Wave-absorbing structure, support system and target radar cross section test system

Abstract

This invention provides an absorbing structure, a support system, and a target radar cross section testing system, relating to the field of electromagnetic measurement technology. The absorbing structure includes a tubular magnetic material substrate and a low-scattering structure disposed on the outer peripheral wall of the magnetic material substrate. The low-scattering structure includes multiple absorbing units, which are distributed sequentially along the length of the magnetic material substrate and connected in sequence. The outer side of each absorbing unit has a pointed conical cross-section parallel to the length of the magnetic material. Along the length of the magnetic material, the absorbing unit in the middle has the smallest outer diameter, while the outer diameter of the absorbing units at both ends increases. This absorbing structure, taking into account the scattering characteristics of a two-support-one-suspender configuration, combines a low-scattering shape design with the absorbing performance of the magnetic material substrate, significantly optimizing the scattering level of the suspension rope and reducing coupled scattering.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic measurement technology, and more specifically, to an absorbing structure, a support system, and a target radar cross section testing system. Background Technology

[0002] Microwave anechoic chambers primarily simulate electromagnetic interference-free "free space" using metal shielding and absorbing materials, and are widely used in high-precision tests such as stealth performance testing, antenna performance testing, and electronic product testing. The "two supports and one suspension" system is a crucial component of the support system in a large target radar cross-section (RCS) testing system. Its main function is to connect to the target (such as an aircraft) via two supports and a suspension rope, achieving three-point fixation and attitude adjustment. This supports the target within the quiet zone while allowing it to rotate and pitch, mimicking its actual operating state and meeting the requirements for multi-angle and multi-attitude RCS measurements.

[0003] Accurate RCS measurement requires the background level to be at least 20 dB lower than the target's RCS level, which places high demands on the low-scattering performance of the two-support-one-rope system. Currently, two-support-one-rope systems generally suffer from the problem of difficulty in reducing the scattering level, and the coupled scattering between the target and the rope is difficult to eliminate using traditional background cancellation techniques. This interferes with the quiet zone performance and greatly limits the accuracy of the target's radar cross section measurement. Therefore, to further improve the testing capability and accuracy of the testing system, it is urgent to optimize the low-scattering performance of the rope.

[0004] Therefore, this application is hereby submitted. Summary of the Invention

[0005] The present invention aims to provide an absorbing structure, a support system, and a target radar cross section testing system, which can improve the problems of existing radar cross section testing systems where the scattering level of the two-support-one-suspender is difficult to reduce, and the coupled scattering of the target is difficult to eliminate through background cancellation and other techniques. The absorbing structure, which is designed for the scattering characteristics of the two-support-one-suspender, combines a low-scattering shape design with the absorbing performance of a magnetic material substrate, and significantly optimizes the scattering level of the suspension rope and reduces coupled scattering.

[0006] The embodiments of the present invention can be implemented as follows:

[0007] In a first aspect, the present invention provides a microwave absorbing structure, comprising a tubular magnetic material substrate and a low-scattering structure disposed on the outer peripheral wall of the magnetic material substrate;

[0008] The low-scattering structure includes multiple absorbing units, which are distributed and connected sequentially along the length of the magnetic material substrate. The outer side of each absorbing unit has a pointed cone shape in the cross section parallel to the length of the magnetic material. In the length of the magnetic material, the outer diameter of the absorbing unit in the middle is the smallest, and the outer diameter of the absorbing units at both ends is larger.

[0009] In an optional embodiment, the thickness of the magnetic material substrate is 1~20 mm.

[0010] In an optional embodiment, the magnetic material substrate is made of at least one of ferrite, magnetic metal, magnetic nanomaterial, and magnetic graphene and carbon nanotube composite materials.

[0011] In an optional embodiment, each absorbing unit has a thickness of 32-96 mm, an outer diameter of 100-1000 mm, and an inner diameter of 10-100 mm; the absorbing unit includes an annular connecting portion located on the inner side and an annular pointed cone portion located on the outer side; the annular connecting portions of adjacent absorbing units are connected to each other, and the cone angle of the annular pointed cone portion is 12.2-39.1°.

[0012] In an optional implementation, the number of absorbing units is 10 to 30.

