Low-scattering carrier suitable for omnidirectional RCS (radar cross section) test

Abstract

The invention relates to a low-scattering carrier suitable for an omnidirectional RCS test, and relates to the field of electromagnetic scattering characteristic testing, the low-scattering carrier comprises an upper surface, a lower surface, a disc and a plane polygon structure, the upper surface and the lower surface are seamlessly connected, the front end and the rear end of the upper surface are in a flat pointed cone shape, and the disc is rotatably connected with the upper surface through a flange; the plane polygon structure is fixedly connected with the disc through a flange and a bolt pair; the upper surface, the lower surface, the disc and the plane polygon structure are smoothly connected, and the surface roughness is lower than 1.6. The conformal non-step structure design is adopted, tight connection is achieved, connection edge scattering is eliminated, the outer surface structure is shielded, the state of a plane polygon structure target in the actual installation process is well simulated, and the measurement accuracy of the plane polygon structure target is improved. Therefore, the method has the advantage that RCS measurement and evaluation can be more accurately carried out on the plane polygon-like structure target.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic scattering characteristic testing technology, and in particular to a low-scattering carrier suitable for omnidirectional RCS testing. Background Technology

[0002] After the overall design of the aircraft is completed, the radar cross-section performance of the target components will be evaluated. Once the target detaches from the structure, previously non-existent edges, surfaces, and cavities will be exposed to radar waves. Without any intervention, these exposed structures will severely impact the target's testing and evaluation.

[0003] Therefore, to address the above shortcomings, it is necessary to provide a low-scattering carrier suitable for omnidirectional RCS testing. Summary of the Invention

[0004] (a) Technical problems to be solved The technical problem to be solved by the present invention is to address the issue that a single carrier cannot meet the requirements of omnidirectional RCS testing.

[0005] (II) Technical Solution To address the aforementioned technical problems, this invention provides a low-scattering carrier suitable for omnidirectional RCS testing, comprising an upper surface, a lower surface, a disk, and a planar polygonal structure. The upper and lower surfaces are seamlessly connected, and both ends are flat and pointed cones. The disk is rotatably connected to the upper surface via a flange, and the planar polygonal structure is fixedly connected to the disk via a flange and bolts. The upper surface, lower surface, disk, and planar polygonal structure are smoothly connected, and the surface roughness of each is less than 1.6.

[0006] As a further explanation of the present invention, preferably, the tips of the upper and lower surfaces are sharp angles formed by two straight lines.

[0007] As a further explanation of the present invention, preferably, the tips of the upper and lower surfaces are sharp angles formed along the tangent of the curve.

[0008] As a further explanation of the present invention, preferably, the forward tip angle of the upper surface and the lower surface is smaller than the backward tip angle.

[0009] As a further explanation of the present invention, preferably, the angle between the tip angle of the upper surface and the lower surface and the horizontal direction is in the range of 40° to 70°.

[0010] As a further explanation of the present invention, preferably, the plane where the curves of the upper and lower surfaces intersect makes an angle of 5° with the horizontal plane.

[0011] As a further explanation of the present invention, preferably, the upper and lower surfaces have a length of 0.5 to 5 m, a width of 0.2 to 2 m, and a height of 0.1 to 0.8 m.

[0012] As a further explanation of the present invention, preferably, the installation position of the planar polygonal structure is the target installation position, and the planar polygonal structure is removed to install a target of the same shape at the target installation position.

[0013] As a further explanation of the present invention, preferably, the RCS of the upper surface, the lower surface and the disk are higher than the target RCS.

[0014] As a further explanation of the present invention, preferably, aluminum foil is pasted at the connection between the target and the disk.

