Interconnection structure for connection of feed sheet and cable of curved antenna and assembly method

Abstract

The invention relates to the technical field of curved surface antennas, and particularly discloses an interconnection structure for connection of a feed sheet and a cable of a curved surface antenna and an assembly method, and the interconnection structure comprises a mounting base body and a radio frequency connector mounted on the mounting base body; one end of the feed sheet passes through the mounting base body and is interconnected with the radio frequency connector; the installation base body comprises an installation structure body used for installing the radio frequency connector and an installation supporting body installed at the bottom of the installation structure body. According to the invention, high-reliability switching interconnection between the feed line of the curved-surface antenna and the rear radio frequency cable can be ensured, and the manufacturability and the reworkability of the curved-surface antenna are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of curved antennas, and more particularly to an interconnection structure and an assembly method for connecting a feed plate and a cable of a curved antenna. Background Art

[0002] Compared with ordinary antennas, curved antennas have obvious advantages in aerodynamic layout, stealth, detection distance and range. This has also prompted low-profile, form-fitting deployment, high-density integration and integration to become the hot spots in current antenna design and manufacturing.

[0003] In order to integrate with the platform structure, antennas are often designed in a curved form. Curved antennas radiate or receive electromagnetic waves through the radiating surface, and need to use a three-dimensional feeding network with a balun circuit to transmit electromagnetic signals up and down between the radiating surface and the rear-end RF cable. Therefore, a highly reliable three-dimensional feeding plate-rear-end RF cable transition structure is crucial for the realization of curved antennas.

[0004] In order to transmit the electromagnetic signal from the top radiating surface to the inside of the product, the current conventional method of vertical interconnection between layers is to use various forms of vertical feeding plates to connect to the radiating surface to achieve vertical interconnection between layers, such as using the technical solutions recorded in Chinese patents with application numbers 202211277023.8, 202311063549.0, and 202311063543.3, thereby turning the electromagnetic signal from the radiating surface 90° to transmit to the inside of the curved surface; this type of interconnection method is to produce the required balun pattern through a circuit chip to solve the three-dimensional interconnection of the electromagnetic signal from the radiating surface in the vertical direction.

[0005] However, this type of interconnection method requires assembly from the radiating surface backwards layer by layer. The vertical feed plate is usually made in the form of a microstrip line, and the RF coaxial connector is required to transfer with the rear-end coaxial RF cable. The current assembly sequence of the curved antenna starts from the radiating surface, and the feed plate, support body, welding connector conductor and circuit plate are installed in sequence, the antenna mounting structure is assembled, and the antenna support structure and connector housing are fixed. In order to meet the sequential installation starting from the radiating surface, the RF coaxial connector usually needs to weld the connector conductor and the feed conductor first, and then assemble the connector housing and the structure by welding or fastening. This will violate the aerospace restricted process and cause low reliability problems for the product. At the same time, because the connection point between the RF coaxial connector conductor and the antenna feed plate is inside the overall structure of the antenna, if the connection point or the RF coaxial connector fails, there will be no possibility of repair, and the antenna will be scrapped as a whole. Significant losses. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an interconnection structure and an assembly method for connecting a feed plate of a curved antenna to a cable; the structure can ensure a highly reliable transfer interconnection between the feed line of the curved antenna and the rear RF cable, and improve the manufacturability and repairability of the curved antenna;

[0007] The solution adopted by the present invention to solve the technical problem is:

[0008] A feed plate of a curved antenna is connected to an interconnection structure with a cable, comprising a mounting base and a radio frequency connector mounted on the mounting base; one end of the feed plate passes through the mounting base and is interconnected with the radio frequency connector; the mounting base comprises a mounting structure for mounting the radio frequency connector, and a mounting support mounted at the bottom of the mounting structure.

