Segmented Integrated Assembly Skin Stealth Antenna Process Method

Abstract

A segmented integrated assembly process method for a skin stealth antenna disclosed by the present invention relates to the technical field of antennas. First, the designed curved skin antenna is divided into N segments where N≥2. Secondly, each of the divided antenna segments is further divided into left and right segments by bisecting the antenna from the horizontal center line position of the curved arc top; in the longitudinal and transverse directions of the radio frequency functional layer of the air back cavity under the left and right skin segments, the radiation metal pattern is connected by means of a balun structure to achieve conformal assembly of the curved surface circuit plane and the skin curved surface. Through the healing process of the fixing tool and the self-healing conductive material, the automatic assembly and connection of the circuit on the curved surface are completed; finally, the N antenna segments are assembled to obtain a complete skin antenna. The present invention uses processes such as structural segmentation, step-by-step assembly, and integrated assembly to achieve the integrated assembly and manufacturing of the skin antenna carrier, metal pattern, and balun structure, and can also achieve the integrated assembly of the reconfigurable radio frequency front-end components through the feeding points in the balun structure.

Description

Technical Field

[0001] The present invention relates to the technical field of antennas, and particularly to a segmented integrated assembly skin stealth antenna process method. Background Art

[0002] Due to a large number of traditional antennas protruding from the surface of the airborne platform and being installed on the aircraft nose or other positions through mechanical drilling, the radar cross-section of the fighter aircraft becomes larger, which not only seriously affects the aerodynamic performance of the aircraft, but also easily leads to a decline in stealth performance; the additional antenna support structure and auxiliary facilities greatly increase the weight, complexity, cost, and occupied space of the aircraft; the independent installation mode of the antenna and the opening of holes in the aircraft skin result in a larger airframe, shorter in-air standby time, lower survivability, and increased airframe structure repair and maintenance costs. Therefore, it is very difficult for traditional antennas to meet the functional requirements of a new generation of aircraft.

[0003] For this reason, the skin antenna directly uses a low-profile and easily foldable microstrip antenna array to achieve conformal with the platform, avoiding the back-and-forth reflection of electromagnetic waves between the radome and the antenna array in traditional conformal antennas, and better stealth performance can be achieved. The skin antenna integrates an antenna or antenna array conformal with the fuselage into the skin of the aircraft, making it both a structural member and an electronic device. The antenna and the aircraft body surface structure are seamlessly and smoothly integrated, which can eliminate many defects of traditional airborne antennas. At present, the skin technology is in a stage of rapid development, and the main research focuses on the overall architecture, antenna, T / R, radio frequency channel, preprocessing, packaging, structural process manufacturing, thermal management, etc.

[0004] Limited by current process capabilities such as traditional printed circuit board processing and structural part machining, it is difficult to break through the manufacturing process of skin antennas, which has become the main technical bottleneck for the development of skin antennas. Therefore, new process technologies need to be introduced. Additive manufacturing is an effective way to solve the integrated manufacturing problem of skin antennas. Based on metal 3D printing technology and inkjet 3D printing technology, the curved surface integrated manufacturing of the skin carrier and circuit function can be realized. At the same time, by compoundly applying 3D printing process technology, key technologies such as curved surface conformal circuit manufacturing and micro-structure three-dimensional manufacturing can be broken through, the integrated manufacturing of the skin bearing structure and radio frequency sensing, system thermal control and other functional configurations can be realized, and the integrated integration with the microsystem module can be achieved through three-dimensional assembly in the later stage, and finally the whole machine manufacturing of the intelligent skin antenna can be realized. Summary of the Invention

[0005] The object of the present invention is to propose a segmented integrated assembly process method for skin antennas according to the new characteristics of multi-functional radio frequency skin technology, which can realize the segmented and step-by-step integrated assembly of skin antennas, and while meeting the manufacturing accuracy requirements, can also solve the requirements of antenna stealth.

