Phased array film antenna and method of making same

Abstract

The application relates to the field of low-orbit satellite communication antennas, and discloses a phased array film antenna and a preparation method thereof. The phased array film antenna comprises a first support and a second support. A driving radiation layer is arranged on the first support and located between the first support and the second support. A parasitic radiation layer is arranged on the second support and located on the side of the second support away from the driving radiation layer. The driving radiation layer and the parasitic radiation layer both comprise a PET film and a copper-based array unit arranged on the upper surface of the PET film. The copper-based array unit of the driving radiation layer corresponds to the copper-based array unit of the parasitic radiation layer in a one-to-one manner. A plurality of air medium layers are arranged on the second support and penetrate the upper and lower surfaces of the second support. The air medium layers are located between the copper-based array unit of the driving radiation layer and the copper-based array unit of the parasitic radiation layer. An adhesive layer is arranged on the upper and lower surfaces of the second support to adhesively fix the driving radiation layer and the parasitic radiation layer. The application improves the comprehensive performance of the antenna.

Description

Technical Field

[0001] This application relates to the field of low-orbit satellite communication antenna technology, specifically to a phased array thin-film antenna and its fabrication method. Background Technology

[0002] With the large-scale deployment of low-Earth orbit satellite internet, ground terminal phased array antennas are developing towards lightweight, low-cost, high-frequency, and high-performance designs. Currently, the mainstream Ku-band (10.7-14.5GHz) antenna solutions fall into two categories: one is a thin-film antenna formed by printing silver paste onto a PET substrate. While this approach aligns with the trend towards lightweight antennas, the high cost of silver paste, low printing precision, and susceptibility to oxidation and sulfidation lead to insufficient long-term antenna reliability; the other is a phased array antenna based on a multilayer rigid PCB (using high-frequency substrates such as hydrocarbon resin or PTFE). However, this approach is hampered by the high cost of high-frequency substrates, complex multilayer lamination processes, and low yield rates, hindering the development of lightweight terminals. Therefore, designing a lightweight, low-cost, and high-performance thin-film antenna has become a pressing technical challenge. Summary of the Invention

[0003] In view of this, this application provides a phased array thin-film antenna and its fabrication method to solve the aforementioned technical problems.

[0004] In a first aspect, embodiments of this application disclose a phased array thin-film antenna applied in the 10.7-14.5 GHz band, comprising: A first bracket and a second bracket disposed above the first bracket; A driving radiation layer is disposed on the first support and located between the first support and the second support; A parasitic radiation layer is disposed on the second support and located on the side of the second support opposite to the driving radiation layer. Both the driving radiation layer and the parasitic radiation layer include a PET film and copper-based array units disposed on the upper surface of the PET film. The copper-based array units of the driving radiation layer correspond one-to-one with the copper-based array units of the parasitic radiation layer. Both the driving radiation layer and the copper-based array units of the parasitic radiation layer are provided with a protective layer covering the surface of the copper-based array units. An air dielectric layer, a plurality of said air dielectric layers are arranged on the second support and penetrate the upper and lower surfaces of the second support, and said air dielectric layers are located between the copper-based array units of the driving radiation layer and the copper-based array units of the parasitic radiation layer; An adhesive layer is provided on the upper and lower surfaces of the second bracket to bond and fix the driving radiation layer and the parasitic radiation layer.

[0005] In one possible example, in a direction perpendicular to the upper and lower surfaces of the second support, the vertical projection of the copper-based array element of the parasitic radiation layer overlaps the vertical projection of the copper-based array element of the driving radiation layer.

[0006] In one possible example, the adhesive layer has a window in the vertical projection area corresponding to the air medium layer in a direction perpendicular to the upper and lower surfaces of the second bracket.

[0007] In one possible example, the protective layer includes a nickel-phosphorus-carbon alloy layer, a tin layer, or an insulating ink layer.

[0008] In one possible example, the protective layer is a nickel-phosphorus-carbon alloy layer, and the thickness of the nickel-phosphorus-carbon alloy layer is 1-5 μm.

