A strong pulse protection fractal metasurface radome design preparation method and a radome prepared by the same
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NO 33 RES INST OF CHINA ELECTRONICS TECHNOOGY GRP
- Filing Date
- 2023-03-28
- Publication Date
- 2026-07-21
AI Technical Summary
Existing technologies in protective materials operate in a single frequency band and have insufficient protective effectiveness, failing to meet the protection requirements for high-frequency electromagnetic pulses. At the same time, traditional protection technologies cut off the exchange of electromagnetic waves between the equipment and space, thus failing to meet communication requirements.
A high-pulse protective fractal metasurface radome was designed. It was modeled using CST software, and utilized a cross-shaped fractal structure and complementary structure combined with field-path co-design. It was fabricated through laser etching and integrated molding process to achieve dual functions of wave transmission/shielding in the L and X bands, thereby enhancing the protection effectiveness.
It achieves low insertion loss and high protection performance in the L and X bands, meeting the communication and protection requirements of radar antennas in high-power microwave attack environments. The insertion loss in the transparent state is ≤1dB, and the shielding effectiveness in the protective state is 27.3dB and 30.3dB respectively when the high-power microwave field strength is 20kV/m.
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Figure CN116111340B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of radome design and fabrication methods, specifically relating to a design and fabrication method for a strong pulse protection fractal metasurface radome and the radome fabricated therefrom. Background Technology
[0002] Radar radio frequency systems of drones, launch vehicles, and fortified platforms are vulnerable to high-power microwave weapons, such as the CHAMP anti-electronics high-power microwave advanced missile, which generates strong electromagnetic pulses with power densities exceeding 100 GW. This poses a serious threat to the electronic equipment of radar systems in the battlefield environment. Strong electromagnetic pulses can couple to electronic equipment through front doors (such as antennas and sensors) and back doors (such as holes, gaps, cables, and doors / windows on the casing). When the entire electronic equipment is attacked by an electromagnetic weapon, and the frequency of the attacking electromagnetic wave is close to the antenna's operating frequency, a large amount of energy will couple into the equipment, damaging electronic system components and causing equipment failure.
[0003] In actual battlefield operations, communication between combat units and between combat units and the command center is essential, making antennas, which receive electromagnetic waves, indispensable. Antennas must be exposed to the electromagnetic environment to function properly. Traditional high-pulse protection technology primarily uses conductive metal casings to isolate electronic devices from the outside world. However, most electronic devices have components such as antenna ports and ventilation openings that connect to the outside world. Conductive metal casings would cut off the exchange of electromagnetic waves between the device and the surrounding environment, failing to meet communication requirements.
[0004] Antennas are crucial channels for strong electromagnetic pulse coupling. Using adjustable or switchable radomes can effectively prevent strong electromagnetic pulses from coupling into the equipment. Many researchers have designed limiting metasurface microwave devices, frequency-selective surface materials (FSS), and energy-selective metasurface materials (ESS) using electromagnetically sensitive devices such as varactor diodes, PIN diodes, and MEMS devices. These can be used as radomes or placed in waveguides to meet the requirements of strong electromagnetic pulse protection for communication systems.
[0005] Zhang Jihong et al. from the National University of Defense Technology designed an energy selective microwave device (ESS) for high-power microwave protection of waveguides. This device protects sensitive RF front-ends by reflecting electromagnetic waves exceeding the conduction threshold. Based on the nonlinear characteristics of PIN diodes, experiments verified that within the 1.8 GHz to 2.2 GHz range, the insertion loss for low-power signals is no higher than 1.5 dB, and the protection efficiency for high-power signals is 10 dB, based on the nonlinear transmission characteristics of input power.
[0006] Wu Huancheng and colleagues from the China Academy of Engineering Physics used a Spice model of PIN diodes and employed three-dimensional electromagnetic simulation software to conduct time-domain field-circuit co-simulation of the ESS material, thus obtaining the ESS material. Through optimized design, the field strength at the selective surface through which electromagnetic energy is transmitted was reduced, while peak leakage was decreased. When the field strength reached 1.2 kV / m, the protection effectiveness reached 15 dB. The ESS improved the anti-interference and anti-damage capabilities of communication systems in complex electromagnetic environments.