[0006] To achieve the above object of the present invention, a segmented integrated assembly process method for a skin antenna provided by the present invention includes the following steps:

[0007] Step 1: Use simulation software to design the required curved surface skin antenna; achieve the conformal of the low-profile and easily foldable microstrip antenna array surface and the skin antenna; the concave surface of the curved surface skin antenna has protruding balun structures arranged in an array, and radiation metal patterns arranged in an array connected by the balun structure as a bridge, and the convex surface of the curved surface has metal patterns arranged in an array;

[0008] Step 2: According to the curved surface skin antenna designed in Step 1, obtain a skin carrier with the same curvature and divide it into N segments, N≥2;

[0009] Step 3: From the transverse center line position of the curved surface apex of each segmented skin carrier, divide the skin carrier into a left skin carrier and a right skin carrier;

[0010] Then, use 3D printing or machining methods to process N left and right two-segment skin carriers, manufacture balun structures, radiation metal patterns arranged in an array on the inner surface of the skin carrier, and prepare metal patterns on the outer surface to obtain a skin carrier with an antenna curved surface circuit attached to its surface;

[0011] Step 4: Use the designed positioning tooling for the curved surface skin antenna to place the left and right skin carriers of the same segment in the positioning tooling, use a fixing tool to align and install the left and right two-segment skin carriers according to the metal patterns. After the positioning and installation are completed, use a foaming agent to fill the curved surface grooves of the assembled left and right skin carriers. After the foaming agent foams and cures, use a fixing tool and a self-healing conductive material to complete the healing process, and complete the automatic assembly and connection of the circuit on the skin curved surface;

[0012] Step 5: After successively completing the positioning and assembly of the N segmented left and right skin carriers, use the positioning tooling and the foaming agent to complete the foaming and fixing of the N segmented antennas, assemble the N segmented antennas into a complete skin antenna, and finally achieve the integrated integration of the skin antenna.

[0013] Further, when segmenting the antenna, it is necessary to avoid splitting the surface metal pattern into two.

[0014] Further, the radiation metal patterns are regularly arranged in the longitudinal and transverse directions on the concave surface; the metal pattern is a meandering metal pattern.

[0015] Further, use paper-cutting technology to cut and prepare radiation metal patterns with a multi-interpenetrating network structure with the help of tools.

[0016] Further, the skin carrier substrate is specifically polyether ether ketone, polyimide, polymethacrylimide or other non-metallic materials, aluminum alloy or other metallic materials.

[0017] Further, a back cavity with a low profile of a conformal skin antenna is designed based on HFSS software. Coaxial connection is used to feed and impedance-match a tapered microstrip line, and the microstrip line couples slots for energy radiation. Then, a shunt stub is added at the antenna feeding position for standing wave debugging; an open microstrip stub is introduced into the feeding network, and by changing the length of the stub, the frequency of the antenna can be adjusted without changing other parameters of the antenna; the antenna is tightly combined with the skin to achieve conformal installation of the antenna.

[0018] Further, the balun structure includes a balun, which is a balun-unbalun converter. After neatly winding the insulated copper wire on a coaxial cable or a non-magnetic core around a cylindrical magnetic material as a skeleton and fixing it, a balun with a working range of 3.5 - 7 MHz frequency multiplication is made. Through two mutually isolated coils, the matching input is converted into a differential output in dB units to achieve the conversion from balanced to unbalanced.

[0019] Further, the balun structure is a bridge connecting at least three rows of radiating metal patterns to form a radiation unit of an antenna feeding network in the shape of a turtle-back feeding point grid.

[0020] Further, the process of automatic assembly and connection of the circuit on the skin surface is as follows:

[0021] Check the alignment of the loop metal patterns on the surfaces of the left and right skin carriers. If the alignment is accurate, use the electrical installation process to apply conductive glue at the docking positions of the loop metal patterns and the radiating metal patterns on the left and right skin carriers to complete the closed interconnection of the loop metal patterns and the radiating metal patterns; if the alignment is inaccurate, use a scalpel to clean part of the foaming agent, then reuse the foaming agent to foam again, and reposition and assemble until the positioning is accurate, and then use conductive glue to perform closed interconnection at the docking positions of the loop metal patterns and the radiating metal patterns on the left and right skin carriers.

[0022] Further, the conductive glue is specifically conductive silver paste or a self-healing conductive material based on conductive nano-Ag powder and polycaprolactone polymer.

