Dual-polarization electromagnetic wave reflectivity large-dynamic-range real-time adjustable material plate

Abstract

The invention relates to the field of wave absorbing devices, and particularly discloses a dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate, which comprises a plurality of structural units which are periodically and repeatedly arranged, and each structural unit comprises a regulation and control layer, a first isolation layer, a wave absorbing layer, a second isolation layer and a metal substrate layer which are sequentially stacked from top to bottom, impedance matching is regulated and controlled through the regulation and control layer, and electromagnetic waves in respective corresponding polarization directions are absorbed through the metal patch patterns on the front side and the back side of the wave absorbing layer. An electronic signal regulation and control mode is adopted, the real-time reversible regulation and control function of the material plate on the electromagnetic wave reflectivity is achieved, the characteristic of large regulation and control range is achieved, and the electromagnetic wave reflection characteristic can be remarkably regulated; the material plate is light in weight, good cost economy and cost-effectiveness ratio can be achieved through simple circuit board design and component resistance value control, and an ideal material structure style is provided for equipment radar characteristic regulation and control.

Description

Technical Field

[0001] This application relates to the field of wave-absorbing devices, and in particular to a material plate with a large dynamic range and real-time adjustability of the reflectivity of dual-polarized electromagnetic waves. Background Art

[0002] With the rapid development of radar detection and identification systems, precision strike weapons, etc., the survival space of equipment is continuously compressed. Therefore, radar signature stealth design needs to be carried out on the equipment. Radar signature stealth design can be achieved through various technical means such as shape design and stealth wave-absorbing materials. Among them, stealth wave-absorbing materials can absorb electromagnetic waves irradiated on the surface of the material plate, thereby effectively reducing the reflection intensity of electromagnetic waves. Real-time adjustable wave-absorbing materials, also known as reconfigurable electromagnetic wave absorbing materials, are a relatively novel type of electromagnetic wave reflection characteristic regulation materials. Real-time adjustable wave-absorbing materials can dynamically adjust the electromagnetic wave reflectivity in real time, thereby dynamically adjusting the overall scattering characteristics of the target, and cooperating with sensing and control modules to form an intelligent adaptive electromagnetic signature stealth regulation system, which can automatically and adaptively process radar detection threats.

[0003] Early adjustable material plates included an array structure composed of butterfly units. The butterfly units were formed by a multi-layer structure of a metal substrate, a dielectric plate, and a metal pattern layer loaded with adjustable components, and then multiple butterfly units were regularly arranged to form an array, constituting the entire material plate. PIN diodes were loaded in the slits of the butterfly units, and the resistance change caused by different magnitudes of current in the forward conduction section of the diode was used to realize the resistance regulation of the device, thereby regulating the reflectivity / absorptivity of the entire material plate array. The regulation range of the reflectivity could reach 20 dB, but limited by the symmetry of the unit, it was only effective for electromagnetic waves in a single polarization direction, restricting its application value.

[0004] The material plate proposed by Chambers can achieve high preparation accuracy, and then realize the real-time adjustable absorption of electromagnetic waves. This material plate structure pattern has gradually become the main pattern in the design of electromagnetic wave reflectivity adjustable material plates. In order to overcome the dual-polarization property, Jiang Jianjun et al. designed an adjustable material plate symmetric in the X-Y direction on the basis of Chambers et al., using a quarter-disk splicing pattern and loading a resistance-adjustable device at the connection of the disks, which could achieve a reflectivity reduction of -10 dB magnitude in a wide frequency band. L.L. Qiu et al. proposed a unit pattern based on a square loop unit loaded with components in 2023, and realized an adjustable electromagnetic wave absorption effect based on a relatively symmetric structure in the X-Y direction. However, its pattern layer was relatively simple, so there were fewer design variables. The thickness of the material plate was 75 microns, and the structural strength was relatively limited.

[0005] The mechanical regulation of the electromagnetic wave absorption structure is another structural form for realizing adjustable electromagnetic wave absorption. It mainly utilizes the real-time reversible elastic change of the unit size to achieve the regulation of the wave absorption characteristics. Some scholars proposed a mechanical regulation unit in 2023, which adopted an inflatable origami structure. By changing the structure height according to different inflation amounts, the regulation of the wave absorption characteristics was achieved. As the inflation amount gradually increased, the height of the origami air column continuously increased, and the wave absorption frequency band shifted to the low frequency. The mechanical regulation of the electromagnetic wave absorption material plate has the problems of slow response speed and relatively low regulation accuracy.