[0013] In an optional embodiment, the microwave absorbing unit is integrally molded from a foamed conductive mixture, which, by weight, comprises 70-80 parts of a polymer and 20-30 parts of microwave absorbing filler.

[0014] In an optional embodiment, the polymer is selected from at least one of polypropylene, polystyrene, polyethylene, ethylene-vinyl acetate copolymer, polylactic acid, polycarbonate, polyamide, polyetheretherketone, and polyimide.

[0015] In an optional embodiment, the microwave absorbing filler is selected from at least one of graphite, carbon black, carbon nanotubes, carbon fibers, carbon nanofibers, graphite nanosheets, graphene, nickel-coated graphite powder, nickel-coated carbon fiber carbon black, metal powder, liquid metal, sheet iron-based metal powder, sheet iron-based alloy powder, sheet iron-silicon-aluminum alloy powder, sheet iron-silicon alloy powder, sheet iron-silicon-chromium alloy powder, sheet cobalt-based alloy powder, and sheet iron-nickel alloy powder.

[0016] Secondly, the present invention provides a support system comprising a wave-absorbing structure as described in any of the foregoing embodiments.

[0017] Thirdly, the present invention provides a target radar cross section testing system, including a support system as described in the foregoing embodiments.

[0018] The beneficial effects of the absorbing structure, support system, and target radar cross section testing system provided in this embodiment of the invention include:

[0019] The absorbing structure provided in this invention incorporates two energy dissipation mechanisms: dielectric loss (low scattering structure) and magnetic loss (magnetic material substrate). These two loss mechanisms exhibit stronger absorption characteristics in different frequency ranges, complementing each other and enabling the overall structure to maintain high absorption performance over a wider frequency band. Furthermore, the composite structure of the absorbing unit and the magnetic substrate achieves strong broadband absorption with a smaller total thickness, significantly benefiting volume-sensitive applications. Specifically, the low-scattering structure features a minimum outer diameter absorbing unit in the middle, with larger outer diameters towards the ends. Multiple absorbing structures connected in series form a periodically varying diameter structure. This structure allows electromagnetic waves to undergo multiple scattering losses between the absorbing units periodically. The gradual change in the size of the absorbing units creates a phase difference between the reflected echoes from different units, preventing the superposition of scattering from each unit and thus achieving a better absorption effect.

[0020] Therefore, the absorbing structure provided in this embodiment of the invention can significantly optimize the low scattering performance of the suspension rope in the P-band to Ku-band and even higher frequency bands, improve the quiet zone quality and background level of the anechoic chamber, and significantly improve the testing capability and accuracy of the radar cross section testing system. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the absorbing structure provided in this embodiment;

[0023] Figure 2 for Figure 1 Schematic diagram of the cross section at point AA;

[0024] Figure 3 This is a comparison chart of the simulation results for Example 1 and Comparative Example 1;

[0025] Figure 4 A comparison chart of simulation results for Comparative Example 1 and Comparative Example 2;

[0026] Figure 5 A comparison chart showing the simulation results of Comparative Example 3 and Comparative Example 2;

[0027] Figure 6 A comparison chart of simulation results for Example 1 and Comparative Example 2;

[0028] Figure 7 This is a comparison chart of simulation results for Example 1 and Comparative Example 4;

[0029] Figure 8 A comparison chart of simulation results for Example 1 and Comparative Example 5;

[0030] Figure 9 The diagram shows the actual test results of the absorbing structure provided in Example 1.

[0031] Icons: 100 - Absorbing structure; 110 - Absorbing unit; 111 - Ring-shaped connection; 112 - Ring-shaped cone; 120 - Magnetic material substrate. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0036] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0037] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0038] like Figure 1 and Figure 2 As shown, an absorbing structure 100 provided in this embodiment of the invention includes a tubular magnetic material substrate 120 and a low-scattering structure disposed on the outer peripheral wall of the magnetic material substrate 120.

[0039] The low-scattering structure includes multiple absorbing units 110, which are distributed and connected sequentially along the length of the magnetic material substrate 120. The outer side of each absorbing unit 110 has a pointed cone shape in the cross section parallel to the length of the magnetic material. In the length of the magnetic material, the outer diameter of the absorbing unit 110 located in the middle is the smallest, and the outer diameter of the absorbing unit 110 at both ends is larger.