[0023] The present invention has the following advantages compared with the prior art:

[0024] The present invention first proposes a segmented integrated assembly process method for a skin antenna. By means of innovations such as structural segmented design, step-by-step assembly process innovation, and integrated assembly process innovation, etc., it realizes the integrated assembly and manufacturing of the skin antenna carrier, metal pattern, and balun structure, and can also realize the integrated assembly of a reconfigurable RF front-end component through the feeding points in the balun structure. Compared with the traditional integrated assembly processes of skin antennas and phased array antennas, the present invention also has the technical advantages of high integration, high stealth performance, low cost, and multi-functionality.

[0025] The present invention can not only realize the integrated manufacturing of the metal pattern and balun structure of the skin antenna, but also realize the integrated assembly with the reconfigurable RF front-end component through the feeding points in the balun structure.

[0026] The present invention is particularly applicable to the new generation of skin antennas, and can significantly improve the functional performance of the aircraft, especially the stealth performance. The specific technical effects will be further described in the embodiments. Description of the Drawings

[0027] Figure 1 It is a schematic flow chart of the segmented composition of the reconfigurable RF front-end component by the antenna skin of the present invention.

[0028] Figure 2 It is a schematic diagram of the positioning and assembly tooling for the curved surface skin antenna.

[0029] Figure 3 It is a schematic diagram of the segmented assembly effect of the skin antenna (when N = 4).

[0030] In the figure: 1, left skin carrier; 2, right skin carrier; 3, loop metal pattern; 4, radiating metal pattern; 5, balun structure; 6, positioning tooling; 7, positioning tool; 8, foaming agent. Detailed Embodiments

[0031] A segmented integrated assembly process method for a skin stealth antenna provided by the present invention includes the following steps:

[0032] Step 1: Design the required curved surface skin antenna, and perform simulation analysis using HFSS software to realize the conformal of the low-profile and easy-to-fold microstrip antenna array surface with the skin antenna; specifically, the designed curved surface skin antenna is as Figure 3 shown. There are arrayed balun structures on the concave surface of the curved surface of this skin antenna, and arrayed radiating metal patterns 4 connected by the protruding balun structure 5 as a bridge. There are arrayed loop metal patterns 3 on the convex surface of the curved surface, as Figure 1 shown; furthermore, the radiating metal patterns 4 are regularly arranged in the longitudinal and transverse directions on the concave surface.

[0033] Furthermore, using the configuration transformation characteristics of the smooth scrolling kirigami technique, the complex curved surface circuit is unfolded onto a plane through dimensionality reduction mapping to construct a reconfigurable model of sub-array units. Then, on the skin carrier substrate, a dot matrix conformal array structure with no less than two radiation units arranged regularly or randomly is printed, and a panel with radiation characteristics is obtained through appropriate excitation. By setting antenna unit installation interfaces distributed according to certain rules on the panel, a spherical patch that is the vector sum of the radiation fields of each unit of the antenna array is formed to achieve conformal coverage of regularly arranged antenna units, thereby realizing the conformal antenna function with conformal coverage;

[0034] Design a low-profile back cavity for the conformal skin antenna. Feed and impedance match through a coaxial-connected tapered microstrip line, and radiate energy through the coupled slots of the microstrip line. Then, add a shunt stub at the antenna feeding position for standing wave debugging; introduce a microstrip open stub in the feeding network to adjust the antenna frequency by changing the stub length without changing other parameters of the antenna; closely combine the antenna with the skin to achieve conformal installation of the antenna; adjust the antenna structure parameters according to the simulation results to achieve the best working performance; fabricate an actual antenna array according to the simulation results and conduct tests in the actual environment to verify the design effect.

[0035] Through the above steps, conformal shaping of the low-profile and foldable microstrip antenna array surface and the skin antenna can be achieved to meet specific application requirements.

[0036] Furthermore, the balun in the balun structure 5 is a balun (balanced-unbalanced converter). After neatly winding the insulated copper wire on a coaxial cable or a non-magnetic core around a cylindrical magnetic material used as a skeleton and fixing it, a balun with a frequency doubling range of 3.5 - 7 MHz is made. Through two mutually isolated coils, the matching input is converted into a differential output in dB units to achieve the conversion from balanced to unbalanced.

