Modular low-scattering foam stand for radar cross-section testing of large targets

Abstract

This invention discloses a modular low-scattering foam support for testing the radar scattering characteristics of large targets, belonging to the field of microwave measurement technology. It includes: a foam support base, a first foam support body, a second foam support body, a foam mechanical support base, and an absorbing baffle, all connected coaxially in sequence. The foam support base supports the large target for radar scattering characteristic testing and is tenon-and-mortise connected to the first foam support body. The first and second foam support bodies are also tenon-and-mortise connected, each including several foam support sub-bodies, each with the same inclination angle and a diameter that gradually increases from top to bottom. The foam mechanical support base is tenon-and-mortise connected to the second foam support body. The absorbing baffle is located in front of the foam mechanical support base. An arc-shaped groove is provided at the center of the upper end of the foam support base for placing a calibration metal ball. This invention effectively lowers the center of gravity of the foam support and significantly improves the stability of the support during rotation.

Description

Technical Field

[0001] This invention belongs to the field of microwave measurement technology, specifically relating to a modular low-scattering foam support for testing the radar scattering characteristics of large targets. Background Technology

[0002] The Compact Antenna Test Range (CATR) is a core facility in the field of microwave measurement. It simulates a far-field plane wave environment within a confined space using a parabolic reflector and is widely used for antenna radiation characteristic testing and radar cross section (RCS) measurement. With the development of stealth technology, the demand for compact antenna test ranges for large targets with low RCS values ​​is increasing. For such targets, the scattering characteristics, load-bearing capacity, and stability of the foam support directly affect the accuracy of the test results. Traditional foam supports mainly employ classic frustum configurations and low-density foam, and their design and fabrication face the following technical bottlenecks:

[0003] Stability: Due to the extremely low density of the foam material, large supports are easily subjected to mechanical disturbances during target hoisting, resulting in positional shifts or structural deformations. This leads to unstable changes in the scattering characteristics of the supports, severely affecting the accuracy of background vector cancellation processing and ultimately introducing significant measurement errors.

[0004] Load-bearing capacity: The mechanical strength of foam materials decreases significantly with the increase of foaming ratio. Conventional foam supports are difficult to support heavy test targets (such as large targets exceeding tons). Under heavy load conditions, they are prone to compression deformation or even structural failure, and cannot meet the requirements of modern RCS testing for high load-bearing capacity of supports.

[0005] Self-scattering interference: Although the classic frustum-shaped foam support has certain low scattering characteristics, its self-scattering signal can still cause significant interference to the test results. Especially in the measurement of heavy-load, low-RCS targets, the classic frustum-shaped foam support design often has to be designed with a small tilt angle and a large foam support volume due to the high height of the darkroom and the large weight of the target. By sacrificing the scattering performance of the foam support to obtain sufficient mechanical strength, this interference becomes more obvious and seriously affects the accurate acquisition of the true scattering characteristics of the target.

[0006] Therefore, there is an urgent need to develop a new type of foam scaffold, which should possess the following core characteristics:

[0007] Better stability: The support is stable during rotation with minimal sway;

[0008] Enhanced mechanical properties: The support structure has a stronger load-bearing capacity and resistance to deformation;

[0009] Minimize self-scattering: By designing special geometries and surface treatment processes, a wave-absorbing material baffle is introduced in front of the foam mechanical support base to effectively block strong scattering sources in the base part, thereby minimizing the self-scattering of the support.

[0010] This new modular foam support will effectively solve key problems in current RCS testing, significantly improve testing accuracy and reliability, and provide more accurate test data support for radar system development and target stealth technology evaluation. Summary of the Invention

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0012] A modular low-scattering foam support for testing the radar scattering characteristics of large targets includes: a foam support base, a first foam support body, a second foam support body, a foam mechanical support base, and a radar-absorbing baffle connected coaxially in sequence.

[0013] The foam support base is used to directly support large targets for radar scattering characteristic testing and is mortise and tenon connected to the first foam support body.

[0014] The first foam support body is a regular low-scattering truncated cone-shaped modular structure, including several first foam support sub-bodies. Each first foam support sub-bodies has the same inclination angle θ, and the diameter of each first foam support sub-bodies gradually increases from top to bottom. It is mortise and tenon connected to the second foam support body.

