Electromagnetic energy-scattering regulation and control method applied to imaging stealth of synthetic aperture radar
By acquiring the weed background environment and the SAR imaging scattering characteristics of radar vehicles, the electromagnetic energy-scattering with amplitude-phase distribution is designed to simultaneously regulate the metasurface structure, which solves the problem of insufficient stealth ability of traditional wave absorbing structures under SAR imaging, and achieves an efficient radar stealth effect.
Patent Information
- Application Number
- CN202411334586.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-24
- Publication Date
- 2025-04-25
AI Technical Summary
Traditional wave absorbing structures are difficult to meet the stealth needs under synthetic aperture radar (SAR) imaging, and cannot effectively suppress the scattering characteristics of SAR imaging.
By acquiring the weed background environment and the SAR imaging scattering characteristics of radar vehicles, electromagnetic energy-scattering with amplitude-phase distribution is designed to simultaneously regulate the metasurface structure and load it on the radar vehicle for stealth.
The perfect integration of radar vehicles and background environment has been achieved, and the imaging similarity reaches more than 87%, which significantly improves the stealth effect.
Smart Images
Figure CN119881889A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of synthetic aperture radar imaging stealth, and in particular relates to an electromagnetic energy-scattering control method applied to synthetic aperture radar imaging stealth. Background Art
[0002] Synthetic Aperture Radar (SAR) is a high-resolution imaging radar that works in the microwave band. Due to its all-day and all-weather characteristics, various satellite-borne and airborne SAR imaging radar technologies have developed rapidly in recent years. They are now widely used on various platforms such as land, sea, air, and space, and have become a killer weapon on the military battlefield. Traditional radars can only detect the overall reflection of the target, while SAR radars can perform high-resolution imaging of the local details of the target, which makes the traditional stealth technology that only reduces the reflection amplitude, such as wave-absorbing layers and unique appearance designs, sharply reduce its stealth capabilities. Summary of the invention
[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides an electromagnetic energy-scattering control method for synthetic aperture radar imaging stealth, which solves the problem that the traditional absorbing structure can only provide a single fixed scattering amplitude suppression effect and is difficult to meet the stealth requirements under SAR imaging.
[0004] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: an electromagnetic energy-scattering control method applied to synthetic aperture radar imaging stealth, comprising the following steps:
[0005] S1. Acquire SAR imaging of weed background environment and radar vehicle SAR imaging;
[0006] S2, respectively obtaining the scattering characteristics of the weed background environment SAR imaging and the scattering characteristics of the radar vehicle SAR imaging;
[0007] S3, obtaining the electromagnetic energy-scattering characteristics of the stealth metasurface according to the scattering characteristics of the weed background environment SAR imaging and the scattering characteristics of the radar vehicle SAR imaging;
[0008] S4. According to the electromagnetic energy-scattering characteristics of the stealth metasurface, an electromagnetic energy-scattering and simultaneously regulating metasurface structure with amplitude-phase distribution is constructed;
[0009] S5. Load the electromagnetic energy-scattering simultaneous control metasurface structure onto the radar vehicle to achieve synthetic aperture radar imaging stealth.
[0010] Furthermore, the expressions of the scattering characteristics of the weed background environment SAR imaging and the scattering characteristics of the radar vehicle SAR imaging in step S2 are respectively:
[0011]
[0012] in, The scattering characteristics of SAR imaging in weed background environment; Scattering characteristics of radar vehicle SAR imaging; Fast time; t m A is slow time; c A is the amplitude of the weed background echo signal; t is the amplitude characteristic of the radar vehicle signal; e is a natural constant; j is an imaginary unit; is the scattering characteristic of the transmitted signal; ψ c is the phase characteristic of the weed background echo signal; ψ t is the phase characteristic of the radar vehicle signal.
[0013] Furthermore, the step S3 is specifically as follows:
[0014] S301, making the scattering characteristics of the weed background environment SAR imaging consistent with the scattering characteristics of the radar vehicle SAR imaging, and obtaining the echo of the modulated signal:
[0015]
[0016] Where, p is the echo of the modulated signal; A c A is the amplitude of the weed background echo signal; t is the amplitude characteristic of the radar vehicle signal; e is a natural constant; j is an imaginary unit; ψ c is the phase characteristic of the weed background echo signal; ψ t is the phase characteristic of the radar vehicle signal;
[0017] S302. According to the echo of the modulated signal, the characteristics of the modulated signal are used as the amplitude and phase distribution that the stealth metasurface needs to satisfy, and the electromagnetic energy-scattering characteristics of the stealth metasurface are obtained.
[0018] Furthermore, in step S4, the electromagnetic energy-scattering simultaneous regulation metasurface structure includes a first unit structure and a second unit structure.
