Marine radar electromagnetic wave shielding device and method

Abstract

The application discloses a marine radar electromagnetic wave shielding device and method, and relates to the technical field of electromagnetic shielding. The device comprises a shielding net; the shielding net comprises a metal wire woven net with a multilayer structure and a spacing device for spacing every two adjacent metal wire woven nets; wherein each metal wire woven net is formed by longitudinally and transversely interlaced joint of a plurality of longitudinal metal wires and a plurality of transverse metal wires, and an outer contour surface of each metal wire is divided into an outward reflection absorption surface and an inward reflection absorption surface. The application adopts integrated combination forming, realizes the function of efficiently weakening electromagnetic wave reflection. The complete set of devices not only has simple structure and good electromagnetic wave shielding effect, but also can comprehensively consider effective ventilation area at the installation opening, and is practical and reliable.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic shielding technology, and more specifically to a marine radar electromagnetic wave shielding device and method. Background Technology

[0002] Ship air inlets and outlets are typically designed into the ship's bulkheads, directly exposed to the marine environment, making the ship easily detectable by radar. This is because the large size of the air inlet and outlet openings and the complex and varied structures of the installed equipment (such as air filters) easily cause strong electromagnetic wave reflections, resulting in strong reflected signals being received by detection radar.

[0003] To avoid easy radar detection of ships, current methods often optimize the structural form of equipment at openings to reduce electromagnetic wave reflection intensity. However, limited by the main functions and structural design requirements of the installed equipment, this method has limited effectiveness in reducing electromagnetic wave reflection intensity and cannot work in conjunction with the ship's main structure to achieve the performance requirement of low radar electromagnetic wave reflection. In addition, the method of applying stealth materials is being gradually tested. However, due to the corrosive marine environment, stealth materials are prone to peeling off and require regular recoating, leading to increased ship maintenance and upkeep costs.

[0004] Therefore, there is an urgent need to propose a new electromagnetic wave shielding device and method for marine radar in order to reduce electromagnetic wave reflection and maintenance costs. Summary of the Invention

[0005] In view of this, the present invention provides a marine radar electromagnetic wave shielding device and method for reducing electromagnetic wave reflection and maintenance costs.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] On one hand, the present invention discloses a marine radar electromagnetic wave shielding device, including a shielding mesh;

[0008] The shielding mesh includes a multi-layered metal wire braided mesh and a spacer for separating each adjacent two layers of metal wire braided mesh.

[0009] Each layer of the metal wire mesh is composed of several longitudinal and several transverse metal wires interlaced together, and the outer contour surface of each metal wire is divided into an outward reflection and absorption surface and an inward reflection and absorption surface.

[0010] Preferably, the above-mentioned marine radar electromagnetic wave shielding device further includes a frame for mounting the shielding net.

[0011] Preferably, the frame is formed by connecting multiple grooved frame components end to end, and the shielding mesh is embedded in the grooves of the frame components.

[0012] Preferably, each of the metal wires has multiple evenly spaced bends, with the longitudinal and transverse metal wires overlapping at the bends.

[0013] Preferably, the spacer includes a metal spacer bar.

[0014] Preferably, in the outer contour surface of each of the metal wires, the outward reflection absorption surface is an arc surface, the inward reflection absorption surface is a flat inclined surface, and the two flat inclined surfaces and one arc surface constitute the outer contour surface of the metal wire.

[0015] Preferably, the intersection of the arc surface and the flat inclined surface, as well as the intersection of two flat inclined surfaces, are all smoothed.

[0016] On the other hand, the present invention also discloses a method for shielding electromagnetic waves from marine radar, comprising the following steps:

[0017] By using a multi-layered metal wire mesh to receive incident electromagnetic waves, the incident electromagnetic waves can be repeatedly reflected between the layers of the metal wire mesh and gradually absorbed.

[0018] Preferably, in the multi-layer metal wire woven mesh, each layer of the metal wire woven mesh is woven together by several longitudinal metal wires and several transverse metal wires, and the outer contour surface of each metal wire is divided into an outward reflection absorption surface and an inward reflection absorption surface.

[0019] Preferably, the outer contour surface of the metal wire is smoothed as a whole.

[0020] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a marine radar electromagnetic wave shielding device and method, which has the following beneficial effects:

[0021] When an incident electromagnetic wave is received, it is repeatedly reflected and absorbed through a multi-layered woven metal wire mesh. This invention can effectively reduce electromagnetic reflection and enhance electromagnetic shielding effect. Moreover, this invention has a simple structure and low maintenance cost. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of the marine radar electromagnetic wave shielding device provided in an embodiment of the present invention.