[0040] The absorbing structure 100 provided in this embodiment of the invention, when in use, selects an appropriate number of supports to be fitted over the suspension ropes according to the length requirements of the two-support-one-suspender structure. The suspension ropes pass through the hollow portion of the magnetic material substrate 120 of each absorbing structure 100. This absorbing structure 100 simultaneously introduces two energy dissipation mechanisms: dielectric loss (low scattering structure) and magnetic loss (magnetic material substrate 120). The two loss mechanisms exhibit stronger absorption characteristics in different frequency ranges, complementing each other, so that the overall structure can maintain high absorption performance over a wider frequency band. At the same time, the composite structure of the absorbing unit 110 and the magnetic substrate can achieve the goal of wide-band strong absorption with a smaller total thickness, which is of great help to volume-sensitive applications. In particular, the outer diameter of the absorbing unit 110 located in the middle of the low-scattering structure is the smallest, while the outer diameter of the absorbing units 110 at both ends increases. Multiple absorbing structures are connected in series to form a periodically varying diameter structure. This structure allows electromagnetic waves to be absorbed through multiple scattering losses between the absorbing units periodically. The gradual change in the size of the absorbing units creates a phase difference between the reflected echoes from different units, preventing the superposition of scattering from each unit and thus achieving a better absorption effect. This absorbing structure is simple to implement, highly operable, and very suitable for upgrading and optimizing existing suspension ropes.

[0041] Optionally, the thickness of the magnetic material substrate 120 is 1 to 20 mm (e.g., 1 mm, 5 mm, 10 mm or 20 mm).

[0042] The magnetic substrate material refers to a material that primarily dissipates electromagnetic wave energy through magnetic loss mechanisms. Within this thickness range, it exhibits excellent wave absorption performance. If the thickness is too small, the absorption effect is not significant; if the thickness is too large, it does not further reduce the RCS value but instead increases the overall weight of the absorbing structure and makes installation more difficult. Furthermore, this thickness of magnetic material substrate provides high mechanical strength, ease of processing, transportation, installation, and maintenance, relatively low cost, and enhances the overall mechanical stability and durability of the structure.

[0043] Optionally, the magnetic material substrate 120 is made of at least one of ferrite, magnetic metal (e.g., magnetic metal powder, magnetic metal film or sheet), magnetic nanomaterial, and magnetic graphene and carbon nanotube composite material.

[0044] Optionally, each absorbing unit 110 has a thickness of 32-96 mm, an outer diameter of 100-1000 mm, and an inner diameter of 10-100 mm. The absorbing unit 110 includes an annular connecting portion 111 located on the inner side and an annular pointed cone portion 112 located on the outer side; the annular connecting portions 111 of adjacent absorbing units 110 are interconnected, and the cone angle α of the annular pointed cone portion 112 is 12.2-39.1°. Under the above conditions, the dimensions and cone angle of the absorbing unit 110 provide better absorption performance. If the thickness, outer diameter, inner diameter, and cone angle do not meet the above ranges, the absorption performance will be slightly worse.

[0045] The absorbing structure 100 provided by this invention is used as a support system in a large target radar cross section testing system (two supports and one hanger). Its length can be adjusted according to actual needs, for example, to 0.96m. To ensure good absorption performance at this length, the number of absorbing units 110 can optionally be 10 to 30. This range of absorbing units 110 will give the low-scattering structure a better absorption effect.

[0046] Optionally, to improve the microwave absorption effect of the microwave absorbing unit 110, the microwave absorbing unit 110 is integrally molded from a foamed conductive mixture, and the foaming method is physical foaming. By weight, the conductive mixture comprises 70-80 parts of a polymer and 20-30 parts of microwave absorbing filler. The conductive mixture is formed by melt blending the above materials.

[0047] Optionally, the polymer is selected from at least one of polypropylene, polystyrene, polyethylene, ethylene-vinyl acetate copolymer, polylactic acid, polycarbonate, polyamide, polyetheretherketone and polyimide.

