Effective reflection area expansion structure for large umbrella antenna and design method

Abstract

The invention discloses an effective reflection area expansion structure for a large umbrella antenna and a design method, and the structure comprises an umbrella antenna reflector and a cable rod structure. Wherein the cable rod structure is arranged at the boundary position of the umbrella-shaped antenna reflector. According to the invention, the concave condition of the boundary of the traditional spatial umbrella-shaped antenna can be improved, a stable cable rod expansion structure meeting the profile precision requirement is obtained, and the effective reflection area of a large spatial umbrella-shaped antenna reflector is expanded.

Description

Technical Field

[0001] The invention belongs to the technical field of space antenna reflectors, and in particular relates to an effective reflection area expansion structure and a design method for a large umbrella antenna. Background Art

[0002] With the development of space technology, the demand for high-orbit satellite communications and deep space exploration is increasing day by day, and the demand for the ability to send and receive tiny electromagnetic waves is also gradually increasing. Traditional small antennas can no longer meet their working requirements. The larger the effective reflection area of ​​the antenna reflector, the greater the gain of the antenna under the same loss conditions, which can improve the communication transmission capability, remote sensing target perception capability and earth observation resolution. Therefore, large-diameter, high-precision antennas are needed to ensure smooth communication of satellites.

[0003] Among them, the effective reflection area of ​​the antenna is an important indicator for evaluating its performance. The effective reflection area of ​​the reflector is proportional to the antenna gain, so the size of the available area of ​​the reflector will directly affect the signal reception and transmission capabilities. At present, the main way to increase the effective reflection area of ​​the reflection surface is to directly increase the antenna aperture to meet performance requirements. However, due to quality requirements, space constraints of structural design and other engineering limitations, the antenna aperture is also subject to certain restrictions. Therefore, in the design process, various factors must be weighed. It is impossible to increase the antenna aperture indefinitely. On the premise of not increasing the geometric aperture of the antenna reflector, expanding the effective reflection area of ​​the reflection surface and thereby increasing the gain of the antenna is of great engineering significance.

[0004] In an umbrella antenna, the antenna mesh is spread out in space into a parabola, forming a corresponding polygonal boundary. Boundary ropes are usually used to balance the inward pulling force of the metal mesh. This makes the boundary rope concave toward the center of the reflector, forming a catenary shape, such as Figure 1 As shown. After the mesh is stretched, it will cause the overhang effect of the boundary, resulting in the effective reflection area of ​​the antenna being smaller than the theoretical area enclosed by the polygon. Therefore, the present invention expands the boundary of the umbrella antenna reflector to increase the effective reflection area and improve the antenna gain.

[0005] In the currently published literature, there are the following solutions to the problem of increasing the effective reflection area of ​​umbrella mesh antennas: 1. By reducing the boundary overhang depth, the effective reflection area of ​​the reflector is increased. This method will increase the force on the support ribs, and the upper limit of the effective reflection area is the polygonal area. 2. Expand the effective reflection area of ​​the antenna reflector through a bifurcated rib structure. This method will increase the weight and complexity of the reflector. 3. Add a foldable ring as support at the boundary of the reflector to obtain a larger effective reflection area. This method has a large support ring mass and is not suitable for umbrella antennas with larger calibers.

[0006] Current research on how to increase the effective reflection area of ​​the umbrella-shaped mesh antenna has the following shortcomings: the effective area expansion effect is not obvious, the mass increases significantly, and the structural complexity increases. Summary of the invention

[0007] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to provide an effective reflection area expansion structure and design method for large umbrella antennas, to improve the concave boundary of traditional space umbrella antennas, to obtain a stable cable rod expansion structure that meets the surface accuracy requirements, and to expand the effective reflection area of ​​the reflector of the large space umbrella antenna.

[0008] The object of the present invention is achieved through the following technical solution: an effective reflection area expansion structure for a large umbrella antenna, comprising: an umbrella antenna reflector and a cable rod structure; wherein the cable rod structure is arranged at the boundary position of the umbrella antenna reflector.

[0009] In the above-mentioned effective reflection area expansion structure facing the large umbrella antenna, the cable rod structure includes an auxiliary rope net, a boundary working rope net and a support rod; wherein the secondary net node of the auxiliary rope net is connected to one end of the support rod, and the main net node of the boundary working rope net is connected to the other end of the support rod.