[0037] Step 2: According to the curved surface skin antenna designed in Step 1, obtain a skin carrier with the same curvature and divide it into N segments (N≥2), Figure 3 where N = 4; when segmenting the antenna, it should be considered to avoid the situation that the surface metal pattern is split in two between each segment of the antenna. This is because it is very difficult to achieve the closed interconnection of the metal patterns between each segment of the antenna subsequently, and even if the closed interconnection can be achieved, it will have a huge negative impact on the stealth performance of the antenna.

[0038] Step 3: For each of the (N segments) of the antenna separated, bisect the antenna into two parts, left and right, from the position of the transverse center line at the top of the curved surface: left skin carrier 1 and right skin carrier 2. The purpose of doing this is to enable the processing and manufacturing of the balun structure 5, the loop metal pattern 3 and the radiating metal pattern 4 in the inner groove of the antenna using 3D printing technology. However, since there must be a loop metal pattern 3 and a radiating metal pattern 4 at the top of the curved surface of the antenna, it is inevitable to bisect the loop metal pattern 3 and the radiating metal pattern 4.

[0039] The base material of the skin carrier can be selected from non-metallic materials such as polyether ether ketone (PEEK), polyimide (PI), and polymethacrylimide (PMI), or metallic materials such as aluminum alloy.

[0040] Then, use 3D printing or machining methods to process N pairs of left and right skin carriers, mainly processing curved surface circuits such as the left and right skin carriers, the balun structure 5, the radiating metal pattern 4 on the inner surface of the skin, and the loop metal pattern 3 on the outer surface of the skin. Using the balun structure 5 as a bridge to connect at least three rows of radiating metal patterns 4 to form a turtle-back feed point grid-shaped antenna feed network radiation unit, realizing the conformal assembly of the curved surface circuit planar manufacturing and the skin curved surface. Specifically, use the kirigami technique to cut and prepare the radiating metal pattern 4 with a multi-interpenetrating network structure with the help of tools. As Figure 3 shown, the upper right corner of the figure is a partial enlarged view of the final product of the skin antenna, and it can be seen that the balun structure 5 is perpendicular to the skin carrier and arranged in an array.

[0041] Step 4: As Figure 2As shown, the designed curved skin antenna positioning fixture 6 is used to place the left and right skin carriers of the same section in the positioning fixture 6, and the left skin carrier 1 and the right skin carrier 2 are aligned and installed according to the skin surface pattern using the positioning tool 7. The positioning tool 7 can be a high-temperature tape. After the positioning and installation are completed, a two-component foaming agent 8 (such as polyurethane, etc.) is used, mixed evenly according to a 1:1 combination, and poured and filled in the curved surface grooves of the assembled left and right skin carriers. After the foaming agent 8 is foamed and cured, the positioning tool 7 and the self-healing conductive material are used to perform a healing process to complete the automatic assembly and connection of the circuit on the curved surface of the skin. Specifically, check the alignment of the left and right skin carriers. If the alignment is accurate, use the electrical installation process to apply conductive silver paste or self-healing conductive material based on conductive nano-Ag powder and polycaprolactone (PCL) polymer on the butt joint of the zigzag metal pattern 3 and the radiating metal pattern 4 of the left and right skin carriers to complete the closed interconnection of the zigzag metal pattern 3 and the radiating metal pattern 4. If the alignment is inaccurate, use a scalpel to clean part of the foaming agent 8, and then repeat the foaming, re-position and assemble, until the positioning is accurate, and then use conductive glue to close the butt joint of the zigzag metal pattern 3 and the radiating metal pattern 4 of the left and right skin carriers.

[0042] This self-healing conductive material based on conductive nano-Ag powder and polycaprolactone (PCL) polymer can exhibit excellent electrical properties and mechanical strength. At temperatures above 80°C, it can exhibit extremely high performance recovery rates. When the Ag content is 80%, the conductivity recovery rate can reach 90%. At the same time, the self-healing conductive material also has excellent processability. The self-healing circuits prepared by means of coordinate transformation and patterned cutting can achieve high alignment on the curved surface, thereby ensuring the stability and smoothness of the circuit connectivity. It should be noted that the thickness of the conductive glue should be kept as consistent as possible with the thickness of the circular metal pattern 3 and the radiating metal pattern 4, so as not to affect the stealth performance; for spherical patches, the width should be less than 0.28R.

