Foldable opposite-vertex double-prismatic-table corner reflector

Abstract

The invention belongs to the field of corner reflectors, and particularly relates to a foldable opposite-vertex double-prismatic-table corner reflector which comprises a regular polygon reflecting surface and two groups of regular prismatic tables, the regular polygon reflecting surface is provided with N sides, and each regular prismatic table is formed by combining N isosceles trapezoid reflecting surfaces, the short bottoms of the N isosceles trapezoid reflecting surfaces are fixedly arranged on the N sides of the regular polygon reflecting surface one by one, and the two groups of regular prismatic tables are arranged in a mirror image mode according to the regular polygon reflecting surface; and a round hole is formed in the middle of the regular polygon reflecting surface. According to the foldable opposite-vertex double-prismatic-table corner reflector provided by the invention, an omnidirectional strong RCS effect is realized. The circular holes are dug in the vertical reflecting surface of the regular polygon reflecting surface, so that the problem that the RCS of a traditional double-cone-angle reflector in the vertical direction is too large can be relieved to a certain extent, and more uniform scattering performance is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of corner reflectors, and particularly relates to a foldable opposed double frustum corner reflector. Background Art

[0002] A corner reflector is a device widely used in radar calibration, target simulation, and electromagnetic scattering research. Its core principle is to make the incident electromagnetic wave return along the original direction through multiple reflections, thereby generating a high radar cross section (RCS). The corner reflector is usually designed as a dihedral angle structure, a trihedral angle structure, or an opposed double cone structure, and uses its geometric characteristics to achieve retroreflection: when the electromagnetic wave is incident on the reflector surface, it will be reflected successively on multiple mutually perpendicular reflecting surfaces, and finally the direction is completely opposite to the incident direction.

[0003] This characteristic enables it to efficiently simulate the signal echo of a target in a radar and is widely used in fields such as radar system calibration, target simulation, marine navigation markers, and spacecraft positioning. Among them, the opposed double cone corner reflector is a classic and efficient scattering structure, and its unique design enables it to form a trihedral angle reflection for the incoming wave incident from any direction, with excellent retroreflection performance. Its core advantages are as follows: through the upper and lower opposed conical surface structures, the electromagnetic wave incident from the horizontal direction, the vertical direction, or any inclined direction can finally return along the original direction during multiple reflection processes, thereby achieving a high RCS value. In addition, the simple geometric form of the opposed double cone structure not only reduces the design and manufacturing difficulty but also can ensure stable scattering performance in a complex environment. Compared with the trihedral angle reflector, it can form an effective reflection for the incoming wave in any direction, avoiding the problem of performance degradation of the traditional trihedral angle reflector at certain specific angles.

[0004] However, since the RCS value of the traditional opposed double cone corner reflector in the vertical direction is significantly larger than that in the non-vertical direction, its scattering omnidirectionality will be affected to a certain extent. In addition, the structure of the traditional double cone corner reflector cannot be folded, has a large volume, and poor portability, which to a certain extent limits its application in the field or mobile scenarios. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a foldable opposed double frustum corner reflector that realizes omnidirectional scattering efficiency.

[0006] The present invention provides a foldable opposed double frustum corner reflector, including a regular polygon reflecting surface and 2 groups of regular frustums. The regular polygon reflecting surface has N sides, and the regular frustum is formed by combining N isosceles trapezoidal reflecting surfaces. The short bases of N isosceles trapezoidal reflecting surfaces are fixedly arranged on the NOn the edges, two groups of the regular frustums are arranged in a mirror image with respect to the regular polygon reflecting surface; A circular hole is provided in the middle of the regular polygon reflecting surface.

