or the metal floor.

[0025] In a possible implementation manner of the first aspect, a height between each metal sheet in the first layer sub-surface and the metal floor is 25 mm.

[0026] In a possible implementation manner of the first aspect, the material of the metal floor, the metal sheet, and the metal is copper.

[0027] In a possible implementation manner of the first aspect, a dielectric constant of the foam board is 1.05.

[0028] An embodiment of the present invention provides a device for applying an ultra-wideband radar cross-section reduction structure provided by the embodiment of the present invention.

[0029] The technical solution of the present invention has the following advantages:

[0030] The ultra-wideband radar cross-section reduction structure provided by the embodiment of the present invention includes a metal floor and a metal surface layer formed on the metal floor; wherein the metal surface layer includes a plurality of sub-surfaces stacked in sequence away from the metal floor, each layer of sub-surfaces is composed of a plurality of metal sheets and a plurality of gaps arranged alternately, along the direction away from the metal floor, the number of metal sheets in the sub-surfaces increases layer by layer according to a preset increasing method, along the direction away from the metal floor, the area of ​​each metal sheet in the sub-surfaces decreases layer by layer according to a preset area decreasing method; each metal sheet in each layer of sub-surfaces has the same distance from the metal sheet or metal floor of the next layer, and along the direction away from the metal floor, each metal sheet in each layer of sub-surfaces has a height that decreases layer by layer according to a preset height decreasing method with respect to the metal sheet or metal floor of the next layer. The above structure solves the problem of insufficient bandwidth of the existing radar cross-section reduction technology, and the structure is insensitive to the polarization direction, and has good portability of the working frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 It is a structural diagram of an ultra-wideband radar cross-section reduction structure in an embodiment of the present invention;

[0033] Figure 2 A structural diagram of a dielectric plate of an ultra-wideband radar cross-section reduction structure according to an embodiment of the present invention;

[0034] Figure 3 It is a schematic diagram of copper cladding of each layer of dielectric board of the ultra-wideband radar cross section reduction structure in an embodiment of the present invention;

[0035] Figure 4 This is a diagram of the first layer sub-surface structure of the ultra-wideband radar cross section reduction structure in an embodiment of the present invention;

[0036] Figure 5 This is a diagram of the second layer sub-surface structure of the ultra-wideband radar cross section reduction structure in an embodiment of the present invention;

[0037] Figure 6 A structural diagram of two layers of sub-surfaces stacked in an ultra-wideband radar cross-section reduction structure in an embodiment of the present invention;

[0038] Figure 7 Schematic diagram of RCS value of ultra-wideband radar cross section reduction structure in an embodiment of the present invention;

[0039] Figure 8 Schematic diagram of the RCS reduction effect of the ultra-wideband radar cross-section reduction structure in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] 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.

[0041] The ultra-wideband radar cross section reduction structure provided by the embodiment of the present invention is as follows: Figure 1 As shown, Figure 1 The structure diagram of the radar cross section reduction for ultra-wideband includes:

[0042] Metal flooring;

[0043] The metal surface layer formed on the metal floor;

[0044] The metal surface layer includes a plurality of sub-surfaces stacked in sequence in a direction away from the metal floor, each layer of the sub-surface is composed of a plurality of metal sheets and a plurality of gaps arranged alternately, and along the direction away from the metal floor, the number of metal sheets in the sub-surface increases layer by layer according to a preset increasing method, and along the direction away from the metal floor, the area of ​​each metal sheet in the sub-surface decreases layer by layer according to a preset area decreasing method;

[0045] The distance between each metal sheet in each layer of sub-surface and the metal sheet or metal floor of the next layer is the same. Along the direction away from the metal floor, the height between each metal sheet in each layer of sub-surface and the metal sheet or metal floor of the next layer decreases layer by layer according to a preset height reduction method.

[0046] In this embodiment, the ultra-wideband radar scattering cross-section reduction structure includes a metal floor, and a metal surface layer formed by m layers of sub-surfaces stacked on the metal floor, wherein the sub-surfaces of each layer in this special metal surface layer are formed by alternating arrangement of metal sheets and gaps.

[0047] Taking the metal floor surface as the plane, sub-surfaces are stacked in sequence from the metal floor surface upward in the vertical direction, and the number of metal sheets in the sub-surfaces increases layer by layer. At the same time, the area of ​​each metal sheet in the sub-surfaces decreases layer by layer, and the height of each metal sheet in each layer of sub-surfaces and the metal sheet or metal floor of the next layer decreases layer by layer according to a preset height reduction method.

[0048] The final radar cross section reduction structure is given by It is composed of a metal sheet and a metal floor. The final radar cross-section reduction structure can achieve the best RCS reduction effect within.

[0049] In one embodiment, the dielectric layer is disposed between the metal sheet on each sub-surface layer and the metal sheet or metal floor of the next layer;

[0050] The dielectric layer is formed by stacking a number of dielectric plates arranged in sequence away from the metal floor, or is composed of foam plates.

