Integrated satellite-borne four-arm spiral measurement and control antenna and manufacturing method thereof

Abstract

The invention provides an integrated satellite-borne four-arm spiral measurement and control antenna, and the antenna comprises an outer conductor which is internally provided with a cylindrical inner cavity, one end of an outer conductor main body is provided with a short-circuit structure, and the other end is provided with a positioning structure; the inner conductor is a strip-shaped cylinder and is nested in the inner cavity of the outer conductor main body, the inner conductor comprises a first conductor section with a first diameter and a second conductor section with a second diameter, the first diameter is larger than the second diameter, a step is formed, the first conductor section of the inner conductor is connected with the short-circuit structure of the outer conductor main body, and the second conductor section of the inner conductor is connected with the short-circuit structure. The second conductor section extends into the positioning structure of the outer conductor and is positioned in the center of the inner diameter of the positioning structure; and the spiral arm is located outside the outer conductor, one end is connected to the base of the outer conductor, and the other end is connected to the end, with the short circuit structure, of the outer conductor. The outer conductor, the inner conductor and the spiral arm are integrally formed through the additive manufacturing process, a positioning medium and an interface medium can be omitted, and the problem that the number of parts of the spiral measurement and control antenna is large is solved.

Description

Technical Field

[0001] The invention relates to a satellite-borne four-arm spiral measurement and control antenna and a manufacturing method thereof. Background Art

[0002] Low-orbit satellites usually use wide-beam circularly polarized antennas as their receiving antennas to ensure that they receive signals from as many satellites as possible. The four-arm helical antenna has excellent circular polarization performance and is relatively insensitive to the environment. It is the most commonly used type of satellite-borne receiving antenna.

[0003] The structure of the existing satellite-borne four-arm helical receiving antenna is as follows: Figure 1 As shown, it is mainly composed of three parts: inner conductor 6, outer conductor 3 and spiral arms 41, 42. The spiral arms of the four-arm spiral antenna are composed of a pair of long spiral arms 41 and a pair of short spiral arms 42 to obtain the circular polarization characteristics of the antenna.

[0004] The inner conductor 6 and the outer conductor 3 are made of aluminum alloy or copper alloy. The spiral arms 41 and 42 are made of beryllium bronze due to their bending requirements. The inner conductor 6 and the outer conductor 3 are connected by a short-circuit plate 2, a positioning / tuning medium 5 and an interface medium 7. The short-circuit plate 2 is connected to the inner conductor 6 and the outer conductor 3 using a silver brazing process. The outer conductor 3 is directly connected to the spiral arms 41 and 42 using a welding process. The antenna uses a coaxial top feeding mode, and an SMA interface is directly welded on the base of the outer conductor as a feeding input terminal. Due to the poor consistency of the spiral arm bending process and the welding process, the standing wave ratio matching of the antenna is usually adjusted by adjusting the position of the positioning / tuning medium 5 during the antenna assembly process.

[0005] The satellite-borne four-arm helical receiving antenna has a complex structure. Without counting the connecting bolts, there are still 9 parts. The materials used for the outer conductor 3 and the spiral arms 41 and 42 are inconsistent. The antenna arm and the outer conductor are connected by welding. The process reliability is poor, and detachment often occurs during the thermal vacuum test phase. The bending of the antenna arm is generally done manually, and the consistency is poor. The antenna assembly is mainly completed manually by the operator, and the consistency is poor. Each antenna must be tuned according to the measured values. In addition, the antenna arm uses beryllium bronze material, which is toxic and has adverse effects on the environment and operators during the manufacturing process. Summary of the invention

[0006] The purpose of the present invention is to solve the above-mentioned problem and provide an integrated satellite-borne four-arm spiral measurement and control antenna. The inner conductor and the spiral arms are formed integrally through an additive manufacturing process, and the positioning medium and the interface medium can be eliminated, thereby solving the problem of the large number of parts of the spiral measurement and control antenna.