[0048] Optionally, the microwave absorbing filler is selected from at least one of graphite (ordinary graphite or flake graphite), carbon black (highly conductive carbon black, acetylene black, nano carbon black particles), carbon nanotubes (ordinary carbon nanotubes or multi-walled carbon nanotubes), carbon fiber, carbon nanofiber, graphite nanosheets, graphene, nickel-coated graphite powder, nickel-coated carbon fiber carbon black, metal powder, liquid metal, sheet iron-based metal powder, sheet iron-based alloy powder, sheet iron-silicon-aluminum alloy powder, sheet iron-silicon alloy powder, sheet iron-silicon-chromium alloy powder, sheet cobalt-based alloy powder, and sheet iron-nickel alloy powder.

[0049] It should be noted that the material of the above-mentioned absorbing unit 110 is only the material selection for some embodiments of the present invention. In other embodiments of the present invention, it is also feasible to use conventional absorbing materials that have been disclosed.

[0050] This invention also provides a support system, including the wave-absorbing structure 100 provided in this invention.

[0051] This invention also provides a target radar cross section testing system, including the support system provided in this invention.

[0052] Example 1

[0053] The absorbing structure 100 is 0.96m long and has 24 absorbing units 110. Each absorbing unit 110 is 40mm thick and has an inner diameter of 60mm. The 12th and 13th absorbing units 110 in the middle region have the smallest outer diameter of 250mm. From the middle to both ends, the outer diameter of the absorbing units 110 gradually increases, with the outer diameter of the absorbing unit 110 at the very end being 360mm. The cone angle of the absorbing unit 110 in the middle is 23.8°, and the cone angle of the absorbing unit 110 at the very end is 15.2°.

[0054] The microwave absorbing unit 110 is integrally molded from a foamed conductive mixture. The foaming method is physical foaming. By weight, the conductive mixture is formed by melt blending 75 parts polystyrene and 25 parts microwave absorbing filler. The microwave absorbing filler is high-conductivity carbon black.

[0055] The magnetic material substrate 120 has a thickness of 5 mm and is made of nickel-zinc ferrite.

[0056] Example 2

[0057] The absorbing structure 100 is 0.96m long and has 10 absorbing units 110. Each absorbing unit 110 is 96mm thick and has an inner diameter of 100mm. The fifth and sixth absorbing units 110 in the middle region have the smallest outer diameter of 800mm. From the middle to both ends, the outer diameter of the absorbing units 110 gradually increases, with the outer diameter of the absorbing unit 110 at the very end being 1000mm. The cone angle of the absorbing unit 110 in the middle is 15.6°, and the cone angle of the absorbing unit 110 at the very end is 12.2°.

[0058] The material of the absorbing unit 110 is the same as that in Example 1.

[0059] The magnetic material substrate 120 has a thickness of 1 mm and is made of the same material as in Example 1.

[0060] Example 3

[0061] The absorbing structure 100 is 0.96m long and has 30 absorbing units 110. Each absorbing unit 110 is 32mm thick and has an inner diameter of 10mm. The 15th and 16th absorbing units 110 in the middle region have the smallest outer diameter of 100mm. From the middle to both ends, the outer diameter of the absorbing units 110 gradually increases. The outer diameter of the absorbing unit 110 at the very end is 110mm. The cone angle of the absorbing unit 110 in the middle region is 39.1° and the cone angle of the absorbing unit 110 at the very end is 35.5°.

[0062] The material of the absorbing unit 110 is the same as that in Example 1.

[0063] The magnetic material substrate 120 has a thickness of 20 mm and is made of the same material as in Example 1.

[0064] Example 4

[0065] This embodiment is basically the same as embodiment 2, except that: the number of absorbing units 110 is 8, the thickness of each absorbing unit 110 is 120mm, the inner and outer diameters of each absorbing unit 110 remain unchanged, the cone angle is increased, the cone angle of the absorbing unit 110 located in the middle is increased to 19.5°, and the cone angle of the absorbing unit 110 located at the very end is increased to 15.2°.

[0066] Example 5

[0067] This embodiment is basically the same as embodiment 3, except that: the number of absorbing units 110 is 40, the thickness of each absorbing unit 110 is 24mm, the inner and outer diameters of each absorbing unit 110 remain unchanged, the cone angle is reduced, the cone angle of the absorbing unit 110 located in the middle is reduced to 29.9°, and the cone angle of the absorbing unit 110 located at the very end is reduced to 27.0°.

