A foldable opposite double frustum corner reflector

Abstract

The present invention belongs to the field of corner reflectors, and particularly relates to a foldable opposed double frustum corner reflector, which includes a regular polygon reflecting surface and two sets 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 one by one on the N sides of the regular polygon reflecting surface, and the two sets of 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. The foldable opposed double frustum corner reflector provided by the present invention achieves an omnidirectional strong RCS effect. By hollowing out a circular hole in 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.

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. Its unique design enables it to form a trihedral angle reflection for incident waves from any direction and has excellent retroreflection performance. Its core advantages are: through the upper and lower opposed conical surface structures, electromagnetic waves incident from the horizontal direction, vertical direction, or any inclined direction can all finally return along the original direction after multiple reflections, 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 incident waves from 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;

[0007] A circular hole is provided in the middle of the regular polygon reflecting surface.

[0008] Furthermore, the size of the foldable opposite double frustum corner reflector can be matched with the frequency of the electromagnetic wave to be reflected through an electromagnetic wave frequency matching model;

[0009] The electromagnetic wave frequency matching model is:

[0010] ;

[0011] In the formula, represents the effective electrical size of this foldable opposite double frustum corner reflector; represents a positive integer; represents the wavelength of the electromagnetic wave;

[0012] 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 a diameter determination model, and the total height of the corner reflector satisfies a total height determination model;

[0013] The diameter determination model is:

[0014] D = ;

[0015] The total height determination model is:

[0016] 2 H；

[0017] In the formula, H is the height of the regular frustum, H The calculation model of

[0018] ;

[0019] 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).

[0020] Furthermore, the radius r of the circular hole satisfies a radius determination model, and the radius determination model is:

[0021] .

[0022] Furthermore, when the incoming wave is an X-band radar wave, The value range of The value range is 3.75 to 11.25 cm; and it satisfies , d The value range is 0.5 to 2 mm, N The value range is 4 to 12.

[0023] Furthermore, the N = 8.

[0024] Furthermore, the included angle between the isosceles trapezoidal reflecting surfaces corresponding to the two frustums of regular pyramids is 90°.

[0025] Furthermore, the short base of each isosceles trapezoidal reflecting surface is rotationally connected to the side of the regular polygon reflecting surface;

[0026] The N isosceles trapezoidal reflecting surfaces of the frustum of regular pyramid are unfolded or combined by rotation.

[0027] Furthermore, after the N isosceles trapezoidal reflecting surfaces of the frustum of regular pyramid are unfolded, the corresponding isosceles trapezoidal reflecting surfaces on the two frustums of regular pyramid are mutually attached, and the two corresponding isosceles trapezoidal reflecting surfaces after attachment are coplanar with the regular polygon reflecting surface.

[0028] 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.

[0029] Furthermore, an extended reflecting surface is added to the long base of the isosceles trapezoidal reflecting surface;

[0030] The extended reflecting surface is at least one of a circular surface, an elliptical surface or a triangular surface.

[0031] The beneficial effect of the present invention is that the foldable opposite-top double frustum corner reflector provided by the present invention has a periodic repetition in the polyhedron space structure of the frustum at a specific angular azimuth, and is symmetrically distributed with respect to a specific azimuth within a specific angular range, realizing 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 realized.

[0032] 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 realizing more uniform scattering performance.

[0033] In addition, hollowing out circular holes on the regular polygon reflecting surface reduces the material usage and reduces the overall weight, making it a more lightweight and lower-cost efficient corner reflector.