[0051] In this embodiment, when stacking, a dielectric layer is used instead of an air plate to support each metal floor layer and the next metal floor layer, or to support each metal floor layer and the previous metal floor layer. The dielectric layer is formed by stacking multiple dielectric plates with copper clad surfaces.

[0052] The dielectric layer can also use a foam board with a dielectric constant of 1.05, so that the dielectric layer is very close to the air, making the propagation of radar waves in the dielectric board more uniform, avoiding the diffusion of radar wave energy in unintended directions due to scattering, and helping to control the scattering of radar waves in specific low-threat directions, thereby improving the stealth effect.

[0053] In one embodiment, if the surface of the dielectric plate is connected to the metal sheet, no metal is applied; if the surface of the dielectric plate is not connected to the metal sheet, a layer of metal is applied;

[0054] If the bottom surface of the dielectric plate is connected to the surface of the dielectric plate of the next layer, no metal is applied. If the bottom surface of the dielectric plate is connected to the surface of the metal floor, a layer of metal is applied to serve as the metal floor.

[0055] In this embodiment, if the bottom dielectric plate in the radar cross section reduction structure has copper on the back as the floor and copper on the top as the sub-surface, and other dielectric plates have copper on the top as the sub-surface and no copper on the back, the dielectric plate structure is as shown in FIG. Figure 2 Specifically, if the surface of the dielectric plate is to be connected to a metal sheet, no metal is applied, and the metal sheet is used as the surface of the dielectric plate; if the surface of the dielectric plate is not to be connected to a metal sheet, a layer of metal is applied, and then connected to the bottom surface of the dielectric plate of the upper layer.

[0056] If the bottom surface of the dielectric plate is connected to the surface of the dielectric plate of the next layer, no metal is covered. If the bottom surface of the dielectric plate is to be connected to the surface of the metal floor, it will become a metal floor directly after being covered with a layer of metal. Figure 3 shown.

[0057] In one embodiment, the metal sheets and gaps in each layer of sub-surface are squares with equal areas, and the number of metal sheets and gaps in each layer of sub-surface is equal.

[0058] In this embodiment, the metal sheets and gaps in each layer of the sub-surface are square, with equal areas, and the number of metal sheets and gaps is also equal, such as Figure 4 As shown, the first layer of sub-surface consists of 2 (2p-1) = 2 sides with lengths of The square metal sheet PEC1 and two square gaps with the same area as the metal sheet are arranged alternately.

[0059] In one embodiment, the preset increasing method is that the number of metal sheets in each layer of sub-surface is calculated according to the number of layers of the sub-surface, wherein the calculation formula for the number of metal sheets in the sub-surface is:

[0060] n=2 (2p-1)

[0061] Where n is the number of metal sheets in the p-th sub-surface, and p is the number of layers where the sub-surface is located.

[0062] In this embodiment, the number of metal sheets in the sub-surface of the p-th layer is 2 (2p-1) , such as Figure 4 As shown, the first layer of sub-surface consists of 2 (2p-1) = 2 square metal sheets PEC1 and 2 square gaps with the same area as the metal sheets are arranged alternately;

[0063] like Figure 5 As shown, the second layer sub-surface consists of 2 (2p-1) = 8 square metal sheets PEC2 and 8 gaps with the same area as the metal sheets are arranged alternately;

[0064] like Figure 6 As shown, the above two layers of sub-surfaces are stacked on a square metal floor GND with a side length of L = 200 mm. Note that S 金属地板面积 =S 金属片面积 +S 空隙面积 =2S 金属片面积 Finally, the RCS values ​​of the equal-area metal floor and the radar cross-section reduction structure are obtained as follows: Figure 7 The dashed and solid lines show the RCS reduction effect of the radar cross section reduction structure. Figure 8 As shown. Figure 8 It can be seen that the radar cross-section reduction structure can achieve an RCS reduction effect within.

[0065] In one embodiment, the preset area reduction method is that the area of ​​each metal sheet in the sub-surface is calculated according to the side length of the metal sheet, wherein the side length of each metal sheet in the sub-surface is:

[0066]

[0067] Where L is the side length of the metal floor, and p is the number of layers where the metal sheet is located.

[0068] In this embodiment, the area of ​​each metal sheet in the sub-surface is calculated according to the side length of the metal sheet, wherein the side length of each metal sheet in the sub-surface is:

[0069]

[0070] Where L is the side length of the metal floor, and p is the number of layers where the metal sheet is located.

[0071] As an example of this embodiment, the first layer of sub-surface consists of two side lengths of The square metal sheet PEC1 and two square gaps with the same area as the metal sheet are arranged alternately;

[0072] like Figure 5As shown, the second layer subsurface consists of 8 sides with lengths of The square metal sheet PEC2 and 8 gaps with the same area as the metal sheet are arranged alternately;

[0073] like Figure 6 As shown, the above two layers of sub-surfaces are stacked on a square metal floor GND with a side length of L = 200 mm. Note that S 金属地板面积 =S 金属片面积 +S 空隙面积 =2S 金属片面积 .