[0068] Example 6

[0069] This embodiment is basically the same as embodiment 3, except that the thickness of the magnetic material substrate 120 is 25mm.

[0070] Example 7

[0071] This embodiment is basically the same as embodiment 2, except that the thickness of the magnetic material substrate 120 is 0.1 mm.

[0072] Comparative Example 1

[0073] This comparative example is basically the same as Example 1, except that it does not have a magnetic material substrate 120.

[0074] Comparative Example 2

[0075] This comparative example is basically the same as Example 1, except that each absorbing unit 110 has an annular connecting portion 111, does not have an outer annular pointed cone portion 112, and does not have a magnetic material substrate 120.

[0076] Comparative Example 3

[0077] This comparative example is basically the same as Example 1, except that each absorbing unit 110 has an annular connecting portion 111 and does not have an outer annular pointed cone portion 112.

[0078] Comparative Example 4

[0079] This comparative example is basically the same as Example 1, except that all absorbing units 110 are the same size, and there is no trend of the absorbing unit 110 in the middle having a smaller diameter and the diameter increasing towards the sides.

[0080] Comparative Example 5

[0081] This comparative example is basically the same as Example 1, except that it does not have a magnetic substrate. The outer diameter of the 12th and 13th absorbing units 110 located in the middle region is the smallest, at 700 mm. From the middle to both ends, the outer diameter of the absorbing units 110 gradually increases, and the outer diameter of the absorbing unit 110 located at the very end is 900 mm.

[0082] Experimental Example

[0083] I. Using Altair Feko software, simulated the RCS of the absorbing structure 100 provided in the various embodiments and comparative examples under horizontal and vertical polarization in the P-Ku band.

[0084] (1) The simulation results of Example 1 and Comparative Example 1 are compared as shown in the figure below. Figure 3 As shown, Figure 3 The solid line represents Example 1, and the dashed line represents Comparative Example 1.

[0085] As can be seen from the figure, compared with the absence of a magnetic material substrate 120, Embodiment 1 achieved the following effects:

[0086] In the P-band, horizontal polarization decreased by 11.9–22.9 dB, and vertical polarization decreased by 5.4–20.1 dB.

[0087] In the L-band, horizontal polarization is reduced by 14.4–17.8 dB, and vertical polarization is reduced by 9.8–20.4 dB.

[0088] In the S-band, horizontal polarization decreased by 5.8–31.6 dB, and vertical polarization decreased by -1.5–10.5 dB.

[0089] In the C-band, horizontal polarization decreased by 9.5–20.1 dB, and vertical polarization decreased by -3.9–15.1 dB.

[0090] In the X-band, horizontal polarization decreased by 5.9–12.4 dB, and vertical polarization decreased by -3.1–15.8 dB.

[0091] In the Ku band, horizontal polarization is reduced by 3.9~15.6dB, and vertical polarization is reduced by -1.5~11.8dB.

[0092] Therefore, by setting a magnetic material substrate 120, the horizontal polarization RCS low scattering performance of the suspension rope / support is significantly optimized.

[0093] (2) The simulation results of Comparative Example 1 and Comparative Example 2 are compared as shown in the figure below. Figure 4 As shown, Figure 4 The solid line represents Comparative Example 1, and the dashed line represents Comparative Example 2.

[0094] As can be seen from the figure, Comparative Example 1 with the annular pointed cone portion 112 achieves the following effects compared to the one without the annular pointed cone portion 112:

[0095] In the P-band, horizontal polarization decreases by -9.5 to 5.7 dB, and vertical polarization decreases by 0.7 to 15.1 dB.

[0096] In the L-band, horizontal polarization is reduced by 7.6–11.6 dB, and vertical polarization is reduced by 8.9–13.5 dB.

[0097] In the S-band, horizontal polarization decreased by 15.9–21.8 dB, and vertical polarization decreased by 14.9–33.8 dB.

[0098] In the C-band, horizontal polarization decreased by 18.6–27.4 dB, and vertical polarization decreased by 27.0–43.3 dB.