[0009] In one possible example, the PET film has a thickness of 0.08-0.25 mm, the copper-based array unit has a thickness of 3-18 μm, and the air dielectric layer has a thickness of 0.5-2 mm.

[0010] In one possible example, the first and second supports are injection molded from polyphenylene ether or polyphenylene sulfide plastic, and the dielectric loss tanδ ≤ 0.002.

[0011] Secondly, this application discloses a method for fabricating a phased array thin-film antenna, used to fabricate the phased array thin-film antenna described in any of the above embodiments, comprising: Copper foil is pressed onto the surface of PET film using an adhesive to form a PET copper foil composite material; After the PET copper foil composite material is wound up, it is reverse-wound and cured at 50-120℃ for 5-30 hours, and then wound up again under low tension to reduce the internal stress of the material. A dry film is pressed onto the surface of the PET copper foil composite material, and an antenna array pattern mask is formed by exposure and development. Based on the antenna array pattern mask, the copper foil is etched to form copper-based array units on the upper surface of the PET film; The PET film and the copper-based array units on the upper surface of the PET film constitute the driving radiation layer and the parasitic radiation layer of the phased array thin-film antenna.

[0012] In one possible example, the copper foil is low-roughness rolled copper or electrolytic copper, with a copper tooth height ≤1μm; the copper foil thickness is 3-18μm.

[0013] In summary, compared with the prior art, this application discloses a phased array thin-film antenna and its fabrication method. The phased array thin-film antenna uses PET film instead of traditional rigid PCB substrate as the carrier of the radiating layer, and in conjunction with the stacked support structure of the first and second supports, the driving radiating layer is sandwiched between the two supports, and the parasitic radiating layer is set on the outside of the second support. At the same time, the air dielectric layer penetrating the upper and lower surfaces of the second support forms a low dielectric constant air gap between the corresponding copper-based array units to ensure the high performance requirements of the antenna. The driving radiating layer and the parasitic radiating layer are fixed by adhesive layer. Thus, the whole constitutes a lightweight thin-film stacked architecture, which significantly reduces weight and simplifies the lamination process and reduces material costs compared with the multilayer PCB rigid board solution. At the same time, the copper-based array units can avoid the problems of high cost of silver paste, low printing accuracy and easy oxidation and sulfidation leading to insufficient long-term reliability. Furthermore, the flexible characteristics of PET film fit the development direction of lightweight antennas, thus effectively taking into account the comprehensive requirements of low-orbit satellite communication terminals for lightweight, low cost and high frequency performance antennas. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of a phased array thin-film antenna according to an embodiment of this application; Figure 2 This is another structural schematic diagram of the phased array thin-film antenna according to an embodiment of this application; Figure 3 This is a flowchart of the phased array thin-film antenna fabrication method according to an embodiment of this application; Figure 4 This is a schematic diagram of a structural change in the fabrication process of the phased array thin-film antenna according to an embodiment of this application. Detailed Implementation

[0016] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the claims.

[0017] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0018] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0019] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" may be used interchangeably.

[0020] In the description of this application, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] The technical solutions shown in this application will be described in detail below through specific embodiments. It should be noted that the order of description of the following embodiments is not intended to limit the priority of the embodiments.

[0022] Please refer to Figure 1 As a preferred embodiment of this application, the phased array thin-film antenna includes a first support 1, a second support 2, a driving radiation layer 3, a parasitic radiation layer 4, an air dielectric layer 5, and an adhesive layer 6.

[0023] In the specific implementation process, the second bracket 2 is located above the first bracket 1. The first bracket 1 serves as the bottom support base of the entire phased array thin-film antenna, providing a stable physical support platform for the upper structure. The second bracket 2 is located above the first bracket 1, and the two together constitute the antenna's skeleton structure.

[0024] Furthermore, the driving radiation layer 3 is disposed on the first support 1 and located between the first support 1 and the second support 2, and the parasitic radiation layer 4 is disposed on the second support 2 and located on the side of the second support 2 away from the driving radiation layer 3. Both the driving radiation layer 3 and the parasitic radiation layer 4 include a PET film 10 and a copper-based array unit 11 disposed on the upper surface of the PET film 10. The copper-based array unit 11 of the driving radiation layer 3 corresponds one-to-one with the copper-based array unit 11 of the parasitic radiation layer 4.

