Welding-free vertical interconnection structure for balance feed of ultra-wideband antenna

Abstract

The invention relates to the technical field of antenna engineering, and discloses a welding-free vertical interconnection structure for balance feed of an ultra-wideband antenna, which comprises an integrated radiation and feed circuit, an integrated radiation and feed dielectric body, a support body, a metal bottom plate and a feed coaxial structure, and is characterized in that the integrated radiation and feed dielectric body is of a T-shaped dielectric substrate structure; the bottom of the antenna is connected with the metal bottom plate; the support body is filled between the integrated radiation and feed dielectric body and the metal bottom plate; the feed coaxial structure comprises an inner conductor and an outer conductor, the inner conductor is connected with the integrated radiation and feed circuit, and the outer conductor is connected with the metal bottom plate. According to the invention, good electrical connection between the feed structure and the radiation structure in a complex application environment can be realized, and the feed stability of the antenna is significantly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of antenna engineering, and in particular to ultra-wideband antennas such as microstrip dipole antennas and spiral antennas that require a balanced feed network, which are used for highly reliable vertical interconnection and integration of the antenna radiation surface and the feed network, replacing the original vertical interconnection method between the antenna radiation surface and the feed network achieved by welding means. Background Art

[0002] Microstrip dipole antennas are widely used due to their advantages such as simple structure, low manufacturing cost, wide coverage frequency range, strong directivity, and high applicability. The feeding methods of this type of antenna mainly include unbalanced feeding and balanced feeding. The unbalanced current generated by the former will cause the antenna pattern to be distorted and the maximum radiation direction to deviate from the axis. In this context, a balanced feeding tapered microstrip balun with both unbalanced-to-balanced transformation and impedance transformation functions has emerged.

[0003] Currently, the common way to feed a dipole antenna using a tapered microstrip balun is that the feeding dielectric plate passes above the antenna radiation dielectric substrate, and the metal conductors on both sides of the balanced output end of the tapered balun are respectively welded to the two radiation arms of the dipole antenna to achieve vertical electrical connection, as Figure 1 shown.

[0004] The literature "Research on Ultra-Wideband Antenna Elements and Arrays Fed by Tapered Baluns" published in the Journal of Radio Science and the patent (CN114552169A) both adopt the above feeding scheme, and soldering is introduced at the feeding point to achieve effective feeding. In order to transmit the electromagnetic signal on the top radiation surface to the inside of the product, the conventional implementation method is to use various forms of vertical feeding circuits to connect with the radiation surface to achieve vertical interconnection between layers, so as to transmit the electromagnetic signal 90° from the radiation surface to the inside.

[0005] The patent (CN117276879A) realizes vertical electrical connection through elastic contact connection between the vertical feeding circuit component and the top radiation layer. The patent (CN117096596A) realizes vertical electrical connection through riveting of the rigid-flexible feeding piece and the top radiation layer. The patent (CN117525873A) realizes vertical electrical connection through elastic connection contact between the vertical feeding circuit component and the riveting of the top radiation layer. The patent (CN114069257A) ensures stable connection by providing positioning slots on the horizontal dielectric substrate and the dipole unit for fixing the two feeding structures. However, connection methods such as soldering of the split feeding piece, elastic crimping, and contact connection have obvious deficiencies. Especially for antennas installed on high-speed and highly maneuverable aircraft, due to severe vibration, it is difficult to ensure the strength of the solder joints, and individual solder joints are prone to breakage and falling off. Open circuits occur in elastic crimping or contact connection, resulting in antenna function failure.