[0019] Furthermore, the first unit structure includes a first PET board with a length, width and height of pmm, pmm and dmm respectively, a first PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, a second PET board with a length, width and height of pmm, pmm and dmm respectively, and a second PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, which are connected in sequence from top to bottom; a square ring-shaped ITO transparent conductive film is attached to the upper surfaces of the first PET board and the second PET board; the width of the ring-shaped ITO transparent conductive film above the first PET board is d2, and the square resistance is Z2; the width of the ring-shaped ITO transparent conductive film above the second PET board is d1, and the square resistance is Z1.
[0020] Furthermore, the second unit structure includes a third PET board with a length, width and height of pmm, pmm and dmm respectively, a third PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, a fourth PET board with a length, width and height of pmm, pmm and dmm respectively, and a fourth PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, which are connected in sequence from top to bottom; a square ring-shaped ITO transparent conductive film is attached to the upper surface of the fourth PET board; the square ring-shaped ITO transparent conductive film attached to the upper surface of the fourth PET board has a width of d1 and a square resistance of z1.
[0021] The beneficial effects of the present invention are as follows: while satisfying the wave absorbing performance, the present invention selects a variety of unit structures with different phase responses for array arrangement to reshape the overall scattering characteristics. Among them, amplitude regulation can control the size of the metasurface scattering energy, and phase regulation can control the distribution of the scattering energy, thereby realizing the overall electromagnetic energy-scattering simultaneous regulation characteristics. When the electromagnetic energy-scattering simultaneous regulation metasurface is loaded on the radar vehicle, it is found that the stealth vehicle and the background environment are perfectly integrated, and the imaging similarity reaches more than 87%, indicating that the imaging result of the stealth vehicle is completely different from the real target object, but very similar to the surrounding environment, while the similarity coefficient between the vehicle loaded with the camouflage net structure and the background is only 5%, achieving good imaging stealth characteristics. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 The figure is a flow chart of the method of the present invention.
[0023] Figure 2 Schematic diagram of SAR imaging scattering characteristic distribution and super-structure unit design in an embodiment of the present invention.
[0024] Figure 3 It is the amplitude characteristic under the condition of 4-8 GHz TM polarized electromagnetic wave incident in the embodiment of the present invention.
[0025] Figure 4It is the amplitude characteristic under the condition of 8-12 GHz TM polarized electromagnetic wave incident in the embodiment of the present invention.
[0026] Figure 5 It is the amplitude characteristic under the condition of 12-18 GHz TM polarized electromagnetic wave incident in the embodiment of the present invention.
[0027] Figure 6 Schematic diagram of the experimental results of loading electromagnetic energy-scattering and simultaneously regulating the metasurface in an embodiment of the present invention.
[0028] in, Figure 2 (a) is a schematic diagram of the SAR imaging characteristics of a metal roof; Figure 2 (b) is a schematic diagram of SAR imaging characteristics of weed background; Figure 2 (c) Schematic diagram of the designed electromagnetic energy-scattering simultaneous control metasurface; Figure 2 (d) is a schematic diagram of the first unit structure of the design, where p = 5 mm, h = 6 mm, d = 0.375 mm, d2 = 1.5 mm; Figure 2 (e) is a schematic diagram of the designed second unit structure, where p = 5 mm, h = 6 mm, d1 = 0.8 mm; Figure 2 (f) is a schematic diagram of the amplitude and phase curves of the first unit structure and the second unit structure, wherein the blue curve represents the first unit structure and the red curve represents the second unit structure; DETAILED DESCRIPTION
[0029] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.
[0030] like Figure 1 As shown, in one embodiment of the present invention, an electromagnetic energy-scattering control method applied to synthetic aperture radar imaging stealth includes the following steps:
[0031] S1. Acquire SAR imaging of weed background environment and radar vehicle SAR imaging;
[0032] S2, respectively obtaining the scattering characteristics of the weed background environment SAR imaging and the scattering characteristics of the radar vehicle SAR imaging;
[0033] S3, obtaining the electromagnetic energy-scattering characteristics of the stealth metasurface according to the scattering characteristics of the weed background environment SAR imaging and the scattering characteristics of the radar vehicle SAR imaging;
[0034] S4. According to the electromagnetic energy-scattering characteristics of the stealth metasurface, an electromagnetic energy-scattering and simultaneously regulating metasurface structure with amplitude-phase distribution is constructed;
[0035] S5. Load the electromagnetic energy-scattering simultaneous control metasurface structure onto the radar vehicle to achieve synthetic aperture radar imaging stealth.