[0007] Furthermore, the size of the foldable opposed double frustum corner reflector can be matched with the frequency of the electromagnetic wave to be reflected through an electromagnetic wave frequency matching model; The electromagnetic wave frequency matching model is: ; In the formula, represents the effective electrical size of this foldable opposed double frustum corner reflector; represents a positive integer; represents the wavelength of the electromagnetic wave; Among them, take the larger value of the diameter of the circumscribed circle of the projection of the top view of the regular frustum and the total height of the corner reflector. The diameter of the circumscribed circle of the projection of the top view of the regular frustum satisfies the diameter determination model, and the total height of the corner reflector satisfies the total height determination model; The diameter determination model is: D = ; The total height determination model is: 2 H； In the formula, H is the height of the regular frustum, H The calculation model of is; ; In the formula, is the long base of the isosceles trapezoidal reflecting surface (1), is the short base of the isosceles trapezoidal reflecting surface (1) or the side length of the regular polygon reflecting surface (2).

[0008] Furthermore, the radius r of the circular hole satisfies the radius determination model, and the radius determination model is: .

[0009] Furthermore, when the incoming wave is an X-band radar wave, The value range of is 5 - 15 cm, The value range of is 3.75 - 11.25 cm; and it satisfies , d The value range of is 0.5 - 2 mm, N The value range of is 4 - 12.

[0010] Furthermore, the N = 8.

[0011] Furthermore, the included angle between the isosceles trapezoidal reflecting surfaces corresponding to the two frustums of regular pyramids is 90°.

[0012] Furthermore, the short base of each of the isosceles trapezoidal reflecting surfaces is rotationally connected to the side of the regular polygon reflecting surface; The N isosceles trapezoidal reflecting surfaces of the frustum of a regular pyramid are unfolded or combined by rotation.

[0013] Furthermore, after the N isosceles trapezoidal reflecting surfaces of the frustum of a regular pyramid are unfolded, the corresponding isosceles trapezoidal reflecting surfaces on the two frustums of regular pyramids are mutually attached, and the two corresponding isosceles trapezoidal reflecting surfaces after attachment are coplanar with the regular polygon reflecting surface.

[0014] Furthermore, the short base of the isosceles trapezoidal reflecting surface is rotationally connected to the side of the regular polygon reflecting surface through a hinge.

[0015] Furthermore, an extended reflecting surface is added to the long base of the isosceles trapezoidal reflecting surface; The extended reflecting surface is at least one of a circular surface, an elliptical surface, or a triangular surface.

[0016] The beneficial effects of the present invention are as follows: The foldable opposite-top double frustum corner reflector provided by the present invention has a frustum polyhedron spatial structure that repeats at a specific angular azimuth as a period and is symmetrically distributed within a specific angular range with respect to a specific azimuth, achieving omnidirectional scattering efficiency. Whether the incident wave is HH polarization or VV polarization, the present invention has a good strong RCS effect in the full direction of the incident wave elevation angle of 0 to 180° and azimuth angle of 0 to 360°. Finally, an omnidirectional strong RCS effect is achieved.

[0017] In addition, by hollowing out circular holes on the vertical reflecting surface of the regular polygon reflecting surface, the problem of excessive RCS in the vertical direction of the traditional double-cone corner reflector can be alleviated to a certain extent, thereby achieving more uniform scattering performance.

[0018] In addition, by hollowing out circular holes on the regular polygon reflecting surface, the material usage is reduced, the overall weight is lowered, and it becomes a more lightweight and lower-cost efficient corner reflector.