[0025] The driving radiating layer 3 is the core active part of the antenna, directly connected to the feed network, used to convert electrical signals into electromagnetic wave energy for outward radiation. Its placement on the first support 1 utilizes the large area provided by the first support 1 to prevent the thin film layer from sagging or deforming due to gravity or external forces. The parasitic radiating layer 4, as a passive coupling layer, amplifies and radiates signals through electromagnetic coupling with the driving radiating layer 3. This effectively extends the antenna's impedance bandwidth and improves its gain. It is particularly suitable for wideband (Ku-band) applications in the 10.7-14.5 GHz range.

[0026] The PET film 10, as a flexible substrate, has the advantages of low cost, stable dielectric constant, and ease of processing. The copper-based array units 11 on its upper surface achieve processing accuracy superior to traditional silver paste printing (e.g., ±0.02 mm). The copper-based array units 11 of the driving radiating layer 3 and the parasitic radiating layer 4 are in a one-to-one correspondence. This aligned arrangement ensures the strongest coupling efficiency, enabling the parasitic radiating layer 4 to be effectively excited by the driving radiating layer 3. Furthermore, the shape of the copper-based array units 11 can be a rectangular patch, a circular patch, or a ring patch, etc., the specific shape determined by the required polarization and radiation characteristics of the antenna.

[0027] It should be noted that the copper-based array units 11 are arranged in an array on the surface of the PET film 10. For example, if an XY plane coordinate is constructed on the upper surface of the PET film 10, then multiple copper-based array units 11 are arranged at equal intervals along the first direction (X direction) and the second direction perpendicular to the first direction (Y direction). The center spacing (i.e., the element spacing) between two adjacent copper-based array units 11 can be set to 0.5λ0 to 0.8λ0 in the 10.7-14.5GHz frequency band (λ0 is the wavelength of the center frequency of the corresponding frequency band in free space).

[0028] Furthermore, several air dielectric layers 5 are arranged on the second support 2 and penetrate the upper and lower surfaces of the second support 2. The air dielectric layers 5 are located between the copper-based array unit 11 of the driving radiation layer 3 and the copper-based array unit 11 of the parasitic radiation layer 4.

[0029] Specifically, the air dielectric layer 5 is a structural unit composed of several through holes or hollow areas, essentially utilizing air as the primary medium for electromagnetic wave transmission. Since air has a dielectric constant close to 1 and extremely low dielectric loss (tanδ≈0), introducing the air dielectric layer 5 significantly reduces the average dielectric constant of the effective medium between the radiating layers, thereby reducing electromagnetic wave transmission loss within the dielectric layer. The air dielectric layer 5 penetrates the upper and lower surfaces of the second support 2, allowing direct coupling between the copper-based array units 11 driving the radiating layer 3 and the copper-based array units 11 of the parasitic radiating layer 4 through air gaps, rather than being completely filled by a high-dielectric-constant solid support material. Several air dielectric layers 5 are arranged in an array on the second support 2, their arrangement matching the distribution of the copper-based array units 11. This maximizes the optimization of the electromagnetic environment while ensuring the second support 2 has sufficient mechanical strength to support the parasitic radiating layer 4.

[0030] It should be noted that the adhesive layer 6 is provided on the upper and lower surfaces of the second bracket 2 to bond and fix the driving radiation layer 3 and the parasitic radiation layer 4. By setting the adhesive layer 6, the driving radiation layer 3, the second bracket 2 and the parasitic radiation layer 4 can be firmly combined into an integral module, improving the structural rigidity and vibration resistance of the antenna and simplifying the assembly process of the whole device.

[0031] The adhesive layer 6 can also be disposed between the driving radiation layer 3 and the upper surface of the first support 1 to fix the connection between the driving radiation layer 3 and the first support 1.

[0032] Optionally, the adhesive layer 6 can be in the form of double-sided adhesive, liquid optical adhesive, or hot melt adhesive film. Preferably, the adhesive layer 6 is a hot melt adhesive film with low dielectric constant and low loss.