[0034] In addition, by adjusting the sizes of the isosceles trapezoidal reflector, regular prism frustum, and circular holes, the electromagnetic wave frequency matched by the present invention can be changed to meet different task requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is the overall structural schematic diagram of the foldable double prism corner reflector with opposite vertices of the present invention;

[0036] Figure 2 is the front view of the foldable double prism corner reflector with opposite vertices of the present invention;

[0037] Figure 3 is the left view of the foldable double prism corner reflector with opposite vertices of the present invention;

[0038] Figure 4 is the top view of the foldable double prism corner reflector with opposite vertices of the present invention;

[0039] Figure 5 is the schematic diagram of the folding process of the foldable double prism corner reflector with opposite vertices of the present invention;

[0040] Figure 6 is the structural schematic diagram of the foldable double prism corner reflector with opposite vertices of the present invention in the folded state;

[0041] Figure 7 is the front view of the foldable double prism corner reflector with opposite vertices of the present invention in the folded state;

[0042] Figure 8 is the left view of the foldable double prism corner reflector with opposite vertices of the present invention in the folded state;

[0043] Figure 9 is the top view of the foldable double prism corner reflector with opposite vertices of the present invention in the folded state;

[0044] Figure 10 is the FEKO simulation spatial relationship diagram of the RCS of the foldable double prism corner reflector with opposite vertices of the present invention when the reflector surface uses a metal aluminum surface;

[0045] Figure 11 is the RCS simulation result diagram of the foldable double prism corner reflector with opposite vertices of the present invention under the condition of HH polarization and azimuth angle of 0°;

[0046] Figure 12 is the RCS simulation result diagram of the foldable double prism corner reflector with opposite vertices of the present invention under the condition of HH polarization and azimuth angle of 10°;

[0047] Figure 13 is the RCS simulation result diagram of the foldable double prism corner reflector with opposite vertices of the present invention under the condition of HH polarization and azimuth angle of 20°;

[0048] Figure 14 It is the RCS simulation result diagram of the present invention's foldable opposite-top double frustum corner reflector under the condition that the azimuth angle is 0° in the VV polarization;

[0049] Figure 15 It is the RCS simulation result diagram of the present invention's foldable opposite-top double frustum corner reflector under the condition that the azimuth angle is 10° in the VV polarization;

[0050] Figure 16 It is the RCS simulation result diagram of the present invention's foldable opposite-top double frustum corner reflector under the condition that the azimuth angle is 20° in the VV polarization;

[0051] Figure 17 It is the structural diagram of adding partial circular or elliptical surfaces to the isosceles trapezoidal reflector surface of the present invention;

[0052] Figure 18 It is the structural diagram of adding triangular surfaces to the isosceles trapezoidal reflector surface of the present invention.

[0053] In the figure, 1 - isosceles trapezoidal reflector surface; 11 - reflector surface I; 12 - reflector surface II; 13 - reflector surface III; 2 - regular polygon reflector surface. Specific embodiments

[0054] 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 of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0055] It should be noted that all 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.

[0056] 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, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0057] In the present invention, unless otherwise clearly specified and defined, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. 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.

[0058] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. 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 scope of protection required by the present invention.

[0059] As Figures 1 - 18 shown, the present invention provides a foldable top-to-top double frustum corner reflector, which includes a regular polygon reflecting surface 2 and 2 sets 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 reflecting surface 1 has a long bottom (the lower bottom of the isosceles trapezoid) and a short bottom (the upper bottom of the isosceles trapezoid) that are parallel to each other and two non-parallel but equal-length waists. N The short bottoms of N isosceles trapezoidal reflecting surfaces 1 are fixedly arranged on the N sides of the regular polygon reflecting surface 2 one by one, that is, the short bottom of one isosceles trapezoidal reflecting surface 1 is fixed on each side of the regular polygon reflecting surface 2, and the waists of adjacent isosceles trapezoidal reflecting surfaces 1 are close to and aligned with each other. The 2 sets of regular frustums are arranged in a mirror image with respect to the regular polygon reflecting surface 2. At this time, the smaller bottom surfaces of the two hollowed-out multi-frustrums on the top and bottom are opposite to each other, forming an open double frustum structure. When electromagnetic waves are incident from different directions, multiple reflections will occur on the isosceles trapezoidal reflecting surface 1, and finally retro-reflection will be formed to achieve efficient omnidirectional scattering performance. In particular, a strong RCS effect can be achieved in the X band omnidirectionally;

[0060] A circular hole is provided in the middle of the regular polygon reflecting surface, and the axis of the circular hole perpendicularly passes through the center of the circumcircle of the regular polygon reflecting surface 2. The provision of the circular hole realizes the reduction of RCS near the vertical incident direction, solves the problem that the electromagnetic wave incident in the vertical direction only needs one reflection to return, resulting in an abnormally high RCS in this direction, thereby improving the omnidirectionality of the scattering of the corner reflector, further enhancing the uniformity and stability of the scattering, and being able to provide reliable reflected signals for receiving devices in different directions.

