Air medium laminated coupling flexible thin film phased array antenna and preparation method

Abstract

The application discloses an air medium laminated coupling flexible thin film phased array antenna and belongs to the technical field of phased array. The antenna comprises a positioning assembly coaxial, and a protective antenna cover, an upper parasitic thin film radiation layer, a hollow support medium unit, a lower driven thin film radiation layer, an active circuit module, a beam forming module and a circular hollow support structure which are coaxially nested and laminated from top to bottom and are integrally assembled and formed. The thin film antenna unit adopts a double-layer coupling structure of the upper parasitic thin film radiation layer and the lower driven thin film radiation layer, is supported by a hexagonal and circular combined hollow support structure, and is surrounded by adjacent laminated layers to form an air medium filled cavity as a closed filled cavity of the only electromagnetic coupling transmission medium, so that fast electronic scanning of pure electronic beams is realized, and radio frequency transmission loss is greatly reduced. The phased array has the advantages of flexibility, wide band, low loss, lightness, bendability and low-cost batch production.

Description

Technical Field

[0001] This invention belongs to the technical field of phased array antenna structure design and flexible radio frequency communication devices. It is an interdisciplinary field of microwave antennas and flexible electronics, involving technologies related to flexible thin film antennas, phased array antennas and microwave / millimeter wave devices. It can be applied to conformal installation scenarios of low-altitude economic UAV airborne communication, low-orbit broadband satellite communication terminals, and vehicle-mounted mobile communication systems. It is compatible with the industrialization of lightweight civilian low-orbit satellite communication terminals, and can also meet the usage needs of wearable devices, curved carriers, airborne flexible communication, low-altitude communication and portable radar. Background Technology

[0002] Low-Earth orbit (LEO) satellite internet communication, with its technological advantages of high-speed, full-area coverage through constellation networking, low-latency transmission, and high-capacity concurrent transmission, has been widely adopted in fields such as civilian broadband access, emergency communication in the field, all-weather networking for mobile devices, and aerospace special communications. The core component of lightweight civilian LEO satellite communication terminals is the phased array antenna. The antenna's slim and lightweight structure, conformal adaptation capability, low-loss RF transmission characteristics, wideband performance, and low-cost mass production capabilities directly determine the overall installation compatibility of the communication terminal, the stability of the communication link, and the degree of market penetration.