[0033] Therefore, in this embodiment, the phased array thin-film antenna uses PET film 10 instead of the traditional rigid PCB substrate as the carrier of the radiating layer. In conjunction with the stacked support structure of the first bracket 1 and the second bracket 2, the driving radiating layer 3 is sandwiched between the two brackets, and the parasitic radiating layer 4 is disposed on the upper surface of the second bracket 2. At the same time, the air dielectric layer 5 that penetrates the upper and lower surfaces of the second bracket 2 forms a low dielectric constant air gap between the corresponding copper-based array units 11 to ensure the high performance requirements of the antenna. The driving radiating layer 3 and the parasitic radiating layer 4 are bonded and fixed by the adhesive layer 6. Thus, a lightweight thin-film stacked architecture is formed as a whole. Compared with the multilayer PCB rigid board solution, the weight is greatly reduced, the lamination process is simplified, and the material cost is reduced. At the same time, the copper-based array unit 11 can avoid the problems of high cost of silver paste material, low printing accuracy, and easy oxidation and sulfidation leading to insufficient long-term reliability. Furthermore, the flexible characteristics of PET film 10 fit the trend of lightweight antenna development, thus effectively taking into account the comprehensive requirements of low-orbit satellite communication terminals for antenna lightweight, low cost, and high frequency performance.

[0034] In one example, the adhesive layer 6 has a window in the direction perpendicular to the upper and lower surfaces of the second support 2, corresponding to the vertical projection area of ​​the air dielectric layer 5. That is, the adhesive layer 6 is connected to the upper and lower surfaces of the second support 2, excluding the air dielectric layer 5. This achieves effective fixation of the radiating layer by the adhesive layer 6 and maintains the low-loss characteristics of the air dielectric layer 5. This structure ensures that the air dielectric layer 5 is unobstructed from top to bottom, maintaining a pure air dielectric environment and avoiding the increase in dielectric constant and loss caused by colloid infiltration. This ensures the signal transmission efficiency and radiation performance of the antenna at high frequencies, improving the overall reliability and electrical performance consistency of the phased array thin-film antenna.

[0035] As another preferred embodiment of this application, reference is made to Figure 2 The phased array thin-film antenna includes a first support 1, a second support 2, a driving radiating layer 3, a parasitic radiating layer 4, an air dielectric layer 5, and a thermoplastic column 7. That is, while the first support 1, the second support 2, the driving radiating layer 3, the parasitic radiating layer 4, and the air dielectric layer 5 are configured the same as in the previous embodiment, this embodiment has a different design for the thermoplastic column 7 than the adhesive layer 6 in the previous embodiment. Specifically, the thermoplastic column 7 is located above the first support 1 and sequentially connects the parasitic radiating layer 4, the second support 2, and the driving radiating layer 3.

[0036] Therefore, unlike the adhesive layer 6, this embodiment uses a hot-melt column 7 to connect the parasitic radiation layer 4, the second support 2, and the driving radiation layer 3 to achieve reliable fixation of the antenna without an adhesive layer. Overall, this constitutes a lightweight thin-film laminated architecture, significantly reducing weight and simplifying the lamination process compared to multilayer PCB rigid board solutions, while lowering material costs. Furthermore, replacing silver paste printing patterns with copper-based array units 11 avoids the problems of high silver paste material cost, low printing accuracy, and easy oxidation and sulfidation leading to insufficient long-term reliability. The flexible characteristics of the PET film 10 also align with the lightweight development trend of antennas, effectively meeting the comprehensive requirements of low-orbit satellite communication terminals for lightweight, low-cost, and high-frequency high-performance antennas.

[0037] The thermoplastic post 7 offers the advantage of easy replacement. When the antenna needs repair, simply heat the head of the thermoplastic post 7 to melt it, allowing for the seamless separation of the parasitic radiation layer 4, the second support 2, and the driving radiation layer 3. After replacing the damaged thin film layer, a new thermoplastic post 7 can be used for fixation. In other words, the thermoplastic post 7 functions as a thermoplastic screw.

[0038] Preferably, a plurality of hot-melt columns 7 are evenly distributed and avoid the copper-based array unit 11 of the driving radiation layer 3 and the parasitic radiation layer 4.