[0043] Step 5: After completing the positioning and assembly of the N segmented left and right skin carriers in sequence, use the positioning tool 6 and the foaming agent 8 to complete the foaming and fixing of the N segmented antennas, assemble the N segmented antennas into a complete skin antenna, and finally realize the integrated integration of the skin antenna.

[0044] The present invention utilizes innovative designs of structural segmentation, step-by-step assembly process methods, and integrated assembly processes to achieve the integrated assembly and manufacturing of the antenna skin carrier, metal pattern, and balun structure. It can also realize a reconfigurable radio frequency front-end component, and integrally integrate and assemble a conformal antenna through the feed points in the balun structure. This kind of skin antenna directly uses a low-profile and easily foldable microstrip antenna array to achieve conformal with the platform, avoiding the back-and-forth reflection of electromagnetic waves between the radome and the antenna array in traditional conformal antennas, and can achieve better stealth performance. Due to the segmented integrated assembly process method of the skin antenna, it can realize the segmented and step-by-step integrated assembly of the skin antenna. Compared with the integrated assembly processes of traditional skin antennas and phased array antennas, the conformal antenna can reduce the interference to the surface shape of the carrier while maintaining good radiation performance. In addition to the technological advancement, the present invention also has the technical advantages of high integration, high stealth performance, low cost, and multi-functionality.

[0045] When the antenna of the present invention is segmented, it is considered to avoid the situation where the metal pattern is split in two between each segment of the antenna. This is because it is very difficult to achieve the closed interconnection of the metal patterns between each segment of the antenna in the follow-up. Even if the closed interconnection can be achieved, it will have a huge negative impact on the stealth performance of the antenna. Therefore, a low-profile and easily foldable microstrip antenna array is used to achieve conformal with the skin antenna. By setting antenna unit mounting interfaces distributed according to certain rules on the array panel, the regular arrangement of the antenna units can be realized, thereby realizing the function of the antenna. This segmented integrated assembly process method of the antenna skin designs a segmented skin antenna structure assembled from left to right first, and then assembles N segments of skin antennas into one body, innovating a segmented assembly process method. At the same time, it also innovates the positioning tooling for the skin antenna, so as to meet the manufacturing requirements of the skin antenna, especially the manufacturing requirements of the skin antenna with a balun structure. It realizes the high-gain wide-angle scanning of the intelligent skin antenna, solves the defect that the array gain loss of the classical phased array antenna is too large at large scanning angles; in the broadband distributed array beam synthesis, a sub-array beam synthesis method based on digital delay can also be adopted to solve the distributed beam synthesis and alignment of the intelligent skin antenna.

[0046] The present invention uses the configuration transformation characteristics of smooth rolling paper cutting technology (kirigami) to expand the complex curved circuit to a plane through dimensionality reduction mapping, and then prints a conformal array structure of a dot matrix with no less than two radiation units arranged regularly or randomly or periodically on a non-metallic material skin carrier substrate or an aluminum alloy metal material. The configuration transformation characteristics of the Kirigami technology are used to expand the complex curved circuit to a plane through dimensionality reduction mapping to achieve complete conformal bonding, and transform the original complex curved surface processing problem into a mature planar circuit preparation process, ensuring that there is sufficient strong interface adhesion and that no fracture occurs during the deformation of the patch. Even under complex wind conditions, the skin can still be stably conformal to the curved surface and ensure the stable operation of the sensor system. The high-precision functional circuit prepared on the plane uses the Kirigami shear structure to achieve conformal coating of the regularly arranged antenna units by setting antenna unit installation interfaces distributed according to certain rules on the array panel, and finally completes the automatic assembly and connection of the circuit on the curved surface through the healing process of the self-healing conductive material. The skin structure with functions of identification, analysis, judgment, and reaction is composed of structures and units that complete the two major functions of sensing or action by coupling with physical quantities such as electricity, magnetism, heat, light, sound, rheology, and mechanical motion, and sensing the changes of these quantities. It not only has the functions of traditional skin in bearing loads, maintaining the aerodynamic shape of the aircraft, and protecting internal devices, but also has the functions of enhancing stealth, reducing vibration and noise, sensing the environment, and sending and receiving information.