[0006] For a multi - unit array antenna, the number of feed channels ranges from dozens to over a thousand. The overall integration density is relatively large, making it impossible to achieve large - scale and highly efficient vertical interconnection and assembly. At the same time, there are very high - precision assembly and positioning requirements between the discrete feed network and the radiation surface, which greatly reduces the manufacturing efficiency of the antenna. Summary of the Invention

[0007] The purpose of the present invention is to achieve highly reliable vertical interconnection integration between the antenna radiation surface and the feed network, overcome the deficiencies of existing feed technologies, and solve problems such as poor reliability, poor quality consistency, and complex assembly caused by feed structures such as solder welding, elastic crimping, and contact connection. To solve the aforementioned problems, the present invention proposes a solder - free vertical interconnection structure for balanced feeding of ultra - wideband antennas. It adopts an integrated molding design of a radiation dielectric plate and a feed dielectric plate. The antenna radiation surface and the feed network form an integrated "T" - shaped structure. Solder - free vertical feeding is achieved through tapered balun metallized vias, and the specific structure of this feeding form and its achieved good performance are described. The present invention can achieve good electrical connection between the feed structure and the radiation structure in a complex application environment, and significantly improve the feeding stability of the antenna.

[0008] The technical solution adopted by the present invention is as follows:

[0009] A solder - free vertical interconnection structure for balanced feeding of ultra - wideband antennas, comprising an integrated radiation and feed circuit, an integrated radiation and feed dielectric body, a support body, a metal bottom plate, and a feed coaxial structure. The integrated radiation and feed dielectric body is arranged in a "T" - shaped dielectric substrate structure for carrying the integrated radiation and feed circuit and is connected to the metal bottom plate at the bottom. The support body is filled between the integrated radiation and feed dielectric body and the metal bottom plate. The feed coaxial structure includes an inner conductor and an outer conductor. The inner conductor is connected to the integrated radiation and feed circuit, and the outer conductor is connected to the metal bottom plate.

[0010] Further, the integrated radiation and feed dielectric body includes a radiation dielectric body and a feed dielectric body. The radiation dielectric body and the feed dielectric body are integrally connected and orthogonally vertically interconnected.

[0011] Further, the integrated radiation and feed dielectric body further includes vertical vias for feeding, and the vertical vias are arranged on both sides of the connection between the radiation dielectric body and the feed dielectric body.

[0012] Further, the integrated radiation and feed dielectric body further includes a rounded - corner structure, and the rounded - corner structure is arranged at the connection between the radiation dielectric body and the feed dielectric body.

[0013] Furthermore, the integrated radiation and feeding circuit includes a radiation dipole arm, a metallized via hole, and a three-dimensional tapered microstrip balun with an open end. The radiation dipole arm is connected to the three-dimensional tapered microstrip balun through the metallized via hole.

[0014] Furthermore, the three-dimensional tapered microstrip balun is arranged in a trapezoidal tapered and three-dimensional structure with the balanced end extended and bent.

[0015] Furthermore, the three-dimensional tapered microstrip balun includes an upper conductor and a lower conductor, and the upper conductor and the lower conductor are respectively located on both sides of the feeding dielectric body of the integrated radiation and feeding dielectric body.

[0016] Furthermore, the outer conductor of the feeding coaxial structure is welded and fixed to the metal bottom plate, and the inner conductor is welded and fixed to the upper conductor of the three-dimensional tapered microstrip balun. The lower conductor of the three-dimensional tapered microstrip balun is welded and fixed to the metal bottom plate.

[0017] Furthermore, the integrated radiation and feeding circuit is manufactured on the integrated radiation and feeding dielectric body by an additive manufacturing method, including:

[0018] Manufacturing the radiation dipole arm and the three-dimensional tapered microstrip balun on the integrated radiation and feeding dielectric body based on the laser micro-cladding additive manufacturing method;

[0019] Preparing a continuous copper layer on the vertical vias of the integrated radiation and feeding dielectric body based on the electroless copper plating - electroplating thickening method to form a solder-free metallized via hole, and interconnecting the metallized via holes with the metal pads of the radiation dipole arm and the three-dimensional tapered microstrip balun respectively.

[0020] Furthermore, the support body includes a filling foam, and the filling foam includes a polymethacrylimide foam with a dielectric constant of 1.1.

[0021] The beneficial effects of the present invention are as follows:

[0022] (1) The present invention adopts an integrated molding design of a radiation dielectric plate and a feeding dielectric plate. The feeding network and the antenna radiation surface are in an integrated "T" shape structure. Through the tapered balun metallized via hole, solder-free vertical feeding is realized, solving the problems of poor electrical connection, poor vibration resistance, and complex assembly caused by connection methods such as soldering, elastic pressing, and contact connection of the separate feeding pieces, realizing good electrical connection between the feeding structure and the radiation structure in a complex application environment, significantly improving the feeding stability of the antenna. At the same time, the new feeding structure will not deteriorate the antenna standing wave and will not introduce additional radiation loss.

