A conformal antenna and method of manufacture

Abstract

The application discloses a kind of conformal antennas and preparation method, conformal antenna includes antenna unit, skin unit and positioning unit;Antenna unit includes antenna cabin body and radiating unit;Skin unit has respectively curved inner side and outer side;Positioning unit includes multiple positioning members, positioning member includes for with the connection of antenna cabin body and for with the positioning of skin unit connection, antenna cabin body is set in the inner side of skin unit by the positioning unit, and make the opening one end of antenna cabin body towards skin unit setting.This application is aimed at the structural characteristics of antenna unit and skin unit, using the mode of positioning member connection, the stable connection and installation of antenna unit on skin unit can be realized, and through the setting and adjustment of positioning member, the best matching effect between antenna unit and skin unit is achieved, to compensate the influence of skin unit, antenna unit manufacturing process error on conformal antenna performance.

Description

Technical Field

[0001] This invention belongs to the field of radio technology, specifically relating to a conformal antenna and its fabrication method. Background Technology

[0002] Aircraft antennas, as devices for radiating and receiving radio waves, are crucial structures for monitoring external information. Due to the special nature of their operating environment, antennas typically require a skin to protect their radiating surface, enabling them to function normally in varying external conditions. Although commonly used antennas and skins are two independent units, their performance is complementary.

[0003] During the design phase, the antenna and skin are optimized for electrical performance matching. However, during the manufacturing process, the antenna and skin are manufactured independently. Assembly errors between the two can easily lead to a decrease in the matching between the antenna and skin, resulting in electrical performance problems such as beam shift and increased sidelobes. Summary of the Invention

[0004] The purpose of this invention is to provide a conformal antenna and its fabrication method to solve the problem of low matching between the antenna and the skin in conformal antennas.

[0005] This invention is achieved through the following technical solution:

[0006] A conformal antenna includes: an antenna element, a skin element, and a positioning element;

[0007] The antenna unit includes an antenna housing and a radiating unit. The antenna housing is a shell structure with an opening at one end. A feed port is provided at the center of the bottom of the antenna housing. The radiating unit is disposed in the antenna housing. The radiating unit is a conical shell structure with an opening at one end. One end of the radiating unit is connected to one end of the feed port that extends into the antenna housing. The opening end of the radiating unit is oriented away from the antenna housing. The antenna housing is electrically connected to the negative terminal of the feed port, and the radiating unit is electrically connected to the positive terminal of the feed port.

[0008] The skin unit has an inner surface and an outer surface that are respectively curved.

[0009] The positioning unit includes multiple positioning components, each including a connecting part for connecting to the antenna housing and a positioning part for connecting to the skin unit. The antenna housing is disposed inside the skin unit via the positioning unit, with one opening of the antenna housing facing the skin unit.

[0010] In some embodiments, the antenna housing includes a hexagonal pyramidal working chamber and a connecting frame connected to the opening end of the working chamber. The connecting frame includes two sets of frame plate assemblies symmetrically arranged along a mounting reference line on the antenna housing. Each frame plate assembly includes a central frame plate and side frame plates located on both sides of the central frame plate. The central frame plate is parallel to the mounting reference line and its upper surface is set as a horizontal plane. The upper surface of the side frame plate is an inclined surface that slopes downward toward the side away from the central frame plate.

[0011] In some embodiments, the mounting reference line of the antenna housing is set along the lateral direction of the skin unit, and the positioning unit includes four positioning members, wherein two positioning members are respectively disposed opposite to each other on two central frame plates, and the other positioning members are respectively disposed on two side frame plates that are disposed opposite to each other.

[0012] In some embodiments, the positioning element is an L-shaped folded plate structure.

[0013] In some embodiments, the positioning portion is bonded to the skin unit.

[0014] In some embodiments, the positioning element is made of carbon fiber composite material.

[0015] On the other hand, the present invention also provides a method for fabricating a conformal antenna, comprising the following steps:

[0016] Fabrication of skin unit and antenna unit;

[0017] A matching analysis is performed on the installation positions of the current antenna unit and the skin unit. The installation positions of the positioning components are determined on the skin unit, and the installation positions of the positioning components on the antenna housing are determined based on the curved surface characteristics of the inner side of the skin. The positioning components are then installed on the antenna housing, and the antenna unit is connected to the skin unit through the positioning components.

[0018] In some embodiments, the preparation of the skin unit includes the following steps:

[0019] S01. Lay the outer skin on the tooling, and after the layering is completed, cure and shape it in the autoclave.