[0047] According to the functional composition method of the intelligent skin antenna, the designed antenna curved surface skin is divided into N encapsulation functional layers, radio frequency functional layers, and control and signal processing functional layers with N≥2. The encapsulation functional layer can achieve three major functions: First, the structural load-bearing function to meet the special requirements of the intelligent skin antenna in terms of structural strength, aerodynamics, etc., and can play a role in preventing oxidation, attenuating ultraviolet rays, protecting against rain and snow erosion, and resisting aerodynamic loads; second, the system heat dissipation function to ensure the normal operation of the power amplifier chip; third, the electromagnetic protection function, including both the protection against external electromagnetic attacks and the protection against internal electromagnetic interference within the system. The radio frequency functional layer can realize the reconfigurability of the electromagnetic signal radiation / scattering characteristics. After each divided section of the antenna, the antenna skin is further divided into two parts, the left skin carrier 1 and the right skin carrier 2, from the position of the horizontal center line at the top of the curved surface: The purpose of this is to be able to complete the processing and manufacturing of the balun structure 5, the meandering metal pattern 3 in the antenna inner groove, and the radiation metal pattern 4 using the 3D printing process. Due to the high flexibility and plasticity of 3D printing technology, different types of antenna accessories can be printed according to the different shapes and functional requirements of the antenna. At the same time, 3D printing technology can precisely control the printing quality and size to ensure the accuracy and precision of the antenna. Moreover, 3D printing technology can efficiently complete the manufacturing of antenna devices within a certain period of time, greatly improving the manufacturing efficiency and enhancing the performance of the intelligent skin antenna, overcoming the defects of traditional antenna manufacturing technologies that require multiple steps for manufacturing and have relatively high time and input costs.

[0048] The present invention uses 3D printing or machining methods to process about N antenna skins and balun structures for both the left and right sections, and connects at least three rows of radiating metal patterns in the longitudinal and transverse directions of the RF functional layer in the air back cavity below the left and right skins with the balun structure to form a turtle-back feed point grid-shaped antenna feed network radiation unit, realizing the manufacturing of a broadband feed network and a curved surface circuit plane that achieve good impedance matching and amplitude-phase distribution within a wider frequency band and conformal assembly with the skin surface. The antenna feed network radiation unit can form multiple transmitting and receiving beams, and has the following main advantages compared with traditional antennas using passive feed networks: (1) The formation and scanning of transmitting beams can be fully digital, and the beam scanning speed is faster; (2) The amplitude and phase are continuously adjustable, the control is very precise, it is easy to achieve ultra-low sidelobe beams, and an adaptive beam control can be formed, such as adaptive nulls to reduce the impact of interference signals on the system; (3) It is convenient for array element pattern calibration, and DBF can quickly and accurately calibrate the impact caused by mutual coupling and channel differences, thereby improving the quality of the pattern; (4) Multi-beam control; DBF can perform digital processing on received signals to form multiple simultaneous low-sidelobe dense beams. In theory, an infinite number of arbitrary and dense beams can be generated, and each beam can fully adapt to the electronic environment characteristics of that instant, thus providing the ability of simultaneous detection and tracking, especially suitable for the tracking detection of multiple positions in smart antennas. (5) The broadband channel can be divided into several narrow sub-bands, and the optimal amplitude-phase weights are assigned to each channel in different sub-bands, so as to optimize the pattern beams in each sub-band and eliminate the adverse impact of frequency dispersion on the pattern, which is difficult to achieve in passive feed networks. (6) And it can generate the required radiation / scattering characteristics according to the external electromagnetic environment, enable the radiation unit to have the ability of electromagnetic characteristic reconfiguration, complete the electromagnetic dynamic regulation of the RF functional layer, and have the ability of beam pointing agility and beam shape agility. This antenna is based on a cavity-backed microstrip slot antenna, realizes coupled feeding and impedance matching through a tapered microstrip line, realizes a low-profile design by reducing the depth of the air back cavity and adding a microstrip shunt open stub at the connection position between the antenna feed network and the antenna array surface, and realizes adjustable antenna resonance frequency points by adjusting the length of the stub. Different from traditional antenna design methods, through the use of reconfiguration technology in the RF functional layer and signal processing methods at the backend, the beam adaptivity of the intelligent skin antenna is realized, and the limitation of traditional antennas relying only on signal processing methods to achieve antenna beam adaptivity is solved. The adaptivity of the antenna can be completed not only by the control and signal processing unit at the backend of the device, but also by realizing the reconfiguration of radiation / scattering characteristics in the RF functional layer, that is, adding one-dimensional freedom in the RF functional layer. Different from traditional antennas, it can not only achieve a high degree of integration of the device and the antenna structure packaging functional layer, but also realize the electromagnetic characteristic dynamic regulation of the RF functional layer, breaking through the limitation that phased array antennas rely only on the control and signal processing unit at the backend to achieve antenna beam adaptivity.