[0061] The foldable opposed 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 for a specific azimuth, achieving omnidirectional scattering efficiency. Whether the incident wave is HH polarization or VV polarization, the present invention has good strong RCS effects in all directions with the incident wave elevation angle from 0° to 180° and azimuth angle from 0° to 360°. Finally, an omnidirectional strong RCS effect is achieved. In addition, by hollowing out circular holes on the vertical reflecting surface of the regular polygon reflecting surface 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 achieving more uniform scattering performance. In addition, hollowing out circular holes on the regular polygon reflecting surface 2 reduces the material usage and the overall weight, making it a more lightweight and lower-cost efficient corner reflector. In addition, by adjusting the sizes of the isosceles trapezoid reflecting surface 1, the regular frustum, and the circular holes, the electromagnetic wave frequency matched by the present invention can be changed to adapt to different mission requirements.

[0062] In one of the embodiments, 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;

[0063] The electromagnetic wave frequency matching model is:

[0064] ;

[0065] In the formula, represents the effective electrical size of the present foldable opposed double frustum corner reflector; represents a positive integer; represents the electromagnetic wave wavelength;

[0066] 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;

[0067] The diameter determination model is:

[0068] D = ;

[0069] The total height determination model is:

[0070] 2 H；

[0071] In the formula, H is the height of the regular frustum, H The calculation model of

[0072] ;

[0073] 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).

[0074] In this embodiment, when the size of the foldable opposed double frustum corner reflector meets the electromagnetic wave frequency matching model, it can provide an omnidirectional strong RCS performance for the electromagnetic wave frequency corresponding to the wavelength of . Thus, according to different task requirements, the shape parameters can be flexibly adjusted to change the electromagnetic wave frequency matched by the present invention to adapt to different task requirements.

[0075] In one of the embodiments, the long base of the isosceles trapezoidal reflector 1 is , the short base is , and the thickness is d ;

[0076] The side length of the regular polygon reflector 2 is , the thickness is 2 d , the radius r of the round hole meets the radius determination model, and the radius determination model is:

[0077] .

[0078] Using the above radius determination model to determine the value of the radius r of the round hole, that is, the radius of the round hole is less than or equal to the radius of the inscribed circle of the regular polygon reflector 2, can improve the size of the round hole as much as possible and relieve the RCS in the vertical direction as much as possible.

[0079] In one of the embodiments, when the incoming wave is an X-band radar wave, has a value range of 5 to 15 cm, has a value range of 3.75 to 11.25 cm; and it satisfies , d has a value range of 0.5 to 2 mm, N has a value range of 4 to 12.

[0080] Among them, N ≥3, and N is a natural number. In one of the preferred embodiments, 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.

[0081] In one of the embodiments, the included angle between the isosceles trapezoidal reflectors 1 corresponding to the 2 groups of regular frustums is 90°. Such a setting can ensure that the incoming wave on the side can point to the incoming wave direction after multiple reflections.

[0082] In one embodiment, the short base of each isosceles trapezoidal reflector 1 is rotatably connected to the side of the regular polygonal reflector 2;

[0083] of the regular prism frustum N The isosceles trapezoidal reflectors 1 are unfolded or combined by rotation.

[0084] In this embodiment, the regular prism frustum is a foldable structure. By combining several congruent isosceles trapezoidal reflectors and a rotating structure, a foldable double prism corner reflector can be 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.