[0015] The second foam support body is a regular low-scattering truncated cone-shaped modular structure, which includes several second foam support sub-body, each of which has the same tilt angle θ' and the diameter of each second foam support sub-body gradually increases from top to bottom;

[0016] The foam mechanical support base is a cylindrical base, which is mortised and tenoned to the second foam support body.

[0017] The wave-absorbing baffle is located in front of the foam mechanical support base, including a first wave-absorbing baffle and a second wave-absorbing baffle facing the direction of incoming waves from the compaction field. The projected dimensions of the first wave-absorbing baffle and the second wave-absorbing baffle completely cover the foam mechanical support base.

[0018] The upper center of the foam support has an arc-shaped groove for placing the calibration metal ball.

[0019] The present invention has the following beneficial effects:

[0020] This invention effectively lowers the center of gravity of the foam support by introducing a modular mortise and tenon structure design and a high-strength foam mechanical support base, significantly improving the stability of the support during rotation and reducing the amount of swaying during rotation, thus significantly improving the stability and accuracy of the test results.

[0021] This invention also effectively improves load-bearing capacity and deformation resistance by using specially designed high-density foaming materials, supporting the testing requirements of large targets. When bearing large targets, the foam support has small deformation and small sway during rotation, thus improving the RCS test background cancellation effect.

[0022] This invention combines mechanical performance and low scattering characteristics through an innovative design of a foam mechanical support base and a wave-absorbing baffle in front of the foam support. The presence of the foam support base allows the upper foam support body to be designed as a truncated cone geometry with a larger inclination angle compared to the traditional frustum-shaped bracket, significantly reducing volume and scattering. At the same time, the large wave-absorbing baffle introduced in front of the foam mechanical support base completely blocks the foam mechanical support base, effectively reducing the scattering of the foam mechanical support base and minimizing the scattering of the bracket itself. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the modular low-scattering foam support for testing the radar scattering characteristics of large targets according to the present invention, wherein 1-foam support base, 2-first foam support sub-body, 3-second foam support sub-body, 4-third foam support sub-body, 5-first foam support sub-body, 6-second foam support sub-body, 7-third foam support sub-body, 8-fourth foam support sub-body, 9-foam mechanical support base, and 10-absorbing baffle.

[0024] Figure 2 This is a top view of the modular low-scattering foam support for testing the radar scattering characteristics of large targets according to the present invention, wherein 10 is an absorbing baffle.

[0025] Figure 3 This is a schematic diagram of an implementation method of the modular low-scattering foam support for testing the radar scattering characteristics of large targets according to the present invention, when setting up a large target for testing. In the diagram, 4-first foam support sub-body No. 3, 5-second foam support sub-body No. 1, 6-second foam support sub-body No. 2, 7-second foam support sub-body No. 3, 8-second foam support sub-body No. 4, 9-foam mechanical support base, and 10-wave-absorbing baffle. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0027] like Figure 1 , Figure 2 As shown, the present invention provides a modular low-scattering foam support (hereinafter referred to as support) for testing large targets, which is suitable for electromagnetic measurement scenarios such as radar cross section (RCS) testing of large targets in a compact field. It includes a foam support base 1, a first foam support body, a second foam support body, a foam mechanical support base 9, and a wave-absorbing baffle 10 connected coaxially in sequence.

[0028] Foam support 1: It adopts a cylindrical modular structure and is used to directly support large targets for radar scattering characteristic testing. It is connected to the first foam support body by mortise and tenon joints.

[0029] The first foam support body adopts a regular low-scattering truncated cone-shaped modular structure, designed according to the height of the quiet zone of the anechoic chamber and the characteristics of the target. It has low scattering characteristics and includes several first foam support sub-body, each of which has the same tilt angle θ, which is 6°-12°. The diameter of each first foam support sub-body gradually increases from top to bottom. This design can reduce the backscattering of the incident wave. It is connected to the second foam support body by mortise and tenon joints.