[0039] Based on any of the foregoing embodiments, in one example, in a direction perpendicular to the upper and lower surfaces of the second support 2, the vertical projection of the copper-based array unit 11 of the parasitic radiation layer 4 covers the vertical projection of the copper-based array unit 11 of the driving radiation layer 3.

[0040] Because the copper-based array elements 11 of the parasitic radiating layer 4 completely cover the copper-based array elements 11 of the driving radiating layer 3 in vertical projection, the parasitic radiating layer 4 is always located in the near-field strong coupling region of the driving radiating layer 3, maximizing the energy transfer efficiency of interlayer electromagnetic coupling. This effectively solves the problems of decreased coupling coefficient, limited bandwidth expansion, and increased gain fluctuation caused by the misalignment of the two radiating elements. Thus, while ensuring the antenna is lightweight and low-cost, it significantly improves the overall radiation performance and beam scanning stability of the phased array thin-film antenna in the 10.7-14.5 GHz band.

[0041] Based on any of the foregoing embodiments, in one example, the copper-based array units 11 of the driving radiation layer 3 and the parasitic radiation layer 4 are both provided with a protective layer 12. The protective layer 12 covers the surface of the copper-based array unit 11 to isolate the metal surface of the copper-based array unit 11 from corrosive media (such as oxygen, sulfides, etc.) in the external environment, thereby avoiding the increase in high-frequency loss due to the increase in resistance.

[0042] Optionally, the protective layer 12 may include a nickel-phosphorus-carbon alloy layer, a tin layer, or an insulating ink layer to ensure the protective effect of the protective layer 12.

[0043] Preferably, the protective layer 12 is a nickel-phosphorus-carbon alloy layer. As a protective coating covering the surface of the copper-based array unit 11, the nickel-phosphorus-carbon alloy layer primarily provides a dense physical barrier to isolate oxygen, sulfur vapor, and corrosive media from the external environment, thereby preventing oxidation, sulfidation, or electrochemical corrosion of the copper-based array unit 11. When using a nickel-phosphorus-carbon alloy layer, its coating thickness can be 1-5 μm to achieve a balance between protective performance and coating quality. A nickel-phosphorus-carbon alloy layer of this thickness can pass the double 85 test (i.e., 85°C, 85% relative humidity environment) for over 1000 hours without corrosion. When using a tin layer, the coating thickness can be, for example, 2-3 μm; when using an insulating ink layer, its thickness can be, for example, 5-10 μm.

[0044] Based on any of the foregoing embodiments, in one example, the thickness of the PET film 10 is 0.08-0.25 mm, the thickness of the copper-based array unit 11 is 3-18 μm, and the thickness of the air dielectric layer 5 is 0.5-2 mm.

[0045] Specifically, the thickness of the PET film 10 is limited to between 0.08 and 0.25 mm to balance the physical properties of the film with the requirements of lightweighting. When the thickness is less than 0.08 mm, the PET film 10 is very prone to tearing or breakage in subsequent etching, assembly and other processes, and its anti-warping ability is significantly reduced, making it difficult to maintain flatness, which in turn affects the consistency of the antenna array unit. When the thickness is greater than 0.25 mm, although the mechanical strength is improved, it will significantly increase the overall weight of the antenna, reduce flexibility, and the excessively thick substrate will increase dielectric loss, which is not conducive to the transmission of high-frequency signals.

[0046] The thickness of the copper-based array element 11 is limited to 3-18 μm, based on a comprehensive consideration of conductivity, processing technology, and cost-effectiveness. As a conductive layer, the thickness of copper directly affects the antenna's radiation efficiency and signal transmission loss. If the thickness is less than 3 μm, the conductive cross-section of the copper layer is insufficient, leading to increased ohmic loss, reduced antenna radiation efficiency, and a tendency for over-etching during the etching process, making linewidth accuracy difficult to control. If the thickness is greater than 18 μm, although conductivity is further improved, excessively thick copper foil will cause severe lateral etching during etching, resulting in increased geometric deviations in the fine patterns, affecting the antenna's electrical performance in the Ku-band, and also increasing material cost and overall weight. Controlling the thickness of the copper-based array element 11 to 3-18 μm satisfies the low-loss conductivity requirements in the 10.7-14.5 GHz frequency band while also accommodating high-precision FPC etching processes, ensuring that the array element's geometry meets design tolerances.

