Low-scattering carrier for RCS (radar cross section) test of antenna

Abstract

The invention provides a low-scattering carrier for RCS test of an antenna, and relates to the technical field of target far-field electromagnetic scattering characteristic test, the low-scattering carrier is a hollow structure formed by seamless connection of a first curved surface and a second curved surface; the low-scattering carriers are symmetrically distributed about a vertical plane mirror image where the front end and the rear end are located; the horizontal projection of the low-scattering carrier is a diamond-like shape with a sharp front part and a round rear part; the first curved surface is provided with an opening and a detachable cover plate matched with the opening; the opening is provided with a fixing part used for installing and fixing an antenna. The first curved surface and the outer surface of the antenna are conformal, free of order difference and continuous in curvature. The low-scattering carrier has low radar back scattering in a large angular domain range, when the low-scattering carrier is used for an antenna RCS test, edge diffraction of an antenna can be eliminated, the internal structure of the antenna is shielded, the state of the antenna in actual installation can be well simulated, and the accuracy of the antenna RCS test is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of far-field electromagnetic scattering characteristic testing of targets, and particularly relates to a low-scattering carrier for RCS testing of antennas. Background Art

[0002] In recent years, with the development of radar detection technology, in order to improve the survivability of aircraft, it has become very necessary to optimize the low-scattering design of the aircraft's shape and layout. However, after the overall low-scattering design of the aircraft is completed in the prior art, most of them adopt the component-level disassembly and evaluation method. When the target is separated from the structure, structures such as edges, surfaces, and cavities that did not exist before will be exposed to radar wave irradiation. If no treatment measures are taken, these exposed structures will have a serious impact on the test and evaluation of the target. In order to more accurately evaluate the RCS index of target components, it is necessary to shield structures such as edges, surfaces, and cavities that did not originally appear and simulate their actual installation states. Summary of the Invention

[0003] Aiming at one or more problems existing in the prior art, the present invention provides a low-scattering carrier for RCS testing of antennas. The low-scattering carrier of the present invention has low radar backscattering in a large angular range and does not affect the RCS testing of antennas. When used for antenna RCS testing, it can not only eliminate the edge diffraction of the antenna but also shield its internal structure, can better simulate the state when the antenna is actually installed, improve the accuracy of antenna RCS testing, is applicable to the accurate test and evaluation of most antennas, and is easy to promote.

[0004] The present invention provides a low-scattering carrier for RCS testing of antennas. The low-scattering carrier is a hollow structure formed by seamlessly connecting a first curved surface and a second curved surface. The low-scattering carrier is symmetrically distributed about the vertical plane where the front end and the rear end are located; the horizontal projection of the low-scattering carrier is a rhomboid-like shape with a pointed front and a round rear; the first curved surface is provided with an opening and a detachable cover plate matching the opening; a fixing component for installing and fixing the antenna is arranged at the opening; the first curved surface and the outer surface of the antenna are conformal without step difference and have continuous curvature.

[0005] In a possible design, the first curved surface, the second curved surface, and the detachable cover plate are smooth curved surfaces.

[0006] In a possible design, the roughness of the first curved surface, the second curved surface, and the detachable cover plate is less than 1.6.

[0007] In a possible design, the first curved surface and the detachable cover plate are conformal without step difference and have continuous curvature.

[0008] In a possible design, the rhomboid-like shape includes a sharp angle at the front, a first rounded angle at the rear, and second rounded angles on both sides.

[0009] In a possible design, the sharp angle is 45 to 90°.

[0010] In a possible design, the first rounded angle is 90 to 180°; and / or

[0011] The radius corresponding to the first rounded angle is 100 to 1000 mm.

[0012] In a possible design, the second rounded angle is greater than the sharp angle and less than 90°; and / or

[0013] The radius corresponding to the second rounded angle is 100 to 1000 mm.

[0014] In a possible design, the length of the low-scattering carrier is 1 to 2 m, the width is 0.5 to 1.5 m, and the height is 0.2 to 0.6 m.

[0015] In a possible design, the fixing component is a flange interface.

[0016] The present invention has at least the following beneficial effects compared with the prior art:

[0017] The surface of the low-scattering carrier provided by the present invention has no step difference and continuous curvature, has no concave cavity and other structures, and there are no strong scattering sources such as specular reflection and multiple reflections on the surface, and has a good surface current guiding effect. The horizontal projection of the low-scattering carrier is a rhomboid-like shape with a sharp front and a round rear, and the lateral and rear sides are rounded angles, which can reduce the diffraction of the sharp point and the scattering of the traveling wave, and can ensure that the low-scattering carrier has low-scattering characteristics within the required angular range. The first curved surface is conformal and has no step difference with the outer surface of the antenna, and is tightly connected, which can not only block the structures exposed when the antenna was not separated from the overall structure, but also avoid the echo reflection and strong specular reflection sources caused by surface discontinuity at the connection, and can better simulate the state of the antenna during actual installation, and more accurately measure and evaluate the RCS of the antenna target.

