A support rod ball head low scattering target phantom

Abstract

This invention relates to the field of low-scattering enclosures and provides a low-scattering target simulator with a support rod ball head. The simulator includes an integral metal enclosure and a connector detachably attached to the bottom of the integral metal enclosure. The integral metal enclosure is a thin-shell metal structure. When projected from a top-down view, the integral metal enclosure has symmetrical parabolic edge structures on both sides and wedge-shaped ends. When the bottom surface of the connector is horizontal, the two ends of the integral metal enclosure form an upward sweep angle with the horizontal plane. The upward sweep angle transitions smoothly with the bottom surface of the integral metal enclosure. Therefore, this device possesses excellent broadband and dual-angle domain low-scattering performance, effectively eliminates strong scattering sources formed by the internal support structure, and ensures seamless connection with the external body. It significantly improves the background purity and measurement accuracy of the target simulator in low-scattering background testing scenarios.

Description

Technical Field

[0001] This invention relates to the field of low-scattering shields and provides a low-scattering target simulation body with a support rod ball head. Background Technology

[0002] In recent years, various stealth aircraft have required extensive radar cross section (RCS) testing during the development, manufacturing, evaluation, and maintenance stages. Through detailed testing, the stealth defects of the aircraft can be identified, supporting iterative optimization of the aircraft and performance evaluation. Aircraft whole-body testing generally adopts methods such as indoor compact field testing, outdoor static far-field testing, and outdoor near-far-field transformation testing.

[0003] An ideal target simulator needs to possess extremely low and stable scattering levels across a wide frequency band, particularly in specific angular domains critical to stealth performance evaluation, such as the forward (e.g., nose-direction) and rearward (e.g., tail-direction) directions. However, the shape geometry of existing low-scattering target simulators often fails to achieve excellent low-scattering performance simultaneously across a wide frequency band, especially in the critical forward and rearward angular domains.

[0004] Common shapes such as simple pyramids, prisms, or combinations thereof do not provide precise control over scattered energy, making it difficult to effectively guide strong specular reflections and coupled scattering peaks to non-critical angle regions. This results in high residual RCS in the nose and tail directions, where the threat is greatest. Secondly, while relying solely on surface absorbing materials can absorb some energy, if the shape design is poor, the absorbing layer cannot fully compensate for or suppress residual structural scattering, and maintaining a high absorption rate over a wide frequency band is also quite difficult. Meanwhile, although the target simulation body needs to cover the internal support structure, such as the support column and its spherical head, to prevent it from becoming a strong scattering source, there is still room for optimization in the existing enclosure design to achieve a seamless, low-scattering connection with the internal structure. Utility Model Content

[0005] To address the aforementioned deficiencies, the present invention aims to provide a low-scattering target simulator with a support rod ball head, in order to solve the problems mentioned in the background art. The simulator includes an integral metal cover and a detachable connector attached to the bottom of the integral metal cover. The integral metal cover is a thin-shell metal structure. Under a top-view projection, the integral metal cover has symmetrical parabolic edge structures on both sides and wedge-shaped ends. When the bottom surface of the connector is horizontal, the two ends of the integral metal cover form an upward sweep angle with the horizontal plane. The upward sweep angle transitions into an arc shape with the bottom surface of the integral metal cover.

[0006] Furthermore, the top surface of the integral metal cover is a smooth, protruding curved surface.

[0007] Furthermore, the outer surface of the integral metal cover is covered with a wave-absorbing layer.

[0008] Furthermore, the cross-section of the arc shape containing the outline of one end of the integral metal cover forms a forward sweep angle θ1 with the horizontal plane, and the cross-section of the arc shape containing the outline of the other end forms a backward sweep angle θ2 with the horizontal plane; thus, θ1 = 16° and θ2 = 9°.

[0009] Furthermore, the angle between the tangent plane corresponding to the middle section of the smooth protruding curved surface of the top surface and the horizontal plane is θ3, so θ3 = 3°.

[0010] Furthermore, the connecting body includes a second mounting plate that can be detachably connected to the bottom surface of the overall metal cover. The bottom of the second mounting plate is integrally connected to a first mounting plate that can be connected to an external support column. The first mounting plate has a receiving cavity in the middle.

[0011] Furthermore, the inner wall shape of the receiving cavity is adapted to the spherical shape of the top of the support column.

[0012] Furthermore, the inner wall of the receiving cavity is a circular arc surface; when the diameter of the circular surface of the top of the support column is D, the radius R of the circular arc of the receiving cavity satisfies R=D / 2+D / 20.

[0013] Therefore, this utility model solves the key problems of large scattering interference from the support structure, high scattering level of the cover itself, and scattering introduced by assembly gaps in low scattering target simulation through the synergistic effect of the following two aspects:

[0014] 1. Precision fit design with the support rod ball head: The first mounting plate 21 and the second mounting plate 22 of the bottom connector 2, along with their specially designed internal receiving cavity 20, achieve complete and tight coverage of the top of the support column, and ensure a stable and reliable connection through a detachable bolt connection. This eliminates the exposure of the support column head and the assembly gaps that may occur at the connection with the cover, thereby eliminating the strong scattering source introduced by the support structure itself.