[0003] Currently, phased array antennas for satellite communication in existing technologies generally use traditional rigid PCB multilayer boards as the core dielectric substrate, coupled with multilayer patch-coupled antenna structures, and designed as flat panel antenna structures using AIP (Air-In-Package) technology. This traditional structure has many inherent technical shortcomings in practical engineering applications, making it difficult to meet the stringent requirements of next-generation lightweight low-Earth orbit satellite communication terminals and mobile carriers such as drones and vehicles. The core defects are concentrated in the following aspects: First, there is high loss and narrow bandwidth. Traditional antennas rely on high dielectric constant PCB substrates and multilayer lamination processes for molding. The dielectric itself will generate large radio frequency signal transmission loss, and the antenna's working bandwidth is severely limited. It cannot meet the high-frequency band, large bandwidth and high-speed data transmission requirements of low-orbit satellites, and is prone to problems such as severe signal attenuation, large fluctuations in communication rate and poor link stability. Secondly, it is rigid and cannot be conformally adapted. The rigid PCB substrate has poor bending performance and high structural rigidity, making it impossible to achieve conformal installation on the curved and irregular surfaces of the carrier. In addition, the antenna is thick and heavy, which brings great load pressure and installation space limitations to drones, small vehicles and portable terminals. Third, the process is complicated and the mass production cost is high. Traditional multilayer PCB patch antennas require multiple complex processing steps such as substrate etching, multilayer lamination, precision alignment, and surface electroplating. The processing accuracy requirements are strict, the production yield is low, and the overall manufacturing cost remains high, which is not conducive to the large-scale mass production and promotion of civilian communication terminals. Fourth, the power consumption is high and the application scenarios are limited. The power consumption of traditional phased array antennas is relatively high. When applied to light and small UAVs in low-altitude economic scenarios, it will not only quickly consume the limited onboard power, significantly shorten the flight range and operating radius, but also squeeze the power supply margin of onboard equipment, causing various onboard electrical appliances to malfunction. At the same time, the large amount of heat generated by high power consumption is easy to accumulate in the small fuselage, causing the performance of radio frequency devices to degrade and the equipment to overheat and crash. The additional battery and heat dissipation structure will increase the weight and volume of the whole aircraft, weaken the flight maneuverability, and the high current and high power operation state is also prone to electromagnetic interference, affecting the stability of navigation and remote control links, ultimately severely restricting the operational capability and reliability of UAVs in the low-altitude economic field. Current semiconductor stacked packaging relies solely on a single bottom substrate for heat dissipation, with only simple conductive solder balls between layers and no central support heat-conducting structure penetrating the entire layer. The top cover and middle layer heat-conducting plates have a single, non-replaceable structure, making them prone to misalignment and warping during thermal cycling. The overall heat dissipation path is singular, making it impossible to balance heat dissipation efficiency and structural reliability. Furthermore, existing flexible air-cavity coupled thin-film phased array antennas suffer from long-standing, unresolved technical contradictions: conventional flexible thin-film antennas are affected by the bending deformation characteristics of the substrate; under bending conditions, the upper and lower radiating layers are prone to collapse, adhesion, and deformation displacement, resulting in distortion of the air coupling cavity thickness and directly causing the electromagnetic coupling characteristics of the double-layer radiating layer to fail. A common problem with existing technologies is that double-layer coupled antennas either have high losses due to the dielectric substrate or suffer from impedance mismatch, narrow bandwidth, and high reflection due to pure air coupling, making it impossible to simultaneously achieve low loss and wide bandwidth. Moreover, after bending, the upper and lower radiating layers collapse, adhere, and deform, distorting the air cavity thickness and completely failing electromagnetic coupling. The industry has long been unable to reconcile the two major contradictions of flexibility and constant air cavity spacing. This has led to a long-standing technological bias in the industry (flexible antennas are inherently deformable, and air cavities are prone to collapse). Furthermore, traditional flexible antennas use ordinary inkjet printing to form the conductive radiating layer, which has poor adhesion, is easily cracked and detached after repeated bending, has high RF transmission loss, and insufficient electrical stability, making it unsuitable for the long-term reliable operation requirements of high-precision phased arrays. Moreover, existing technologies also suffer from common problems such as multiple soldering and connector requirements in phased arrays, susceptibility to breakage during flexible bending, and poor channel consistency. Existing technology: (Conventional air-dielectric dual-layer coupled flexible thin-film phased array antenna) The typical approach involves stacking a protective shield, multiple thin-film radiating layers, circuit modules, and beam modules from top to bottom; using air cavity coupling for feeding; adapting to curved surfaces with a flexible thin-film substrate; employing digital beam scanning control for the phased array; and printing the radiating antenna with nano-silver ink. Its inherent technical drawbacks include: 1. A single rigid / flexible support cannot simultaneously handle load-bearing and deformation; after bending, the air cavity coupling distance drifts significantly, leading to electromagnetic performance failure; 2. Dual-layer coupled antennas require an additional dielectric matching layer / microstrip matching circuit, making pure air self-impedance matching impossible; 3. The radiating layer and beam module are rigidly connected by welding and connectors, which are prone to failure upon bending, making multi-channel near-field synchronous amplitude and phase calibration impossible; 4. The support structure is doped with metal inserts, which disturb the electromagnetic field within the cavity, resulting in high additional losses.