[0015] (III) Beneficial Effects The above-described technical solution of the present invention has the following advantages: This invention designs a low-scattering carrier suitable for omnidirectional RCS testing. It eliminates edge scattering of planar polygonal targets and obscures their originally embedded outer surface structures, thus better simulating the actual installation state of planar polygonal targets. It also exhibits low radar backscattering over a large angular range and does not affect the RCS testing of planar polygonal targets, allowing for more accurate measurement and evaluation of the RCS of planar polygonal targets. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a top view of the present invention; Figure 3 This is a side view of the present invention.

[0017] In the diagram: 1. Upper surface; 2. Lower surface; 3. Disk; 4. Planar polygonal structure; 5. Target installation position. Detailed Implementation

[0018] 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, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] A low-scattering carrier suitable for omnidirectional RCS testing, combined with Figure 1 , Figure 2The system comprises an upper surface 1, a lower surface 2, a disk 3, and a planar polygonal structure 4. The upper surface 1 and lower surface 2 are seamlessly connected. The upper surface 1 is mounted and fixed to the planar disk 3 and planar polygonal structure 4 via connecting flanges. The installation position of the planar polygonal structure 4 is the target installation position 5. The planar polygonal structure 4 is removed to install a planar polygonal structure target of the same shape at the target installation position 5. The two have continuous curvature. The upper surface 1 and lower surface 2 have high surface finish, with surface roughness Ra (arithmetic mean deviation of the profile) less than 1.6. The low-scattering carrier and the upper surface of the disk 3, and the disk 3 and the planar polygonal structure target are conformally designed without step difference, and are tightly connected. During testing, after the target, disk, and carrier are installed sequentially, only the joints between the three need to be treated with aluminum foil.

[0020] Combination Figure 1 , Figure 2 The carrier has two relatively sharp, flattened cones at its front and rear ends to ensure a low scattering angle range in the forward, lateral, and backward directions. When the tip is formed by two straight lines, the two lines form a tip angle; when the tip is formed by a curve, the angle formed by the tangents of the curve forms the tip angle. The forward tip angle is smaller than the backward tip angle. In practical applications, the horizontal angle between the two tips is between 40° and 70°. According to electromagnetic scattering theory, the magnitude of the forward and backward angles of the carrier determines the low scattering angle range of the low-scattering carrier. Therefore, for specific RCS angle requirements, selecting an appropriate tip angle is extremely important, preferably 50°.

[0021] Combination Figure 1 , Figure 3 The plane containing the intersection curves of the upper surface 1 and the lower surface 2 has an angle of approximately 5° with the horizontal plane. This makes it easier to connect the upper surface 1 of the carrier with the flat plate surface at this angle, while ensuring that the actual installation angle and state of the planar polygonal structure target remain unchanged.

[0022] The low-scattering carrier designed above, due to its relatively continuous surface curvature and the absence of cavities or other structures, lacks strong scattering sources such as specular reflection and multiple reflections, thus exhibiting good surface current conduction. During carrier verification, the carrier demonstrates low scattering characteristics relative to the tested planar polygonal target structure, with minimal impact on target evaluation. In actual testing, the RCS of the low-scattering carrier is significantly superior to that of the planar polygonal target. Furthermore, the size and weight of the aforementioned low-scattering carrier are within the testing capabilities of most experimental platforms, facilitating operation.

[0023] Combination Figure 1 , Figure 2The disc 3 is rotatably connected to the upper surface 1 via a flange, and the planar polygonal structure 4 is fixedly connected to the disc 3 via a flange and bolts. When testing the planar polygonal structure target, the planar polygonal structure 4 with the same shape on the upper surface of the carrier needs to be removed. The planar polygonal structure target is then placed inside the carrier with a hollow structure and connected to the disc 3 via a connecting flange, and then connected to the upper surface 1. This obscures the structure that was exposed when the target was not detached from the overall structure, ensuring the accuracy of the RCS during target evaluation. The upper surface of the target and the upper surface 1 of the carrier are flush and without step difference at the joint, and the surface curvature is continuous. Aluminum foil is pasted into the small gap between them for treatment, ensuring that there are no surface discontinuities in echo reflection or strong specular reflection sources at the joint. By adjusting the target's forward and backward orientations to be installed with the forward orientation of the carrier twice, the forward and backward RCS of the target can be evaluated.