[0085] In one embodiment, after the N isosceles trapezoidal reflectors 1 of the regular prism frustum are unfolded, the corresponding isosceles trapezoidal reflectors 1 on the two groups of regular prism frustums are attached to each other. At this time, the thickness of the regular polygonal reflector 2 is twice the thickness of the isosceles trapezoidal reflector 1, and the two corresponding isosceles trapezoidal reflectors 1 after attachment are coplanar with the regular polygonal reflector 2. Furthermore, it can be ensured that both sides of the opposite double prism corner reflector after folding are flat, which greatly facilitates transportation and storage.

[0086] Exemplarily, the rotating structure of the short base of the isosceles trapezoidal reflector 1 and the side of the regular polygonal reflector 2 can be structures such as shaft holes, etc. It only needs to realize the rotational connection between the isosceles trapezoidal reflector 1 and the regular polygonal reflector 2. In one preferred embodiment, the short base of the isosceles trapezoidal reflector 1 and the side of the regular polygonal reflector 2 are rotatably connected by a hinge. The installation of the hinge is convenient and fast, and it will not damage the structures of the isosceles trapezoidal reflector 1 and the regular polygonal reflector 2, ensuring the stability of the original structure. Preferably, the hinge is arranged on the outside of the isosceles trapezoidal reflector 1 and the regular polygonal reflector 2 to reduce the influence on the inner reflector 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.

[0087] In one embodiment, the waist of the isosceles trapezoidal reflector 1 and the waist of the adjacent isosceles trapezoidal reflector 1 can be fixed and disassembled through a detachable connection structure. When N the isosceles trapezoidal reflectors 1 are combined to form a regular prism frustum, the waist of the isosceles trapezoidal reflector 1 and the waist of the adjacent isosceles trapezoidal reflector 1 are fixed through a detachable connection structure. When NWhen the isosceles trapezoidal reflector 1 is folded into a plane, the detachable connection structure is separated. Exemplarily, the detachable connection structure can be a card slot buckle; or a magnet; or a lock catch, etc. Of course, the specific structure of the detachable connection structure is not limited thereto, and any structure that can detachably connect two adjacent waists is within the scope of the technical solution protected by the embodiments of the present invention.

[0088] In one embodiment, the surfaces of the regular polygon reflector 2 and the isosceles trapezoidal reflector 1 are made of polished highly conductive metal materials, and the highly conductive metal materials can be aluminum or copper, so as to achieve a high electromagnetic wave reflectivity. In addition, changing the materials of the reflector and the hinge may further reduce the weight of the present invention and improve the portability, but does not affect the excellent omnidirectional strong RCS performance of the present invention.

[0089] In one embodiment, an extended reflector is added to the long bottom of the isosceles trapezoidal reflector 1;

[0090] The extended reflector is at least one of a circular surface, an elliptical surface or a triangular surface.

[0091] By adding an extended reflector with the same size to the long bottom of the isosceles trapezoidal reflector 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 is a schematic diagram of an improvable method for such a structure, Figure 17 is a structural diagram of adding a partial circular surface or an elliptical surface to the isosceles trapezoidal reflector, Figure 18 is a structural diagram of adding a triangular surface to the isosceles trapezoidal reflector.

[0092] The present invention also provides a specific embodiment. Refer to Figure 1 , taking the regular polygon reflector 2 as a regular octagon and the regular prismoid being formed by combining 8 isosceles trapezoidal reflectors 1 as an example, the foldable opposite vertex double prismoid corner reflector is composed of 16 isosceles trapezoidal reflectors 1 and 1 regular octagonal reflector with a circular hole. The overall configuration is two congruent hollowed regular prismoids that are opposite to each other at the top and bottom. Each prismoid is composed of 8 isosceles trapezoidal reflectors 1, and a total of 16 isosceles trapezoidal reflectors 1 are composed. The length of the long bottom of the isosceles trapezoidal reflector 1 is , and the length of the short bottom is . Define an isosceles trapezoidal reflector 1 in the figure as reflector Ⅰ11, the isosceles trapezoidal reflector 1 corresponding to and connected to reflector Ⅰ11 is defined as reflector Ⅱ12, and the isosceles trapezoidal reflector 1 adjacent to reflector Ⅰ11 is defined as reflector Ⅲ13. Then the included angle between reflector Ⅰ11 and reflector Ⅱ12 is fixed at , and the included angle between reflector Ⅰ11 and reflector Ⅲ13 is (when N changes, ).