[0049] Finally, after the positioning and assembly of N segmented antenna skins are completed in sequence, the positioning tooling is used to complete the fixing of the foaming agent for the N segmented antenna skins, and the N segmented antenna skins are assembled into a complete skin antenna of the reconfigurable RF front-end component, breaking the limitation of the traditional antenna installed by opening holes in the aircraft skin, and forming a new type of antenna that can be highly integrated with the structure of the airborne platform and directly bear environmental loads. The positioning tooling completes the fixing of the foaming agent for the N segmented antenna skins, mainly solving the assembly process problem of the skin antenna of the avionics information equipment, so that the assembled skin antenna can meet the requirements such as assembly accuracy. The simulation results show that the skin antenna achieves a standing wave resonance frequency offset of more than ±20 MHz, and the bandwidth with a standing wave less than 2 during the frequency offset process is greater than 20 MHz. The self-healing hydrogel has high mechanical deformation ability (strain up to 200%), low stiffness, recyclability and biocompatibility, and can also recover from physical damage caused by extreme strain, pressure or tearing by using spontaneous intermolecular forces. Based on the organic gel composite material, it has high conductivity (7×104 S m-1), low stiffness (Young's modulus ~20 kPa), high stretchability (strain limit >400%) and mechanical and electrical self-healing properties.

[0050] The present invention can not only realize the integrated manufacturing of the metal pattern and the balun structure of the skin antenna, but also realize the integrated assembly with the reconfigurable RF front-end component through the feed point in the balun structure, which can reduce the manufacturing process difficulty and process requirements of the skin antenna. Even by combining various antennas on it with the wing and fuselage skins, the exposed antennas on the aircraft can be effectively cancelled, and at the same time, the RCS area is greatly reduced. It can also effectively utilize the surface area of the aircraft, reduce the weight, and reduce the aerodynamic drag of the aircraft. While meeting the manufacturing accuracy requirements, it can also solve the requirement of antenna stealth and realize the intelligent beam adaptability of the skin antenna. The present invention is particularly suitable for the new generation of skin antennas, and can significantly improve the functional performance of the aircraft, especially the stealth performance.