[0004] In summary, the traditional PCB-based phased array flat panel antennas and existing conventional flexible thin-film antennas suffer from significant technical shortcomings, including bulkiness, high loss, narrow bandwidth, non-conformal design, high power consumption, structural deformation failure, and high mass production costs. These limitations make them unsuitable for the core application requirements of next-generation low-Earth orbit satellite mobile communication terminals and various mobile carriers. Therefore, there is an urgent need to develop a novel stacked-coupled flexible thin-film phased array antenna that combines flexible conformal adaptation, low-loss transmission in air medium, structural stability under deformation conditions, wideband operation, simplified manufacturing process, and low mass production costs. Summary of the Invention

[0005] Purpose of the Invention: This invention aims to overcome a series of technical defects in existing traditional PCB multilayer patch phased array antennas, such as rigidity and non-conformal design, high RF signal loss, limited operating bandwidth, complex processing technology, high mass production cost, and high overall power consumption, as well as the deformation collapse, electromagnetic coupling failure, and poor durability of conductive layers in conventional flexible air cavity antennas. It provides an air-dielectric stacked coupled flexible thin-film phased array antenna and its fabrication method. This invention utilizes a unique rigid-flexible composite topology support structure, a complementary symmetrical gradient slotted coupling topology structure for upper and lower thin-film radiating layers, a proprietary nano-metallurgical inkjet printing process, and a weld-free air near-field synchronous collaborative beam control architecture. It addresses the two core requirements of flexible curved surface conformal installation and the stability of the air cavity constant-spacing structure. Leveraging the low-loss coupling transmission characteristics of pure air dielectric, it expands the operating bandwidth, simplifies the overall fabrication process, reduces mass production costs, and fully meets the application requirements of space-weight-sensitive and curvilinearly conformal adaptation scenarios such as low-altitude economic UAV airborne communication, low-orbit satellite communication terminals, and vehicle-mounted mobile communication.

[0006] Technical Solution: To achieve the above-mentioned objectives, the present invention adopts the following technical solution: an air-dielectric stacked coupled flexible thin-film phased array antenna, comprising a positioning and assembly coaxial inner groove 11, and a protective antenna cover 1, an upper parasitic thin-film radiating layer 2, a hollow supporting dielectric unit 3, a lower driving thin-film radiating layer 4, an active circuit module 5, a beamforming module 6, and a circular hollow supporting structure 8, which are sequentially coaxially nested and stacked from top to bottom via a positioning and assembly coaxial 7. The positioning and assembly coaxial 7 provides coaxial positioning and assembly positioning for the entire stacked structure. Its characteristic is that: The protective radome 1 is fabricated to conform to the shape and contour of the carrier, using a conformal curved surface structure. It is made of polyimide honeycomb sandwich composite wave-transparent material with low dielectric constant, low loss tangent, and high strength and corrosion resistance. Through the optimization of the integrated structure of the layup arrangement, sandwich ratio, and wall thickness gradient, the shell structure protection and low-loss electromagnetic wave transmission are integrated into one molding. It is then installed on the curved surface of the carrier using a molding and thermosetting process. The sandwich composite structure reduces antenna signal insertion loss, reflection, and beam distortion, and simultaneously achieves all-weather environmental protection for the whole device, including impact resistance, rain protection, and corrosion resistance. The honeycomb sandwich core layer thickness is 2~5mm, the upper and lower skin thickness is 0.1~0.3mm, the layup angle adopts 0° / 90° orthogonal cross layup, and the wall thickness gradient rate is 0.05~0.15mm / cm along the curvature radius of the curved surface. The hollow support medium unit 3 and the circular hollow support structure 8 are interleaved and locked to form a rigid-flexible composite topological support grid, forming a flexible deformation adaptive air cavity constant spacing locking structure. Relying on the periodic nesting and cooperation of hexagonal rigid load-bearing periodic cells and circular flexible deformation buffer cells, the static load-bearing stiffness and dynamic bending deformation adaptability of the antenna are taken into account. Under the conditions of conformal antenna curvature and repeated high-frequency bending, the deviation of electromagnetic coupling spacing between air dielectric filling cavity layers can be controlled and locked within ±0.05mm, eliminating the defects of deformation collapse, interlayer coupling spacing offset and electromagnetic parameter drift of traditional flexible air cavity antennas. The side length of the hexagonal rigid load-bearing periodic cell is 3~8mm, the diameter of the circular flexible deformation buffer cell is 0.6~0.8 times the diameter of the inscribed circle of the hexagon, and the height of both types of cells is 0.8~1.2mm, which corresponds to 1 / 4 of the free space wavelength of the center frequency of the antenna operating frequency band. The upper parasitic thin film radiating layer 2 and the lower driving thin film radiating layer 4 adopt a complementary symmetrical gradient slotted coupling topology configuration with upper and lower alignment and fit. This eliminates the external impedance matching dielectric layer and transition microstrip matching line of the traditional double-layer coupled antenna, relying solely on the air dielectric filling cavity as a single transmission medium to achieve natural self-matching of RF impedance across the entire operating frequency band, simplifying the antenna stack-up structure and reducing assembly thickness. The complementary symmetrical gradient slot is an exponentially gradient slot line with a slot line length of 0.4 to 0.6 times the free space wavelength of the center frequency and a slot line width that exponentially varies from 0.1 mm to 1.5 mm with a gradient exponent of 0.5 to 1.0. The upper parasitic thin film radiation layer 2 and the lower driving thin film radiation layer 4 are both printed using gradient layer inkjet printing with nano-silver low-temperature sintering conductive ink, combined with an in-situ low-temperature curing metallurgical conductivity-specific molding process, forming a dense nano-metallurgical conductive thin film integrated radiation structure, which effectively ensures the stability of radio frequency conductivity and radiation performance under flexible deformation conditions; the number of gradient layer inkjet printing layers is 4 to 6, the thickness of each layer after drying is 0.5 to 1 μm, the total conductive film thickness is 2 to 6 μm, the low-temperature sintering temperature is 120 to 180℃, and the holding time is 30 to 60 min; The beamforming module 6 and the lower driving thin-film radiating layer 4 abandon rigid RF welding and external connector connection structure, and build an air near-field multi-channel phase and amplitude synchronous collaborative calibration array control architecture. It independently controls the RF phase and amplitude of each thin-film antenna unit channel and realizes multi-channel linkage calibration. It completes high-precision electronic scanning of the beam by relying on spatial electromagnetic wave interference, and the gain fluctuation is controlled within ±0.5dB throughout the beam scanning process. The multi-channel linkage calibration adopts the least squares iterative algorithm, the calibration period is 10ms, and after calibration, the phase error of each channel is ≤1° and the amplitude error is ≤0.1dB.