[0007] A team led by Gao Yang from Shanxi University proposed a novel Energy Separation Shield (ESS) material. The unit cell consists of a cross-shaped patch and rectangular metal branches loaded on its four arms, with PIN diodes loaded between the units, creating a surface structure that is selective for both energy and frequency. When a low-power signal is incident, the surface operates in a transmission mode, functioning as a Free-Side (FSS) structure; when a high-power pulse is incident, the surface adaptively activates a protection mode, shielding electromagnetic waves, functioning as an ESS structure. Simulation results show that the ESS achieves a protection efficiency of -20 dB (0~3.4 GHz) in protection mode and a -3 dB bandwidth of 1.3 GHz (0~1.3 GHz) in transmission mode, effectively switching between FSS and ESS functions.
[0008] In summary, space electromagnetic pulse protection technologies mainly include FSS and ESS technologies. FSS / ESS structures based on PIN diode loading can be directly excited by incident strong fields, and diodes are suitable for designing energy protection materials. However, due to limitations in the number of conductive layers, the single resonance mode, and structural size of protective materials, most current electromagnetic pulse protection materials operate in the L or S bands. This single operating frequency band and insufficient protection effectiveness still cannot meet the equipment's demand for high-frequency, high-strength protective materials. Summary of the Invention
[0009] To address the technical problem that traditional electromagnetic protection technologies, while protecting against strong pulses in space, simultaneously cut off the exchange between the equipment and electromagnetic waves in space, thus failing to meet communication requirements, this invention provides a design and fabrication method for a strong pulse protection fractal metasurface radome and the fabricated radome thereof. This method achieves a multi-functional integrated design that satisfies low insertion loss transmission in the L and X bands and strong pulse protection, thus solving the problems of normal system reception and electromagnetic pulse protection.
[0010] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for designing and fabricating a fractal metasurface radome for protection against strong pulses includes the following steps: S1. Optimization of unit structure to obtain L and X operating frequency band selection and optimization design: The geometric structure of the metasurface radome is modeled using CST software. The metasurface radome includes a first matching layer, a first metasurface conductive layer, a first dielectric layer, a core layer, a second dielectric layer, a second metasurface conductive layer, and a second matching layer. The thickness of the first matching layer is h1, and its dielectric constant is... The first metasurface conductive layer represents a cross-shaped metasurface unit etched onto a conductive thin film with conductivity ρ1; the first dielectric layer has a thickness of h2 and a dielectric constant of... The core layer thickness is h3, and the dielectric constant is... The second dielectric layer has a thickness of h4 and a dielectric constant of [value missing]. The second metasurface conductive layer represents complementary cross-shaped second metasurface units etched onto a conductive thin film with conductivity ρ2; the second matching layer has a thickness of h5 and a dielectric constant of... The diodes used are BAR 63-04V, and the number of diodes is 2000; among them, the conductivity ρ1 and ρ2 are 6.3×10. 7 S / m; dielectric constant , , , The dielectric constant is 3.3~4.3. The thickness is 1.05, and the thicknesses h1, h2, h3, h4, and h5 are 1mm ± 0.1mm, 0.7mm ± 0.05mm, 5mm ± 0.1mm, 0.7mm ± 0.05mm, and 1mm ± 0.1mm, respectively, with loss tangent values of 0.01, 0.01, 0.002, 0.01, and 0.01, respectively. S2. Using field-circuit co-design, a transparent / protected state circuit model is established to simulate the performance of LX dual-band, high field strength, and high-efficiency protection. The method for simulating the performance of LX dual-band, high field strength, and high-efficiency protection in S2 is as follows: a field-circuit co-design model of a transparent / protected metasurface radome is established. When the protection frequency band is located in the L and X bands, the protection effectiveness of the L band (1GHz~2GHz) is ≥20dB, and the peak shielding effectiveness reaches 30dB; the shielding effectiveness of the X band (9.5GHz~10GHz) is ≥20dB, and the peak shielding effectiveness reaches 34dB. S3. Perform laser etching process; the method for performing laser etching process in S3 is as follows: draw the required metasurface pattern using CAD drawing software, with a unit size of 15mm×15mm, a period number of 20×20, and an overall size of 300mm×300mm; draw a blue-white microstructure process diagram using a laser photoplotter, where the blue part of the blue-white microstructure process diagram is the laser-etched part, and the white part of the blue-white microstructure process diagram is the metasurface structure pattern; focus a high-beam-quality, low-power laser beam into an extremely small spot, forming a very high power density at the focal point, causing the blue pattern part to vaporize and evaporate instantaneously, forming a metasurface structure unit; S4. Perform integrated molding process; S5. Insertion loss and protection performance test.