[0023] (2) In terms of large-scale array high-density integration, the high-precision assembly and positioning requirements between the separate feeding network and the radiation surface are eliminated.

[0024] (3) For a multi - unit array antenna, all radiation and feeding structures are realized through machining and additive manufacturing, avoiding the inconsistencies in welding and assembly caused by human operation factors, and improving the amplitude and phase consistency of the units in the antenna array.

[0025] (4) On the antenna radiation surface, the protrusions caused by the prominent feeding dielectric plate and solder joints are avoided, which is more conducive to the co - curing integration of the antenna and the radome.

[0026] (5) This feeding method can be extended to the design and manufacture of conformal antennas on curved surfaces, replacing the manufacturing method of bending and bonding the flexible radiation surface to the conformal surface and then welding and assembling it with a separate feeding network. Description of the Drawings

[0027] Figure 1 It is a schematic diagram of the traditional balanced feeding structure of a dipole antenna.

[0028] Figure 2 It is a three - dimensional view of the balanced feeding and non - welding vertical interconnection structure of the ultra - wideband antenna of the present invention.

[0029] Figure 3 It is a front view of the balanced feeding and non - welding vertical interconnection structure of the ultra - wideband antenna of the present invention.

[0030] Figure 4 It is a top view of the balanced feeding and non - welding vertical interconnection structure of the ultra - wideband antenna of the present invention.

[0031] Figure 5 It is a left view of the balanced feeding and non - welding vertical interconnection structure of the ultra - wideband antenna of the present invention.

[0032] Figure 6 It is a three - dimensional view of the integrated radiation and feeding dielectric body of the present invention.

[0033] Figure 7 It is a three - dimensional view of the integrated radiation and feeding circuit of the present invention.

[0034] Figure 8 It is a three - dimensional view of the 1×8 antenna array of the present invention.

[0035] Figure 9 It is a curve graph of the simulated voltage standing - wave ratio of the antenna array of the present invention varying with frequency.

[0036] Figure 10 It is the two - dimensional gain pattern (E - plane) of the simulated antenna array of the present invention.

[0037] Figure 11 It is the two - dimensional gain pattern (H - plane) of the simulated antenna array of the present invention. Detailed Embodiment

[0038] To have a clearer understanding of the technical features, objectives, and effects of the present invention, the specific embodiments of the present invention will now be described. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. That is, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0039] Embodiment 1

[0040] As Figures 2 to 5 shown, this embodiment provides a solderless vertical interconnection structure for ultra-wideband antenna balanced feeding, which can achieve high-reliability vertical interconnection integration between the antenna radiation surface and the feeding network. The solderless vertical interconnection structure includes an integrated radiation and feeding circuit 1, an integrated radiation and feeding dielectric body 2, a support body 3, a metal bottom plate 4, and a feeding coaxial structure 5. The integrated radiation and feeding dielectric body 2 is arranged as a "T"-shaped dielectric substrate structure for carrying the integrated radiation and feeding circuit 1, and is connected to the metal bottom plate 4 at the bottom; the support body 3 is filled between the integrated radiation and feeding dielectric body 2 and the metal bottom plate 4; the feeding coaxial structure 5 includes an inner conductor 51 and an outer conductor 52, the inner conductor 51 is connected to the integrated radiation and feeding circuit 1, and the outer conductor 52 is connected to the metal bottom plate 4.

[0041] Preferably, as Figure 6 shown, the integrated radiation and feeding dielectric body 2 includes a radiation dielectric body 21, a feeding dielectric body 22, a vertical via 23, and a rounded corner structure 24. The radiation dielectric body 21 and the feeding dielectric body 22 are integrally connected and orthogonally vertically interconnected. The vertical via 23 is arranged on both sides of the connection between the radiation dielectric body 21 and the feeding dielectric body 22, and the rounded corner structure 24 is arranged at the connection between the radiation dielectric body 21 and the feeding dielectric body 22, which can increase the structural strength of the "T"-shaped dielectric substrate.