[0047] The thickness of the air dielectric layer 5, ranging from 0.5 to 2 mm, determines the electromagnetic coupling strength between the driving radiating layer 3 and the parasitic radiating layer 4. When the thickness is less than 0.5 mm, the coupling between the two layers is too strong, easily leading to resonant frequency splitting, thus narrowing the effective operating bandwidth of the antenna and making it difficult to cover the wideband requirement of 10.7-14.5 GHz. When the thickness is greater than 2 mm, the coupling strength weakens. Although the bandwidth may increase, it will lead to a decrease in the antenna's radiation efficiency and an increase in profile height, which is not conducive to the thin and light design of terminal equipment. Through the synergistic optimization of the above three key dimensions, this application constructs a high-performance microwave transmission structure. The PET film 10 provides stable and thin mechanical support, the copper-based array unit 11 ensures efficient electromagnetic energy conversion, and the precisely controlled air dielectric layer 5 optimizes interlayer coupling and impedance matching. The combined effect of these three elements enables the phased array thin-film antenna to have excellent VSWR characteristics, high gain, and good amplitude and phase consistency between units in the Ku band.

[0048] Based on any of the foregoing embodiments, in one example, the first support 1 and the second support 2 are injection molded from polyphenylene ether or polyphenylene sulfide plastic, and the dielectric loss tanδ ≤ 0.002. In the high-frequency electromagnetic environment of the Ku band (10.7-14.5GHz), this effectively suppresses the polarization hysteresis effect and heat conversion generated when electromagnetic waves propagate within the medium, thereby reducing energy loss during signal transmission. This significantly improves the antenna's radiation efficiency and gain performance.

[0049] Based on any of the foregoing embodiments, the phased array thin-film antenna of this application further includes a radome, which is disposed above the parasitic radiation layer 4 and covers the first support 1, the second support 2, and the driving radiation layer 3. As the outermost protective component of the phased array thin-film antenna, the radome provides physical protection for the internal antenna structure, isolating harmful factors such as moisture, dust, salt spray, and ultraviolet radiation from the external environment, while ensuring efficient transmission of electromagnetic wave signals. The radome is typically made of a wave-transmitting material with low dielectric constant and low dielectric loss, such as polycarbonate (PC), acrylonitrile-butadiene-styrene copolymer (ABS), or fiberglass composite materials.

[0050] Based on any of the foregoing embodiments, the phased array thin-film antenna of this application further includes a PCB control board 8, with the first support 1 disposed on the PCB control board 8. As the electrical control core of the antenna, the PCB control board 8 not only supports the first support 1, but also integrates electronic components such as RF front-end circuits, beam control chips, and power management modules to achieve precise power distribution and phase control of each copper-based array unit 11.

[0051] Continue to refer to Figure 3 and Figure 4 This application also provides a method for fabricating a phased array thin-film antenna, which can fabricate any of the phased array thin-film antennas described in the foregoing embodiments.

[0052] Specifically, the fabrication methods for phased array thin-film antennas include: S201, copper foil 11a is pressed onto the upper surface of PET film 10 using adhesive 11b to form PET copper foil composite material.

[0053] Optionally, the adhesive 11b is an epoxy resin or a transparent epoxy adhesive, with a uniform coating thickness to ensure a tight and bubble-free bond between the copper foil 11a and the PET film 10. Through a lamination process, the copper foil 11a is firmly attached to the PET film 10, forming a PET copper foil composite material.

[0054] In one example, copper foil 11a is low-roughness rolled copper or electrolytic copper with a copper tooth height ≤1μm to ensure the accuracy of subsequent etching processes. The thickness of copper foil 11a is 3-18μm.

[0055] S202 involves rewinding the PET copper foil composite material after winding it up, curing it at 50-120℃ for 5-30 hours, and then winding it up again under low tension to reduce the internal stress of the material.