[0011] The method for the integrated molding process in S4 is as follows: the multi-functional layer alignment technology of the metasurface structure is realized by using compression molding or autoclave molding process, and the processing accuracy of the multi-layer metasurface structure and the alignment accuracy between each layer are controlled.
[0012] The method for testing insertion loss and shielding effectiveness in S5 is as follows: refer to the test standards GJB 8820-2015 Electromagnetic Shielding Material Shielding Effectiveness Measurement Method and GJB 9257-2017 High Power Microwave Effect Test Method - Narrowband High Power Microwave Irradiation Method to test insertion loss and shielding effectiveness, with the operating frequency band located in the L and X bands.
[0013] A high-pulse protective fractal metasurface radome, fabricated by a design and fabrication method, is characterized by comprising a first matching layer, a first metasurface conductive layer, a first dielectric layer, a core layer, a second dielectric layer, a second metasurface conductive layer, and a second matching layer. The first matching layer is disposed below the first metasurface conductive layer, the first dielectric layer is disposed below the first metasurface conductive layer, the core layer is disposed below the first dielectric layer, the second dielectric layer is disposed below the core layer, the second metasurface conductive layer is disposed below the second dielectric layer, and the second matching layer is disposed below the second metasurface conductive layer.
[0014] A first layer of metasurface units is etched on the conductive film of the first metasurface conductive layer, and a second layer of metasurface units is etched on the conductive film of the second metasurface conductive layer.
[0015] The first layer of metasurface unit adopts a cross-shaped fractal structure, and the second layer of metasurface unit is a complementary structure to the first layer of metasurface unit.
[0016] Compared with the prior art, the beneficial effects of this invention are: This invention utilizes a cross-shaped and its fractal and complementary resonant structures to obtain a metasurface with polarization-insensitive, dual-frequency electromagnetic transparency, enabling the design of operating frequency bands in the L and X bands. Furthermore, compared to traditional high-pulse shielding materials, this invention expands its function from a single electromagnetic shielding function to dual transparency and shielding, satisfying the transceiver functions of radar antenna RF systems while improving the shielding effectiveness of the antenna system under high-power microwave attack environments. This invention achieves expanded operating frequency bands and improved performance for the radome; in the transparency state, the insertion loss in the L and X bands is ≤1dB; in the shielding state, with a high-power microwave field strength of 20kV / m, the shielding effectiveness is 27.3dB in the L band and 30.3dB in the X band. Attached Figure Description
[0017] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.
[0018] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.
[0019] Figure 1 This is a flowchart illustrating the preparation process of the present invention; Figure 2 Cross-sectional view of the present invention; Figure 3 This is a schematic diagram of the structure of the first layer metasurface unit of the present invention; Figure 4 This is a schematic diagram of the structure of the second metasurface unit of the present invention; Figure 5 This is a schematic diagram of the wave-transmitting state field path design of the present invention; Figure 6 This is a schematic diagram of the protective state field circuit design of the present invention; Figure 7 This is a simulation curve of the protective performance of the present invention.
[0020] Wherein: 1 is the first matching layer, 2 is the first metasurface conductive layer, 3 is the first dielectric layer, 4 is the core layer, 5 is the second dielectric layer, 6 is the second metasurface conductive layer, 7 is the second matching layer, 8 is the first metasurface unit, and 9 is the second metasurface unit. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. These descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the claims of the present invention. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0022] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.
[0023] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.