[0007] The integrated satellite-borne four-arm spiral measurement and control antenna provided by the present invention comprises:

[0008] The outer conductor has a cylindrical barrel body with a cylindrical inner cavity inside, one end of the outer conductor body has a short-circuit structure, and the other end has a positioning structure, the positioning structure is an opening of the cylindrical barrel body, the inner diameter of the opening is smaller than the inner diameter of the outer conductor body, so as to form a step, and the outer side of the end of the outer conductor with the positioning structure has a base;

[0009] The inner conductor is a strip-shaped cylinder, which is nested in the inner cavity of the outer conductor body. The inner conductor includes a first conductor segment with a first diameter and a second conductor segment with a second diameter, wherein the first diameter is greater than the second diameter to form a step. The first conductor segment of the inner conductor is connected to the short-circuit structure of the outer conductor body, and the second conductor segment extends into the positioning structure of the outer conductor and is located at the inner diameter center of the positioning structure.

[0010] The spiral arm is located outside the outer conductor, one end of the spiral arm is connected to the base of the outer conductor, and the other end is connected to the end of the outer conductor with a short-circuit structure.

[0011] The outer conductor, the inner conductor and the spiral arm are integrally formed by an additive manufacturing process.

[0012] In at least one embodiment, the outer conductor, the inner conductor, and the spiral arms are integrally formed by an electron beam additive manufacturing process.

[0013] In at least one embodiment, after the antenna is integrally formed by an additive manufacturing process, it undergoes a stress relief process in a temperature chamber, and the annealing temperature is 250° C. to 300° C., and the annealing time is 60 to 120 minutes.

[0014] In at least one embodiment, the antenna is integrally formed by an additive manufacturing process and then undergoes a shot peening process, wherein the shot peening process includes: using ASH110 steel shot peening to shot peen the outer wall of the antenna, with a shot peening coverage of 100% and a shot peening intensity of 4 to 7A.

[0015] In at least one embodiment, the side wall structure of the cylindrical tube body is combined with electrical performance simulation to thicken the side wall and add a chamfer structure for step-shaped matching to avoid thin walls and axial size mutation structures.

[0016] In at least one embodiment, the antenna does not have a positioning medium, a tuning medium, or an interface medium.

[0017] In at least one embodiment, the positioning structure is used to adapt to an SMA socket.

[0018] In at least one embodiment, the antenna is integrally formed of Ti material by an additive manufacturing process.

[0019] The present invention also provides a method for manufacturing the above antenna, comprising:

[0020] S1: Using additive manufacturing technology to manufacture the integrated satellite-borne four-arm spiral tracking and control antenna described in claim 1;

[0021] S2: placing the measurement and control antenna in a temperature box for annealing, the annealing temperature is 250° C. to 300° C., and the annealing time is 60 to 120 minutes;

[0022] S3: Shot peening process: Place the measurement and control antenna into the shot peening device, and use ASH110 steel shot peening to peen the outer wall of the antenna. The shot peening coverage rate is 100%, and the shot peening intensity is 4 to 7A.

[0023] In at least one embodiment, the additive manufacturing process is an electron beam additive manufacturing process.

[0024] The integrated satellite-borne four-arm spiral measurement and control antenna provided by the present invention uses an additive manufacturing process to manufacture the inner conductor, outer conductor, spiral arm, and short-circuit plate into an integrated structure. High-strength materials can be used to directly manufacture the antenna spiral arm, thereby unifying the materials between the inner and outer conductors and the spiral arm. There is no need for welding process to connect them, which avoids detachment and solves the problem of manufacturing the antenna spiral arm with complex structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The following will further explain the above characteristics, technical features, advantages and implementation methods of the present application in a clear and understandable manner through the description of the preferred embodiments and in combination with the accompanying drawings. The following drawings are only intended to illustrate and explain the present application, and do not limit the scope of the present application. Among them:

[0026] Figure 1 The present invention shows a satellite-borne quadrilateral helical receiving antenna in the prior art;

[0027] Figure 2 A schematic diagram of the structure of a satellite-borne four-arm helical receiving antenna provided by the present invention;

[0028] Figure 3 A cross-sectional view of the satellite-borne four-arm helical receiving antenna provided by the present invention. DETAILED DESCRIPTION

[0029] In order to have a clearer understanding of the technical features, purposes and effects of the present application, the specific implementation methods of the present application are now described with reference to the accompanying drawings.