[0020] S02. Lay the core film on the outer skin, lay the honeycomb core on the core film, inject resin glue into the chamfered area of ​​the honeycomb core edge, then lay the core film on the upper end face of the honeycomb core, lay the core film on the flange area of ​​the outer skin, and then heat seal in the oven.

[0021] S03. Lay a thickened layer of prepreg in the flange area of ​​the outer skin, with the number of layers being half of the total number of layers. Lay an inner skin prepreg on the inside of the outer skin, with the number of layers being half of the total number of layers. Then, lay the remaining thickened layer of prepreg in the flange area again, and lay the remaining inner skin prepreg on the inside of the outer skin. Then, cure and shape it in an autoclave.

[0022] In some embodiments, the positioning portion of the positioning member is glued to the skin unit.

[0023] In some embodiments, a low-temperature adhesive is used to bond the positioning part of the positioning component to the skin unit. After bonding, the component is placed at room temperature for 4-6 hours. Then, the entire connected conformal antenna is placed in an oven and cured at 50℃-60℃ for 1-2 hours.

[0024] The advantages of this invention compared to the prior art are as follows:

[0025] The conformal antenna of this invention has a simple antenna element structure. The antenna housing and radiating element adopt a disk-conical structure, so that the antenna element as a whole forms an open waveguide, which can generate a uniform phase wavefront at a larger aperture than the waveguide, thereby obtaining better directional performance.

[0026] The skin unit of this invention adopts a conformal curved surface design, which enables it to be well adapted to the installation on the aircraft and achieves a good conformal effect.

[0027] In this invention, based on the structural characteristics of the antenna unit and the skin unit, a positioning component is used for connection, which enables the stable connection and installation of the antenna unit on the skin unit. At the same time, by setting and adjusting the positioning component, the antenna unit and the skin unit can achieve the best matching effect, so as to compensate for the impact of manufacturing process errors of the skin unit and the antenna unit on the performance of the conformal antenna. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the conformal antenna structure of the present invention.

[0030] Figure 2 This is a schematic diagram of the skin unit structure of the present invention.

[0031] Figure 3 This is a schematic diagram of the outer skin structure of the present invention.

[0032] Figure 4 This is a schematic diagram of the honeycomb core structure of the present invention.

[0033] Figure 5 This is a schematic diagram of the antenna unit structure of the present invention.

[0034] Figure 6 This is a bottom view of the antenna element of the present invention.

[0035] Figure 7 This is a schematic diagram of the installation structure of the antenna unit on the skin unit of the present invention.

[0036] in:

[0037] 10-Skin unit, 11-Outer skin, 12-Honeycomb core, 13-Inner skin, 14-Flange area;

[0038] 20-Antenna unit, 21-Antenna housing, 211-Working compartment, 212-Central frame plate, 213-Side frame plate, 214-Installation reference line, 22-Radiating unit, 23-Nylon pad, 24-Feed port;

[0039] 30 - Positioning component. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0041] To meet the performance requirements of aircraft, conformal antennas typically have complex shapes. Furthermore, ensuring antenna performance during the design process presents significant challenges to the design and manufacturing of conformal antennas. To address these issues, this invention provides a conformal antenna applicable to the L-band and a method for its fabrication, resolving problems encountered in performance design, performance matching, and manufacturing.

[0042] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 In some embodiments, the conformal antenna includes an antenna element 20, a skin element 10, and a positioning element.

[0043] like Figure 5 and Figure 6As shown, the antenna element 20 includes an antenna housing 21 and a radiating element 22. The antenna housing 21 is a shell structure with an opening at one end. A feed port 24 is located at the center of the bottom of the antenna housing 21. The radiating element 22 is disposed inside the antenna housing 21 and is a conical shell structure with an opening at one end. One end of the radiating element 22 is connected to one end of the feed port 24 that extends into the antenna housing 21. The open end of the radiating element 22 faces away from the antenna housing 21. The antenna housing 21 is electrically connected to the negative terminal of the feed port 24, and the radiating element 22 is electrically connected to the positive terminal of the feed port 24. The feed port 24 in the antenna element 20 serves as the electrical signal input terminal and is the waveguide port of the entire antenna element 20, providing signal and energy input to the antenna element 20.

[0044] The antenna unit 20 has a disc-conical structure for the antenna housing 21 and the radiating element 22, which makes the antenna unit 20 as a whole form an open waveguide. This allows for the generation of a uniform phase wavefront at a larger aperture than the waveguide, thereby achieving better directional performance. Furthermore, this antenna unit 20 has a simple structure, which facilitates its manufacturing and assembly.