[0009] When connecting the feed plate to the cable, first assemble the RF connector, the mounting structure, and the mounting support, and then pass the end of the feed plate away from the antenna radiation surface through the mounting support, the mounting structure, and the RF connector in sequence; using this method, the assembly between the connector conductor and the feed plate is completed first, and then the assembly between the connector housing and the mounting structure is completed, which is changed to completing the overall assembly first and then the electrical assembly, so that the electrical interconnection solder joints are not subjected to assembly and structural stress, thereby improving the overall structural reliability and avoiding the aerospace banned process.

[0010] In some possible implementations, the RF connector includes a body mounted on a mounting structure and connected to a cable, and an inner conductor mounted on the body and interconnected with a feed plate; the inner conductor and the body are axially perpendicular to each other to form an L-shaped structure.

[0011] The body of the RF connector is used for coaxial connection with the cable; the inner conductor is interconnected with the body to achieve interconnection between the inner conductor and the cable. The inner conductor is placed on the outside of the body, so that the welding point of the inner conductor of the RF connector and the feeding circuit will be placed on the outer side of the RF connector and will not be blocked by the connector shell itself, thereby enabling visual operation when welding the two, greatly improving welding efficiency and accuracy; further, the axial direction of the inner conductor is perpendicular to the insertion direction of the feeding plate; the grounding of the feeding plate can be achieved by directly connecting to the mounting structure.

[0012] In some possible implementations, the RF connector further includes a grounded outer conductor mounted on the body and forming a channel with the inner conductor; the grounded outer conductor is connected to the feeding plate.

[0013] In some possible implementations, a feeding circuit is provided on one side of the feeding plate close to the inner conductor and the grounded outer conductor, respectively; a gap L1 is formed between the feeding circuit close to the inner conductor and the inner conductor; a gap L2 is formed between the feeding circuit close to the grounded outer conductor and the grounded outer conductor. By providing the gap L1 and the gap L2, the feeding plate can effectively pass through the position between the inner conductor and the grounded outer conductor when the feeding plate is assembled.

[0014] In some possible implementations, in order to facilitate welding and interconnection between the feed plate and the inner conductor and the grounded outer conductor, the width of the gap L1 and the gap L2 are both 0.1 mm to 0.2 mm.

[0015] In some possible implementations, in order to effectively enable the feed plate to pass through the mounting base and connect with the RF connector to achieve interconnection; a mounting groove for installing the RF connector is provided on the mounting structure, and a through cavity is provided at the bottom of the mounting groove, which is connected to the mounting groove and for the feed plate to pass through.

[0016] In some possible implementations, the through cavity includes a through groove disposed at the bottom of the mounting groove and communicating with the mounting groove, and a guide groove connected to the other side of the through groove and disposed at the bottom of the mounting structure;

[0017] The cross section of the guide groove is trumpet-shaped, and the small end thereof is communicated with the through groove.

[0018] In some possible implementations, the distance between the side of the feeding plate close to the inner conductor and the inner side of the through slot is L3, and the distance between the side of the feeding plate away from the inner conductor and the inner side of the through slot is L4, where L3 is a positive tolerance and L4 is a negative tolerance.

[0019] An assembly method of the interconnection structure for connecting the feed plate and the cable of the curved antenna according to the above-mentioned method specifically comprises the following steps:

[0020] Step S1: manufacturing a mounting structure, a mounting support, a feed plate, and a radio frequency connector;

[0021] Step S2: interconnecting the RF connector with the mounting structure;

[0022] Step S3: bonding and assembling the mounting structure, mounting support, and feeding sheet assembled with the RF connector, and heating and curing them;

[0023] Step S4: interconnecting the inner conductor and the grounded outer conductor of the RF connector with the feeding circuit respectively by welding, wherein the grounded outer conductor is welded first and then the inner conductor; during welding, the melting point of the solder is higher than the subsequent process temperature;

[0024] Step S5: Apply adhesive to the position where the feed plate passes through the mounting structure.

[0025] In some possible implementations, in step S4, when the solder is tin-lead solder, the subsequent process temperature is lower than 135°C; when the solder is tin-silver-copper solder, the subsequent process temperature is lower than 205°C; when the solder is gold-tin solder, the subsequent process temperature is lower than 245°C.