[0036] The expressions of the scattering characteristics of the weed background environment SAR imaging and the scattering characteristics of the radar vehicle SAR imaging in step S2 are respectively:
[0037]
[0038] in, The scattering characteristics of SAR imaging in weed background environment; Scattering characteristics of radar vehicle SAR imaging; Fast time; t m A is slow time; c A is the amplitude of the weed background echo signal; t is the amplitude characteristic of the radar vehicle signal; e is a natural constant; j is an imaginary unit; is the scattering characteristic of the transmitted signal; ψ c is the phase characteristic of the weed background echo signal; ψ t is the phase characteristic of the radar vehicle signal.
[0039] The step S3 is specifically as follows:
[0040] S301, making the scattering characteristics of the weed background environment SAR imaging consistent with the scattering characteristics of the radar vehicle SAR imaging, and obtaining the echo of the modulated signal:
[0041]
[0042] Where, p is the echo of the modulated signal; A c A is the amplitude of the weed background echo signal; t is the amplitude characteristic of the radar vehicle signal; e is a natural constant; j is an imaginary unit; ψ c is the phase characteristic of the weed background echo signal; ψ t is the phase characteristic of the radar vehicle signal;
[0043] S302. According to the echo of the modulated signal, the characteristics of the modulated signal are used as the amplitude and phase distribution that the stealth metasurface needs to satisfy, and the electromagnetic energy-scattering characteristics of the stealth metasurface are obtained.
[0044] In this embodiment, the background of SAR imaging stealth is set as weeds, and SAR imaging stealth is realized for vehicles. First, the SAR imaging effect of the weed background environment needs to be extracted, and the electromagnetic energy-scattering characteristics that the invisible cloak needs to meet are extracted by analyzing the scattering pattern characteristics, amplitude characteristics and phase characteristics; then, a metasurface structure with amplitude-phase distribution is designed within the ultra-wideband range to realize specific electromagnetic energy-scattering characteristics.
[0045] In step S4, the electromagnetic energy-scattering simultaneously regulates the metasurface structure including a first unit structure and a second unit structure.
[0046] In this embodiment, two basic unit structures are designed respectively, which not only have excellent broadband scattering suppression capability, but also can provide good phase difference, which is used for array arrangement to control scattering characteristics.
[0047] The first unit structure includes a first PET plate with a length, width and height of pmm, pmm and dmm respectively, a first PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, a second PET plate with a length, width and height of pmm, pmm and dmm respectively, and a second PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, which are connected in sequence from top to bottom; a square ring-shaped ITO transparent conductive film is attached to the upper surfaces of the first PET plate and the second PET plate; the width of the ring-shaped ITO transparent conductive film above the first PET plate is d2, and the square resistance is Z2; the width of the ring-shaped ITO transparent conductive film above the second PET plate is d1, and the square resistance is Z1.
[0048] The second unit structure includes a third PET plate with a length, width and height of pmm, pmm and dmm respectively, a third PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, a fourth PET plate with a length, width and height of pmm, pmm and dmm respectively, and a fourth PMI foam layer with a length, width and height of pmm, p mm and hmm respectively, which are connected in sequence from top to bottom; a square ring-shaped ITO transparent conductive film is attached to the upper surface of the fourth PET plate; the square ring-shaped ITO transparent conductive film attached to the upper surface of the fourth PET plate has a width of d1 and a square resistance of z1.
[0049] In this embodiment, p=5 mm, h=6 mm, d=0.375 mm, d1=1 mm, and d2=1.5 mm.
[0050] like Figure 2 As shown, in this embodiment, the above two unit structures are simulated, and their phase and amplitude responses are observed. The simulation results are as follows: Figure 2 (f) as shown. Figure 2(f) The upper part is the amplitude response of the two structures, and the lower part is the phase response. It can be seen that the two structural units can achieve effective regulation of amplitude and phase in a wide frequency range. For the first unit structure, the scattering suppression amplitude is less than 0.25 at an operating frequency of 4GHz to 18GHz; for the second unit structure, the scattering suppression amplitude is less than 0.3 at an operating frequency of 4GHz to 18GHz, and the two phases have a phase difference of 180°.
[0051] According to the electromagnetic energy-scattering characteristic distribution required by the weed background, a metasurface with electromagnetic energy-scattering simultaneous regulation was prepared. Figure 2 (c) A microwave vector network analyzer was used to measure the amplitude characteristics of the electromagnetic energy-scattering and simultaneous regulation of the metasurface under TE and TM polarization states. The results are shown in Figure 3-Figure 5 The results show that the designed stealth material has a reflection characteristic of less than -20dB in the range of 4-16.2GHz, is phase-controllable, and has full polarization characteristics. It is only 12mm thick, has a mass of less than 1kg / m2, and has a minimum reflection of less than -50dB.