[0093] Reference Figures 2 - 4 . Let Figure 2 On the outward-opening plane of the middle frustum, the left and right endpoints are points A and B respectively. On the plane of the regular polygon reflecting surface 2, the left and right endpoints are points C and D respectively. Then the distance between points A and B , and the distance between points C and D (as Figure 2 and Figure 4 shown). Let Figure 3 On the outward-opening plane of the middle frustum, the left and right endpoints are points E and F respectively. On the plane of the regular polygon reflecting surface 2, the left and right endpoints are points G and H respectively. The distance between points E and F , and the distance between points C and D (as Figure 3 and Figure 4 shown). The height of a single frustum (as Figure 2 and Figure 3 shown), and the radius of the hollowed-out circular hole at the center of the regular octagon reflecting surface is r (as Figure 4 shown). When the number of frustum faces N changes, the above parameters will change accordingly. Specifically:

[0094] ;

[0095] ;

[0096] ;

[0097] ;

[0098] .

[0099] 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.

[0100] Figure 5 is a schematic diagram of the folding process of the present invention. Each pair of upper and lower isosceles trapezoidal reflecting surfaces 1 are folded together through the hinge in the middle to form a folded state, achieving a significant reduction in volume and facilitating transportation, storage, and deployment.

[0101] Figure 6 is a schematic diagram of the structure of the present invention in the folded state, where the thickness of a single isosceles trapezoidal reflecting surface 1 is d , the thickness of the regular octagon reflecting surface 2 is 2 d , and the radius of the hollowed-out circular hole at its center is r . Figures 7 - 9These are the three views 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 faces N changes, .

[0102] It can be seen that the present invention has a very compact spatial structure in the folded state, and can greatly compress the volume space compared with the unfolded state, having significant spatial storage advantages.

[0103] Figure 10 This is the FEKO simulation spatial schematic diagram of the RCS of the foldable opposite-top double-prism corner reflector of the present invention, showing the establishment of the spatial coordinate system and the spatial relationship between the elevation angle , azimuth angle and the geometric body.

[0104] Figures 11 - 16 This is the RCS simulation result of the foldable opposite-top double-prism corner reflector of the present invention. In this embodiment, the reflecting surface 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.

[0105] The variation diagrams of RCS with respect to the elevation angle of the incident wave are respectively simulated when the azimuth angle of the incident wave is several common angles. In the figure, the abscissa is the elevation angle of the incident wave, ranging from 0 to 90°, and the ordinate is the RCS value (unit: dBsm). Figure 11 is the case of azimuth angle 0° under HH polarization, Figure 12 is the case of azimuth angle 10° under HH polarization, Figure 13 is the case of azimuth angle 20° under HH polarization, Figure 14 is the case of azimuth angle 0° under VV polarization, Figure 15 is the case of azimuth angle 10° under VV polarization, Figure 16This is the case where the azimuth angle is 20° under VV polarization. Since the spatial structure of the octagonal pyramid polyhedron of this embodiment is repeated at an azimuth angle of 45°, and is symmetrically distributed about an azimuth angle of 22.5° in the azimuth range of 0~45°, the effect when the azimuth angle is greater than 22.5° is not demonstrated. The spatial structure of this embodiment is symmetrically distributed about a pitch angle of 90°, so the effect when the pitch angle is greater than 90° is not demonstrated.