[0030] In this embodiment of the invention, the first foam support body includes three first foam support sub-body 2, first foam support sub-body 3 and first foam support sub-body 4 that are detachably connected by a tenon and mortise structure. The diameter gradually increases from top to bottom, and the inclination angle is θ.

[0031] The second foam support body adopts a regular low-scattering truncated cone-shaped modular structure, designed according to the height of the quiet zone of the anechoic chamber and the characteristics of the target. It has low scattering characteristics and includes several second foam support sub-body, each of which has the same tilt angle θ', with the tilt angle θ' ranging from 6° to 12°. The diameter of each second foam support sub-body gradually increases from top to bottom. This design can reduce the backscattering of the incident wave.

[0032] The second foam support body includes four second foam support sub-body 5, second foam support sub-body 6, third foam support sub-body 7, and fourth foam support sub-body 8 that are detachably connected by a mortise and tenon structure. The diameter of each foam support sub-body gradually increases from top to bottom, and the inclination angle is θ.

[0033] Foam mechanical support base 9: A cylindrical base used to provide stable mechanical support, coaxial with the first foam support body and the second foam support body, and mortise and tenon connected to the fourth second foam support sub-body 8 of the second foam support body.

[0034] Wave-absorbing baffle 10: Located in front of the foam mechanical support base 9, the two baffles facing the direction of incoming waves from the compaction field are the first wave-absorbing baffle and the second wave-absorbing baffle, respectively. The included angle α between the first wave-absorbing baffle and the second wave-absorbing baffle adopts a special low scattering angle design, with a value of 120°-150°. Both the first wave-absorbing baffle and the second wave-absorbing baffle are covered with wave-absorbing material, and their projected size completely blocks the foam mechanical support base 9 behind them, which can effectively reduce bottom scattering. Figure 2 This is a top view of the modular low-scattering foam support for testing the radar scattering characteristics of large targets according to the present invention. The position of the absorbing baffle 10 is as follows: Figure 2 As shown.

[0035] The foam support base 1, the first foam support body, the second foam support body, and the foam mechanical support base 9 are all made of polystyrene (EPS) foam, and the wave-absorbing baffle 10 is made of wood, fiber-reinforced resin-based composite material, or metal material.

[0036] Both the first foam support body and the second foam support body are truncated conical in shape, with the second foam support body being taller than the first foam support body.

[0037] The foam mechanical support base 9 is cylindrical, and its diameter is the same as the bottom diameter of the fourth second foam support sub-body 8 of the second foam support body.

[0038] The upper center of the foam support 1 is provided with an arc groove for placing the calibration metal ball. This arc groove can improve the placement stability of the calibration metal ball in corner tests and background tests, thereby improving the accuracy of radar scattering characteristic tests.

[0039] The upper end of the foam support base 1 is equipped with a leveling mechanism for placing the foam column carrying the calibration metal ball. During testing, the foam column carrying the calibration metal ball is first placed on the foam support base 1, and then the calibration metal ball is placed in the arc-shaped groove at the upper end of the foam column. This structure can effectively reduce the shaking of the calibration metal ball during rotation. Combined with the compacted field laser alignment device, the calibration metal ball is leveled and aligned, ensuring it is located on the horizontal plane at the center of the compacted field's static zone, achieving stable rotation and thus improving the accuracy of radar scattering characteristic testing.

[0040] Example 1:

[0041] like Figure 1As shown, a modular low-scattering foam support for testing the radar scattering characteristics of large targets includes a foam support base 1, a first foam support body composed of a first foam support sub-body 2, a second foam support sub-body 3, and a third foam support sub-body 4, a second foam support body composed of a second foam support sub-body 5, a second foam support sub-body 6, a third foam support sub-body 7, and a fourth foam support sub-body 8, a foam mechanical support base 9, and a radar-absorbing baffle 10.

[0042] A calibration metal ball or test target is placed on the upper end of the foam support 1.

[0043] The lower end of the foam support base 1 is connected to the upper end of the first foam support body, that is, the upper end of the first foam support sub-body 2, by a tenon and mortise joint.

[0044] The structure consists of three parts: No. 1 first foam support sub-body 2, No. 2 first foam support sub-body 3, and No. 3 first foam support sub-body 4, which are connected sequentially by mortise and tenon joints.