[0056] In this step, the PET copper foil composite material obtained in the previous steps is wound up, then reverse-wound, and cured at a temperature of 50-120°C for 5-30 hours. The curing process is preferably carried out at a constant temperature of 75°C for 24 hours. This low-temperature, long-time curing process promotes the full cross-linking reaction of the polymer chains in the adhesive 11b, while simultaneously releasing the mechanical and thermal stresses generated during the pressing process.

[0057] After curing, the material is rewound using a low-tension winding method. Through the synergistic effect of reverse winding, low-temperature curing, and low-tension winding, residual stress inside the PET copper foil composite material can be effectively eliminated, preventing warping or deformation of the material during subsequent processing or use. This ensures the warpage of the finished antenna and guarantees the flatness and reliability of the finished antenna under harsh temperature cycling environments.

[0058] The resulting PET copper foil composite material exhibits dimensional stability with MD (Machine Direction) ≤ ±0.03% and TD (Transverse Direction) ≤ ±0.03%. In other words, the absolute value of the dimensional change rate does not exceed 0.03%.

[0059] S203, a dry film 11c is pressed onto the surface of a PET copper foil composite material, and an antenna array pattern mask 11d is formed by exposure and development.

[0060] In this step, a photoresist dry film 11c is laminated onto the surface of the cured PET copper foil composite material. This dry film 11c covers the surface of the copper foil 11a and serves as a photosensitive medium for subsequent pattern transfer. The dry film 11c is exposed, and after exposure, the areas of the dry film that have not undergone photopolymerization are removed, while the polymerized areas are retained, thereby forming an antenna array pattern mask 11d on the surface of the copper foil 11a that perfectly matches the shape of the copper-based array unit 11. This mask precisely covers the copper-based circuit areas that need to be retained and exposes the excess copper foil areas that need to be etched away, providing an accurate photolithographic template for high-precision pattern transfer.

[0061] S204, based on the antenna array pattern mask 11d, copper foil 11a is etched to form copper-based array units 11 on the upper surface of PET film 10.

[0062] In this step, the PET copper foil composite material is etched using the antenna array pattern mask 11d formed in the previous steps as a resist layer. The etching solution, for example, is an acidic copper chloride etching solution or an alkaline etching solution, which chemically reacts with the exposed copper foil not covered by the mask, dissolving and removing excess copper material; while the copper foil in the area covered by the antenna array pattern mask 11d is protected and completely preserved. After etching reaches a predetermined depth and thoroughly removing excess copper foil, the resist layer is removed, thereby forming a copper-based array unit 11 with a precise geometric shape on the upper surface of the PET film 10.

[0063] The copper-based array element 11 constitutes the radiating conductor of the phased array thin-film antenna. Its etching accuracy can reach ±0.02mm, which significantly improves the dimensional accuracy and edge steepness compared with the traditional silver paste printing process, and effectively reduces the high-frequency loss of the Ku band.

[0064] In one example, a protective layer 12 may also be formed on the outer surface of the copper-based array unit 11. The protective layer 12 may include a nickel-phosphorus-carbon alloy layer, a tin layer, or an insulating ink layer.

[0065] S205, the PET film 10 and the copper-based array unit 11 on the upper surface of the PET film 10 constitute the driving radiation layer 3 and the parasitic radiation layer 4 of the phased array thin film antenna.

[0066] Through the above process steps, the PET copper foil composite material is pressed, stress-relieved, photolithographic pattern transfer and etching to finally form a high-precision, low-warpage driving radiation layer 3 and parasitic radiation layer 4, providing a reliable process implementation path for the lightweight, low-cost and high-performance manufacturing of phased array thin film antennas.

[0067] It is understood that the above preparation method describes the formation of the driving radiation layer 3 and the parasitic radiation layer 4. Based on this, the preparation process may further include: providing a first support 1 and a second support 2 for assembly; placing the driving radiation layer 3 on the first support 1 and between the first support 1 and the second support 2; placing the parasitic radiation layer 4 on the second support 2 and on the side of the second support 2 opposite to the driving radiation layer 3; arranging an air dielectric layer 5 on the second support 2 and penetrating the upper and lower surfaces of the second support 2, with the air dielectric layer 5 located between the copper-based array units 11 of the driving radiation layer 3 and the copper-based array units 11 of the parasitic radiation layer 4.