[0052] The present invention loads the electromagnetic energy-scattering simultaneous control metasurface on the radar vehicle and tests its SAR imaging characteristics. For the weed background, the radar vehicle scattering is designed to be consistent with the surrounding background environment (weeds). Figure 2 (b) The vehicles used for comparison include 4 bare vehicles, 1 vehicle with a protective net, and 1 vehicle with a multi-layer protective net. UAVs were used to perform imaging detection on 7 radar vehicles, see Figure 6 It can be seen that the stealth vehicle is perfectly integrated with the background environment, and the imaging similarity reaches more than 87%, which means that the imaging result of the stealth vehicle is completely different from the real target object, but very similar to the surrounding environment. The similarity coefficient between the vehicle loaded with the protective net structure and the background is only 5%.
Claims
1. An electromagnetic energy-scattering control method for synthetic aperture radar imaging stealth, characterized in that: The following steps are involved: S1. Acquire SAR imaging of weed background environment and radar vehicle SAR imaging; S2, respectively obtaining the scattering characteristics of the weed background environment SAR imaging and the scattering characteristics of the radar vehicle SAR imaging; S3, obtaining the electromagnetic energy-scattering characteristics of the stealth metasurface according to the scattering characteristics of the weed background environment SAR imaging and the scattering characteristics of the radar vehicle SAR imaging; S4. According to the electromagnetic energy-scattering characteristics of the stealth metasurface, an electromagnetic energy-scattering and simultaneously regulating metasurface structure with amplitude-phase distribution is constructed; S5. Load the electromagnetic energy-scattering simultaneous control metasurface structure onto the radar vehicle to achieve synthetic aperture radar imaging stealth.
2. The electromagnetic energy-scattering control method for synthetic aperture radar imaging stealth according to claim 1 is characterized in that: The expressions of the scattering characteristics of the weed background environment SAR imaging and the scattering characteristics of the radar vehicle SAR imaging in step S2 are respectively: in, The scattering characteristics of SAR imaging in weed background environment; Scattering characteristics of radar vehicle SAR imaging; Fast time; t m A is slow time; c A is the amplitude of the weed background echo signal; t is the amplitude characteristic of the radar vehicle signal; e is a natural constant; j is an imaginary unit; is the scattering characteristic of the transmitted signal; ψ c is the phase characteristic of the weed background echo signal; ψ t is the phase characteristic of the radar vehicle signal.
3. The electromagnetic energy-scattering control method for synthetic aperture radar imaging stealth according to claim 1 is characterized in that: The step S3 is specifically as follows: S301, making the scattering characteristics of the weed background environment SAR imaging consistent with the scattering characteristics of the radar vehicle SAR imaging, and obtaining the echo of the modulated signal: Where, p is the echo of the modulated signal; A c A is the amplitude of the weed background echo signal; t is the amplitude characteristic of the radar vehicle signal; e is a natural constant; j is an imaginary unit; ψ c is the phase characteristic of the weed background echo signal; ψ t is the phase characteristic of the radar vehicle signal; S302. According to the echo of the modulated signal, the amplitude and phase information of the modulated signal are obtained as the amplitude and phase distribution that the stealth metasurface needs to satisfy, and the electromagnetic energy-scattering characteristics of the stealth metasurface are obtained.
4. The electromagnetic energy-scattering control method for synthetic aperture radar imaging stealth according to claim 1 is characterized in that: In step S4, the electromagnetic energy-scattering simultaneously regulates the metasurface structure including a first unit structure and a second unit structure.
5. The electromagnetic energy-scattering control method for synthetic aperture radar imaging stealth according to claim 4 is characterized in that: The first unit structure includes a first PET plate with a length, width and height of pmm, pmm and dmm respectively, a first PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, a second PET plate with a length, width and height of pmm, pmm and dmm respectively, and a second PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, which are connected in sequence from top to bottom; a square ring-shaped ITO transparent conductive film is attached to the upper surfaces of the first PET plate and the second PET plate; the width of the ring-shaped ITO transparent conductive film above the first PET plate is d2, and the square resistance is Z2; the width of the ring-shaped ITO transparent conductive film above the second PET plate is d1, and the square resistance is Z1.
6. The electromagnetic energy-scattering control method for synthetic aperture radar imaging stealth according to claim 4 is characterized in that: The second unit structure includes a third PET board with a length, width and height of pmm, pmm and dmm respectively, a third PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, a fourth PET board with a length, width and height of pmm, pmm and dmm respectively, and a fourth PMI foam layer with a length, width and height of pmm, pmm and hmm respectively, which are connected in sequence from top to bottom; a square ring-shaped ITO transparent conductive film is attached to the upper surface of the fourth PET board; the square ring-shaped ITO transparent conductive film attached to the upper surface of the fourth PET board has a width of d1 and a square resistance of z1.