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

[0027] The present invention interconnects the L-shaped radio frequency connector and the feed sheet through one end of the mounting structure, thereby enabling visual operation of the two.

[0028] Compared with the prior art, the present invention completes the overall assembly first and the electrical assembly last, so that the electrical interconnection solder joints are not subjected to assembly and structural stress, thereby improving the reliability of the overall structure and avoiding the aerospace-prohibited process; at the same time, the RF connector is placed in the installation structure, so that the entire connection structure is repairable;

[0029] The present invention is suitable for applications of complex antenna feed plates and rear electrical interconnections. It has strong overall manufacturability, an open structure and is easy to process, and can meet the assembly requirements of high consistency and high reliability between antenna feed circuits and cables in a closed structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0031] Figure 2 It is a schematic diagram of the connection relationship between the radio frequency connector, the feeding circuit, the grounded outer conductor, the mounting structure, and the mounting support in the present invention;

[0032] Figure 3 is a cross-sectional view of the present invention;

[0033] Figure 4 for Figure 1 Schematic diagram of the structure of the inner conductor, feed circuit, grounded outer conductor, and through-hole cavity;

[0034] Figure 5 for Figure 1 Schematic diagram of the structure of the inner conductor, feed circuit and grounded outer conductor;

[0035] Figure 6 A schematic diagram of the structure of the present invention when a radio frequency connector is connected to a mounting structure by bolts;

[0036] Figure 7 A schematic diagram of the internal structure of the mounting structure when the RF connector is connected to the mounting structure by welding;

[0037] Wherein: 1. mounting structure; 11. through cavity; 111. through groove; 12. welding positioning groove; 112. guide groove; 2. RF connector; 20. body; 21. inner conductor; 22. grounded outer conductor; 3. antenna support body; 4. feed plate; 41. feed circuit. DETAILED DESCRIPTION

[0038] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. The "first", "second" and similar words mentioned in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "one" or "one" and other similar words do not indicate a quantity restriction, but indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "multiple" refers to two or more. For example, multiple positioning columns refer to two or more positioning columns. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] The present invention is described in detail below.

[0040] like Figure 1-Figure 7 As shown:

[0041] A feeding plate of a curved antenna is connected to an interconnection structure with a cable, comprising a mounting base and a radio frequency connector 2 mounted on the mounting base; one end of a feeding plate 4 passes through the mounting base and is interconnected with the radio frequency connector 2; the mounting base comprises a mounting structure 1 for mounting the radio frequency connector 2, and a mounting support 3 mounted at the bottom of the mounting structure 1; the impedance matching of the radio frequency connector 2 is set to 50 ohms.

[0042] When connecting the feed plate 4 to the cable, the RF connector 2, the mounting structure 1, and the mounting support 3 are first assembled, and then the end of the feed plate 4 away from the antenna radiation surface is passed through the mounting support 3, the mounting structure 1, and the RF connector 2 in sequence; compared with the prior art in which the RF connector conductor and the feed plate 4 are assembled first and then the connector housing and the mounting structure 1 are assembled, this method is changed to first completing the overall assembly and then completing the electrical assembly, so that the electrical interconnection solder joints are not subjected to assembly and structural stresses, thereby improving the overall structural reliability and avoiding aerospace-prohibited processes.

[0043] In some possible implementations, the RF connector 2 includes a main body mounted on the mounting structure 1 and connected to the cable, and an inner conductor 21 mounted on the main body and interconnected with the feeding plate 4; the inner conductor 21 and the main body are perpendicular to each other and form an L-shaped structure.