[0045] In some embodiments, the power supply port 24 is typically fixedly connected to the antenna housing 21, and the radiating unit 22 is connected to the power supply port 24 by soldering. At the same time, a nylon gasket 23 is provided between the radiating unit 22 and the antenna housing 21 to achieve the effect of insulation and circuit breaking between the radiating unit 22 and the antenna housing 21.

[0046] In some embodiments, a flange ring is provided on the outer edge of the opening end of the radiating unit 22, and the flange ring is connected to the antenna housing 21 by nylon bolts, so that the radiating unit 22 is more stably connected to the antenna housing 21.

[0047] The skin unit 10 has inner and outer surfaces that are both curved. (Refer to...) Figure 2 , Figure 3 and Figure 4 The skin unit 10 includes an outer skin 11, a honeycomb core 12 and an inner skin 13 arranged sequentially. The outer skin 11 is designed as a curved structure. The honeycomb core 12 is wrapped between the inner skin 13 and the outer skin 11. A flange area 14 is formed between the honeycomb core 12 and the outer skin 11 at the outer edge of the outer skin 11.

[0048] Typically, the outer skin 11 and inner skin 13 can be made of carbon fiber composite material, and the honeycomb core 12 can be made of aramid paper absorbing material. The skin unit 10 is cured and molded in a thermostatic tank. The honeycomb core 12 enables the skin unit 10 to have reliable structural strength, so that it can protect the antenna unit 20 without affecting the overall radiation performance of the antenna.

[0049] A thickened layer of carbon fiber composite material can be provided in the flange area 14 of the skin unit 10 to improve the overall structural strength of the skin unit 10.

[0050] Since the antenna element and the skin element are two independent units in this conformal antenna, certain manufacturing and processing errors are inevitable during the processing and assembly process. Furthermore, due to the structure of the antenna element and the curved surface structure of the skin element, it is difficult to stably connect the antenna element to the skin element and ensure better matching performance between the two, which brings great difficulties to the assembly of this conformal antenna.

[0051] To address this issue, the conformal antenna uses a positioning unit to connect the skin unit 10 and the antenna unit 20. Specifically, the positioning unit includes multiple positioning elements 30, each of which includes a connecting part for connecting to the antenna housing 21 and a positioning part for connecting to the skin unit 10. The antenna housing 21 is connected to the inside of the skin unit 10 through the positioning unit, and at this time, one end of the opening of the antenna housing 21 faces the skin unit 10. At this time, the positioning component 30 can be used to easily and stably connect the antenna unit 20 to the skin unit 10, so that the skin unit 10 can provide effective protection for the antenna unit 20. At the same time, through the transition connection and setting of the positioning component 30, the setting position of the positioning component 30 on the antenna unit 20 and the skin unit 10 can be adjusted to ensure that the antenna unit 20 and the skin unit 10 meet the requirements of the installation distance and angle, so that the antenna unit 20 and the skin unit 10 have the best matching performance. At the same time, it can also effectively compensate for the process errors of the antenna unit 20 and the skin unit 10 during the manufacturing process, so that the conformal antenna can achieve good overall performance.

[0052] In some embodiments, refer to Figure 5 , Figure 6 and Figure 7 The antenna housing 21 includes a hexagonal pyramidal working chamber 211 and a connecting frame connected to the opening end of the working chamber 211. The connecting frame includes two sets of frame plate assemblies symmetrically arranged along the mounting reference line 214 on the antenna housing 21. The frame plate assembly includes a central frame plate 212 and side frame plates 213 located on both sides of the central frame plate 212. The central frame plate 212 is parallel to the mounting reference line 214 and its upper end surface is set as a horizontal plane. The upper end surface of the side frame plate 213 is an inclined surface that gradually slopes downward toward the side away from the central frame plate 212.

[0053] By designing the antenna housing structure, the antenna unit can have a better waveguide structure. At the same time, the antenna housing can be structurally matched with the specific shape of the skin unit to reduce interference between the antenna housing and the skin unit at various positions during assembly. This facilitates the fixing, positioning, and installation of the antenna unit on the skin unit and can well meet the requirement of arbitrarily adjusting the distance and angle between the antenna unit and the skin unit when they are installed on the skin unit.

[0054] In some embodiments, such as Figure 7 As shown, the mounting reference line 214 of the antenna housing 21 is set along the transverse direction of the skin unit 10, where the transverse direction refers to the direction of the short side of the skin unit. The positioning unit includes four positioning elements 30, two of which are respectively positioned opposite each other on the two central frame plates 212, and the other positioning elements are respectively positioned on the two side frame plates 213 which are opposite each other. (Refer to...) Figure 7 Two positioning components are arranged as a group and are respectively positioned at two opposite corners of the hexagonal pyramid structure of the antenna housing 21, thereby stably connecting the antenna housing 21 to the skin unit 10 and making the stress distribution between the antenna unit 20 and the skin unit 10 more uniform, avoiding the influence of internal stress on the skin unit 10 and the antenna unit 20.