[0099] In the X-band, horizontal polarization decreased by 5.3–18.6 dB, and vertical polarization decreased by 3.9–34.6 dB.

[0100] In the Ku band, horizontal polarization is reduced by 5.3–15.1 dB, and vertical polarization is reduced by 0.2–12.1 dB.

[0101] Therefore, when the absorbing unit 110 has an annular cone portion 112, the horizontal polarization RCS low scattering performance of the suspension rope / support is significantly optimized.

[0102] (3) The simulation results of Comparative Example 3 and Comparative Example 2 are compared as shown in the figure below. Figure 5 As shown, Figure 5 The solid line represents Comparative Example 3, and the dashed line represents Comparative Example 2.

[0103] As can be seen from the figure, Comparative Example 3, which includes a magnetic material substrate 120, achieves the following effects compared to the example without a magnetic material substrate 120:

[0104] In the P-band, horizontal polarization decreases by 2.8–6.7 dB, and vertical polarization decreases by 2.5–7.4 dB.

[0105] In the L-band, horizontal polarization is reduced by 6.6–23.6 dB, and vertical polarization is reduced by 10.5–12.7 dB.

[0106] In the S-band, horizontal polarization decreased by 0.3–24.4 dB, and vertical polarization decreased by 7.4–18.1 dB.

[0107] In the C-band, horizontal polarization decreased by 8.8–10.1 dB, and vertical polarization decreased by 8.8–10.4 dB.

[0108] In the X-band, horizontal polarization decreased by 9.8–13.5 dB, and vertical polarization decreased by 2.8–11.1 dB.

[0109] In the Ku band, horizontal polarization is reduced by 6.8–12.2 dB, and vertical polarization is reduced by 2.8–11.1 dB.

[0110] Therefore, when a magnetic material substrate 120 is provided, the horizontal polarization RCS low scattering performance of the suspension rope / support is significantly optimized.

[0111] (4) The simulation results of Example 1 and Comparative Example 2 are shown in the figure below. Figure 6 As shown, Figure 6 The solid line represents Example 1, and the dashed line represents Comparative Example 2.

[0112] As can be seen from the figure, compared with the absence of a magnetic material substrate 120 and annular cone portion 112, Embodiment 1, by providing a magnetic material substrate 120 and an annular cone portion 112, achieves the following effects:

[0113] In the P-band, horizontal polarization decreased by 10.9–25.3 dB, and vertical polarization decreased by 14.1–32.6 dB.

[0114] In the L-band, horizontal polarization decreased by 19.9–32.6 dB, and vertical polarization decreased by 23.3–30.0 dB.

[0115] In the S-band, horizontal polarization decreased by 22.5–53.2 dB, and vertical polarization decreased by 20.3–34.6 dB.

[0116] In the C-band, horizontal polarization decreased by 30.5–43.6 dB, and vertical polarization decreased by 29.5–48.3 dB.

[0117] In the X-band, horizontal polarization decreased by 23.2–30.9 dB, and vertical polarization decreased by 7.0–50.5 dB.

[0118] In the Ku band, horizontal polarization is reduced by 11.1–22.8 dB, and vertical polarization is reduced by 8.2–14.7 dB.

[0119] The test results of (2), (3) and (4), namely the reduction data of Example 1, Comparative Example 1 and Comparative Example 3 compared with Comparative Example 2, are shown in Table 1.

[0120] Table 1 compares the polarization reduction data with that of Comparative Example 2.

[0121]

[0122] As can be seen from Table 1, the polarization degree of Examples 1, 2, and 3 is significantly reduced compared to Comparative Example 2, especially Example 1, which shows a significant reduction in polarization degree compared to Comparative Example 2. The sum of the reduction degrees of Comparative Example 1 and Comparative Example 3 is lower than that of Example 1 in certain wavelength bands, indicating that the combination of a magnetic substrate and an annular cone portion 112 has a synergistic effect, and that the combined effect makes the reduction in polarization more significant.

[0123] (5) The simulation results of Example 1 and Comparative Example 4 are shown in the figure below. Figure 7 As shown, Figure 7 The solid line represents Example 1, and the dashed line represents Comparative Example 4.