[0010] In the above-mentioned effective reflection area expansion structure facing the large umbrella antenna, the cable rod structure also includes a cable rod crimping terminal; wherein the secondary network node of the auxiliary rope net is connected to one end of the support rod through the cable rod crimping terminal, and the main network node of the boundary working rope net is connected to the other end of the support rod through the cable rod crimping terminal.

[0011] In the above-mentioned effective reflection area expansion structure facing the large umbrella antenna, the auxiliary rope net and the boundary working rope net have the same structure, both including a main net, a secondary net and multiple vertical ropes; wherein each main net node of the main net is connected to the secondary net node of the secondary net corresponding to each main net node through the vertical rope.

[0012] In the above-mentioned effective reflection area expansion structure facing the large umbrella antenna, when the umbrella antenna reflector is in the unfolded state, the main network node of the boundary working rope net is located at the intersection line formed by the standard parabola where the umbrella antenna reflector is located and the cylindrical section.

[0013] In the above-mentioned effective reflection area expansion structure for large umbrella antennas, the ideal support force vector provided by the support rod is obtained by the following formula:

[0014] C s T QC s S = F;

[0015] Among them, C sis the connection matrix of the boundary working rope net unit; Q is the diagonal matrix composed of the force density of the boundary working rope net unit; S is the coordinate matrix of the boundary working rope net node position; F is the ideal support force vector provided by the support rod.

[0016] In the above-mentioned effective reflection area expansion structure facing the large umbrella antenna, the main network node coordinates and the auxiliary network node coordinates of the auxiliary rope network are obtained by the following formula:

[0017] Find α i ,β j

[0018] min f j =d(β j ,l j )

[0019]

[0020] 0 <T k

[0021] 0.03≤|α i -β j |;

[0022] Among them, i is the main network node number of the auxiliary rope network; j is the secondary network node number of the auxiliary rope network; k is the auxiliary rope network unit number; α i is the main network node coordinate of the auxiliary rope net; β j is the coordinates of the auxiliary network nodes of the auxiliary rope network; d(β j ,l i ) is the distance from the point to the line; f i is the coordinates of the auxiliary network nodes of the auxiliary rope network β j The distance to the ideal straight line where the support rod is located; l j is the direction vector of the straight line where the support rod is located in the ideal case; St is the constraint condition; C f is the connection matrix of the auxiliary rope net unit; Q' is the diagonal matrix composed of the force density of the auxiliary rope net unit; S' is the coordinate matrix of the auxiliary rope net node position; F' is the external force on the auxiliary rope net node; T k is the internal force of all auxiliary rope net units.

[0023] In the above-mentioned effective reflection area expansion structure for large umbrella antennas, the main net and the auxiliary net both use carbon fiber material as the inner core and are wrapped with polyimide material on the outside; the support rods are made of carbon fiber material.

[0024] In the above-mentioned effective reflection area expansion structure facing the large umbrella antenna, the cable rod crimping terminal is made of copper alloy material; one end of the cable rod crimping terminal is crimped to the support rod, and the other end of the cable rod crimping terminal is sewn to the secondary net node of the auxiliary rope net or the main net node of the boundary working rope net.

[0025] A design method for an effective reflection area expansion structure for a large umbrella antenna comprises: determining an ideal main net node position and a vertical cable tension of a boundary working rope net according to preset umbrella antenna reflector structural parameters; determining an ideal support force vector provided by a support rod according to the ideal main net node position of the boundary working rope net; obtaining an auxiliary rope net according to the ideal support force vector provided by the support rod; determining the length of the support rod according to the connection relationship of the support rod; determining a critical load of the support rod according to the ideal support force provided by the support rod, and finally determining the cross-sectional diameter of the support rod in combination with the length of the support rod; arranging a cable rod structure at a boundary position of the umbrella antenna reflector; wherein the cable rod structure comprises an auxiliary rope net, a boundary working rope net and a support rod; a secondary network node of the auxiliary rope net is connected to one end of the support rod, and a main network node of the boundary working rope net is connected to the other end of the support rod; wherein the auxiliary rope net and the boundary working rope net have the same structure, both comprising a main net, a secondary net and a plurality of vertical cables; wherein each main network node of the main net is connected to a secondary network node of the secondary net corresponding to each main network node through the vertical cable.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The present invention improves the problem of loss of effective reflection area caused by the concave boundary of the traditional umbrella-shaped antenna, and adopts a cable rod structure to expand the reflector boundary to a certain extent, thereby improving the antenna gain;