[0055] In some embodiments, such as Figure 7 The positioning component 30 is an L-shaped folded plate structure composed of a connecting part and a positioning part. It is fixedly connected to the connecting frame of the antenna housing 21 through the connecting part, and then the positioning part is connected to the skin unit 10 to realize the connection between the antenna unit 20 and the skin unit 10. Here, the positioning component 30 is made of carbon fiber composite material and is formed by autoclaving. After curing, it is machined and polished according to the setting requirements.

[0056] In some embodiments, the positioning part and the skin unit are connected by adhesive bonding. Combined with the material used for the positioning part 30, the connection of the positioning part 30 on the skin unit 10 will not cause any damage to the structure of the skin unit 10, thereby ensuring the overall performance of the conformal antenna and making it easier to ensure the assembly accuracy of the antenna unit 20 and the skin unit 10 during assembly.

[0057] On the other hand, the present invention also relates to a method for manufacturing a conformal antenna, which addresses the structural characteristics of the conformal antenna and solves problems such as assembly errors and performance matching in the assembly process.

[0058] In some embodiments, the conformal antenna fabrication method includes the following steps:

[0059] Fabricate skin unit 10 and antenna unit 20;

[0060] A matching analysis is performed on the installation positions of the current antenna element 20 and the skin element 10. The installation position of the positioning component 30 is determined on the skin element 10, and the installation position of the positioning component 30 on the antenna housing 21 is determined based on the curved surface characteristics of the inner side of the skin. The positioning component 30 is then installed on the antenna housing 21, and the antenna element 20 is connected to the skin element 10 through the positioning component 30. This ensures that the relative position, distance, and angle between the antenna element and the skin element are well maintained, thereby achieving optimal matching performance. The matching analysis of the installation positions between the antenna element and the skin element, achieved through numerical simulation analysis of the currently fabricated skin element and antenna element, is easily obtained using existing analysis software.

[0061] Specifically, in some embodiments, the fabrication steps of the skin unit 10 are as follows:

[0062] S01. After cleaning, lay the outer skin 11 on the tooling according to the tooling markings. After laying, send it into the autoclave to cure and form the outer skin 11 with the designed surface. After curing, check the surface quality and observe whether it is flat and whether there are any marks. Do not demold after leaving the autoclave.

[0063] S02. Lay the core film on the corresponding position on the outer skin 11, lay the honeycomb core 12 on the core film, inject resin glue into the chamfered area of ​​the honeycomb core 12 to reinforce the edge of the honeycomb core 12, then lay another layer of core film on the upper surface of the honeycomb core 12, lay the plate film on the flange area 14 of the outer skin 11, and then send the whole thing into the oven for heat sealing and pressing.

[0064] S03. A thickened layer of prepreg is laid in the flange area 14 of the outer skin 11, with the number of layers being half of the total number of thickened prepreg layers. An inner skin prepreg is laid on the inner side of the outer skin 11, with the number of layers being half of the total number of inner skin prepreg layers. Then, the remaining thickened layer of prepreg is laid in the flange area 14 again. Finally, the remaining inner skin prepreg is laid on the inner side. The mixture is then cured in an autoclave. After curing, the mixture is demolded, ground, and cut. In this step, considering the presence of the honeycomb core 12, the curing pressure can be reduced to avoid damage to the honeycomb core 12 during curing.

[0065] The above molding process can effectively ensure the molding quality of the skin unit 10 and give the skin unit 10 better structural strength.

[0066] like Figure 2 As shown, the steps for fabricating antenna element 20 are as follows:

[0067] Connect the feed port 24 to the antenna housing 21 with metal screws, then pass the nylon gasket 23 through the feed port 24, and then install the radiating element 22 at the feed port 24. The feed port 24 and the radiating element 22 are connected by soldering. Connect the flange ring of the opening edge of the radiating element 22 to the antenna housing 21 with nylon bolts. After the connection is completed, use a multimeter to check whether the radiating element 22 is in an open circuit state with the antenna housing 21.

[0068] The connection steps between antenna element 20 and skin element 10 are as follows:

[0069] Determine the installation position of the positioning component 30 on the antenna cabin, fix each positioning component 30 to the installation position of the antenna cabin body 21 with screws, and then, according to the digital model position on the skin unit 10, glue the positioning part of the positioning component 30 to the skin and press it to fix the positioning.