[0042] Preferably, as Figure 7 shown, the integrated radiation and feeding circuit 1 includes a radiation dipole arm 11, a metallized via 12, and a three-dimensional tapered microstrip balun 13 with an open end at the end. The radiation dipole arm 11 is connected to the three-dimensional tapered microstrip balun 13 through the metallized via 12. The three-dimensional tapered microstrip balun 13 is arranged as a trapezoidal taper and a three-dimensional structure with the balanced end extended and bent. The three-dimensional tapered microstrip balun 13 includes an upper conductor 131 and a lower conductor 132, and the upper conductor and the lower conductor 132 are respectively located on both sides of the feeding dielectric body 22 of the integrated radiation and feeding dielectric body 2.

[0043] Preferably, the outer conductor 52 of the feeding coaxial structure 5 is fixedly welded to the metal bottom plate 4, and the inner conductor 51 is fixedly welded to the upper conductor 131 of the three-dimensional tapered microstrip balun 13. The lower conductor 132 of the three-dimensional tapered microstrip balun 13 is fixedly welded to the metal bottom plate 4, so as to realize the coaxial feeding excitation of the ultra-wideband antenna.

[0044] Preferably, in this embodiment, the integrated radiation and feeding circuit 1 is manufactured on the integrated radiation and feeding dielectric body 2 by additive manufacturing, including:

[0045] Based on the laser micro-cladding additive manufacturing method, the radiation dipole arms 11 and the three-dimensional tapered microstrip balun 13 are manufactured on the integrated radiation and feeding dielectric body 2;

[0046] Based on the electroless copper plating - electroplating thickening method, a continuous copper layer is prepared on the vertical vias 23 of the integrated radiation and feeding dielectric body 2 to form a solderless metallized via 12, and the metallized via 12 is respectively interconnected with the metal pads of the radiation dipole arms 11 and the three-dimensional tapered microstrip balun 13, so as to realize the solderless vertical interconnection between the antenna radiation surface and the feeding network.

[0047] Preferably, the support 3 can be realized by filling with foam, such as polymethacrylimide (PMI) foam with low dielectric constant and high temperature resistance.

[0048] Embodiment 2

[0049] Based on Embodiment 1, this embodiment:

[0050] This embodiment provides a solderless vertical interconnection structure for balanced feeding of an ultra-wideband antenna, including an integrated radiation and feeding circuit 1, an integrated radiation and feeding dielectric body 2, a support 3, a metal bottom plate 4, and a feeding coaxial structure 5

[0051] As Figure 3 、 Figure 4 and Figure 5 shown, after the support 3 is filled between the integrated radiation and feeding dielectric body 2 and the metal bottom plate 4, it is bonded and cured to form a shape, thereby increasing the structural strength of the ultra-wideband antenna. Specifically, the support 3 can adopt polymethacrylimide (PMI) foam with a dielectric constant of 1.1. The depth of the bottom medium of the integrated radiation and feeding dielectric body 2 inserted into the metal bottom plate 4 can be 1 mm. The outer conductor 52 of the feeding coaxial structure 5 is fixedly welded to the metal bottom plate 4, the inner conductor 51 of the feeding coaxial structure 5 is fixedly welded to the upper conductor 131 of the three-dimensional tapered microstrip balun 13, and the lower conductor 132 of the three-dimensional tapered microstrip balun 13 is fixedly welded to the metal bottom plate 4.

[0052] As Figure 6As shown, the radiation dielectric body 21 and the feeding dielectric body 22 of the integrated radiation and feeding dielectric body 2 are integrally designed and manufactured. At the bottom of the dielectric with orthogonal and vertical interconnection, a fillet 24 with a radius of 2 mm is provided at the guide to increase the structural strength of the "T"-shaped dielectric substrate, and two vertical vias 23 with a diameter Ф of 0.8 mm are made at the fillet. The dielectric body can be made of polyimide (PI) with a dielectric constant of 3.4, the tangent of the dielectric loss angle can be 0.0027, and the thicknesses of the radiation dielectric body 21 and the feeding dielectric body 22 can be 0.6 mm.