[0018] The low-scattering carrier of the present invention has low radar backscattering in a large angular range and does not affect the RCS test of the antenna. When used for the RCS test of the antenna, it can not only eliminate the edge diffraction of the antenna, but also block its internal structure, can better simulate the state of the antenna during actual installation, improve the accuracy of the antenna RCS test, is applicable to the accurate test and evaluation of most antenna RCS, and is easy to promote. Description of the Drawings

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 It is a schematic structural diagram of a low-scattering carrier for RCS testing of an antenna provided by the present invention;

[0021] Figure 2 It is a top view of a low-scattering carrier for RCS testing of an antenna provided by the present invention;

[0022] Figure 3 It is an axonometric view of a low-scattering carrier for RCS testing of an antenna provided by the present invention;

[0023] Figure 4 It is a horizontal projection view of a low-scattering carrier for RCS testing of an antenna provided by the present invention.

[0024] Reference numerals:

[0025] 11 - First curved surface; 12 - Second curved surface; 111 - Detachable cover plate; 112 - Fixing component; 21 - Sharp corner; 22 - First rounded corner; 23 - Second rounded corner. Detailed implementation manners

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0027] The present invention provides a low-scattering carrier for RCS testing of an antenna, as Figures 1-4 shown. The low-scattering carrier is a hollow structure formed by seamlessly connecting a first curved surface 11 and a second curved surface 12. The low-scattering carrier is symmetrically distributed about the vertical plane where the front end and the rear end are located; the horizontal projection of the low-scattering carrier is a rhombus-like shape with a pointed front and a round rear; the first curved surface 11 is provided with an opening and a detachable cover plate 111 that matches the opening; a fixing component 112 for installing and fixing the antenna is provided at the opening; the first curved surface 11 and the outer surface of the antenna are conformal without step difference and the curvature is continuous.

[0028] The surface of the low-scattering carrier provided by the present invention has no step difference and continuous curvature without concave cavity and other structures, and there are no strong scattering sources such as specular reflection and multiple reflections on the surface, and it has a good surface current guiding effect. The horizontal projection of the low-scattering carrier is a rhomboid-like shape with a pointed front and a round rear, and the lateral and rear directions are arc angles, which can reduce the diffraction of the cusp and the scattering of the traveling wave, so as to ensure that the low-scattering carrier has low-scattering characteristics within the required angular range. The first curved surface is conformal and has no step difference with the outer surface of the antenna, and is tightly connected, which can not only block the structure that was originally exposed when the antenna was not separated from the overall structure, but also avoid the echo reflection and strong specular reflection sources caused by surface discontinuity at the connection, and can better simulate the state of the antenna during actual installation, and more accurately measure and evaluate the RCS of the antenna target.

[0029] The low-scattering carrier of the present invention has low radar backscattering within a large angular range and does not affect the RCS test of the antenna. When used for the RCS test of the antenna, it can not only eliminate the edge diffraction of the antenna, but also block its internal structure, can better simulate the state of the antenna during actual installation, improve the accuracy of the antenna RCS test, is applicable to the accurate test and evaluation of the RCS of most antennas, and is easy to promote.

[0030] In some preferred embodiments, the first curved surface 11, the second curved surface 12 and the detachable cover plate 111 are smooth curved surfaces.

[0031] In some preferred embodiments, the roughness of the first curved surface 11, the second curved surface 12 and the detachable cover plate 111 is less than 1.6. The roughness of the first curved surface and the second curved surface of the low-scattering carrier of the present invention is less than 1.6 (profile arithmetic mean deviation), which is more conducive to reducing the scattering generated when electromagnetic waves propagate on the carrier.

[0032] In some preferred embodiments, the first curved surface 11 and the detachable cover plate 111 are conformal and have no step difference and continuous curvature.

[0033] In some preferred embodiments, as Figure 4 shown, the horizontal projection of the low-scattering carrier is a rhomboid-like shape with a pointed front and a round rear, and the rhomboid-like shape includes a sharp angle 21 at the front, a first arc angle 22 at the rear, and a second arc angle 23 on both sides. The front of the present invention is a sharp angle, and the lateral and rear directions are arc angles, which can reduce the diffraction of the cusp and the scattering of the traveling wave, and can ensure that the low-scattering carrier has low-scattering characteristics within the required angular range.

[0034] In some preferred embodiments, the sharp angle 21 is 45-90°. It should be noted that when the tip of the horizontal projection of the low-scattering carrier is composed of two straight lines, the two straight lines form a sharp angle (tip angle); when the tip is composed of a curve, the angle formed by the tangent along the curve forms a sharp angle (tip angle).

[0035] In some preferred embodiments, the first arc angle 22 is 90 to 180°; and / or

[0036] The radius corresponding to the first arc angle 22 is 100 to 1000 mm.

[0037] In some preferred embodiments, the second arc angle 23 is greater than the sharp angle and less than 90°; and / or

[0038] The radius corresponding to the second arc angle 23 is 100 to 1000 mm.