[0070] The positioning element 30 is bonded to the skin unit 10 with adhesive. This prevents the positioning element 30 from damaging the surface of the skin unit 10 at the connection point, and also does not affect the structure of the skin unit 10, thus avoiding damage to the electrical performance of the skin unit 10.

[0071] During the bonding process, a low-temperature adhesive such as DG-3 is used to bond the positioning component 30 to the skin unit 10. DG-3, a low-temperature curing adhesive, requires more than 12 hours to fully cure at room temperature, and only 4 hours at 60℃. However, prolonged exposure to high temperatures may affect the performance of the skin unit 10. To improve the fabrication efficiency of the conformal antenna and ensure skin performance, the bonded components are left at room temperature for 4-6 hours after bonding. Once a certain connection strength has been achieved, the entire conformal antenna assembly is placed in an oven and cured at 50℃-60℃ for 1-2 hours to fully cure the DG-3.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A conformal antenna, characterized by, Includes antenna unit, skin unit, and positioning unit; The antenna unit includes an antenna housing and a radiating unit. The antenna housing is a shell structure with an opening at one end. A feed port is provided at the center of the bottom of the antenna housing. The radiating unit is disposed in the antenna housing. The radiating unit is a conical shell structure with an opening at one end. One end of the radiating unit is connected to one end of the feed port that extends into the antenna housing. The opening end of the radiating unit is oriented away from the antenna housing. The antenna housing is electrically connected to the negative terminal of the feed port, and the radiating unit is electrically connected to the positive terminal of the feed port. The skin unit has an inner surface and an outer surface that are respectively curved. The positioning unit includes multiple positioning components, each including a connecting part for connecting to the antenna housing and a positioning part for connecting to the skin unit. The antenna housing is disposed inside the skin unit via the positioning unit, with one opening of the antenna housing facing the skin unit.

2. The conformal antenna of claim 1, wherein, The antenna housing includes a hexagonal pyramid-shaped working cabin and a connecting frame connected to the opening end of the working cabin. The connecting frame includes two sets of frame plate assemblies symmetrically arranged along the mounting reference line on the antenna housing. The frame plate assembly includes a central frame plate and side frame plates located on both sides of the central frame plate. The central frame plate is parallel to the mounting reference line and its upper end face is set as a horizontal plane. The upper end face of the side frame plate is an inclined plane that slopes downward toward the side away from the central frame plate.

3. The conformal antenna of claim 2, wherein, The mounting reference line of the antenna housing is set along the transverse direction of the skin unit. The positioning unit includes four positioning components, two of which are respectively set opposite to each other on the two central frame plates, and the other positioning components are respectively set on the two side frame plates that are opposite to each other.

4. The conformal antenna of claim 1, wherein, The positioning element is an L-shaped folded plate structure.

5. The conformal antenna according to claim 1, characterized in that, The positioning part is bonded to the skin unit.

6. The conformal antenna according to claim 1, characterized in that, The positioning component is made of carbon fiber composite material.

7. A method for fabricating a conformal antenna, used to fabricate the conformal antenna according to any one of claims 1-6, characterized in that, Includes the following steps: Fabrication of skin unit and antenna unit; A matching analysis is performed on the installation positions of the current antenna unit and the skin unit. The installation positions of the positioning components are determined on the skin unit. Based on the curved surface characteristics of the inner side of the skin, the installation positions of the positioning components on the antenna housing are determined. The positioning components are then installed on the antenna housing, and the antenna unit is connected to the skin unit through the positioning components. The preparation of the skin unit includes the following steps: S01. Lay the outer skin on the tooling, and after the layering is completed, cure and shape it in the autoclave. S02. Lay the core film on the outer skin, lay the honeycomb core on the core film, inject resin glue into the chamfered area of ​​the honeycomb core edge, then lay the core film on the upper end face of the honeycomb core, lay the core film on the flange area of ​​the outer skin, and then heat seal in the oven. S03. Lay a thickened layer of prepreg in the flange area of ​​the outer skin, with the number of layers being half of the total number of layers. Lay an inner skin prepreg on the inside of the outer skin, with the number of layers being half of the total number of layers. Then, lay the remaining thickened layer of prepreg in the flange area again, and lay the remaining inner skin prepreg on the inside of the outer skin. Then, cure and shape it in an autoclave.

8. The conformal antenna fabrication method according to claim 7, characterized in that, The positioning part of the positioning component is glued to the skin unit.

9. The conformal antenna fabrication method according to claim 8, characterized in that, The positioning part of the positioning component is bonded to the skin unit using low-temperature adhesive. After bonding, it is placed at room temperature for 4-6 hours. Then, the connected conformal antenna is placed in an oven and cured at 50℃-60℃ for 1-2 hours.

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