[0015] 2. The integral metal dome 1 integrates wedge-shaped stealth and radar-absorbing material stealth technologies. Its special shape actively controls the distribution of scattered energy and guides strong reflections; the broadband radar-absorbing layer effectively absorbs the incident wave energy, enabling the integral metal dome 1 to achieve an extremely low radar cross-section level at key angles and within a wide operating frequency band. Attached Figure Description

[0016] Figure 1 A first-person view structural diagram of the overall metal enclosure;

[0017] Figure 2 This is a schematic diagram of the overall metal enclosure from a second-view perspective.

[0018] Figure 3A schematic diagram of the main body shape of the overall metal enclosure from an upward perspective;

[0019] Figure 4 A schematic diagram of the main body shape of the overall metal enclosure from a top-down perspective;

[0020] Figure 5 This is a view of the entire metal enclosure from direction A.

[0021] Figure 6 This is a view of the entire metal enclosure from direction B.

[0022] Figure 7 This is a side view of the overall metal enclosure;

[0023] In the diagram: 1-Integral metal cover; 2-Connector; 20-Receiving cavity; 21-First mounting plate; 22-Second mounting plate; 3-Straight line segment; 4-Circular arc segment. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0025] It should be noted that, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model 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 utility model. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] Furthermore, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0028] See Figure 1-7 The purpose of this utility model is to provide a low-scattering target simulation body with a support rod ball head, including an integral metal cover 1 and a connecting body 2 located at the bottom of the integral metal cover.

[0029] The overall metal enclosure 1 is a thin-walled metal shell structure with a certain height, bilateral symmetry, and wedge-shaped front and back. The metal material is aluminum alloy. The outer surface of the overall metal enclosure 1 is coated with an absorbing layer, which is made of absorbing material. The absorbing material is polyurethane or other types of absorbing material with a certain thickness, covering the overall metal enclosure 1. In this design, the absorbing layer should have good absorption performance in the 1–18 GHz range, and the absorption rate should be greater than 10 dB throughout the entire test band.

[0030] See appendix Figure 3 The overall shape of the metal enclosure 1 is characterized by the following features: In top / bottom view projections, the cross-sectional profiles of the top and bottom surfaces of the enclosure are symmetrical parabolic edge structures on the left and right sides, with wedge-shaped ends. Other key design parameters include the sweep angle of the cross-sectional cones, the inclination angles of the front and rear wedges, the height of the enclosure, and the width of the enclosure.

[0031] Specifically, the overall outline of the metal enclosure 1 in this design is shown in the attached figure. Figure 4 As shown, in the top-view projection, the two pointed cones of the cover's shape are both composed of straight line segments 3 at both ends, and the outer contour between the two pointed cones is transitioned by an arc segment 4 in the middle; that is, the outer contour is formed by two straight line segments 3. Figure 3 The pointed outline at end B, the end furthest from end B, is composed of two straight line segments 3. Figure 3 The pointed profile of end A. For the pointed profiles of ends A and B, the angle formed by the two straight line segments 3 of each end is θ0, where θ0 is 60°.

[0032] See appendix Figure 7 With the bottom surface of connector 2 positioned horizontally, both tips, A and B, form a sweep angle with the horizontal plane. The sweep angles of tips A and B are the forward sweep angle and the backward sweep angle, respectively. Specifically, the sweep angles of tips A and B transition into the arc shape of the bottom surface of the overall metal shroud 1. For tip A, the forward sweep angle between the tangent of the arc and the horizontal plane is θ1, which is 16°; for tip B, the backward sweep angle between the tangent of the arc and the horizontal plane is θ2, which is 9°. θ1 and θ2 characterize the positions where specular scattering peaks occur in the forward and backward directions. In radar cross section (RCS) testing, the forward and backward sweep angles suppress specular scattering and coupled scattering of the overall metal shroud 1, reducing its scattering to an extremely low level.

[0033] See appendix Figure 2Appendix Figure 3 Appendix Figure 7 As shown, the top surface of the overall metal enclosure 1 has a smooth, protruding curved shape. The angle between the tangent plane corresponding to the middle section of the curved surface and the horizontal plane is θ2, where θ2 is 3°. The internal space of the top surface of the overall metal enclosure 1 must accommodate the load-bearing support columns, as shown in the attached diagram. Figure 2 As shown, connector 2 is used for detachable connection with support column.

[0034] The connecting body 1 has a second mounting plate 22 that is detachably connected to the integral metal cover 1 and a first mounting plate 21 that is fixedly connected to the bottom of the second mounting plate 22. The second mounting plate 22 and the first mounting plate 21 are integrally connected, and a receiving cavity 20 is provided in the middle of the second mounting plate 22 and the first mounting plate 21. The receiving cavity 20 can accommodate the column head of the test site support column. The column head is a ball head structure. The first mounting plate 212 can be bolted to the support column, and the second mounting plate 22 is bolted to the bottom surface of the integral metal cover 1.