[0124] As can be seen from the figure, the distribution of the absorbing unit 110 in the middle of Embodiment 1, with the smallest diameter increasing towards both ends, achieves the following effects compared to a method where all absorbing units 110 have the same diameter:

[0125] In the P-band, horizontal polarization decreased by 15.0–31.8 dB, and vertical polarization decreased by 2.2–21.4 dB.

[0126] In the L-band, horizontal polarization decreased by 21.8–30.2 dB, and vertical polarization decreased by 5.2–11.8 dB.

[0127] In the S-band, horizontal polarization decreased by 22.4–39.4 dB, and vertical polarization decreased by -0.14–14.4 dB.

[0128] In the C-band, horizontal polarization decreased by 10.9–37.0 dB, and vertical polarization decreased by 5.4–24.1 dB.

[0129] In the X-band, horizontal polarization decreased by 18.6–28.5 dB, and vertical polarization decreased by 5.3–32.2 dB.

[0130] In the Ku band, horizontal polarization is reduced by 13.5–29.6 dB, and vertical polarization is reduced by 2.9–10.5 dB.

[0131] The results show that the diameter-gradient type of the absorbing unit 110 has a better effect than the diameter-uniform type.

[0132] (6) The simulation results of Example 1 and Comparative Example 5 are shown in the figure below. Figure 8 As shown, Figure 8 The solid line represents Example 1, and the dashed line represents Comparative Example 5.

[0133] from Figure 8 As can be seen, Example 1, with its magnetic substrate and small absorbing unit size, achieves the following advantages compared to the scheme without a magnetic substrate and with a large absorbing unit size:

[0134] In the P-band, horizontal polarization decreases by -8.0 to 15.3 dB, and vertical polarization decreases by -9.1 to 16.3 dB.

[0135] In the L-band, horizontal polarization decreased by 5.9–13.2 dB, and vertical polarization decreased by 4.7–12.8 dB.

[0136] In the S-band, horizontal polarization decreases by -1.9 to 21.9 dB, and vertical polarization decreases by 0.2 to 7.6 dB.

[0137] In the C-band, horizontal polarization decreased by 0.7–20.3 dB, and vertical polarization decreased by 7.4–22.6 dB.

[0138] In the X-band, horizontal polarization decreases by -3.2 to 1.9 dB, and vertical polarization decreases by -4.7 to 14.3 dB.

[0139] In the Ku band, horizontal polarization decreases by 2.0–11.7 dB, and vertical polarization decreases by 0.9–11.1 dB.

[0140] The results show that the absorbing unit 110 can achieve a stronger absorption effect with a smaller thickness compared to the scheme without a magnetic substrate and with an increased diameter.

[0141] (6) Record the RCS values ​​of horizontal and vertical polarization in each band of Examples 2 to 5 and Comparative Example 2 in Table 2.

[0142] Table 2 RCS values ​​of horizontal and vertical polarization in each embodiment

[0143]

[0144] As can be seen from Table 2, the RCS values ​​of each embodiment are significantly lower in all bands compared to those of Comparative Example 2 for horizontal and vertical polarization, indicating that each embodiment of the present invention has better absorption properties.

[0145] Comparing Example 4 with Example 2, Example 4 shows slightly larger RCS values ​​for both horizontal and vertical polarization in each band compared to Example 2. Similarly, comparing Example 5 with Example 3, Example 5 shows slightly larger RCS values ​​for both horizontal and vertical polarization in each band compared to Example 3. The number of absorbing units 110, the thickness of each absorbing unit 110, and the cone angle in Examples 4 and 5, compared to Examples 2 and 3, are outside the range required by this invention, demonstrating that when the size of the absorbing unit 110 is within the range required by this invention, the polarization can be reduced to an even lower level.

[0146] Comparing Example 6 with Example 3, the RCS values ​​of horizontal and vertical polarization in Example 6 were not significantly reduced, indicating that an excessively thick magnetic material substrate 120 cannot further reduce the RCS value; instead, it increases the overall weight and installation difficulty. Comparing Example 7 with Example 2, the RCS values ​​of the magnetic material substrate 120 in Example 7 were significantly higher in both horizontal and vertical polarization across all wavelengths, indicating that the magnetic material substrate 120 must be within the range required by this invention; otherwise, it is difficult to achieve a significant reduction in polarization.