[0045] The second foam support body is composed of the first second foam support sub-body 5, the second second foam support sub-body 6, the third second foam support sub-body 7, and the fourth second foam support sub-body 8, which are connected in sequence by mortise and tenon joints.

[0046] The upper end of the second foam support body, namely the upper end of the first second foam support sub-body 5, is connected to the lower end of the first foam support body, namely the third first foam support sub-body 4, by a tenon and mortise joint.

[0047] The lower end of the second foam support body, namely the lower end of the fourth second foam support sub-body 8, is tenon-mortise connected to the upper end of the foam mechanical support base 9.

[0048] The foam mechanical support base 9 is placed on a one-dimensional turntable that can rotate in orientation.

[0049] A wave-absorbing baffle 10 is placed in front of the foam mechanical support base 9 to shield the foam mechanical support base 9 and the one-dimensional turntable below it.

[0050] This embodiment represents the most conventional implementation. Compared to existing technologies, this modular low-scattering foam support exhibits high stability and modular functionality, ensuring a constant support position during testing. The foam mechanical support base 9 significantly enhances the load-bearing capacity and mechanical stability of the foam support. By introducing the absorbing baffle 10 and designing the first and second foam support bodies with special geometric shapes and small volumes, the self-scattering of the support can be minimized, reducing its impact on the test and ensuring optimal test results. In this embodiment, the measured RCS value of the foam support in the X-band (8GHz-12GHz) is -37dBsm, a significant reduction of 70% compared to traditional foam supports.

[0051] Example 2:

[0052] like Figure 3 As shown, a modular low-scattering foam support for testing the radar scattering characteristics of large targets is used in an embodiment for setting up large targets for RCS testing. In this case, the modular foam support base 1, the first foam support sub-body 2, and the second foam support sub-body 3 can be quickly removed at the test site through the mortise and tenon structure. The first foam support body composed of the third foam support sub-body 4, the second foam support body composed of the first foam support sub-body 5, the second foam support sub-body 6, the third foam support sub-body 7, and the fourth foam support sub-body 8, as well as the foam mechanical support base 9 and the radar-absorbing baffle 10 are retained. By removing some modules, the target erection height is reduced to accommodate the larger volume and height of larger targets.

[0053] The test target is placed directly on the upper end of the first foam support body, which consists of the third first foam support sub-body 4. The upper end of the second foam support body, i.e., the upper end of the first second foam support sub-body 5, is tenon-jointed to the lower end of the first foam support body. The lower end of the first second foam support sub-body 5 is tenon-jointed to the upper end of the second second foam support sub-body 6. The lower end of the second second foam support sub-body 6 is tenon-jointed to the upper end of the third second foam support sub-body 7. The lower end of the third second foam support sub-body 7 is tenon-jointed to the upper end of the fourth second foam support sub-body 8. The lower end of the second foam support body, i.e., the lower end of the fourth second foam support sub-body 8, is tenon-jointed to the upper end of the foam mechanical support base 9. The foam mechanical support base 9 is placed on a one-dimensional turntable that can rotate in orientation. A wave-absorbing baffle 10 is placed in front of it to shield the foam mechanical support base 9 and the one-dimensional turntable.

[0054] This embodiment eliminates the need for dedicated foam supports when testing larger targets, effectively reducing costs. Compared to conventional large target testing setups, this solution eliminates the need for overall hoisting of the foam support, allowing for flexible adaptation to the testing needs of larger targets. Through modular design, state transition time is significantly shortened, improving testing efficiency while maintaining the low scattering characteristics and testing accuracy of the foam support.

[0055] This invention effectively lowers the center of gravity of the foam support by introducing a modular mortise and tenon structure design and a high-strength foam mechanical support base, significantly improving the stability of the support during rotation and reducing the amount of swaying during rotation, thus significantly improving the stability and accuracy of the test results.

[0056] This invention also effectively improves load-bearing capacity and deformation resistance by using specially designed high-density foaming materials, supporting the testing requirements of large targets weighing up to 2800kg. When bearing large targets, the deformation of the foam support is less than 0.5%, and the amount of shaking during rotation is small, thus improving the effect of RCS test background cancellation.