[0019] In addition, by adjusting the dimensions of the isosceles trapezoidal reflecting surface, the frustum of a regular pyramid, and the circular hole, the electromagnetic wave frequency matched by the present invention can be changed to adapt to different mission requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of the overall structure of the foldable opposite-top double frustum corner reflector of the present invention; Figure 2 is a front view of the foldable opposite-top double frustum corner reflector of the present invention; Figure 3 It is the left view of the foldable opposite-top double frustum corner reflector of the present invention; Figure 4 It is the top view of the foldable opposite-top double frustum corner reflector of the present invention; Figure 5 It is the schematic diagram of the folding process of the foldable opposite-top double frustum corner reflector of the present invention; Figure 6 It is the schematic structural diagram of the foldable opposite-top double frustum corner reflector of the present invention in the folded state; Figure 7 It is the front view of the foldable opposite-top double frustum corner reflector of the present invention in the folded state; Figure 8 It is the left view of the foldable opposite-top double frustum corner reflector of the present invention in the folded state; Figure 9 It is the top view of the foldable opposite-top double frustum corner reflector of the present invention in the folded state; Figure 10 It is the FEKO simulation spatial relationship diagram of the RCS of the foldable opposite-top double frustum corner reflector of the present invention with the reflecting surface using aluminum metal surface; Figure 11 It is the RCS simulation result diagram of the foldable opposite-top double frustum corner reflector of the present invention under the condition that the azimuth angle is 0° in HH polarization; Figure 12 It is the RCS simulation result diagram of the foldable opposite-top double frustum corner reflector of the present invention under the condition that the azimuth angle is 10° in HH polarization; Figure 13 It is the RCS simulation result diagram of the foldable opposite-top double frustum corner reflector of the present invention under the condition that the azimuth angle is 20° in HH polarization; Figure 14 It is the RCS simulation result diagram of the foldable opposite-top double frustum corner reflector of the present invention under the condition that the azimuth angle is 0° in VV polarization; Figure 15 It is the RCS simulation result diagram of the foldable opposite-top double frustum corner reflector of the present invention under the condition that the azimuth angle is 10° in VV polarization; Figure 16 It is the RCS simulation result diagram of the foldable opposite-top double frustum corner reflector of the present invention under the condition that the azimuth angle is 20° in VV polarization; Figure 17 It is the structural diagram of the present invention with partial circular or elliptical surfaces added to the isosceles trapezoidal reflecting surface; Figure 18 It is the structural diagram of the present invention with triangular surfaces added to the isosceles trapezoidal reflecting surface.

[0021] In the figure, 1 - isosceles trapezoidal reflecting surface; 11 - reflecting surface Ⅰ; 12 - reflecting surface Ⅱ; 13 - reflecting surface Ⅲ; 2 - regular polygon reflecting surface. Detailed implementation manners

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] It should be noted that all the directional indications (such as up, down, left, right, front, back,...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0024] In addition, the descriptions such as "first" and "second" in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0025] In the present invention, unless otherwise clearly defined and limited, the terms "connected", "fixed", etc. shall be understood in a broad sense. For example, "fixed" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. 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.

[0026] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0027] As Figures 1 - 18 shown, the present invention provides a foldable opposed double frustum corner reflector, including a regular polygon reflecting surface 2 and 2 groups of regular frustums. The regular polygon reflecting surface 2 has N sides, and the regular frustum is formed by combining N isosceles trapezoidal reflecting surfaces 1, that is, the total number of isosceles trapezoidal reflecting surfaces 1 is 2 N, the isosceles trapezoidal reflector 1 has a long base (the lower base of the isosceles trapezoid) and a short base (the upper base of the isosceles trapezoid) that are parallel to each other, and two non-parallel but equal-length waists. N The short bases of N isosceles trapezoidal reflectors 1 are fixedly arranged one by one on the N sides of the regular polygon reflector 2, that is, the short base of each isosceles trapezoidal reflector 1 is fixed on one side of the regular polygon reflector 2, and the waists of adjacent isosceles trapezoidal reflectors 1 are close to and aligned with each other. The two sets of the regular prisms are arranged in a mirror image with respect to the regular polygon reflector 2. At this time, the smaller bottom surfaces of the upper and lower hollowed multi-prisms are opposite to each other, forming an open double prism structure. When electromagnetic waves are incident from different directions, multiple reflections will occur on the isosceles trapezoidal reflector 1, and finally retro-reflection is formed, realizing efficient omnidirectional scattering performance. In particular, a strong RCS effect can be achieved for the X-band in all directions; A circular hole is arranged in the middle of the regular polygon reflector. The axis of the circular hole perpendicularly passes through the center of the circumcircle of the regular polygon reflector 2. By setting the circular hole, the reduction of RCS near the vertical incident direction is realized, and the problem that the electromagnetic wave incident in the vertical direction can return with only one reflection, resulting in an extremely high RCS in this direction, is solved. Thus, the omnidirectional scattering of the corner reflector is improved, and the uniformity and stability of the scattering are further enhanced, and reliable reflected signals can be provided for receiving devices in different directions.