[0030] The main technical contradictions of the four-arm helical antenna are: the antenna helical arm is small in size and involves a bending process, which requires the use of high-toughness and ductility materials; while the inner and outer conductors determine the stiffness performance of the antenna, which requires the use of high-stiffness materials. This requires the use of welding technology to connect the outer conductor and the helical arm. The multi-material welding process leads to poor reliability of the connection point under the aerospace mechanical and thermal environment.

[0031] In addition, if Figure 1 As shown, in the existing four-arm helical antenna, the inner conductor 6 and the outer conductor 3 are connected by welding through the short-circuit plate 2, so there is a welding deviation, so it is necessary to set a tuning / positioning medium 5 in the middle section of the inner conductor 6, and set an interface medium 7 at the SMA interface to ensure that the inner conductor 6 and the outer conductor 3 maintain the correct relative position. In addition, the spiral arm bend and welding deviation will cause the standing wave ratio to increase, and it is also necessary to adjust the position of the tuning / positioning medium 7 to adjust the antenna impedance matching. Therefore, in the existing four-arm helical antenna, the tuning / positioning medium 5 and the interface medium 7 are indispensable components, which is also an important reason for the large number of components in the four-arm helical antenna.

[0032] In summary, the existing quadrifilar helical antenna has the following disadvantages:

[0033] 1. The satellite-borne four-arm spiral tracking and control antenna has a complex structure and many parts;

[0034] 2. The antenna uses a lot of welding technology, which has poor reliability;

[0035] 3. The assembly process is complicated and the consistency of the assembly process is poor;

[0036] 4. The antenna arm material is toxic.

[0037] In order to overcome the problems of existing four-arm helical antennas, the present application provides an integrated satellite-borne four-arm helical measurement and control antenna. Through an additive manufacturing process, the inner conductor, outer conductor, spiral arm, and short-circuit plate are manufactured into an integrated structure, which can eliminate components such as tuning / positioning media and interface media, thereby overcoming the problem of the large number of components of the satellite-borne four-arm helical measurement and control antenna, and does not require a complicated tuning process.

[0038] According to an embodiment of the present application, an integrated satellite-borne four-arm spiral tracking and control antenna is provided, and its structure is as follows: Figure 2 and Figure 3 As shown, including:

[0039] The outer conductor 13 has a cylindrical body with a cylindrical inner cavity. One end of the outer conductor 3 body has a short-circuit structure 131, and the other end has a positioning structure 132 for adapting to the SMA socket. The positioning structure 132 is an opening of the cylindrical body. The inner diameter of the opening is smaller than the inner diameter of the outer conductor 13 body, forming a step 133. The outer side of the end of the outer conductor 13 with the positioning structure 132 has a base 133;

[0040] The inner conductor 16 is a strip-shaped cylinder, which is nested in the inner cavity of the outer conductor 13 body. The inner conductor 16 includes a first conductor segment 161 with a first diameter and a second conductor segment 162 with a second diameter, wherein the first diameter is greater than the second diameter, forming a step 163. The first conductor segment 161 of the inner conductor 16 is connected to the short-circuit structure 131 of the outer conductor 3 body, and the second conductor segment 162 extends into the positioning structure 132 of the outer conductor 13 and is located at the inner diameter center of the positioning structure 132.