[0028] (2) The present invention has the characteristics of simple structure, light weight, and meeting the requirements for the surface accuracy of the antenna reflector. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0030] Figure 1 It is a schematic diagram of the effective reflection area of ​​a forward-fed hexagonal antenna reflector in the prior art;

[0031] Figure 2 is a schematic diagram of a double-layer network structure provided by an embodiment of the present invention;

[0032] Figure 3is a schematic diagram of an effective reflection area expansion structure provided by an embodiment of the present invention;

[0033] Figure 4 is a schematic diagram of an umbrella-shaped antenna reflector after installing an extended structure provided by an embodiment of the present invention;

[0034] Figure 5 It is a flow chart of a method for determining an effective reflection area expansion structure provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0035] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] This embodiment provides an effective reflection area expansion structure for a large umbrella antenna, the structure comprising: an umbrella-shaped antenna reflector and a cable rod structure; wherein the cable rod structure is arranged at the boundary position of the umbrella-shaped antenna reflector. The cable rod structure is installed at the boundary of the antenna reflector to expand the effective reflection area of ​​the reflector.

[0037] like Figure 3 As shown, the cable-rod structure includes an auxiliary rope net, a boundary working rope net and a support rod; wherein the secondary net node of the auxiliary rope net is connected to one end of the support rod, and the main net node of the boundary working rope net is connected to the other end of the support rod.

[0038] like Figure 3 As shown, the cable rod structure also includes a cable rod crimping terminal; wherein the secondary network node of the auxiliary rope net is connected to one end of the support rod through the cable rod crimping terminal, and the main network node of the boundary working rope net is connected to the other end of the support rod through the cable rod crimping terminal.

[0039] like Figure 2 As shown, the auxiliary rope net and the boundary working rope net have the same structure, both including a main net, a secondary net and multiple vertical cables; wherein each main net node of the main net is connected to the secondary net node of the secondary net corresponding to each main net node through the vertical cable.

[0040] The auxiliary rope net and the boundary working rope net are both double-layer net structures with N vertical cables, and the corresponding nodes of the auxiliary rope net and the boundary working rope net are connected by support rods. N is a positive integer.

[0041] The auxiliary rope net and support rods are both located below the standard parabola of the reflector and only play a supporting role without interfering with the reflecting surface.

[0042] According to the reflector structural parameters, the structural parameters of the boundary working rope net and the tension of each rope are determined; according to the ideal node position of the boundary working rope net, the ideal supporting force vector that the support rod needs to provide is determined; according to the ideal supporting force vector of the support rod, the auxiliary rope net structure, support rod length and cross-sectional diameter are determined.

[0043] When the umbrella antenna reflector is in the unfolded state, the main network node of the boundary working rope net is located on the intersection line formed by the standard parabola where the umbrella antenna reflector is located and the cylindrical section.

[0044] The ideal support force vector provided by the support rod is obtained by the following formula:

[0045] C s T QC s S = F;

[0046] Among them, C s is the connection matrix of the boundary working rope net unit; Q is the diagonal matrix composed of the force density of the boundary working rope net unit; S is the coordinate matrix of the boundary working rope net node position; F is the ideal support force vector provided by the support rod. The boundary working rope net nodes include the main network nodes and the auxiliary network nodes of the boundary working rope net.

[0047] The main network node coordinates and auxiliary network node coordinates of the auxiliary rope network are obtained by the following formula:

[0048] Find α i ,β j

[0049] min f j =d(β j ,l j )

[0050]

[0051] 0 <T k

[0052] 0.03≤|α i -β j |;

[0053] Among them, i is the main network node number of the auxiliary rope network; j is the secondary network node number of the auxiliary rope network; k is the auxiliary rope network unit number; α i is the main network node coordinate of the auxiliary rope net; β j is the coordinates of the auxiliary network nodes of the auxiliary rope network; d(β j ,l i) is the distance from the point to the line; f i is the coordinates of the auxiliary network nodes of the auxiliary rope network β j The distance to the ideal straight line where the support rod is located; l j It is obtained by normalizing the ideal support force vector F, which is the direction vector of the straight line where the support rod is located in the ideal case; St is the constraint condition; C f is the connection matrix of the auxiliary rope net unit; Q' is the diagonal matrix composed of the force density of the auxiliary rope net unit; S' is the coordinate matrix of the auxiliary rope net node position; F' is the external force on the auxiliary rope net node; T k is the internal force of the auxiliary rope net unit. The auxiliary rope net nodes include the main net nodes and the auxiliary net nodes of the auxiliary rope net.