[0006] Currently, the problems existing in the design research of materials with real-time adjustable electromagnetic wave reflectivity mainly include limited polarization adaptability and difficulty in meeting the requirements of the full polarization characteristics in radar observation scenarios; the regulation range of reflectivity is relatively limited, and it is difficult to meet the large dynamic range required for the intelligent radar feature regulation of equipment. The too small dynamic range may lead to the need for a relatively large area of adjustable material plates, which may cause conformal application problems; it is difficult for the adjustable material plate to achieve the collaborative optimization design among design complexity, component cost, and performance, resulting in a relatively high engineering cost for the material structure with excellent performance and only a relatively low cost-effectiveness ratio. Summary of the Invention

[0007] Aiming at the problems of the prior art, the present application provides a material plate with a large dynamic range of real-time adjustable dual-polarization electromagnetic wave reflectivity.

[0008] The material plate with a large dynamic range of real-time adjustable dual-polarization electromagnetic wave reflectivity provided by the present application adopts the following technical solutions: A material plate with a large dynamic range of real-time adjustable dual-polarization electromagnetic wave reflectivity includes a plurality of structural units arranged in a periodic and repetitive manner. Each of the structural units includes a regulation layer, a first isolation layer, an absorption layer, a second isolation layer, and a metal substrate layer stacked in sequence from top to bottom, where: The regulation layer includes a first dielectric plate, and a square metal patch pattern is printed on the front surface of the first dielectric plate; The absorption layer includes a second dielectric plate. A first metal patch pattern is printed on the front surface of the second dielectric plate, and a second metal patch pattern is printed on the back surface of the second dielectric plate; both the first metal patch pattern and the second metal patch pattern include a square pattern and slits provided on both sides of the square pattern, and electronic components are arranged in the slits; Among the multiple structural units, all the electronic components on the front surfaces of the second dielectric plates are connected in series, and all the electronic components on the back surfaces of the second dielectric plates are connected in series; in each structural unit, the series connection direction of the electronic components on the front surface of the second dielectric plate is orthogonal to the series connection direction of the electronic components on the back surface of the second dielectric plate.

[0009] Furthermore, the electronic component is a PIN diode.

[0010] The regulation layer plays the role of regulating impedance matching, guiding the electromagnetic wave energy into the wave-absorbing layer for absorption. At the same time, the regulation layer also plays the role of regulating the wave-absorbing frequency band. The larger the size of the square metal patch pattern, the lower the wave-absorbing frequency band. By selecting an appropriate size, the square metal patch pattern of the regulation layer will produce a resonance effect with the metal patch pattern of the wave-absorbing layer, increasing the absorption rate of electromagnetic waves and expanding the dynamically adjustable range of the reflectivity.

[0011] Power is supplied to the electronic component (PIN diode) through the feeder line, and a strong resonance current is formed in the wave-absorbing layer, thereby converting the electromagnetic wave energy into heat loss and achieving excellent electromagnetic wave absorption effect. By adjusting the current or voltage, using the resistance change caused by different magnitudes of current within the forward conduction section of the PIN diode, the resistance of the PIN diode is regulated, thereby regulating the reflectivity / absorption rate of the entire material plate array.

[0012] The metal patch patterns on both the front and back sides of the second dielectric plate absorb the electromagnetic waves in their respective corresponding polarization directions, thereby having excellent polarization adaptability. By isolating the metal patch patterns on both the front and back sides through the second dielectric plate, the absorption in the two polarization directions is prevented from forming coupling interference. At the same time, compared with the single-sided cross-shaped metal patch pattern in the prior art, the present application sets the metal patch patterns on both the front and back sides, which can simplify the feeder network and is thus beneficial to improving the wave absorption rate.

[0013] Through the series unit design, the entire material plate does not require vias and additional power supply layers and isolation layers, with a simple form, achieving good economy while ensuring a strong wave absorption effect.