[0041] The spiral arm 41 is located outside the outer conductor 13 , and one end of the spiral arm 41 is connected to the base 133 of the outer conductor 13 , and the other end of the spiral arm 41 is connected to one end of the outer conductor 13 having the short-circuit structure 131 .

[0042] The outer conductor 13, the inner conductor 16, and the spiral arm 41 are integrally formed by an additive manufacturing process (eg, electron beam sintering additive manufacturing technology).

[0043] The integrated satellite-borne four-arm spiral tracking and control antenna provided in this embodiment uses an additive manufacturing process to manufacture the inner conductor, outer conductor, spiral arm, and short-circuit plate into an integrated structure. High-strength materials can be used to directly manufacture the antenna spiral arm, thereby unifying the materials between the inner and outer conductors and the spiral arms. There is no need for welding process to connect them, which avoids detachment and solves the problem of manufacturing antenna spiral arms with complex structures.

[0044] Through the additive manufacturing process, the inner and outer conductors are combined into one part, which can eliminate the short-circuit plate, positioning medium and port medium in the prior art, solve the problem of large number of parts and components, and effectively improve the consistency of the assembly process.

[0045] In the integrated satellite-borne four-arm spiral tracking and control antenna provided in this embodiment, the short-circuit structure 131 is formed integrally with the outer conductor 13 and the inner conductor 16 through an additive manufacturing process. After the additive manufacturing is completed, the position between the outer conductor 13 and the inner conductor 16 can be determined without the need to position the inner conductor through a short-circuit plate.

[0046] Due to the good consistency of additive manufacturing, the integrated satellite-borne four-arm spiral measurement and control antenna provided in this application has good impedance matching and the standing wave ratio meets the requirements, thereby eliminating components such as tuning / positioning media and interface media, and thus eliminating the tuning medium and the tuning process of the traditional antenna.

[0047] The four-arm helical antenna in the prior art usually uses a top feeding structure, and generally adopts a slotted hard coaxial line structure to complete the balanced-unbalanced feeding conversion and impedance matching. However, the integrated satellite-borne four-arm helical measurement and control antenna of the present application is formed based on the additive manufacturing process, cancels the impedance matching structure of the tuning / positioning medium, and modifies the inner conductor 16 into a short-step impedance transformer structure to complete the impedance matching work.

[0048] The temperature during the manufacturing process of the additive manufacturing process is relatively high (for example, the temperature at the processing point of the electron beam additive manufacturing process can reach above 500°C), and there is stress concentration during the cooling process. To address this problem, the integrated satellite-borne four-arm spiral tracking and control antenna provided by the present application improves the side wall structure of the cylindrical barrel body of the outer conductor 13, such as Figure 2 As shown, the side wall structure of the cylindrical body is combined with electrical performance simulation, the side wall is thickened, and a chamfer structure is added for step-shaped matching. By adopting the above side wall structure, thin walls and axial size mutation structures can be avoided, and local deformation of the antenna caused by thermal stress concentration can be prevented.

[0049] In order to avoid stress concentration during the cooling process of an integrated satellite-borne four-arm spiral tracking and control antenna manufactured by an additive manufacturing process, the present application also provides an additive manufacturing method for an integrated satellite-borne four-arm spiral tracking and control antenna, comprising the following steps:

[0050] S1: Using electron beam additive manufacturing technology to manufacture the above-mentioned integrated spaceborne four-arm spiral tracking and control antenna;

[0051] S2: Incubator stress relief: placing the measurement and control antenna in an incubator for annealing. The annealing temperature is preferably 250° C. to 300° C., more preferably 270° C., and the annealing time is preferably 60 to 120 minutes, more preferably 90 minutes.

[0052] S3: Shot peening process: Place the measurement and control antenna into the shot peening device, and use ASH110 steel shot peening to peen the outer wall of the antenna. The shot peening coverage rate is 100%, and the shot peening intensity is 4 to 7A.