[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0025] In this embodiment, as Figure 1 As shown, it includes the following steps: Using CST software to model the geometry of metasurface radomes, such as... Figure 2-4 As shown. The metasurface radome comprises a double matching layer, a double dielectric layer, a double conductive layer, and a sandwich layer. The first layer is the first matching layer 1, with a thickness h1 and a dielectric constant of [missing value]. The second layer is the first metasurface conductive layer 2, which represents the first metasurface unit 8 etched onto a conductive thin film with conductivity ρ1; the third layer is the first dielectric layer 3, with a thickness h2 and a dielectric constant of... The fourth layer is the core layer 4, with a thickness h3 and a dielectric constant of [missing value]. The fifth layer is the second dielectric layer 5 with a low dielectric constant, and a thickness of h4. The sixth layer is the second metasurface conductive layer 6, which represents complementary second metasurface units 9 etched onto a conductive thin film with a conductivity of ρ2; the seventh layer is a low-dielectric-constant second matching layer 7 with a thickness h5 and a dielectric constant of The synthesized metasurface radome structure; first layer metasurface unit 8; second layer metasurface unit 9; diodes are BAR63-04V, with a total of 2000 diodes. The conductivity of the conductive thin film ρ1 and ρ2 is 6.3 × 10⁻⁶. 7 S / m; dielectric constant of the dielectric layer 、 、 、 The dielectric constant is 3.3~4.3. The thickness is 1.05, and the thicknesses h1 (h5), h2 (h4) and h3 are 1mm ± 0.1mm, 0.7mm ± 0.05mm, and 5mm ± 0.1mm, respectively, with loss tangent values of 0.01, 0.01, and 0.002, respectively.
[0026] To investigate changes in protection status, a field-circuit co-design model for a transparent / protective metasurface radome was established, as follows: Figure 5 , Figure 6 As shown. Figure 5 , Figure 6 Provide circuit diagrams for both the transparent and protected states. Figure 7 The simulated protection performance curves show that when the protection frequency band is located in the L and X bands, the protection effectiveness of the L band (1GHz~2GHz) is ≥20dB, and the peak shielding effectiveness reaches 30dB; the shielding effectiveness of the X band (9.5GHz~10GHz) is ≥20dB, and the peak shielding effectiveness reaches 34dB.
[0027] Laser etching technology: The required metasurface pattern is drawn using CAD software, with a unit size of 15mm × 15mm, a period number of 20 × 20, and an overall size of 300mm × 300mm. A blue-white microstructure process diagram is then drawn using a laser photoplotter (the blue area represents the laser-etched portion, and the white area represents the metasurface structure pattern). A high-beam-quality, low-power laser beam is focused into an extremely small spot, creating a very high power density at the focal point. This causes the blue patterned portion to vaporize and evaporate instantaneously, forming the metasurface structure unit, such as... Figure 5 As shown.
[0028] Integrated molding technology: This technology utilizes compression molding or autoclave molding processes to achieve the alignment of multi-functional layers in metasurface structures. Key control focuses on the processing precision of the multi-layer metasurface structure and the alignment precision between layers. Strict control is maintained over heating curves, pressurization curves, temperature and holding time, cooling and depressurization rates, etc., and related process parameters are optimized to eliminate the impact of processing errors on the performance of the radar radome / protection radome.
[0029] The insertion loss and shielding effectiveness were tested according to the reference testing standards GJB 8820-2015 "Method for Measuring the Shielding Effectiveness of Electromagnetic Shielding Materials" and GJB 9257-2017 "Test Method for High Power Microwave Effects - Narrowband High Power Microwave Irradiation Method". The operating frequency bands were L and X bands. Transparency test results: Insertion loss ≤1dB in L and X bands (1.4GHz-1.7GHz, 9.5GHz-10GHz); Shielding effectiveness test results: When the high power microwave field strength is 20kV / m, the shielding effectiveness is 27.3dB in the L band and 30.3dB in the X band.
[0030] The above description only illustrates the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention, and all such changes should be included within the protection scope of the present invention.
Claims
1. A method for designing and fabricating a fractal metasurface radome for strong pulse protection, characterized in that: Includes the following steps: S1. Optimization of unit structure to obtain L and X working frequency band selection and optimization design: The geometric structure of the metasurface radome is modeled using CST software. The metasurface radome includes a first matching layer (1), a first metasurface conductive layer (2), a first dielectric layer (3), a core layer (4), a second dielectric layer (5), a second metasurface conductive layer (6), and a second matching layer (7). The thickness h1 of the first matching layer (1) has a dielectric constant of . The first metasurface conductive layer (2) represents the first metasurface unit (8) etched in a cross-shaped pattern on a conductive film with conductivity ρ1; the first dielectric layer (3) has a thickness of h2 and a dielectric constant of The thickness of the sandwich layer (4) is h3, and its dielectric constant is The second dielectric layer (5) has a thickness of h4 and a dielectric constant of The second metasurface conductive layer (6) represents complementary cross-shaped second metasurface units (9) etched on a conductive film with a conductivity of ρ2; the second matching layer (7) has a thickness of h5 and a dielectric constant of The diodes used are BAR 63-04V, and the number of diodes is 2000; among them, the conductivity ρ1 and ρ2 are 6.3×10. 7 S / m; dielectric constant , , , The dielectric constant is 3.3~4.