[0147] II. Using Example 1 as the experimental model, the RCS of horizontal and vertical polarization in the P-Ku band was tested. The specific test method is GJB 5022-2001.

[0148] Test results are as follows Figure 9 As shown, comparison Figure 9 The direction of the curve and Figure 8 The similarity in the direction of the solid lines indicates that the data obtained from the aforementioned simulation experiment is similar to the actual measured results, and the data is reliable for reference.

[0149] In summary, this invention provides an absorbing structure 100 that incorporates two energy dissipation mechanisms: dielectric loss (low scattering structure) and magnetic loss (magnetic material substrate 120). These two loss mechanisms exhibit stronger absorption characteristics in different frequency ranges, complementing each other and enabling the overall structure to maintain high absorption performance across a wider frequency band. Furthermore, the composite structure of the absorbing unit 110 and the magnetic substrate achieves strong absorption across a smaller total thickness, significantly benefiting volume-sensitive applications. In particular, the specific arrangement of having the smallest outer diameter for the absorbing unit 110 in the middle of the low scattering structure and increasing the outer diameter towards both ends allows electromagnetic waves to be periodically absorbed through multiple scattering losses between the absorbing units. The gradual change in the size of the absorbing units creates a phase difference between the reflected echoes from different units, preventing the superposition of scattering from each unit and thus achieving a better absorption effect.

[0150] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A wave-absorbing structure, characterized in that, It includes a tubular magnetic material substrate and a low-scattering structure disposed on the outer peripheral wall of the magnetic material substrate; The low-scattering structure includes multiple absorbing units, which are distributed and connected sequentially along the length of the magnetic material substrate. The outer side of each absorbing unit has a pointed cone shape in cross-section parallel to the length of the magnetic material. Along the length of the magnetic material, the outer diameter of the absorbing unit located in the middle is the smallest, and the outer diameter of the absorbing unit at both ends is larger. The absorbing unit includes an annular connecting portion located on the inner side and an annular pointed cone portion located on the outer side; the annular connecting portions of adjacent absorbing units are connected to each other.

2. The absorbing structure according to claim 1, characterized in that, The thickness of the magnetic material substrate is 1~20mm.

3. The absorbing structure according to claim 2, characterized in that, The magnetic material substrate is made of at least one of ferrite, magnetic metal, magnetic nanomaterial, and magnetic graphene and carbon nanotube composite materials.

4. The absorbing structure according to claim 1, characterized in that, Each of the aforementioned absorbing units has a thickness of 32~96mm, an outer diameter of 100~1000mm, and an inner diameter of 10~100mm; The cone angle of the annular pointed part is 12.2~39.1°.

5. The absorbing structure according to claim 4, characterized in that, The number of the absorbing units is 10 to 30.

6. The microwave absorbing structure according to claim 1, characterized in that, The microwave absorbing unit is integrally molded from a foamed conductive mixture, which, by weight, comprises 70-80 parts of a polymer and 20-30 parts of microwave absorbing filler.

7. The microwave absorbing structure according to claim 6, characterized in that, The polymer is selected from at least one of polypropylene, polystyrene, polyethylene, ethylene-vinyl acetate copolymer, polylactic acid, polycarbonate, polyamide, polyetheretherketone, and polyimide.

8. The absorbing structure according to claim 7, characterized in that, The microwave absorbing filler is selected from at least one of graphite, carbon black, carbon nanotubes, carbon fibers, carbon nanofibers, graphite nanosheets, graphene, nickel-coated graphite powder, nickel-coated carbon fiber carbon black, metal powder, liquid metal, sheet iron-based metal powder, sheet iron-based alloy powder, sheet iron-silicon-aluminum alloy powder, sheet iron-silicon alloy powder, sheet iron-silicon-chromium alloy powder, sheet cobalt-based alloy powder, and sheet iron-nickel alloy powder.

9. A support system, characterized in that, Including the wave-absorbing structure as described in any one of claims 1 to 8.

10. A target radar cross section testing system, characterized in that, Includes the support system as described in claim 9.

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