[0054] The main net and the auxiliary net both use carbon fiber material as the inner core, and are wrapped with polyimide material on the outside; the support rods use carbon fiber material.

[0055] The cable rod crimping terminal is made of copper alloy material; one end of the cable rod crimping terminal is crimped to the support rod, and the other end of the cable rod crimping terminal is sewn to the secondary net node of the auxiliary rope net or the main net node of the boundary working rope net.

[0056] The effective reflection area is expanded for a certain type of large space umbrella antenna.

[0057] The extended structure includes: auxiliary rope net, boundary working rope net, support rod, and cable rod crimping terminal. Figure 2 As shown, both the auxiliary rope net and the boundary working rope net are double-layer nets with 7 vertical ropes. The ropes are made of carbon fiber material as the inner core, wrapped with polyimide material on the outside, the support rods are made of carbon fiber material, and the cable rod crimping terminals are made of copper alloy material.

[0058] like Figure 3 As shown, the corresponding nodes of the auxiliary rope net and the boundary working rope net are connected by a support rod, one end of the support rod is connected to the secondary net node of the auxiliary rope net, and the other end is connected to the main net node of the boundary working rope net. The rope net and the support rod are connected by a cable rod crimping terminal, one end of which is crimped to the support rod and the other end is sewn on the rope net node.

[0059] like Figure 4 As shown, the expansion structure is installed at the end of the support rib of the umbrella antenna reflector, that is, the boundary position of the reflector. When the reflector is unfolded, the main network node of the boundary working rope net is located on the intersection line formed by the standard parabola where the reflector is located and the corresponding cylindrical section.

[0060] like Figure 5 As shown, this embodiment also provides a method for designing an effective reflection area expansion structure for a large umbrella antenna, the method comprising:

[0061] According to the preset umbrella antenna reflector structural parameters, the ideal main network node position and the tension of each vertical cable of the boundary working rope net are determined; wherein the umbrella antenna reflector structural parameters include effective aperture, focal length and number of supporting ribs;

[0062] According to the ideal main net node position of the boundary working rope net, determine the ideal support force vector provided by the support rod;

[0063] According to the ideal supporting force vector provided by the supporting rod, the auxiliary rope net is obtained;

[0064] Determine the length of the support rod according to the connection relationship of the support rod; determine the critical load of the support rod according to the ideal supporting force provided by the support rod, and finally determine the cross-sectional diameter of the support rod in combination with the length of the support rod;

[0065] A cable-rod structure is arranged at the boundary position of the umbrella-shaped antenna reflector; wherein the cable-rod structure comprises an auxiliary rope net, a boundary working rope net and a support rod; the auxiliary network node of the auxiliary rope net is connected to one end of the support rod, and the main network node of the boundary working rope net is connected to the other end of the support rod; wherein the auxiliary rope net and the boundary working rope net have the same structure, both comprising a main network, an auxiliary network and a plurality of vertical cables; wherein each main network node of the main network is connected to the auxiliary network node of the auxiliary network corresponding to each main network node through the vertical cable.

[0066] like Figure 5 As shown in the flow chart, a method for determining an effective reflection area expansion structure for a large umbrella antenna is provided in an embodiment of the present invention, including:

[0067] Step 101:

[0068] According to the reflector structural parameters of this embodiment: effective aperture, focal length, number of supporting ribs, the ideal position coordinates of the main network nodes of the boundary working rope net are determined. The ideal nodes are located on the intersection formed by the standard parabola where the reflector is located and the cylindrical section of the corresponding diameter passing through the parabola rotation axis and the center, and are evenly distributed according to the number of nodes. According to the reflector parameters and the main network node position, the auxiliary network and vertical cable length of the boundary working rope net are determined, and the initial pretension is selected based on engineering experience.