[0039] By controlling the sharp angle, the rearward first arc angle, the lateral second arc angle and the radius corresponding to the arc angle within the above ranges, the present invention can ensure that the low-scattering carrier has a low RCS value within the required angular range.

[0040] In some preferred embodiments, the length of the low-scattering carrier is 1 to 2 m, the width is 0.5 to 1.5 m, and the height is 0.2 to 0.6 m. In the present invention, the length of the low-scattering carrier refers to Figure 4 the maximum distance in the horizontal direction (left-right direction) of the horizontal projection; the width of the low-scattering carrier refers to Figure 4 the maximum distance in the vertical direction (up-down direction) of the horizontal projection; the height of the low-scattering carrier refers to Figure 1 the maximum distance in the vertical direction (up-down direction).

[0041] In some preferred embodiments, the fixing member 112 is a flange interface.

[0042] The low-scattering carrier of the present invention is provided with a flange interface on the inner surface at the connection between the first curved surface and the outer surface of the antenna, for connecting the low-scattering carrier with the antenna and the detachable cover; the detachable cover is used as a replacement part of the antenna for RCS test and evaluation of the low-scattering carrier.

[0043] The surface curvature of the low-scattering carrier of the present invention is continuous and there are no structures such as concave cavities. There are no strong scattering sources such as specular reflection and multiple reflections on the surface, and it has a good surface current guiding effect. When verifying the RCS of the low-scattering carrier, the RCS of the low-scattering carrier has low-scattering characteristics relative to the tested antenna and has little impact on the evaluation of the antenna RCS. In actual tests, the RCS of the low-scattering carrier is far better than that of the antenna test piece target. When testing the antenna RCS, the antenna is connected to the first curved surface of the low-scattering carrier through a flange interface. The outer surface of the antenna and the first curved surface of the carrier are flush at the joint without a step difference, and the surface curvature is continuous. After installing the antenna and the low-scattering carrier, aluminum foil is pasted at the small gap between them, so that the structure exposed when the antenna was not separated from the overall structure is blocked, and at the same time, it is ensured that there will be no echo reflection of surface discontinuity and strong specular reflection sources at the connection, so as to better simulate the state of the antenna during actual installation, and thus improve the accuracy of the antenna RCS test.

[0044] In summary, the present invention provides a low-scattering carrier for RCS testing of an antenna. The low-scattering carrier and the tested antenna adopt a conformal and step-free structure design and are tightly connected, which not only eliminates the edge diffraction of the antenna, but also blocks the edges, surfaces, concave cavities and other structures that did not originally appear on the antenna. It can not only better simulate the state of the antenna during actual installation, but also have no impact on the RCS test of the antenna, thereby improving the accuracy of the RCS measurement and evaluation of the antenna. The low-scattering carrier provided by the present invention can be used for accurate test and evaluation of the RCS of antenna targets in most target test fields and is easy to promote.

[0045] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, terms such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; unless otherwise specified or stated, the term "multiple groups" means two or more groups; terms such as "connection" and "fixation" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the description of this specification, it should be understood that the orientation terms such as "upper" and "lower" described in the embodiments of the present invention are described from the angles shown in the drawings and should not be construed as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A low-scattering carrier for RCS testing of an antenna, characterized in that, The low-scattering carrier is a hollow structure formed by seamless connection of a first curved surface and a second curved surface, and the low-scattering carrier is symmetrically distributed with respect to the vertical plane where the front end and the rear end are located; the horizontal projection of the low-scattering carrier is a rhomboid-like shape with a pointed front and a round rear; the first curved surface is provided with an opening and a detachable cover plate matching the opening; a fixing component for installing and fixing the antenna is arranged at the opening; the outer surfaces of the first curved surface and the antenna are conformal without step difference and have continuous curvature.

2. The low-scattering carrier according to claim 1, characterized in that, The first curved surface, the second curved surface and the detachable cover plate are smooth curved surfaces.

3. The low-scattering carrier according to claim 2, wherein The roughness of the first curved surface, the second curved surface and the detachable cover plate is less than 1.

6.

4. The low-scattering carrier according to claim 1, wherein The first curved surface and the detachable cover plate are conformal without step difference and have continuous curvature.

5. The low-scattering carrier according to claim 1, characterized in that, The rhomboid-like shape includes a pointed angle at the front, a first arc angle at the rear, and second arc angles on both sides.

6. The low-scattering carrier according to claim 5, wherein The pointed angle is 45 to 90°.

7. The low-scattering carrier according to claim 5, characterized in that, The first arc angle is 90 to 180°; and / or The radius corresponding to the first arc angle is 100 to 1000 mm.

8. The low-scattering carrier according to claim 5, wherein The second arc angle is greater than the pointed angle and less than 90°; and / or The radius corresponding to the second arc angle is 100 to 1000 mm.

9. The low-scattering carrier according to claim 1, wherein The length of the low-scattering carrier is 1 to 2 m, the width is 0.5 to 1.5 m, and the height is 0.2 to 0.6 m.

10. The low-scattering carrier according to claim 1, wherein The fixing component is a flange interface.

Images