[0035] The cavity 20 has an arc-shaped interior. The diameter of the ball head at the top of the support column is D, and the radius of the arc inside the cavity 20 is R. For ease of assembly, the arc radius should be slightly larger than the radius of the ball head of the support column. The preferred value of R is D / 2 + D / 20.

[0036] The broadband dual-angle domain low-scattering shield designed in this way can be easily wrapped around a cylindrical load-bearing column and can be well applied in low-scattering background test scenarios to obtain typical scattering characteristic curves of the low-scattering shield. The broadband dual-angle domain low-scattering shield has the following functional characteristics:

[0037] The low-scattering dome exhibits good low-scattering performance in both the nose and tail directions, reaching -50 dBsm (X-band) in the nose direction and -40 dBsm (X-band) in the tail direction. The dome completely encloses the internal support columns, with the top of the dome tightly fitted to the bottom of the fuselage, eliminating gap scattering. The surface of the dome is covered with radar-absorbing material to reduce coupling scattering between the dome and the fuselage and the ground.

[0038] In summary, the key design feature of this integral metal dome 1 lies in its unique composite structure. Its main body adopts a specific contour shape with left-right symmetry and front-back wedges. The geometric configuration of its outer contour, including specific tip contour angles θ0, forward sweep angles θ1, and backward sweep angles θ2, effectively guides the reflection direction of radar waves, transferring strong specular scattering peaks in critical directions (such as forward and backward) to non-critical angle regions, thereby significantly suppressing the radar cross section (RCS) in the main lobe direction.

[0039] The broadband high-efficiency absorbing layer covering the outer surface of the shield has good absorption performance throughout the designed operating frequency band. It can effectively attenuate the electromagnetic wave energy irradiating the surface and reduce scattering caused by surface current and coupling between the shield and the external environment (such as the machine body and the ground).

[0040] Therefore, this design not only possesses excellent wideband and dual-angle domain low scattering performance, but also eliminates strong scattering sources formed by the internal support structure and ensures seamless connection with the external body; it greatly improves the background purity and measurement accuracy of the target simulation object in the low scattering background test scenario, laying the foundation for obtaining reliable low scattering characteristic data.

[0041] Of course, there may be other embodiments of this utility model. Without departing from the spirit and essence of this utility model, those skilled in the art can make various corresponding changes and modifications based on this utility model, but these corresponding changes and modifications should all fall within the protection scope of the appended claims of this utility model.

Claims

1. A support pole ball low-scattering target phantom, characterized by, It includes an integral metal cover (1) and a connector (2) detachably connected to the bottom of the integral metal cover (1). The integral metal cover (1) is a thin metal shell structure. When the integral metal cover (1) is projected from a top view, it has symmetrical parabolic edge structures on both sides and wedge-shaped ends. When the bottom surface of the connector (2) is in the horizontal direction, the two ends of the integral metal cover (1) form an upward sweep angle with the horizontal plane. The upward sweep angle transitions to the bottom surface of the integral metal cover (1) in an arc shape.

2. The support pole ball low-scattering target phantom of claim 1, wherein, The top surface of the integral metal cover (1) is a smooth, protruding curved surface.

3. The support pole ball low-scattering target phantom of claim 1, wherein, The outer surface of the integral metal cover (1) is covered with a wave-absorbing layer.

4. The support pole ball low-scattering target phantom of claim 1, wherein, The tangent of the arc shape containing the outline of one end of the integral metal cover (1) forms a forward sweep angle θ1 with the horizontal plane, and the tangent of the arc shape containing the outline of the other end forms a backward sweep angle θ2 with the horizontal plane; then θ1=16°, θ2=9°.

5. The support pole ball low-scatter target phantom of claim 2, wherein, The angle between the tangent plane corresponding to the middle section of the smooth protruding curved surface at the top and the horizontal plane is θ3, so θ3 = 3°.

6. The support pole ball low-scatter target phantom of claim 1, wherein, The connecting body (2) includes a second mounting plate (22) that can be detachably connected to the bottom surface of the overall metal cover (1). The bottom of the second mounting plate (22) is integrally connected to a first mounting plate (21) that can be connected to an external support column. The first mounting plate (21) has a receiving cavity (20) in the middle.

7. The support pole ball low-scatter target phantom of claim 6, wherein, The inner wall shape of the receiving cavity (20) is adapted to the ball head shape at the top of the support column.

8. The support pole ball low-scatter target phantom of claim 7, wherein, The inner wall of the receiving cavity (20) is a circular arc surface; when the diameter of the circular surface of the top column of the support column is D, the radius R of the circular arc of the receiving cavity (20) satisfies R = D / 2 + D / 20.

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