[0014] Both the first isolation layer and the second isolation layer are made of low dielectric constant materials. The first isolation layer isolates the regulation layer from the wave-absorbing layer, and the second isolation layer isolates the wave-absorbing layer from the metal substrate layer.

[0015] The metal substrate layer is made of a flat and smooth conductive metal plate such as copper or aluminum, with a thickness of 1 mm - 5 mm. The metal substrate layer can ensure the effective absorption of electromagnetic waves by the material plate and at the same time isolate the wave-absorbing material plate from the pasted part.

[0016] Furthermore, the first dielectric plate is a single-sided copper clad laminate with a side length of 10 mm - 15 mm.

[0017] Furthermore, the thickness of the first dielectric plate is 0.075 mm - 1 mm.

[0018] Considering that the relative dielectric constant range of the first dielectric plate is usually between 2.00 and 5.00, while the relative dielectric constant of free space is 1, an overly thick first dielectric plate will form a large impedance mismatch, resulting in a poor wave absorption effect or difficulty in optimization. Therefore, the thickness of the first dielectric plate is usually less than 1 mm.

[0019] Further, the side length of the square metal patch pattern above the first dielectric plate is 2 mm - 9 mm.

[0020] According to the resonance absorption principle, the side length of the square metal patch pattern is related to the center frequency of the strong absorption frequency band. The larger the side length, the smaller the center frequency of the absorption frequency band. By selecting an appropriate side length of the square metal patch pattern, the square metal patch pattern of the regulation layer will produce a resonance effect with the metal patch pattern of the absorption layer, increasing the absorption rate of electromagnetic waves and expanding the dynamic adjustable range of the reflectivity.

[0021] Further, the second dielectric plate is a double-sided copper clad laminate with a side length of 10 mm - 15 mm.

[0022] Further, the side length of the square pattern above the second dielectric plate is 1 mm - 7.5 mm.

[0023] Considering the space reserved for the welds of electronic components, the patterns on both sides of the welds, and the feeder, the upper limit of the side length of the square pattern is taken as half of the side length of the second dielectric plate.

[0024] Further, the width of the slit is 0.2 mm - 2 mm.

[0025] The slit can form a capacitor, thereby regulating the absorption frequency. The smaller the slit width, the smaller the corresponding capacitor and the higher the corresponding resonance frequency. In addition, the slit width should be close to the pitch of the solder feet of the electronic components. Therefore, the width of the slit should be reasonably designed based on the above basis.

[0026] Further, both the first isolation layer and the second isolation layer are made of composite material foam or honeycomb board.

[0027] Further, the thickness of both the first isolation layer and the second isolation layer is 1 mm - 10 mm.

[0028] The composite material foam or honeycomb board has a low dielectric constant and a low density, which helps to achieve the lightweight design of the material board while achieving effective isolation.

[0029] In summary, the present application includes the following beneficial technical effects: The reflectivity amplitude adjustable property of a dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material board provided by the present application covers the entire X-band, has good broadband characteristics, and can adapt to various radar detection and observation systems. The material board has achieved lightweight, and through a simple circuit board design and component resistance control, it can achieve good cost economy and cost-effectiveness, providing an ideal material structure style for the radar feature regulation of equipment. Description of the Drawings

[0030] Figure 1It is a schematic structural diagram of a structural unit of an embodiment of the present application; Figure 2 It is a schematic diagram of a square metal patch pattern of the first dielectric plate of the regulation layer in an embodiment of the present application; Figure 3 It is the first metal patch pattern on the front of the second dielectric plate of the wave-absorbing layer in an embodiment of the present application; Figure 4 It is the second metal patch pattern on the back of the second dielectric plate of the wave-absorbing layer in an embodiment of the present application; Figure 5 It is the limit case of the reflectivity regulation curve of a material plate with a large dynamic range of real-time adjustable reflectivity of dual-polarized electromagnetic waves in an embodiment of the present application.

[0031] Reference numerals: 1, square metal patch pattern; 2, first dielectric plate; 3, first isolation layer; 4, first metal patch pattern; 5, second dielectric plate; 6, second metal patch pattern; 7, second isolation layer; 8, metal substrate layer; 9, PIN diode. Detailed implementation manners

[0032] The following further describes the present application in detail with reference to the attached Figures 1-5 drawings.