[0053] As Figure 7 shown, the integrated radiation and feeding circuit 1 includes a radiation dipole arm 11, a metallized via 12, and a three-dimensional tapered microstrip balun 13 with an open end. The three-dimensional tapered microstrip balun 13 is a three-dimensional structure with a trapezoidal taper and the balance end extended and bent, including a metal upper conductor 131 and a metal lower conductor 132 located on both sides of the feeding dielectric body 22, realizing the unbalanced-to-balanced conversion and the impedance transformation function from 50 Ω to 150 Ω. The extended and bent end has two metal pads with a diameter Ф that can be 1.4 mm.

[0054] Preferably, the circuit pattern is manufactured on the integrated radiation and feeding dielectric body 2 by additive manufacturing. The process of pattern manufacturing is as follows: Use laser sintering and curing to form the bottom copper layer, and electroless nickel-palladium-gold plating is carried out on the copper metal layer of the product to ensure good solderability and anti-corrosion performance. The continuous copper layer is prepared on the wall of the vertical via 23 by the method of electroless copper deposition - electroplating thickening to form the metallized via 12 for solderless feeding, and the metallized via 12 is respectively interconnected with the metal pads of the radiation dipole arm 11 and the three-dimensional tapered microstrip balun 13.

[0055] Figure 8 This is a detailed description of the 1×8 tightly coupled antenna array based on the solderless vertical interconnection balanced feeding structure in this embodiment. The antenna unit uses a microstrip dipole antenna based on the solderless vertical interconnection balanced feeding structure. Specifically, the height of the radiation oscillator arm 11 from the metal bottom plate 4 is 8 mm, the element spacing is 12.5 mm, the coupling gap spacing between the radiation oscillator arms 11 is 0.1 mm, PMI foam is filled between the integrated radiation and feeding dielectric body 2 and the metal bottom plate 4 to increase the support strength, and finally the metal bottom plate 4, PMI foam, and the integrated radiation and feeding dielectric body 2 are glued and cured together.

[0056] Specifically, the electromagnetic simulation software is used to perform full-wave simulation on the 1×8 tightly coupled antenna array in the embodiment. The simulation model is set to an infinite large periodic boundary, and the port matching characteristics and far-field radiation performance of the antenna array are obtained. The simulation results are as follows:

[0057] Figure 9The curve of the active voltage standing wave ratio (ActiveVSWR) of the antenna unit in the array versus frequency (Freq) is given. It can be seen that the working bandwidth of the dipole antenna of the present invention is 4GHz-12GHz when the active standing wave ratio is less than 2.5, the relative bandwidth is 100%, and it has good broadband impedance matching characteristics.

[0058] Figure 10 The gain pattern of the E-plane simulation of the 1×8 tightly coupled antenna array is given. It can be seen that the antenna array of the present invention has good far-field radiation performance in the working frequency band of 4GHz-12GHz.

[0059] Figure 11 The gain pattern of the E-plane simulation of the 1×8 tightly coupled antenna array is given. It can be seen that the antenna array of the present invention has good far-field radiation performance in the working frequency band of 4GHz-12GHz.

[0060] In summary, the present invention proposes a solder-free vertical interconnect structure for balanced feeding of ultra-wideband antennas, and introduces an embodiment of the antenna unit in detail. The 1×8 tightly coupled antenna array designed based on this method does not deteriorate the antenna standing wave, nor does it introduce additional radiation loss. It can improve the reliability and consistency of the feeding structure while maintaining good radiation characteristics, and saves a lot of assembly and positioning work of the separate feeding network in terms of large-scale array high-density integration. At the same time, this feeding method can be promoted and applied to the design and manufacture of curved conformal antennas, and has broad application prospects.