[0024] Figure 2This is a schematic diagram of a shielding mesh structure provided in an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of a single-layer metal wire braided mesh structure provided in an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of a metal spacer structure provided in an embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram of the cross-section of a single metal wire provided in an embodiment of the present invention.

[0028] Figure 6 This is a schematic diagram of the overall structure of a single metal wire provided in an embodiment of the present invention.

[0029] Figure 7 This is a schematic diagram of a single grooved frame component structure provided in an embodiment of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] One embodiment of the present invention discloses a marine radar electromagnetic wave shielding device, such as... Figure 1-3 As shown, the marine radar electromagnetic wave shielding device mainly consists of a shielding mesh 2 and a spacer device used to separate each adjacent two layers of woven metal wire mesh. The shielding mesh 1 is mainly composed of multiple layers of woven metal wire mesh 2-1. Each layer of woven metal wire mesh 2-1 is made of several metal wires 2-1-1 that are evenly interwoven in a crisscross pattern. The outer contour surface of each metal wire 2-1-1 is divided into an outward reflection and absorption surface and an inward reflection and absorption surface. The spacer device is used to ensure a certain spacing between each layer of shielding mesh in order to reduce the intensity of electromagnetic waves layer by layer.

[0032] like Figure 4 As shown, the spacer between each layer of woven wire mesh is a metal spacer 3.

[0033] like Figure 5 As shown, in this embodiment, the outward reflection absorption surface is an arc surface, and the inward reflection absorption surface is a flat inclined surface. Thus, the two flat inclined surfaces and the arc surface constitute the outer contour surface of the metal wire.

[0034] It should be noted that the cross-sectional shape of each metal wire 2-1-1 can also be other shapes. For example, in other embodiments, the outward reflection absorption surface is a plane, and the inward reflection absorption surface is a flat slope. However, it should be ensured that the intersections between the outward and inward reflection absorption surfaces, as well as between the inward and inward reflection absorption surfaces, are chamfered and smoothed to ensure that the overall appearance of the metal wire does not have obvious sharp corners, thus avoiding the formation of sharp corners that would enhance the electromagnetic wave reflection intensity. However, after multiple verifications... Figure 5 The smooth curved surface formed by the arc surface and the inclined plane shown is the optimal design for the outline of the metal wire.

[0035] The aforementioned marine radar electromagnetic wave shielding device also includes a frame 1 for mounting the shielding mesh 2, such as... Figure 6 As shown, the frame is formed by connecting multiple grooved frame components 1-1 end to end, and the shielding mesh 2 is embedded in the groove of the frame component 1-1. In this embodiment, the metal spacers 3 are located around the shielding mesh 2, so the metal spacers 3 can be hidden in the groove of the frame component, maximizing the permeability of the multi-layer metal wire woven mesh.

[0036] In other embodiments, when the area of ​​the shielding mesh 2 is large, in order to prevent the shielding mesh 2 from collapsing, cross-shaped reinforcing ribs can be added inside, and the cross section of the reinforcing ribs is the same as that of the metal wire.

[0037] For ease of installation, the frame, shielding mesh, and metal spacers are often assembled as a single unit.

[0038] In the aforementioned marine radar electromagnetic wave shielding device, each layer of woven metal wire mesh 2-1 forms a neat and uniform planar grid structure, such as... Figure 7 As shown, the single metal wire 2-1-1 has a bent structure, with the longitudinal and transverse metal wires contacting and overlapping at the bend to ensure that all metal wires 2-1-1 are in the same plane.

[0039] In the aforementioned marine radar electromagnetic wave shielding device, the arc surface, the flat inclined surface, and the intersection of two flat inclined surfaces are all rounded to avoid forming sharp corners and thus enhance the electromagnetic wave reflection intensity.

[0040] One embodiment of the present invention discloses a method for shielding electromagnetic waves of marine radar, which includes the following steps: using a multi-layer metal wire mesh to receive incident electromagnetic waves, so that the incident electromagnetic waves can be repeatedly reflected between the layers of metal wire mesh and gradually absorbed.