[0044] The body of the RF connector 2 is used for coaxial connection with the cable; the inner conductor 21 is interconnected with the body to realize the interconnection between the inner conductor 21 and the cable. The inner conductor 21 is placed on the outside of the body so that the welding point between the inner conductor 21 of the RF connector 2 and the feeding circuit 41 is placed on the outer side of the RF connector 2 and will not be blocked by the RF connector 2 itself, so that the welding of the two can be visually operated, which greatly improves the welding efficiency and accuracy;

[0045] Furthermore, the axial direction of the inner conductor 21 is perpendicular to the insertion direction of the feeding plate 4;

[0046] The grounding of the feed sheet 4 can be interconnected by directly welding with the mounting structure 1 or bonding with conductive adhesive;

[0047] Of course, in some possible implementations, the RF connector 2 further includes a grounded outer conductor 22 mounted on the body and forming a channel with the inner conductor 21; the grounded outer conductor 22 is connected to the feed sheet 4, which, on the one hand, realizes grounding interconnection, and on the other hand, the provision of the grounded outer conductor 22 can also effectively ensure support for the feed sheet 4;

[0048] Furthermore, since the size of the grounded outer conductor 22 of the RF connector 2 has little relationship with electrical properties such as impedance matching, the structural size can be increased to give priority to satisfying the supporting strength of the feed plate 4 after welding.

[0049] In some possible implementations, a feeding circuit 41 is provided on one side of the feeding plate 4 close to the inner conductor 21 and the grounded outer conductor 22, respectively; a gap L1 is formed between the feeding circuit 41 close to the inner conductor 21 and the inner conductor 21; a gap L2 is formed between the feeding circuit 41 close to the grounded outer conductor 22 and the grounded outer conductor 22. By providing the gap L1 and the gap L2, the feeding plate 4 can effectively pass through the position between the inner conductor 21 and the grounded outer conductor 22 when the feeding plate 4 is assembled.

[0050] The feed plate 4 is used to transmit electromagnetic signals on the antenna radiation surface or actively feed power to the antenna radiation surface from the inside. The feed plate 4 is interconnected with the inner conductor 21 of the RF connector 2, the grounded outer conductor 22 or the mounting structure 1 respectively; the feed plate 4 is installed on the antenna radiation surface or is integrally formed with the antenna radiation surface, and is made of non-metallic materials. The non-metallic materials described here can be quartz cyanate, polyimide, nylon and other materials. The feed circuit pattern on the surface of the feed plate 4 is not limited to being made by magnetron sputtering, plating, laser processing or mechanical processing. A suitable coating should be provided on the surface of the metal pattern to ensure the solderability and corrosion resistance of the circuit.

[0051] In some possible implementations, in order to facilitate welding and interconnection between the feed plate 4 and the inner conductor 21 and the ground outer conductor 22, the widths of the gap L1 and the gap L2 are both 0.1 mm to 0.2 mm.

[0052] In some possible implementations, in order to effectively enable the feed sheet 4 to pass through the mounting base to connect with the RF connector 2 and achieve interconnection; a mounting groove for mounting the RF connector 2 is provided on the mounting structure 1, and a through cavity 11 is provided at the bottom of the mounting groove, which is connected to the mounting groove and through which the feed sheet 4 passes;

[0053] The RF connector 2 can be connected and fixed by brazing or screw fastening, so that the RF connector 2 can be fixed in the installation groove;

[0054] When brazing is used, the melting point of the solder is higher than the subsequent process temperature, and the subsequent process may be bonding; at the same time, a plating layer is arranged at the welding position to ensure the reliability of the brazing connection; as shown in Table 1:

[0055] Plating solder Solder Melting Point Subsequent process temperature Nickel plating 5 microns Tin-Lead 173℃ ＜135℃ Nickel plating 5 microns / gold plating 1.5 microns Tin Silver Copper 245℃ ＜205℃ Nickel plating 5 microns / gold plating 1.5 microns Jin Xi 290℃ ＜245℃

[0056] Table 1

[0057] Furthermore, when brazing is adopted, a welding positioning groove 12 will be set in the installation groove. The setting of the welding positioning groove 12 will effectively ensure the installation position of the RF connector 2. The welding positioning groove 12 is sunken by 0.5 to 1 mm and is 0.05 mm away from the outer side of the RF connector 2 on all sides, and is designed as a negative tolerance.