[0074] In one embodiment, the preset height reduction method is that along the direction away from the metal floor, the height of each metal sheet in each layer of sub-surface relative to the metal sheet of the previous layer is half of the height of the sub-surface relative to the metal sheet of the next layer or the metal floor.

[0075] In this embodiment, the preset height reduction method is that along the direction away from the metal floor, the height of each metal sheet in each layer of sub-surface relative to the metal sheet of the previous layer is half of the height of the sub-surface relative to the metal sheet of the next layer or the metal floor.

[0076] In one embodiment, the height between each metal sheet and the metal floor in the first layer sub-surface is 25 mm.

[0077] In this embodiment, the stacking rule is to ensure that the distance between all the metal sheets PEC1 constituting the first layer of the sub-surface and the nearest metal sheet (that is, the metal floor) below them is always h1=25mm; the distance between all the metal sheets PEC2 constituting the second layer of the sub-surface and the nearest metal sheet (some metal sheets are under the metal floor, and some metal sheets are under the metal sheet PEC1) below them is always h2=12.5mm, h2

[0078] In one embodiment, the metal floor, the metal sheet and the metal are made of copper.

[0079] In this embodiment,

[0080] In one embodiment, the dielectric constant of the foam board is 1.05.

[0081] In this embodiment, a foam board with a dielectric constant of 1.05 is used, which is very close to air.

[0082] An embodiment of the present invention provides a device for applying an ultra-wideband radar cross-section reduction structure provided by the embodiment of the present invention.

[0083] ​The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. An ultra-wideband radar cross-section reduction structure, characterized in that: include: Metal flooring; a metal surface layer formed on the metal floor; Wherein, the metal surface layer includes a plurality of sub-surfaces stacked in sequence in a direction away from the metal floor, each layer of the sub-surface is composed of a plurality of metal sheets and a plurality of gaps arranged alternately, and along the direction away from the metal floor, the number of metal sheets in the sub-surface increases layer by layer according to a preset increasing method, and along the direction away from the metal floor, the area of ​​each metal sheet in the sub-surface decreases layer by layer according to a preset area decreasing method; The distance between each metal sheet in each layer of the sub-surface and the metal sheet or the metal floor in the next layer is the same. Along the direction away from the metal floor, the height between each metal sheet in each layer of the sub-surface and the metal sheet or the metal floor in the next layer decreases layer by layer according to a preset height reduction method.

2. The ultra-wideband radar cross section reduction structure according to claim 1, characterized in that: It also includes a dielectric layer, which is arranged between the metal sheet of each layer of the sub-surface and the metal sheet or metal floor of the next layer; The dielectric layer is formed by stacking a plurality of dielectric plates arranged in sequence away from the metal floor, or is composed of foam plates, and the dielectric constant of the foam plates is 1.

05.

3. The ultra-wideband radar cross section reduction structure according to claim 2, characterized in that: Also includes: If the surface of the dielectric plate is connected to the metal sheet, no metal is applied; if the surface of the dielectric plate is not connected to the metal sheet, a layer of metal is applied; If the bottom surface of the dielectric plate is connected to the surface of the dielectric plate of the next layer, no metal is applied; if the bottom surface of the dielectric plate is connected to the surface of the metal floor, a layer of metal is applied to serve as the metal floor.

4. The ultra-wideband radar cross section reduction structure according to claim 1, characterized in that: It also includes: the metal sheets and the gaps in each layer of the sub-surface are squares with equal areas, and the number of the metal sheets and the gaps in each layer of the sub-surface is equal.

5. The ultra-wideband radar cross section reduction structure according to claim 1, characterized in that: The preset increasing method is that the number of metal sheets in each layer of the sub-surface is calculated according to the number of layers of the sub-surface, wherein the calculation formula for the number of metal sheets in the sub-surface is: n＝2 (2p-1) Wherein, n is the number of metal sheets in the p-th sub-surface, and p is the number of layers where the sub-surface is located.

6. The ultra-wideband radar cross section reduction structure according to claim 1, characterized in that: The preset area reduction method is that the area of ​​each metal sheet in the sub-surface is calculated according to the side length of the metal sheet, wherein the side length of each metal sheet in the sub-surface is: Wherein, L is the side length of the metal floor, and p is the number of layers where the metal sheet is located.

7. The ultra-wideband radar cross section reduction structure according to claim 1, characterized in that: The preset height reduction method is that along the direction away from the metal floor, the height of each metal sheet in each layer of the sub-surface relative to the metal sheet of the previous layer is half the height of the sub-surface relative to the metal sheet of the next layer or the metal floor.

8. The ultra-wideband radar cross section reduction structure according to claim 1, characterized in that: The height between each of the metal sheets and the metal floor in the sub-surface of the first layer is 25 mm.

9. The ultra-wideband radar cross section reduction structure according to claim 1, characterized in that: The metal floor, the metal sheet and the metal are made of copper.

10. A device, characterized in that: The device is used for applying the ultra-wideband radar cross-section reduction structure according to any one of claims 1 to 9.

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