[0069] Step 102:

[0070] According to the ideal node position of the boundary working rope net, the ideal support force vector that the support rod needs to provide is determined, and the support rod is regarded as a two-force rod during calculation. The ideal support force vector is determined according to the following formula:

[0071] C s T QC s S=F

[0072] C sis the connection matrix of the boundary working rope net unit; Q is the diagonal matrix composed of the force density of the boundary working rope net unit; S is the coordinate matrix of the boundary working rope net node position; F is the ideal support force vector provided by the support rod that needs to be determined.

[0073] Step 103:

[0074] According to the ideal support force vector, the auxiliary rope net structure is designed so that the auxiliary rope net can provide the ideal support force in a balanced state. After the auxiliary rope net is balanced, the coordinates of each node are determined according to the following formula:

[0075] Find α i ,β j

[0076] min f j =d(β j ,l j )

[0077]

[0078] 0 <T k

[0079] 0.03≤|α i -β j |

[0080] Among them: i is the node number of the auxiliary rope net main network; j is the node number of the auxiliary rope net secondary network; k is the auxiliary rope net unit number; α i is the coordinates of the nodes of the auxiliary rope net main network; β j is the coordinate of the auxiliary rope net node; α i ,β j are the free node coordinates that need to be optimized; d(β j ,l i ) is the distance from the point to the line, that is, f i is the lower node β j To the ideal straight line l where the support rod is located j The distance; l j It is obtained by normalizing the ideal support force vector F, which is the direction vector of the straight line where the support rod is located in the ideal case; St is the constraint condition; C f is the connection matrix of the auxiliary rope net unit; Q' is the diagonal matrix composed of the force density of the auxiliary rope net unit; S' is the coordinate matrix of the auxiliary rope net node position; F' is the external force on the auxiliary rope net node; T k is the internal force of the auxiliary rope net unit.

[0081] The constraint conditions set are: the cable elements in the extended structure are all in tension, that is, T k>0. Since the distance between the double-layer nets cannot be too small, otherwise the ropes cannot be connected in the actual project, the position distance difference between the upper and lower layers of the nets should not be less than 30mm, that is,

[0082] According to the node coordinates of the auxiliary rope net after balance, the length of each cable segment of the auxiliary rope net can be calculated.

[0083] Step 104:

[0084] According to the connection relationship of the support rod, the length of the support rod is determined. According to the ideal supporting force provided by the support rod, the critical load of the support rod is determined. Combined with the length L of the support rod, the cross-sectional diameter D of the support rod is finally determined to complete the extended structure design.

[0085] The extended structure was made according to the structural parameters determined in the above steps, and the test was carried out on the constructed single sector test platform of the forward-fed umbrella antenna reflector. The test results show that compared with the reflector at the boundary of the traditional suspension line, after installing the extended structure, the reflector reflection area is effectively expanded, and the surface accuracy at the boundary of the reflector meets the design goal of the antenna surface accuracy of this embodiment.

[0086] This embodiment can improve the overhang boundary of the traditional space umbrella antenna, obtain a stable cable rod extension structure that meets the surface accuracy requirements, and has the advantages of simple structure and light weight. It is a reliable solution for expanding the effective reflection area of ​​a large space umbrella antenna and improving the gain of the antenna reflector, and has important scientific significance and application value.

[0087] This embodiment improves the problem of loss of effective reflection area caused by the concave boundary of the traditional umbrella-shaped antenna, and adopts a cable-rod structure to expand the reflector boundary to a certain extent, thereby improving the antenna gain; this embodiment has the characteristics of simple structure, light weight, and meets the requirements for antenna reflector surface accuracy.

[0088] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. 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 protection scope of the technical solution of the present invention.

Claims

1. An effective reflection area expansion structure for large umbrella antennas, characterized in that include: Umbrella-shaped antenna reflector and cable rod structure; wherein, The cable rod structure is arranged at a boundary position of the umbrella-shaped antenna reflector.

2. The effective reflection area expansion structure for large umbrella antennas according to claim 1, characterized in that: The cable rod structure includes an auxiliary rope net, a boundary working rope net and a support rod; wherein, The secondary net node of the auxiliary rope net is connected to one end of the support rod, and the main net node of the boundary working rope net is connected to the other end of the support rod.