[0024] In practical applications, the low-scattering carrier formed by the upper surface 1 and the lower surface 2 has a length of 0.5–5 m, a width of 0.2–2 m, and a height of 0.1–0.8 m. The length and width mentioned above refer to… Figure 2 The length of the line connecting the two ends and the length of the widest part of the carrier perpendicular to that line. Height refers to... Figure 3 The maximum vertical length between the lowest point of the lower surface of the carrier and the highest point of the upper surface of the carrier.

[0025] In summary, this invention provides a low-scattering carrier suitable for omnidirectional RCS testing. The low-scattering carrier and the planar disk, along with the planar polygonal target, are designed with a conformal, step-free structure and are tightly connected. This eliminates edge scattering from the planar polygonal target, obscures its outer surface structure, and effectively simulates the actual installation state of the target. Aluminum foil is used to adhere the carrier to the joints, allowing for more accurate RCS measurement and evaluation. By rotating the planar disk 90°, the carrier can be used to test the forward, backward, and lateral RCS of the planar polygonal target, ultimately completing the omnidirectional RCS test. This low-scattering carrier can be used in most target testing ranges for accurate omnidirectional RCS testing and evaluation of planar polygonal targets. This invention is reliable, applicable, easy to promote, and will generate significant economic benefits.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-scattering carrier suitable for omnidirectional RCS testing, characterized in that: It includes an upper surface (1), a lower surface (2), a disk (3) and a planar polygonal structure (4). The upper surface (1) and the lower surface (2) are seamlessly connected and both ends are flat and pointed cones. The disk (3) is rotatably connected to the upper surface (1) through a flange. The planar polygonal structure (4) is fixedly connected to the disk (3) through a flange and bolt pair. The upper surface (1), the lower surface (2), the disk (3) and the planar polygonal structure (4) are smoothly connected and the surface roughness is less than 1.

6.

2. The low-scattering carrier suitable for omnidirectional RCS testing according to claim 1, characterized in that: The tips of the upper surface (1) and the lower surface (2) are sharp angles formed by two straight lines.

3. The low-scattering carrier suitable for omnidirectional RCS testing according to claim 1, characterized in that: The tips of the upper surface (1) and the lower surface (2) are sharp angles formed by the tangent to the curve.

4. The low-scattering carrier suitable for omnidirectional RCS testing according to claim 1, characterized in that: The forward tip angles of the upper surface (1) and the lower surface (2) are smaller than the backward tip angles.

5. A low-scattering carrier suitable for omnidirectional RCS testing according to claim 4, characterized in that: The angle between the tip angle of the upper surface (1) and the lower surface (2) and the horizontal direction is within the range of 40° to 70°.

6. A low-scattering carrier suitable for omnidirectional RCS testing according to claim 5, characterized in that: The plane where the curves of the upper surface (1) and the lower surface (2) intersect is located makes an angle of 5° with the horizontal plane.

7. A low-scattering carrier suitable for omnidirectional RCS testing according to claim 6, characterized in that: The upper surface (1) and the lower surface (2) have a length of 0.5 to 5 m, a width of 0.2 to 2 m, and a height of 0.1 to 0.8 m.

8. A low-scattering carrier suitable for omnidirectional RCS testing according to claim 7, characterized in that: The installation position of the planar polygonal structure (4) is the target installation position (5). The planar polygonal structure (4) is removed so that a target of the same shape can be installed at the target installation position (5).

9. A low-scattering carrier suitable for omnidirectional RCS testing according to claim 8, characterized in that: The RCS of the upper surface (1), the lower surface (2) and the disk (3) is higher than that of the target.

10. A low-scattering carrier suitable for omnidirectional RCS testing according to claim 8, characterized in that: Aluminum foil is pasted at the connection between the target and the disk (3).

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