[0041] The above method can be implemented based on the marine radar electromagnetic wave shielding device provided in the embodiments of the present invention. In the multi-layer metal wire woven mesh, each layer of metal wire woven mesh 2-1 is woven from several metal wires 2-1-1 in a crisscross pattern. The outer contour surface of each metal wire 2-1-1 is divided into an outward reflection absorption surface and an inward reflection absorption surface. Specifically, the outward reflection absorption surface is an arc surface and the inward reflection absorption surface is a flat inclined surface. The two flat inclined surfaces and one arc surface constitute the outer contour surface of the metal wire, with the arc surface facing outward and the flat inclined surface facing inward. Here, the arc surface facing outward means that the arc surface faces the direction in which the electromagnetic wave is incident on the shielding device, and the flat inclined surface facing inward means that the flat inclined surface is away from the direction in which the electromagnetic wave is incident on the shielding device.

[0042] The arc surface of metal wire 2-1-1 is used to disperse and reflect electromagnetic waves to the upper layer of metal mesh flat and inclined surface or to disperse them to the external space of the bulkhead through the first layer of shielding mesh. The flat and inclined surface of metal wire 2-1-1 is used to reflect electromagnetic waves reflected back by the next layer of metal wire woven mesh 2-1, so as to realize the purpose of reducing the intensity of electromagnetic waves by repeatedly reflecting electromagnetic waves between the layers of metal wire woven mesh 2-1.

[0043] Four interconnected metal spacers 3 are installed between each layer of woven wire mesh 2-1 to fix the spacing between each layer, enabling electromagnetic waves to repeatedly pass through and be reflected between the woven wire meshes 2-1. The number of woven wire mesh layers 2-1, the spacing, the grid unit structure size, and the wire diameter can be set according to actual shielding requirements and special requirements such as airflow and resistance at the installation opening of the radar electromagnetic wave shielding device.

[0044] This invention patent solves the problems of poor shielding effect and high maintenance and upkeep costs of traditional radar electromagnetic wave shielding devices. The entire device adopts an integrated design, which is convenient to install and effectively ensures maintainability.

[0045] The principles of this invention will be further explained below.

[0046] As an embodiment of the present invention, the marine radar electromagnetic wave shielding device is installed in the cabin and the intake and exhaust channels. When the marine radar electromagnetic wave shielding device receives the incident radar electromagnetic wave, the first layer of metal wire mesh absorbs 15% to 30% of the current electromagnetic wave and converts it into heat energy, thereby realizing the electromagnetic wave energy conversion function. 20% to 30% of the current electromagnetic wave returns to the external space of the cabin wall by reflection, and the remaining electromagnetic wave passes through the first layer of metal wire mesh to the next layer.

[0047] Next, the electromagnetic waves that pass through the first layer of wire mesh undergo the same process again in the second layer. The second layer absorbs 15%–30% of the transmitted electromagnetic waves and converts them into heat energy, thus achieving the electromagnetic wave energy conversion function. Simultaneously, 20%–30% of the transmitted electromagnetic waves are reflected again, and the reflected waves are again absorbed and reflected by the first layer of wire mesh, returning to the external space of the bulkhead. The remaining electromagnetic waves continue to pass through the second layer of wire mesh to the next, and so on. Electromagnetic waves that pass through the final layer of wire mesh enter the cavity of the installation opening, are reflected by the internal structure, and then return to the shielding device.

[0048] Therefore, when the incident electromagnetic wave passes through the shielding mesh layer by layer, it will be reflected. The reflected electromagnetic wave is repeatedly reflected between the layers of metal wire mesh and gradually absorbed. Finally, a small amount of the reflected electromagnetic wave returns to the outside space of the bulkhead in a divergent manner.

[0049] The number of layers, spacing, grid unit structure size, and wire diameter of the metal wire mesh determine the strength of the electromagnetic waves returning to the external space of the bulkhead, and ultimately determine the effect of the shielding device in reducing the intensity of reflected electromagnetic waves.

[0050] The metal wire can be made of copper, titanium, stainless steel, etc. In addition to metal wire shielding, non-metallic conductive fibers and their composite materials can also be used. The spacing between every two layers of metal mesh should not be less than 10mm.

[0051] To enhance the reflectivity of the shielding mesh, the surface roughness Ra value of the metal wire should be at least 0.8.

[0052] As an embodiment of the present invention, the design and selection of the number of layers, spacing, grid unit structure size and wire diameter of the metal wire braided mesh also need to take into account special requirements such as the air volume and resistance at the installation opening.