3. The effective reflection area expansion structure for large umbrella antennas according to claim 2, characterized in that: The cable rod structure also includes a cable rod crimping terminal; wherein, The secondary net node of the auxiliary rope net is connected to one end of the support rod through the cable rod crimping terminal, and the main net node of the boundary working rope net is connected to the other end of the support rod through the cable rod crimping terminal.

4. The effective reflection area expansion structure for large umbrella antennas according to claim 2, characterized in that: The auxiliary rope net and the boundary working rope net have the same structure, both of which include a main net, a secondary net and a plurality of vertical ropes; wherein, Each main network node of the main network is connected to a secondary network node of a secondary network corresponding to each main network node through the vertical cable.

5. The effective reflection area expansion structure for large umbrella antennas according to claim 2, characterized in that: When the umbrella antenna reflector is in the unfolded state, the main network node of the boundary working rope net is located on the intersection line formed by the standard parabola where the umbrella antenna reflector is located and the cylindrical section.

6. The effective reflection area expansion structure for large umbrella antennas according to claim 2, characterized in that: The ideal support force vector provided by the support rod is obtained by the following formula: Among them, C s is the connection matrix of the boundary working rope net unit; Q is the diagonal matrix composed of the force density of the boundary working rope net unit; S is the coordinate matrix of the boundary working rope net node position; F is the ideal support force vector provided by the support rod.

7. The effective reflection area expansion structure for large umbrella antennas according to claim 2, characterized in that: The main network node coordinates and auxiliary network node coordinates of the auxiliary rope network are obtained by the following formula: Among them, i is the main network node number of the auxiliary rope network; j is the secondary network node number of the auxiliary rope network; k is the auxiliary rope network unit number; α i is the main network node coordinate of the auxiliary rope net; β j is the coordinates of the auxiliary network nodes of the auxiliary rope network; d(β j ,l i ) is the distance from the point to the line; f i is the coordinates of the auxiliary network nodes of the auxiliary rope network β j The distance to the ideal straight line where the support rod is located; l j is the direction vector of the straight line where the support rod is located in the ideal case; St is the constraint condition; C f is the connection matrix of the auxiliary rope net unit; Q' is the diagonal matrix composed of the force density of the auxiliary rope net unit; S' is the coordinate matrix of the auxiliary rope net node position; F' is the external force on the auxiliary rope net node; T k is the internal force of all auxiliary rope net units.

8. The effective reflection area expansion structure for large umbrella antennas according to claim 4, characterized in that: The main net and the auxiliary net both use carbon fiber material as the inner core, and are wrapped with polyimide material on the outside; the support rods use carbon fiber material.

9. The effective reflection area expansion structure for large umbrella antennas according to claim 3, characterized in that: The cable rod crimping terminal is made of copper alloy material; One end of the cable rod crimping terminal is crimped to the support rod, and the other end of the cable rod crimping terminal is sewn to the secondary net node of the auxiliary rope net or the main net node of the boundary working rope net.

10. A method for designing an effective reflection area expansion structure for a large umbrella antenna, characterized in that include: According to the preset umbrella antenna reflector structure parameters, determine the ideal main net node position and vertical cable tension of the boundary working rope net; According to the ideal main net node position of the boundary working rope net, determine the ideal support force vector provided by the support rod; According to the ideal supporting force vector provided by the supporting rod, the auxiliary rope net is obtained; Determine the length of the support rod according to the connection relationship of the support rod; determine the critical load of the support rod according to the ideal supporting force provided by the support rod, and finally determine the cross-sectional diameter of the support rod in combination with the length of the support rod; A cable-rod structure is arranged at the boundary position of the umbrella-shaped antenna reflector; wherein the cable-rod structure comprises an auxiliary rope net, a boundary working rope net and a support rod; the auxiliary network node of the auxiliary rope net is connected to one end of the support rod, and the main network node of the boundary working rope net is connected to the other end of the support rod; wherein the auxiliary rope net and the boundary working rope net have the same structure, both comprising a main network, an auxiliary network and a plurality of vertical cables; wherein each main network node of the main network is connected to the auxiliary network node of the auxiliary network corresponding to each main network node through the vertical cable.

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