[0058] In some possible implementations, the through cavity 11 includes a through groove 111 disposed at the bottom of the mounting groove and communicating with the mounting groove, and a guide groove 112 connected to the other side of the through groove 111 and disposed at the bottom of the mounting structure 1;

[0059] The cross section of the guide groove 112 is trumpet-shaped, and its small end is connected to the through groove 111 ; by providing the trumpet-shaped guide groove 112 , blind insertion of the feed sheet 4 is effectively facilitated.

[0060] In some possible embodiments, the distance between the side of the feeding plate 4 close to the inner conductor 21 and the inner side of the through slot 111 is L3, and the distance between the side of the feeding plate 4 away from the inner conductor 21 and the inner side of the through slot 111 is L4, L3 is a positive tolerance, and L4 is a negative tolerance; L4 is a negative tolerance, so that the feeding circuit 41 close to the side of the grounded outer conductor 22 can always maintain contact and interconnection with the mounting structure to avoid short circuit.

[0061] An assembly method of the interconnection structure of the feed plate 4 of the curved antenna and the cable according to the above-mentioned method specifically comprises the following steps:

[0062] Step S1: manufacturing a mounting structure 1, a mounting support 3, a feed plate 4, and a radio frequency connector 2;

[0063] The installation structure 1 is used to provide an installation reference and bear the overall load. It has a high strength requirement and its material is not limited to aluminum alloy, steel, high-strength non-metal, etc.

[0064] According to the electrical performance requirements, the mounting structure 1 can be a single-layer structure or a multi-layer structure, and the material can include wave-absorbing materials and wave-transmitting materials, which can be realized by 3D printing, machining, prepreg curing, etc., and the surface is formed with the required coating by electroplating, chemical plating, etc.;

[0065] The mounting support 3 will be made of materials such as foam and ferrite, taking into account the electrical performance characteristics of the adaptive antenna;

[0066] In one embodiment, when the mounting structure 1 is manufactured, a 5-micron thick nickel layer is plated on the surface of the mounting structure 1, and a 1-micron gold layer is partially plated on the portion welded to the RF connector 2; the mounting support 3 is made of ferrite; the feed plate 4 is made of polyimide as a dielectric body, and a feed circuit 41 is manufactured on the surface of the dielectric body by combining magnetron sputtering and electroplating processes.

[0067] Step S2: The RF connector 2 is interconnected with the mounting structure 1 by means of brazing welding or screw fastening;

[0068] In one embodiment, when brazing is used, a preformed gold-tin alloy solder sheet is placed at the welding position of the RF connector 2, and then the RF connector 2 is installed in the welding positioning groove 12 on the mounting structure 1 and clamped using a clamp, and then the whole is passed through a reflow furnace (the highest temperature zone is 300° C.) to complete the brazing, and after welding, the flux is washed off to test whether the housing and the mounting structure 1 are conductive, and whether the inner conductor 21 and the mounting structure 1 are insulated;

[0069] Step S3: bonding and assembling the mounting structure 1, the mounting support 3, and the feeding sheet 4 assembled with the RF connector 2, and heating and curing them;

[0070] In one embodiment, each layer of the structure is bonded with a preformed bonding material, and then the whole structure after bonding is pressed by a clamp, and then the pressed whole is heated and cured in an oven;

[0071] Furthermore, the curing temperature of the adhesive material needs to be lower than the temperature that the solder can withstand during welding to prevent the solder joints from remelting or aging during the curing process; specifically, the adhesive material is a preformed epoxy film;

[0072] Step S4: interconnect the inner conductor 21 and the grounded outer conductor 22 of the RF connector 2 with the feed circuit 41 respectively by welding; wherein the grounded outer conductor 22 is welded first, and then the inner conductor 21 is welded; during welding, the melting point of the solder is higher than the subsequent process temperature;

[0073] In step S4, when the solder is tin-lead solder, the subsequent process temperature is lower than 135° C.; when the solder is tin-silver-copper solder, the subsequent process temperature is lower than 205° C.; when the solder is gold-tin solder, the subsequent process temperature is lower than 245° C.;

[0074] Step S5: Apply adhesive at the position where the feed plate 4 passes through the mounting structure 1; that is, apply epoxy or cyanate adhesive at positions L3 and L4 to improve the overall strength and sealing of the structure.