[0028] The foldable opposite-top double prism corner reflector provided by the present invention has a prismatic polyhedron spatial structure that repeats at a specific angular azimuth as a period and is symmetrically distributed with respect to a specific azimuth within a specific angular range, realizing omnidirectional scattering efficiency. Whether the incoming wave is HH polarization or VV polarization, the present invention has a good strong RCS effect in all directions of the incident wave elevation angle of 0~180° and azimuth angle of 0~360°. Finally, an omnidirectional strong RCS effect is realized. In addition, by hollowing out a circular hole on the vertical reflection surface of the regular polygon reflector 2, the problem of excessive RCS in the vertical direction of the traditional double-cone corner reflector can be alleviated to a certain extent, thereby realizing a more uniform scattering performance. In addition, by hollowing out a circular hole on the regular polygon reflector 2, the material usage is reduced, the overall weight is reduced, and it becomes a more lightweight and lower-cost efficient corner reflector. In addition, by adjusting the sizes of the isosceles trapezoidal reflector 1, the regular prism, and the circular hole, the electromagnetic wave frequency matched by the present invention can be changed to adapt to different mission requirements.

[0029] In one of the embodiments, the size of the foldable opposite-top double prism corner reflector can be matched with the frequency of the electromagnetic wave to be reflected through an electromagnetic wave frequency matching model; The electromagnetic wave frequency matching model is: ; In the formula, represents the effective electrical size of the present foldable opposite-top double prism corner reflector; represents a positive integer; represents the wavelength of an electromagnetic wave; wherein, take the larger value of the diameter of the circumscribed circle of the projection of the top view of a regular frustum and the total height of the corner reflector. The diameter of the circumscribed circle of the projection of the top view of the regular frustum satisfies the diameter determination model, and the total height of the corner reflector satisfies the total height determination model; The diameter determination model is: D = ; The total height determination model is: 2 H； In the formula, H is the height of the regular frustum, H The calculation model of is; ; In the formula, is the long base of the isosceles trapezoidal reflector (1), is the short base of the isosceles trapezoidal reflector (1) or the side length of the regular polygon reflector (2).

[0030] In this embodiment, when the size of the foldable opposite double frustum corner reflector satisfies the electromagnetic wave frequency matching model, it can provide an omnidirectional strong RCS performance for the electromagnetic wave frequency with a wavelength of . Thus, according to different mission requirements, the various shape parameters can be flexibly adjusted to change the electromagnetic wave frequency matched by the present invention to adapt to different mission requirements.

[0031] In one of the embodiments, the long base of the isosceles trapezoidal reflector 1 is , the short base is , and the thickness is d ; The side length of the regular polygon reflector 2 is , the thickness is 2 d , and the radius r of the circular hole satisfies the radius determination model. The radius determination model is: .

[0032] Determine the radius r of the circular hole using the above radius determination model, that is, the radius of the circular hole is less than or equal to the radius of the inscribed circle of the regular polygon reflector 2, which can improve the size of the circular hole as much as possible and alleviate the RCS in the vertical direction as much as possible.

[0033] In one of the embodiments, when the incoming wave is an X-band radar wave, has a value range of 5 to 15 cm, The value range is 3.75 - 11.25 cm; and it satisfies , d The value range is 0.5 - 2 mm, N The value range is 4 - 12.

[0034] Among them, N ≥3, and N is a natural number. In one preferred embodiment, the N =8, that is, the regular polygon reflector 2 is a regular octagon, and the regular frustum is formed by combining 8 isosceles trapezoidal reflectors 1.