[0061] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A solder-free vertical interconnection structure for balanced feeding of ultra-wideband antennas, characterized in that: The invention comprises an integrated radiation and feeding circuit (1), an integrated radiation and feeding dielectric body (2), a support body (3), a metal base plate (4) and a feeding coaxial structure (5); the integrated radiation and feeding dielectric body (2) is configured as a "T"-shaped dielectric base structure for carrying the integrated radiation and feeding circuit (1), and the bottom is connected to the metal base plate (4); the support body (3) is filled between the integrated radiation and feeding dielectric body (2) and the metal base plate (4); the feeding coaxial structure (5) comprises an inner conductor (51) and an outer conductor (52); the inner conductor (51) is connected to the integrated radiation and feeding circuit (1), and the outer conductor (52) is connected to the metal base plate (4).

2. The solder-free vertical interconnect structure for balanced feeding of ultra-wideband antenna according to claim 1, characterized in that: The integrated radiation and feeding dielectric body (2) comprises a radiation dielectric body (21) and a feeding dielectric body (22); the radiation dielectric body (21) and the feeding dielectric body (22) are connected in an integrated manner and are orthogonally and vertically interconnected.

3. The solder-free vertical interconnect structure for balanced feeding of ultra-wideband antenna according to claim 2, characterized in that: The integrated radiation and feeding dielectric body (2) further comprises a vertical via hole (23) for feeding, wherein the vertical via hole (23) is arranged on both sides of the connection between the radiation dielectric body (21) and the feeding dielectric body (22).

4. The solder-free vertical interconnect structure for balanced feeding of ultra-wideband antenna according to claim 2, characterized in that: The integrated radiation and feeding dielectric body (2) further comprises a rounded corner structure (24), wherein the rounded corner structure (24) is arranged at the connection between the radiation dielectric body (21) and the feeding dielectric body (22).

5. The solder-free vertical interconnect structure for balanced feeding of ultra-wideband antenna according to claim 1, characterized in that: The integrated radiation and feeding circuit (1) comprises a radiation dipole arm (11), a metallized through hole (12), and a three-dimensional gradient microstrip balun (13) with an open end; the radiation dipole arm (11) is connected to the three-dimensional gradient microstrip balun (13) via the metallized through hole (12).

6. The solder-free vertical interconnect structure for balanced feeding of ultra-wideband antenna according to claim 5, characterized in that: The three-dimensional gradient microstrip balun (13) is configured as a three-dimensional structure with a trapezoidal gradient and an extended and bent balance end.

7. The solder-free vertical interconnect structure for balanced feeding of ultra-wideband antenna according to claim 5, characterized in that: The three-dimensional gradient microstrip balun (13) comprises an upper conductor (131) and a lower conductor (132), wherein the upper conductor and the lower conductor (132) are respectively located on two sides of a feeding dielectric body (22) of an integrated radiation and feeding dielectric body (2).

8. The solder-free vertical interconnect structure for balanced feeding of ultra-wideband antenna according to claim 6, characterized in that: The outer conductor (52) of the feeding coaxial structure (5) is fixedly welded to the metal base plate (4), the inner conductor (51) is fixedly welded to the upper conductor (131) of the three-dimensional gradient microstrip balun (13), and the lower conductor (132) of the three-dimensional gradient microstrip balun (13) is fixedly welded to the metal base plate (4).

9. The solder-free vertical interconnect structure for balanced feeding of ultra-wideband antenna according to claim 5, characterized in that: An integrated radiation and feeding circuit (1) is manufactured on an integrated radiation and feeding dielectric body (2) by means of additive manufacturing, comprising: Based on a laser micro-cladding additive manufacturing method, a radiation dipole arm (11) and a three-dimensional gradient microstrip balun (13) are manufactured on an integrated radiation and feeding dielectric body (2); Based on a chemical copper deposition-electroplating thickening method, a continuous copper layer is prepared on a vertical via hole (23) of an integrated radiation and feeding dielectric body (2) to form a solder-free metallized through hole (12), and the metallized through hole (12) is interconnected with the metal pads of the radiation dipole arm (11) and the three-dimensional gradient microstrip balun (13) respectively.

10. The solder-free vertical interconnect structure for balanced feeding of ultra-wideband antenna according to claim 1, characterized in that: The support body (3) comprises a filling foam, wherein the filling foam comprises a polymethacrylimide foam having a dielectric constant of 1.1.

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