[0068] The adhesive layer 6 is placed on the upper and lower surfaces of the second support 2 to bond and fix the driving radiation layer 3 and the parasitic radiation layer 4; or the hot melt column 7 is placed above the first support 1 and sequentially connects the parasitic radiation layer 4, the second support 2 and the driving radiation layer 3.

[0069] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only for the purpose of helping to understand the core ideas of the present application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present application. Therefore, the content of this specification should not be construed as a limitation of the present application.

Claims

1. A phased array thin-film antenna for use in the 10.7-14.5 GHz band, characterized in that, include: A first bracket and a second bracket disposed above the first bracket; A driving radiation layer is disposed on the first support and located between the first support and the second support; A parasitic radiation layer is disposed on the second support and located on the side of the second support opposite to the driving radiation layer. Both the driving radiation layer and the parasitic radiation layer include a PET film and copper-based array units disposed on the upper surface of the PET film. The copper-based array units of the driving radiation layer correspond one-to-one with the copper-based array units of the parasitic radiation layer. Both the driving radiation layer and the copper-based array units of the parasitic radiation layer are provided with a protective layer covering the surface of the copper-based array units. An air dielectric layer, a plurality of said air dielectric layers are arranged on the second support and penetrate the upper and lower surfaces of the second support, and said air dielectric layers are located between the copper-based array units of the driving radiation layer and the copper-based array units of the parasitic radiation layer; An adhesive layer is provided on the upper and lower surfaces of the second bracket to bond and fix the driving radiation layer and the parasitic radiation layer.

2. The phased array thin-film antenna as described in claim 1, characterized in that, In a direction perpendicular to the upper and lower surfaces of the second support, the vertical projection of the copper-based array unit of the parasitic radiation layer overlaps the vertical projection of the copper-based array unit of the driving radiation layer.

3. The phased array thin-film antenna as described in claim 1, characterized in that, In a direction perpendicular to the upper and lower surfaces of the second bracket, the adhesive layer has a window in the vertical projection area corresponding to the air medium layer.

4. The phased array thin-film antenna as described in claim 1, characterized in that, The protective layer includes a nickel-phosphorus-carbon alloy layer, a tin layer, or an insulating ink layer.

5. The phased array thin-film antenna as described in claim 4, characterized in that, The protective layer is a nickel-phosphorus-carbon alloy layer, and the thickness of the nickel-phosphorus-carbon alloy layer is 1-5 μm.

6. The phased array thin-film antenna as described in claim 1, characterized in that, The PET film has a thickness of 0.08-0.25 mm, the copper-based array unit has a thickness of 3-18 μm, and the air dielectric layer has a thickness of 0.5-2 mm.

7. The phased array thin-film antenna as described in claim 1, characterized in that, The first and second supports are injection molded from polyphenylene ether or polyphenylene sulfide plastic, and the dielectric loss tanδ≤0.

002.

8. A method for fabricating a phased array thin-film antenna, used to fabricate the phased array thin-film antenna according to any one of claims 1 to 7, characterized in that, include: Copper foil is pressed onto the surface of PET film using an adhesive to form a PET copper foil composite material; After the PET copper foil composite material is wound up, it is reverse-wound and cured at 50-120℃ for 5-30 hours, and then wound up again under low tension to reduce the internal stress of the material. A dry film is pressed onto the surface of the PET copper foil composite material, and an antenna array pattern mask is formed by exposure and development. Based on the antenna array pattern mask, the copper foil is etched to form copper-based array units on the upper surface of the PET film; The PET film and the copper-based array units on the upper surface of the PET film constitute the driving radiation layer and the parasitic radiation layer of the phased array thin-film antenna.

9. The method for fabricating a phased array thin-film antenna as described in claim 8, characterized in that, The copper foil is low-roughness rolled copper or electrolytic copper, with a copper tooth height ≤1μm; the thickness of the copper foil is 3-18μm.

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