[0035] In one embodiment, the included angle between the isosceles trapezoidal reflectors 1 corresponding to the 2 groups of regular frustums is 90°. With such a setting, it can ensure that the incoming wave on the side can point to the incoming wave direction after multiple reflections.

[0036] In one embodiment, the short base of each isosceles trapezoidal reflector 1 is rotationally connected to the side of the regular polygon reflector 2; The N isosceles trapezoidal reflectors 1 of the regular frustum are unfolded or combined by rotation.

[0037] In this embodiment, the regular frustum is a foldable structure. Through the combination of several congruent isosceles trapezoidal reflectors and a rotational structure, a foldable double frustum corner reflector is formed. Through calculation, the volume ratio of the foldable structure before and after folding can reach 1:7.55. The volume of the corner reflector after folding is significantly reduced, which is convenient for transportation, storage and deployment, and improves and supplements the performance of the traditional corner reflector. It is especially suitable for scenarios where frequent movement or limited space is required, such as field tests or temporary radar calibration tasks.

[0038] In one embodiment, after the N isosceles trapezoidal reflectors 1 of the regular frustum are unfolded, the corresponding isosceles trapezoidal reflectors 1 on the 2 groups of regular frustums are attached to each other. At this time, the thickness of the regular polygon reflector 2 is twice the thickness of the isosceles trapezoidal reflector 1. The corresponding two isosceles trapezoidal reflectors 1 after attachment are coplanar with the regular polygon reflector 2. Furthermore, it can ensure that both sides of the folded opposite double frustum corner reflector are flat, which greatly facilitates transportation and storage.

[0039] Exemplarily, the rotational structure between the short base of the isosceles trapezoidal reflecting surface 1 and the side of the regular polygon reflecting surface 2 can be structures such as shaft holes, etc. It only needs to achieve the rotational connection between the isosceles trapezoidal reflecting surface 1 and the regular polygon reflecting surface 2. In one preferred embodiment, the short base of the isosceles trapezoidal reflecting surface 1 and the side of the regular polygon reflecting surface 2 are rotationally connected through a hinge. The installation of the hinge is convenient and fast, and it will not damage the structures of the isosceles trapezoidal reflecting surface 1 and the regular polygon reflecting surface 2, ensuring the stability of the original structure. Preferably, the hinge is arranged on the outer sides of the isosceles trapezoidal reflecting surface 1 and the regular polygon reflecting surface 2 to reduce the influence on the inner reflecting surface. Preferably, the hinge is made of high-strength wear-resistant materials (such as stainless steel, aluminum alloy) to ensure the reliability and durability of the mechanical structure.

[0040] In one embodiment, the waists of the isosceles trapezoidal reflecting surface 1 and the waists of the adjacent isosceles trapezoidal reflecting surface 1 can be fixed and disassembled through a detachable connection structure. When N a plurality of isosceles trapezoidal reflecting surfaces 1 are combined to form a regular prism frustum, the waists of the isosceles trapezoidal reflecting surface 1 and the waists of the adjacent isosceles trapezoidal reflecting surface 1 are fixed through a detachable connection structure. When N a plurality of isosceles trapezoidal reflecting surfaces 1 are folded into a plane, the detachable connection structure is separated. Exemplarily, the detachable connection structure can be a card slot and buckle; or a magnet; or a lock buckle, etc. Of course, the specific structure of the detachable connection structure is not limited to this, and any structure that can detachably connect two adjacent waists is within the scope of the technical solutions protected by the embodiments of the present invention.

[0041] In one embodiment, the surfaces of the regular polygon reflecting surface 2 and the isosceles trapezoidal reflecting surface 1 are made of polished high-conductivity metal materials. The high-conductivity metal materials can be aluminum or copper, so as to achieve a high electromagnetic wave reflectivity. In addition, changing the materials of the reflecting surface and the hinge may further reduce the weight of the present invention and improve the portability, but does not affect the good omnidirectional strong RCS performance of the present invention.