[0033] An embodiment of the present application discloses a material plate with a large dynamic range of real-time adjustable reflectivity of dual-polarized electromagnetic waves. The material plate with a large dynamic range of real-time adjustable reflectivity of dual-polarized electromagnetic waves includes a plurality of periodically and repetitively arranged structural units. Referring to Figure 1 , each structural unit includes a regulation layer, a first isolation layer 3, a wave-absorbing layer, a second isolation layer 7, and a metal substrate layer 8 stacked in sequence from top to bottom.

[0034] Referring to Figure 1 and Figure 2 , the regulation layer includes a first dielectric plate 2. The first dielectric plate 2 is a square single-sided copper-clad plate with a side length of 10 mm - 15 mm and a thickness of 0.075 mm - 1 mm. A square metal patch pattern 1 with a side length of 2 mm - 9 mm and a thickness of 0.017 mm - 0.035 mm is printed at the center of the front of the first dielectric plate 2.

[0035] Referring to Figure 1 , Figure 3 and Figure 4, the wave-absorbing layer includes a second dielectric plate 5, which is a square double-sided copper clad laminate with a side length of 10 mm - 15 mm. The front side of the second dielectric plate 5 is printed with a first metal patch pattern 4, and the back side of the second dielectric plate 5 is printed with a second metal patch pattern 6. The thicknesses of both the first metal patch pattern 4 and the second metal patch pattern 6 are 0.017 mm - 0.035 mm, and they include a square pattern and slits provided on both sides of the square pattern. The side length of the square pattern is 1 mm - 7.5 mm, and the width of the slit is 0.2 mm - 2 mm. PIN diodes 9 are loaded in the slits. One side of each slit is connected to a feeder for powering the PIN diode 9, and the width of the feeder is 0.2 mm - 2 mm.

[0036] In a material plate composed of multiple structural units, all the PIN diodes 9 on the front side of the second dielectric plates 5 are connected in series, and all the PIN diodes 9 on the back side of the second dielectric plates 5 are connected in series; in each structural unit, the series connection direction of the PIN diodes 9 on the front side of the second dielectric plate 5 is orthogonal to the series connection direction of the PIN diodes 9 on the back side of the second dielectric plate 5.

[0037] Specifically, referring to Figure 3 , the first metal patch pattern 4 on the front side of the second dielectric plate 5 includes a square pattern at the center and slits on the left and right sides of the square pattern, and a PIN diode 9 is welded in each slit. The polarity directions of the multiple PIN diodes 9 are the same. For example, the left side is the positive pole and the right side is the negative pole, and the PIN diodes 9 on the front sides of the multiple second dielectric plates 5 form a series connection through two feeders on the left and right.

[0038] Referring to Figure 4 , the second metal patch pattern 6 on the back side of the second dielectric plate 5 includes a square pattern at the center and slits on the upper and lower sides of the square pattern, and a PIN diode 9 is welded in each slit. The polarity directions of the multiple PIN diodes 9 are the same. For example, the lower side is the positive pole and the upper side is the negative pole, and the PIN diodes 9 on the back sides of the multiple second dielectric plates 5 form a series connection through two feeders on the upper and lower.

[0039] The first isolation layer 3 and the second isolation layer 7 are made of low-dielectric-constant materials such as composite foam or honeycomb board, and their thicknesses are both 1 mm - 10 mm. The first isolation layer 3 isolates the regulation layer from the wave-absorbing layer, and the second isolation layer 7 isolates the wave-absorbing layer from the metal substrate layer 8.

[0040] The metal substrate layer 8 is made of a flat and smooth conductive metal plate such as copper or aluminum, and its thickness is 1 mm - 5 mm.

[0041] A preparation method of a material plate with a large dynamic range and real-time adjustable reflectivity of dual-polarized electromagnetic waves includes the following steps: Step 1, preparation of the regulation layer: The single-sided copper clad laminate is processed by an etching process to obtain a first dielectric plate 2 with a square metal patch pattern 1 printed on the front surface.

[0042] Step 2, preparation of the wave-absorbing layer: The front and back surfaces of the double-sided copper clad laminate are respectively processed by an etching process to obtain a second dielectric plate 5 with a first metal patch pattern 4 and a second metal patch pattern 6 printed on the two surfaces; the PIN diodes 9 are welded to the front and back surfaces of the second dielectric plate 5 according to the pre-designed positive and negative directions, and then the control feeder is welded.