3. The thickness is 1.05, and the thicknesses h1, h2, h3, h4, and h5 are 1mm ± 0.1mm, 0.7mm ± 0.05mm, 5mm ± 0.1mm, 0.7mm ± 0.05mm, and 1mm ± 0.1mm, respectively, with loss tangent values of 0.01, 0.01, 0.002, 0.01, and 0.01, respectively. S2. Using field-circuit co-design, a transparent / protected state circuit model is established to simulate the performance of LX dual-band, high field strength, and high-efficiency protection. The method for simulating the performance of LX dual-band, high field strength, and high-efficiency protection in S2 is as follows: a field-circuit co-design model of a transparent / protected metasurface radome is established. When the protection frequency band is located in the L and X bands, the protection effectiveness of the L band is ≥20dB, and the peak shielding effectiveness reaches 30dB; the shielding effectiveness of the X band is ≥20dB, and the peak shielding effectiveness reaches 34dB. S3. Perform laser etching process; the method for performing laser etching process in S3 is as follows: draw the required metasurface pattern using CAD drawing software, with a unit size of 15mm×15mm, a period number of 20×20, and an overall size of 300mm×300mm; draw a blue-white microstructure process diagram using a laser photoplotter, where the blue part of the blue-white microstructure process diagram is the laser-etched part, and the white part of the blue-white microstructure process diagram is the metasurface structure pattern; focus a high-beam-quality, low-power laser beam into an extremely small spot, forming a very high power density at the focal point, causing the blue pattern part to vaporize and evaporate instantaneously, forming a metasurface structure unit; S4. Perform integrated molding process; S5. Insertion loss and protection performance test.
2. The method for designing and fabricating a high-pulse protective fractal metasurface radome according to claim 1, characterized in that: The method for the integrated molding process in S4 is as follows: the multi-functional layer alignment technology of the metasurface structure is realized by using compression molding or autoclave molding process, and the processing accuracy of the multi-layer metasurface structure and the alignment accuracy between each layer are controlled.
3. The method for designing and fabricating a high-pulse protective fractal metasurface radome according to claim 1, characterized in that: The method for testing insertion loss and shielding effectiveness in S5 is as follows: refer to the test standards GJB 8820-2015 Electromagnetic Shielding Material Shielding Effectiveness Measurement Method and GJB 9257-2017 High Power Microwave Effect Test Method - Narrowband High Power Microwave Irradiation Method to test insertion loss and shielding effectiveness, with the operating frequency band located in the L and X bands.
4. The high-pulse-protection fractal metasurface radome prepared by the design and fabrication method of the high-pulse-protection fractal metasurface radome according to any one of claims 1-3, characterized in that: It includes a first matching layer (1), a first metasurface conductive layer (2), a first dielectric layer (3), a core layer (4), a second dielectric layer (5), a second metasurface conductive layer (6), and a second matching layer (7). The first matching layer (1) is provided below the first metasurface conductive layer (2), the first dielectric layer (3) is provided below the first metasurface conductive layer (2), the core layer (4) is provided below the first dielectric layer (3), the second dielectric layer (5) is provided below the core layer (4), the second metasurface conductive layer (6) is provided below the second dielectric layer (5), and the second matching layer (7) is provided below the second metasurface conductive layer (6).
5. The high-pulse protective fractal metasurface radome according to claim 4, characterized in that: The first layer of metasurface units (8) is etched on the conductive film of the first layer of metasurface conductive layer (2), and the second layer of metasurface units (9) is etched on the conductive film of the second layer of metasurface conductive layer (6).
6. The high-pulse protective fractal metasurface radome according to claim 5, characterized in that: The first layer metasurface unit (8) adopts a cross-shaped fractal structure, and the second layer metasurface unit (9) is a complementary structure to the first layer metasurface unit (8).