[0042] In one embodiment, an extended reflecting surface is added to the long base of the isosceles trapezoidal reflecting surface 1; The extended reflecting surface is at least one of a circular surface, an elliptical surface or a triangular surface.

[0043] By adding an extended reflecting surface of equal size to the long base of the isosceles trapezoidal reflecting surface 1, the RCS of the overall structure can be increased, and at the same time, the excellent foldability of the present invention is not affected, thereby further improving the scattering efficiency. Figure 17 、 Figure 18 are schematic diagrams of the improvable methods of such structures, Figure 17 is a structural diagram of adding a partial circular surface or an elliptical surface to the isosceles trapezoidal reflecting surface, Figure 18 is a structural diagram of adding a triangular surface to the isosceles trapezoidal reflecting surface.

[0044] The present invention also provides a specific embodiment. Refer to Figure 1 . Taking the regular polygon reflecting surface 2 as a regular octagon and the regular frustum formed by combining 8 isosceles trapezoidal reflecting surfaces 1 as an example, the foldable opposite double frustum corner reflector is composed of 16 isosceles trapezoidal reflecting surfaces 1 and 1 regular octagon reflecting surface with a circular hole. The overall configuration is two congruent hollow regular frustums that are opposite to each other up and down. Each frustum is composed of 8 isosceles trapezoidal reflecting surfaces 1, and a total of 16 isosceles trapezoidal reflecting surfaces 1 are composed. The length of the long base of the isosceles trapezoidal reflecting surface 1 is , and the length of the short base is . Define one of the isosceles trapezoidal reflecting surfaces 1 in the figure as the reflecting surface Ⅰ11, the isosceles trapezoidal reflecting surface 1 connected corresponding to the reflecting surface Ⅰ11 as the reflecting surface Ⅱ12, and the isosceles trapezoidal reflecting surface 1 adjacent to the reflecting surface Ⅰ11 as the defined reflecting surface Ⅲ13. Then the included angle between the reflecting surface Ⅰ11 and the reflecting surface Ⅱ12 is fixed at , and the included angle between the reflecting surface Ⅰ11 and the reflecting surface Ⅲ13 is (when N changes, ).

[0045] Refer to Figures 2 - 4 . Let the left and right endpoints on the outward-opening plane of the middle frustum in Figure 2 be points A and B respectively, and the left and right endpoints on the plane of the regular polygon reflecting surface 2 be points C and D respectively. Then the distance between points A and B is , and the distance between points C and D is (as shown in Figure 2 and Figure 4 ). Let the left and right endpoints on the outward-opening plane of the middle frustum in Figure 3 be points E and F respectively, and the left and right endpoints on the plane of the regular polygon reflecting surface 2 be points G and H respectively. The distance between points E and F is , and the distance between points C and D is (as shown in Figure 3 and Figure 4 ). The height of a single frustum is (as shown in Figure 2 and Figure 3 ), and the radius of the circular hole dug in the center of the regular octagon reflecting surface is r (as shown in Figure 4 ). When the number of frustum faces N changes, the above parameters will change accordingly. Specifically: ; ; ; ; .

[0046] It can be seen that the present invention has strong multi-directional scattering in space, which is beneficial to achieving omnidirectional reflection of incoming waves.

[0047] Figure 5 It is a schematic diagram of the folding process of the present invention. Each pair of upper and lower isosceles trapezoidal reflectors 1 are folded together through the hinges in the middle to form a folded state, achieving a significant reduction in volume, which is convenient for transportation, storage and deployment.

[0048] Figure 6 It is a schematic structural diagram of the present invention in the folded state, where the thickness of a single isosceles trapezoidal reflector 1 is d , the thickness of the regular octagonal reflector 2 is 2 d , and the radius of the hollow circular hole in its center is r . Figures 7 - 9 It is the three-view drawing of the present invention in the folded state, where Figure 7 is the front view, and the distance between the left and right endpoints is , and the distance between the upper and lower endpoints is 2 d ; Figure 8 is the left view, and the distance between the left and right endpoints is , and the distance between the upper and lower endpoints is 2 d ; Figure 9 is the top view, and the distance between the left and right endpoints is , and the distance between the upper and lower endpoints is . Denote the radius of the circumscribed circle in the top view as R , and there is . When the number of prism frustum faces N changes, .