[0075] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. An interconnection structure for connecting a feed plate of a curved antenna to a cable, characterized in that: It includes a mounting base and a radio frequency connector mounted on the mounting base; one end of the feed plate passes through the mounting base and is interconnected with the radio frequency connector; the mounting base includes a mounting structure for mounting the radio frequency connector and a mounting support mounted at the bottom of the mounting structure.

2. The interconnection structure for connecting the feed plate of the curved antenna to the cable according to claim 1, characterized in that: The radio frequency connector comprises a body mounted on a mounting structure and connected to a cable, and an inner conductor mounted on the body and interconnected with a feed plate; the inner conductor and the axis of the body are perpendicular to each other to form an L-shaped structure.

3. The interconnection structure for connecting the feed plate and the cable of the curved antenna according to claim 2, characterized in that: The radio frequency connector also includes a grounded outer conductor which is mounted on the body and forms a channel with the inner conductor; the grounded outer conductor is connected to the feeding plate.

4. The interconnection structure for connecting the feed plate of the curved antenna to the cable according to claim 3, characterized in that: A feeding circuit is provided on one side of the feeding plate close to the inner conductor and the grounded outer conductor respectively; a gap L1 is formed between the feeding circuit close to the inner conductor and the inner conductor; A gap L2 is formed between the feeding circuit on one side close to the grounded outer conductor and the grounded outer conductor.

5. The interconnection structure for connecting the feed plate of the curved antenna to the cable according to claim 4, characterized in that: The widths of the gaps L1 and L2 are both 0.1 mm to 0.2 mm.

6. The interconnection structure for connecting the feed plate of the curved antenna to the cable according to claim 2, characterized in that: The mounting structure is provided with a mounting groove for mounting a radio frequency connector, and a through cavity which is connected with the mounting groove and for the feeding plate to pass through is provided at the bottom of the mounting groove.

7. The interconnection structure for connecting the feed plate of the curved antenna to the cable according to claim 6, characterized in that: The through cavity includes a through groove arranged at the bottom of the mounting groove and communicating with the mounting groove, and a guide groove connected to the other side of the through groove and arranged at the bottom of the mounting structure; The cross section of the guide groove is trumpet-shaped, and the small end thereof is communicated with the through groove.

8. The interconnection structure for connecting the feed plate of the curved antenna to the cable according to claim 7, characterized in that: The distance between the side of the feeding plate close to the inner conductor and the inner side of the through slot is L3, and the distance between the side of the feeding plate away from the inner conductor and the inner side of the through slot is L4, L3 is a positive tolerance, and L4 is a negative tolerance.

9. A method for assembling an interconnection structure for connecting a feed plate and a cable of a curved antenna according to any one of claims 1 to 8, characterized in that: The specific steps include: Step S1: manufacturing a mounting structure, a mounting support, a feed plate, and a radio frequency connector; Step S2: interconnecting the RF connector with the mounting structure; Step S3: bonding and assembling the mounting structure, mounting support, and feeding sheet assembled with the RF connector, and heating and curing them; Step S4: interconnecting the inner conductor and the grounded outer conductor of the RF connector with the feeding circuit respectively by welding, wherein the grounded outer conductor is welded first and then the inner conductor; during welding, the melting point of the solder is higher than the subsequent process temperature; Step S5: Apply adhesive to the position where the feed plate passes through the mounting structure.

10. The method for assembling the interconnection structure of the feed plate and the cable of the curved antenna according to claim 9, characterized in that: In step S4, when the solder is tin-lead solder, the subsequent process temperature is lower than 135°C; when the solder is tin-silver-copper solder, the subsequent process temperature is lower than 205°C; when the solder is gold-tin solder, the subsequent process temperature is lower than 245°C.

Images