[0057] This invention combines mechanical performance and low scattering characteristics through an innovative design of a foam mechanical support base and a wave-absorbing baffle in front of the foam support. The presence of the foam support base allows the upper foam support body to be designed as a truncated cone geometry with a larger tilt angle (6°-12°) compared to the traditional frustum-shaped bracket, significantly reducing volume and scattering. At the same time, the large wave-absorbing baffle introduced in front of the foam mechanical support base completely blocks the foam mechanical support base, effectively reducing the scattering of the foam mechanical support base and minimizing the scattering of the bracket itself.

[0058] The above description is merely an embodiment of the present invention and does not limit the scope of the invention. Any equivalent structural or procedural transformations made based on the description and drawings of this invention, or direct or indirect applications in other related system fields, are similarly included within the protection scope of this invention. Contents not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A modular low-scattering foam support for testing the radar scattering characteristics of large targets, characterized in that, include: The foam support base, the first foam support body, the second foam support body, the foam mechanical support base, and the wave-absorbing baffle are connected coaxially in sequence. The foam support base is used to directly support large targets for radar scattering characteristic testing and is mortise and tenon connected to the first foam support body. The first foam support body is a regular low-scattering truncated cone-shaped modular structure, including several first foam support sub-bodies. Each first foam support sub-bodies has the same inclination angle θ, and the diameter of each first foam support sub-bodies gradually increases from top to bottom. It is mortise and tenon connected to the second foam support body. The second foam support body is a regular low-scattering truncated cone-shaped modular structure, which includes several second foam support sub-body, each of which has the same tilt angle θ' and the diameter of each second foam support sub-body gradually increases from top to bottom; The foam mechanical support base is a cylindrical base, which is mortised and tenoned to the second foam support body. The wave-absorbing baffle is located in front of the foam mechanical support base, including a first wave-absorbing baffle and a second wave-absorbing baffle facing the direction of incoming waves from the compaction field. The projected dimensions of the first wave-absorbing baffle and the second wave-absorbing baffle completely cover the foam mechanical support base. The upper center of the foam support has an arc-shaped groove for placing the calibration metal ball.

2. The modular low-scattering foam support for testing the radar scattering characteristics of large targets according to claim 1, characterized in that, The foam support base adopts a cylindrical modular structure.

3. The modular low-scattering foam support for testing the radar scattering characteristics of large targets according to claim 1, characterized in that, The foam support base, the first foam support body, the second foam support body, and the foam mechanical support base are all made of polystyrene foam.

4. The modular low-scattering foam support for testing the radar scattering characteristics of large targets according to claim 1, characterized in that, The wave-absorbing baffle is made of wood, fiber-reinforced resin-based composite materials, or metal materials.

5. The modular low-scattering foam support for testing the radar scattering characteristics of large targets according to claim 1, characterized in that, The values ​​of inclination angle θ and inclination angle θ' are both 6°-12°.

6. The modular low-scattering foam support for testing the radar scattering characteristics of large targets according to claim 1, characterized in that, The first foam support body includes three first foam support sub-bodies connected by mortise and tenon joints; the second foam support body includes four second foam support sub-bodies connected by mortise and tenon joints.

7. The modular low-scattering foam support for testing the radar scattering characteristics of large targets according to claim 1, characterized in that, The included angle α between the first and second absorbing baffles is 120°~150°; both the first and second absorbing baffles are covered with absorbing material.

8. The modular low-scattering foam support for testing the radar scattering characteristics of large targets according to claim 1, characterized in that, Both the first and second foam support bodies are truncated conical shapes, with the second foam support body being taller than the first foam support body.

9. The modular low-scattering foam support for testing the radar scattering characteristics of large targets according to claim 1, characterized in that, The foam mechanical support base is cylindrical, and its diameter is the same as the bottom diameter of the second foam support sub-body at the lowest position of the second foam support main body.

10. The modular low-scattering foam support for testing the radar scattering characteristics of large targets according to claim 1, characterized in that, A foam column for supporting the calibration metal ball is placed on the upper end of the foam support base, and the calibration metal ball is placed in the arc groove at the upper end of the foam column.

Images