[0049] It can be seen that the present invention has a very compact spatial structure in the folded state, and compared with the unfolded state, it can greatly compress the volume space, having significant spatial storage advantages.

[0050] Figure 10 It is a schematic spatial diagram of the FEKO simulation of the RCS of the foldable opposed double prism corner reflector of the present invention, showing the establishment of the spatial coordinate system and the spatial relationship between the pitch angle , azimuth angle and the geometric body.

[0051] Figures 11 - 16 It is the RCS simulation result of the foldable opposed double prism corner reflector of the present invention. In this embodiment, the reflector uses a metal aluminum surface, and the hinges and rotating shafts use stainless steel materials. Among them, N =8, cm, cm, r =4.83 cm, d= 0.05 cm, and the incoming wave frequency is set to 10 GHz.

[0052] The variation diagrams of RCS with respect to the elevation angle of the incoming wave are respectively simulated when the azimuth angle of the incoming wave is several common angles. In the diagrams, the abscissa is the elevation angle of the incoming wave, ranging from 0 to 90°, and the ordinate is the RCS value (unit: dBsm). Figure 11 This is the case where the azimuth angle is 0° for HH polarization. Figure 12 This is the case where the azimuth angle is 10° for HH polarization. Figure 13 This is the case where the azimuth angle is 20° for HH polarization. Figure 14 This is the case where the azimuth angle is 0° for VV polarization. Figure 15 This is the case where the azimuth angle is 10° for VV polarization. Figure 16 This is the case where the azimuth angle is 20° for VV polarization. Since the space structure of the octagonal frustum polyhedron with opposite vertices in this embodiment repeats with a period of 45° azimuth angle and is symmetrically distributed about the azimuth angle of 22.5° within the range of 0 to 45° azimuth angle, the effects when the azimuth angle is greater than 22.5° are not demonstrated. The space structure of this embodiment is symmetrically distributed about the elevation angle of 90°, so the effects when the elevation angle is greater than 90° are not demonstrated.

[0053] From Figures 11 - 16 it can be seen that on the basis of restricting its own volume size, regardless of whether the incoming wave is HH polarization or VV polarization, under several selected azimuth angles of the incoming wave, a strong RCS effect can be achieved within the full range of elevation angles ( dBsm). In fact, the present invention has a good strong RCS effect in all directions of the incoming wave elevation angle of 0 to 180° and azimuth angle of 0 to 360°. In the FEKO software, the omnidirectional space of 360° azimuth angle and 180° elevation angle is divided into units with an azimuth angle of 1° and an elevation angle of 1°, generating a total of 360×180 direction units, and the RCS value within each direction unit is calculated. After calculation by MATLAB, the angle proportion of the present invention achieving a strong RCS effect is 93.65%. Calculate the volume proportion of the present invention before and after folding at this time, which can reach 1:7.55.

[0054] From the simulation calculation results, it can be seen that the present invention can achieve an omnidirectional strong RCS effect, and through the folding design, the space utilization rate during carrying and transportation can be greatly reduced, which is an efficient new type of corner reflector. By changing the number of multi - prism faces N , the upper and lower base lengths of the isosceles trapezoidal reflector 1 and , the hole - digging radius of the polygonal reflector r and other parameters, the electromagnetic wave frequency matched by the present invention can be changed, and a better RCS effect can be optimized.

[0055] By adding reflecting surfaces of equal size to the long base of the isosceles trapezoidal reflecting surface 1, the RCS of the overall structure can be increased, while not affecting the excellent foldability of the present invention, thereby further improving the scattering efficiency. Figure 8 It is a schematic diagram of an improvable method for such a structure. Figure 17 It is a structural diagram of adding a partial circular surface or an elliptical surface to the isosceles trapezoidal reflecting surface. Figure 18 It is a structural diagram of adding a triangular surface to the isosceles trapezoidal reflecting surface. In addition, changing the materials of the reflecting surface and the hinge may further reduce the weight of the present invention and improve the portability, but does not affect the good omnidirectional strong RCS performance of the present invention.