[0051] It can be understood that the present invention is described through some embodiments. Those skilled in the art know that various changes or equivalent replacements can be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. A segmented integrated assembly skin stealth antenna process method, characterized in that It includes the following steps: Step 1: Design the required curved skin antenna using simulation software; Realize the conformal of the microstrip antenna array surface and the skin antenna; the concave surface of the curved skin antenna has an array of protruding balun structures (5) arranged in an array, and radiation metal patterns (4) arranged in an array connected by the balun structure (5) as a bridge. The convex surface of the curved surface has an array of metal patterns; Step 2: According to the curved skin antenna designed in Step 1, obtain a skin carrier with the same curvature and divide it into N segments, where N≥2; Step 3: From the transverse centerline position of the curved top of each segmented skin carrier, divide the skin carrier into a left skin carrier and a right skin carrier; Then, use 3D printing or machining methods to process N pairs of left and right skin carriers. Manufacture an array of balun structures (5) and radiation metal patterns (4) on the concave surface of the skin carrier, and prepare metal patterns on the convex surface to obtain a skin carrier with an antenna curved surface circuit attached to its surface; Step 4: Use the designed curved skin antenna positioning tooling (6) to place the left and right skin carriers of the same segment in the positioning tooling (6). Use positioning tools to align and install the left and right skin carriers according to the metal patterns. After the positioning and installation are completed, use foaming agent to fill the curved grooves of the assembled left and right skin carriers. After the foaming agent foams and cures, use positioning tools and self-healing conductive materials for healing to complete the automatic assembly and connection of the circuit on the skin curve; Step 5: After sequentially completing the positioning and assembly of N segmented left and right skin carriers, use this positioning tooling (6) and foaming agent to complete the foaming and fixing of N segmented antennas, assemble the N segmented antennas into a complete skin antenna, and finally realize the integrated integration of the skin antenna.

2. The process method of a segmented integrated assembled skin stealth antenna according to claim 1, characterized in that When segmenting the skin carrier in Step 2, it is necessary to avoid splitting the surface metal pattern in half.

3. The process method of a segmented integrated assembled skin stealth antenna according to claim 2, characterized in that, The radiation metal patterns (4) are regularly arranged in the longitudinal and transverse directions on the concave surface; the metal pattern is a meandering metal pattern (3).

4. A segmented integrated assembled skin stealth antenna process method according to claim 3, characterized in that Use paper-cutting technology to cut and prepare radiation metal patterns (4) with a multi-interpenetrating network structure with the help of tools.

5. A segmented integrated assembled skin stealth antenna process method according to claim 4, characterized in that, The skin carrier substrate is specifically polyetheretherketone, polyimide, polymethacrylimide, or aluminum alloy.

6. The process method of a segmented integrated assembled skin stealth antenna according to claim 5, characterized in that, Design a low-profile back cavity of a conformal skin antenna based on HFSS software. Feed and impedance match through a coaxial-connected tapered microstrip line, and radiate energy through microstrip-coupled slots. Then, add a shunt stub at the antenna feed position for standing wave debugging; introduce a microstrip open stub in the feed network. By changing the length of the microstrip open stub, the frequency of the antenna can be adjusted without changing other parameters of the antenna; the antenna is combined with the skin to achieve conformal installation of the antenna.

7. A segmented integrated assembled skin stealth antenna process method according to claim 6, characterized in that The balun structure (5) includes a balun, which is a balun-unbalun converter. The insulated copper wire on the coaxial cable or non-magnetic core is neatly wound around a magnetic material with a cylinder as the skeleton and fixed to make a balun with a use range of 3.5 - 7Mhz frequency multiplication. Through two groups of mutually isolated coils, the matching input is converted into a differential output in dB units to achieve the conversion from balanced to unbalanced.

8. A segmented integrated assembled skin stealth antenna process method according to claim 7, characterized in that, The balun structure (5) is a bridge connecting at least three rows of radiating metal patterns (4) to form an antenna feed network radiation unit in the shape of a turtle-back feed point grid.

9. A segmented integrated assembled skin stealth antenna process method according to claim 7, characterized in that, The specific process of the automatic assembly and connection of the circuit on the skin surface is as follows: Check the alignment of the meandering metal patterns (3) on the surfaces of the left and right skin carriers. If the alignment is accurate, use the electrical installation process to apply conductive glue at the docking positions of the meandering metal patterns (3) and the radiating metal patterns (4) on the left and right skin carriers to complete the closed interconnection of the meandering metal patterns (3) and the radiating metal patterns (4); If the alignment is inaccurate, use a scalpel to clean the foaming agent, then reuse the foaming agent to foam, reposition and assemble until the positioning is accurate, and then use conductive glue to perform closed interconnection at the docking positions of the meandering metal patterns (3) and the radiating metal patterns (4) on the left and right skin carriers.

10. A segmented integrated assembly skin stealth antenna process method according to claim 9, characterized in that, The conductive glue is specifically conductive silver paste or a self-healing conductive material based on conductive nano-Ag powder and polycaprolactone polymer.

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