[0053] Through the temperature box stress relief and shot peening process, on the one hand, thermal stress can be released, and on the other hand, machining burrs can be removed, the antenna surface can be hardened, and the antenna surface roughness can be reduced. Based on the measured results, after the stress relief and shot peening process, the electrical performance of the Ti material four-arm helical antenna meets the antenna requirements, and the gold plating process can be eliminated.

[0054] The present invention completes the integrated manufacturing of the satellite-borne four-arm spiral measurement and control antenna based on the additive manufacturing technology, eliminating non-metallic dielectric materials such as positioning medium and interface medium. When the antenna is used, it can be used by directly connecting the matching SMA interface at the inner conductor interface.

[0055] The above description is only an illustrative embodiment of the present application and is not intended to limit the scope of the present application. Any equivalent changes, modifications and combinations made by any technician in the field without departing from the concept and principle of the present application shall fall within the scope of protection of the present application.

Claims

1. An integrated satellite-borne four-arm spiral tracking and control antenna, comprising: The outer conductor has a cylindrical barrel body with a cylindrical inner cavity inside, one end of the outer conductor body has a short-circuit structure, and the other end has a positioning structure, the positioning structure is an opening of the cylindrical barrel body, the inner diameter of the opening is smaller than the inner diameter of the outer conductor body, so as to form a step, and the outer side of the end of the outer conductor with the positioning structure has a base; The inner conductor is a strip-shaped cylinder, which is nested in the inner cavity of the outer conductor body. The inner conductor includes a first conductor segment with a first diameter and a second conductor segment with a second diameter, wherein the first diameter is greater than the second diameter to form a step. The first conductor segment of the inner conductor is connected to the short-circuit structure of the outer conductor body, and the second conductor segment extends into the positioning structure of the outer conductor and is located at the inner diameter center of the positioning structure. The spiral arm is located outside the outer conductor, one end of the spiral arm is connected to the base of the outer conductor, and the other end is connected to the end of the outer conductor with a short-circuit structure. The outer conductor, the inner conductor and the spiral arm are integrally formed by an additive manufacturing process.

2. The antenna according to claim 1, wherein: The outer conductor, the inner conductor and the spiral arm are integrally formed by an electron beam additive manufacturing process.

3. The antenna according to claim 1, wherein: After the antenna is integrally formed by an additive manufacturing process, it undergoes a stress relief process in a temperature chamber, with an annealing temperature of 250° C. to 300° C. and an annealing time of 60 to 120 minutes.

4. The antenna according to claim 1, wherein: After the antenna is integrally formed by an additive manufacturing process, it undergoes a shot peening process, which includes: using ASH110 steel shot peening to shot peen the outer wall of the antenna, with a shot peening coverage rate of 100% and a shot peening intensity of 4 to 7A.

5. The antenna according to claim 1, wherein: The side wall of the cylindrical body is thickened in combination with electrical performance simulation, and a chamfer structure is added for step-shaped matching to avoid thin walls and axial size mutation structures.

6. The antenna according to claim 1, wherein: The antenna does not have a positioning medium, a tuning medium, or an interface medium.

7. The antenna according to claim 1, wherein: The positioning structure is used to adapt to the SMA socket.

8. The antenna according to claim 1, wherein: The antenna is integrally formed of Ti material by an additive manufacturing process.

9. A method for manufacturing the antenna according to claim 1, comprising: S1: Using additive manufacturing technology to manufacture the integrated satellite-borne four-arm spiral tracking and control antenna described in claim 1; S2: placing the measurement and control antenna in a temperature box for annealing, the annealing temperature is 250° C. to 300° C., and the annealing time is 60 to 120 minutes; S3: Shot peening process: Place the measurement and control antenna into the shot peening device, and use ASH110 steel shot peening to peen the outer wall of the antenna. The shot peening coverage rate is 100%, and the shot peening intensity is 4 to 7A.

10. The method according to claim 9, wherein: The additive manufacturing process is an electron beam additive manufacturing process.

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