[0056] As described above, this is only an embodiment and does not impose any limitations on the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make many possible changes, modifications or equivalents to the technical solution of the present invention by using the technical content disclosed above. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A foldable double pyramid corner reflector, characterized in that: It comprises a regular polygonal reflection surface (2) and two groups of regular pyramids, wherein the regular polygonal reflection surface (2) has N sides, the regular pyramid consists of N isosceles trapezoidal reflecting surfaces (1) are combined to form, N The short bases of the isosceles trapezoidal reflecting surfaces (1) are fixedly arranged on the regular polygonal reflecting surface (2). N On the sides, the two groups of regular prisms are arranged in a mirror image with the regular polygonal reflection surface (2); A circular hole is provided in the middle of the regular polygonal reflection surface (2).

2. The foldable double pyramid corner reflector according to claim 1, characterized in that: The size of the foldable double-prism corner reflector can be matched with the frequency of the electromagnetic wave to be reflected through the electromagnetic wave frequency matching model; The electromagnetic wave frequency matching model is: ； In the formula, The effective electrical dimensions of the foldable double pyramid corner reflector are shown; represents a positive integer; Indicates the wavelength of electromagnetic waves; in, Take the larger value of the circumscribed circle diameter of the top view projection of the right prism and the total height of the corner reflector, the circumscribed circle diameter of the top view projection of the right prism satisfies the diameter determination model, and the total height of the corner reflector satisfies the total height determination model; The diameter determination model is: D = ； The total height determination model is: 2 H； In the formula, H is the height of the right prism, H The calculation model is: ； In the formula, is the long base of the isosceles trapezoidal reflection surface (1), It is the short base of the isosceles trapezoidal reflection surface (1) or the side length of the regular polygonal reflection surface (2).

3. The foldable double-prism corner reflector according to claim 2, characterized in that: The radius of the circular hole r Satisfies the radius determination model, the radius determination model is: 。 4. The foldable double pyramid corner reflector according to claim 3, characterized in that: When the incoming wave is an X-band radar wave, The value range is 5~15 cm. The value range is 3.75~11.25 cm; and meets , d The value range is 0.5~2 mm. N The value range is 4~12.

5. The foldable double-prism corner reflector according to claim 4, characterized in that: Said N =8.

6. The foldable double-prism corner reflector according to claim 1, wherein: The included angle between the two sets of isosceles trapezoidal reflection surfaces (1) corresponding to the two right prisms is 90°.

7. The foldable double-prism corner reflector according to any one of claims 1 to 6, characterized in that: The short base of each of the isosceles trapezoidal reflecting surfaces (1) is rotatably connected to the edge of the regular polygonal reflecting surface (2); The right prism N The isosceles trapezoidal reflection surfaces (1) are expanded or combined by rotation.

8. The foldable double pyramid corner reflector according to claim 7, characterized in that: On the right prism N After the isosceles trapezoidal reflection surfaces (1) are unfolded, the corresponding isosceles trapezoidal reflection surfaces (1) on the two groups of regular prisms are bonded to each other, and the corresponding two bonded isosceles trapezoidal reflection surfaces (1) are coplanar with the regular polygonal reflection surface (2).

9. The foldable double pyramid corner reflector according to claim 7, characterized in that: The short base of the isosceles trapezoidal reflecting surface (1) and the edge of the regular polygonal reflecting surface (2) are rotatably connected via a hinge.

10. The foldable double-prism corner reflector according to any one of claims 1 to 6, 8 and 9, characterized in that: An extended reflecting surface is added to the long base of the isosceles trapezoidal reflecting surface (1); The extended reflection surface is at least one of a circular surface, an elliptical surface or a triangular surface.

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