[0053] To verify the technical effect of this invention, the shielding effect of the marine radar electromagnetic wave shielding device can be verified by the radar cross section (RCS). Assuming that the radar electromagnetic wave incident on the shielding device is in the X or Ku band (frequency 8-18 GHz), the intensity of the electromagnetic wave received by the receiving radar is generally represented by the radar cross section (RCS) σ:

[0054] σ=-((4π) 2 R 4 P r ) / (G t G r λ 2 P t )

[0055] In the formula: P t For the transmitted radar power, P rFor radar receiving power, G t For radar transmission gain, G r Let σ be the receiving antenna gain, λ be the radar wavelength, and R be the distance from the target to the radar. σ is proportional to the fourth power of R. Once the radar design parameters are determined, reducing the target's RCS can significantly reduce the radar's detection range. Clearly, in practical applications, the smaller the value of σ, the better the shielding performance of the shielding device.

[0056] Example: For far-field radar cross section (RCS) testing, the incident radar electromagnetic wave frequency f (unit: GHz), and the radar cross section of the metal wire mesh in the marine radar electromagnetic wave shielding device with n layers are represented by σ. n (Unit: m) 2 ; n refers to the number of layers of the metal wire mesh, n = 0, 1, 2…), the diameter of the semi-circular wire in the arc surface of the metal wire is d (unit: mm), the spacing between the metal wires in the woven metal wire mesh is δ (unit: mm), the spacing between every two layers of metal mesh is δ0, the overall opening length of the shielding mesh in the marine radar electromagnetic wave shielding device is l1 (unit: mm), and the overall width is l2 (unit: mm). It is generally believed that σ n It is a function of the number of layers n, the diameter d of the semicircular surface of the metal wire, the wire spacing δ, and the opening sizes l1 and l2.

[0057] σ n =f(n,d,δ,l1,l2)

[0058] When f = 10 GHz, d = 2.5 mm, δ = 10 mm, δ0 = 10 mm, l1 = 1000 mm, and l2 = 1000 mm, the frequency f of the reflected radar electromagnetic wave is... n The variation with the number of floors is shown in the table below:

[0059] <![CDATA[σ n (m 2 )]]> 0.82 0.29 0.11 0.04 0.01

[0060] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A marine radar electromagnetic wave shielding device, characterized in that, Including shielding mesh; The shielding mesh includes a multi-layered metal wire braided mesh and a spacer for separating each adjacent two layers of metal wire braided mesh. Each layer of the woven metal mesh is composed of several longitudinal and several transverse metal wires interlaced together. The outer contour surface of each metal wire is divided into an outward reflection and absorption surface and an inward reflection and absorption surface. The outward reflection and absorption surface is an arc surface facing the direction of electromagnetic wave incidence, and the inward reflection and absorption surface is a flat inclined surface facing away from the direction of electromagnetic wave incidence. The two flat inclined surfaces and the arc surface constitute the outer contour surface of the metal wire. The intersection of the arc surface and the flat inclined surface, as well as the intersection of the two flat inclined surfaces, are all smoothed.

2. The marine radar electromagnetic wave shielding device according to claim 1, characterized in that, It also includes a frame for mounting the shielding mesh.

3. The marine radar electromagnetic wave shielding device according to claim 2, characterized in that, The frame is formed by connecting multiple grooved frame components end to end, and the shielding mesh is embedded in the grooves of the frame components.

4. The marine radar electromagnetic wave shielding device according to claim 1, characterized in that, Each of the metal wires has multiple evenly spaced bends, with the longitudinal and transverse metal wires overlapping at the bends.

5. The marine radar electromagnetic wave shielding device according to claim 1, characterized in that, The spacer includes metal spacers.

6. A method for shielding electromagnetic waves from marine radar, characterized in that, Includes the following steps, A multi-layered metal wire mesh is used to receive incident electromagnetic waves, allowing the incident electromagnetic waves to be repeatedly reflected and gradually absorbed between the layers of the metal wire mesh. Each layer of the metal wire mesh is woven from several longitudinal and several transverse metal wires. The outer contour surface of each metal wire is divided into an outward reflection and absorption surface and an inward reflection and absorption surface. The outward reflection and absorption surface is an arc surface facing the direction of electromagnetic wave incidence, and the inward reflection and absorption surface is a flat inclined surface facing away from the direction of electromagnetic wave incidence. The two flat inclined surfaces and the arc surface constitute the outer contour surface of the metal wire. The outer contour surface of the metal wire is smoothed as a whole.

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