[0043] Step 3, assembly of a single structural unit: The regulation layer, the first isolation layer 3, the wave-absorbing layer, the second isolation layer 7 and the metal substrate layer 8 are stacked in sequence from top to bottom, and are connected by means such as glue bonding and high-precision plastic screws. Since there are protrusions on the surface of the second dielectric plate 5 loaded with PIN diodes 9, grooves for accommodating the PIN diodes 9 are provided at the corresponding positions of the first isolation layer 3 and the second isolation layer 7 to prevent the first isolation layer 3 or the second isolation layer 7 from squeezing the PIN diodes 9.

[0044] Step 4, connection of multiple structural units: The PIN diodes 9 on the front and back surfaces of the second dielectric plate 5 in multiple structural units are respectively connected in series according to the pre-designed directions, multiple structural units are combined into a material plate, and the metal substrate layer 8 is attached to the target surface.

[0045] The PIN diodes 9 are fed by a feeder network, a preset DC current or voltage is applied, and the electromagnetic wave reflectivity is regulated in real time. The results are as Figure 5 shown. In the non-powered state, the material plate is in a state close to total reflection, and the reflectivity is basically equal to 0 dB. In the powered state, the material plate is in a state of absorbing electromagnetic waves. With different applied currents and voltages, the absorption rate / reflectivity of the material plate is also different, and the reflectivity can be arbitrarily adjusted in the space constrained by the two curves. In the optimal absorption state, the dual-polarization reflectivity of the material is expected to reach -26 dB, and the electromagnetic wave absorption effect is excellent. The absorption effect of electromagnetic waves can be continuously and precisely adjusted between 0 dB and the optimal absorption state, so as to realize real-time, reversible and high-precision regulation of the electromagnetic scattering characteristics.

[0046] The above are all preferred embodiments of this application, and the protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape and principle of this application should be covered within the protection scope of this application.

Claims

1. A dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate, characterized by: It comprises a plurality of structural units arranged repeatedly in a periodic manner, each of which comprises a regulating layer, a first isolation layer, an absorbing layer, a second isolation layer and a metal substrate layer stacked in sequence from top to bottom, wherein: The regulating layer comprises a first dielectric plate, a front surface of which is printed with a square metal patch pattern; The absorbing layer includes a second dielectric plate, a first metal patch pattern is printed on the front side of the second dielectric plate, and a second metal patch pattern is printed on the back side of the second dielectric plate; the first metal patch pattern and the second metal patch pattern both include a square pattern and slits arranged on both sides of the square pattern, and electronic components are arranged in the slits; In the plurality of said structural units, all the electronic components on the front side of the second dielectric plate are connected in series, and all the electronic components on the back side of the second dielectric plate are connected in series; in each of said structural units, the series connection direction of the electronic components on the front side of the second dielectric plate is orthogonal to the series connection direction of the electronic components on the back side of the second dielectric plate.

2. The dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate according to claim 1, characterized in that: The electronic component is a PIN diode.

3. The dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate according to claim 1, characterized in that: The first dielectric plate is a single-sided copper-clad plate with a side length of 10 mm to 15 mm.

4. The dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate according to claim 3, characterized in that: The thickness of the first dielectric plate is 0.075 mm-1 mm.

5. The dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate according to claim 4, characterized in that: The side length of the square metal patch pattern on the first dielectric plate is 2 mm-9 mm.

6. The dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate according to claim 1, characterized in that: The second dielectric plate is a double-sided copper-clad plate with a side length of 10 mm to 15 mm.

7. The dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate according to claim 6, characterized in that: The side length of the square pattern on the second dielectric plate is 1 mm-7.5 mm.

8. The dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate according to claim 7, characterized in that: The width of the slit is 0.2 mm-2 mm.

9. The dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate according to claim 1, characterized in that: The first isolation layer and the second isolation layer are both made of composite foam or honeycomb board.

10. The dual-polarization electromagnetic wave reflectivity large dynamic range real-time adjustable material plate according to claim 9, characterized in that: The thickness of the first isolation layer and the second isolation layer are both 1 mm-10 mm.

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