[0106] Depend on Figures 11 - 16 It can be seen that the present invention can achieve a strong RCS effect in the full range of pitch angles under several selected incident wave azimuths, regardless of whether the corresponding incoming wave is HH polarized or VV polarized, on the basis of limiting its own volume size ( dBsm). In fact, the present invention has a good strong RCS effect in all directions with an incident wave pitch angle of 0~180° and an azimuth angle of 0~360°. In the FEKO software, the omnidirectional space of 360° azimuth and 180° pitch angle is divided into units of 1° azimuth and 1° pitch angle, generating a total of 360×180 directional units, and calculating the RCS value in each directional unit. According to MATLAB calculation, the angle ratio of the present invention to achieve a strong RCS effect is 93.65%. Calculating the volume ratio of the present invention before and after folding at this time, it can reach 1:7.55.

[0107] It can be seen from the simulation results that the present invention can achieve a strong omnidirectional RCS effect, and through the folding design, it can greatly reduce the space utilization during carrying and transportation, and is a highly efficient new corner reflector. N , the length of the upper and lower bases of the isosceles trapezoidal reflection surface 1 and , the hole radius of the polygonal reflective surface r Parameters such as the frequency of the electromagnetic waves matched by the present invention can be changed to optimize a better RCS effect.

[0108] By adding a reflective surface of equal size on the long base of the isosceles trapezoidal reflective surface 1, the RCS of the overall structure can be increased without affecting the excellent foldability of the present invention, thereby further improving the scattering efficiency. Figure 8 is a schematic diagram of how this type of structure can be improved. Figure 17 To add a part of circular or elliptical surface to the isosceles trapezoidal reflection surface, Figure 18 The structural diagram of adding a triangular surface to the isosceles trapezoidal reflective surface. In addition, changing the material of the reflective surface and the hinge may further reduce the weight of the present invention and improve its portability, but will not affect the good omnidirectional strong RCS performance of the present invention.

[0109] As described above, this is only an embodiment of the present invention 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 equivalent embodiments by using the technical content disclosed above. Therefore, any simple modifications, equivalent changes, and modifications 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 frustum 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 polygon reflecting surface (2).

2. The foldable opposed double frustum corner reflector according to claim 1, characterized in that, The size of the foldable opposite double frustum 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: ； wherein, represents the effective electrical size of the present foldable opposite-top double frustum corner reflector; represents a positive integer; represents the wavelength of electromagnetic wave; Among them, take the larger value between 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: ； 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).

3. The foldable opposite apex double frustum corner reflector according to claim 2, characterized in that, The radius of the circular hole r satisfies the radius determination model, and the radius determination model is as follows: 。 4. The foldable opposed double frustum corner reflector according to claim 3, wherein, When the incoming wave is an X-band radar wave, has a value range of 5 to 15 cm, has a value range of 3.75 to 11.25 cm; and satisfies , d has a value range of 0.5 to 2 mm, d is the thickness of the isosceles trapezoidal reflecting surface (1), N has a value range of 4 to 12.

5. The foldable opposed double frustum corner reflector according to claim 4, wherein, The said N = 8.

6. The foldable opposed double frustum corner reflector according to claim 1, characterized in that, The included angle between the two isosceles trapezoidal reflecting surfaces (1) corresponding to the regular prism frustum is 90°.

7. The foldable opposed double frustum corner reflector according to any one of claims 1-6, characterized in that, The short base of each isosceles trapezoidal reflecting surface (1) is rotatably connected to the side of the regular polygon reflecting surface (2); The N isosceles trapezoidal reflecting surfaces (1) of the regular frustum are unfolded or combined by rotation.

8. The foldable opposite double frustum corner reflector according to claim 7, characterized in that, After the N isosceles trapezoidal reflecting surfaces (1) of a regular frustum are unfolded, the corresponding isosceles trapezoidal reflecting surfaces (1) on two groups of regular frustums are attached to each other, and the two corresponding isosceles trapezoidal reflecting surfaces (1) after attachment are coplanar with the regular polygon reflecting surface (2).

9. The foldable opposed double frustum corner reflector according to claim 7, characterized in that, The short base of the isosceles trapezoidal reflecting surface (1) is rotatably connected to the side of the regular polygon reflecting surface (2) through a hinge.

10. The foldable opposed double frustum corner reflector according to any one of claims 1-6, 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 reflecting surface is at least one of a circular surface, an elliptical surface or a triangular surface.

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