[0007] Furthermore: the hollow support medium unit 3 is sandwiched between the upper parasitic thin film radiation layer 2 and the lower driving thin film radiation layer 4. The solid radio frequency solid dielectric substrate is completely removed between the two radiation layers. The two thin film radiation layers are physically isolated and shaped only through the hollow support medium unit 3. The two surround and seal an integrated air dielectric filling cavity, and the air dielectric filling cavity is the only medium for radio frequency near-field coupling transmission between the two radiation layers. The hollow support medium unit 3 is a hexagonal rigid load-bearing periodic cell, integrally made of rigid expanded polystyrene with a dielectric constant of 1.02. The circular hollow support structure 8 is a circular flexible deformation buffer cell embedded in the inner circle of the hexagonal cell, integrally made of ePTFE flexible material with a dielectric constant of 1.01. The two types of cells are arranged in a planar periodic combination to form a mesh grid. Both types of cells are hollow through-structures, without metal fillers or metal inserts, avoiding the disturbance of the cavity electromagnetic field by the metal structure, minimizing the additional radio frequency loss of the support structure, and matching the low-loss transmission characteristics of pure air. The area ratio of the hexagonal cell to the circular cell is 60%~75%:25%~40%, and the cell arrangement period is 5~10mm.

[0008] The hollow support medium unit 3 and the circular hollow support structure 8 are precisely nested coaxially and arranged evenly in a plane to form a composite honeycomb rigid-flexible coupled support grid. The hexagonal rigid load-bearing periodic cells bear the static stacked load of the whole machine, while the circular flexible deformation buffer cells release high-frequency bending deformation stress. The two-way collaborative locking of the parallelism of the air medium filling cavity and the reference coupling spacing ensures the integrity of the cavity structure and the constant coupling parameters under deformation conditions. The wall thickness of the hexagonal cells is 0.2~0.5mm, and the wall thickness of the circular cells is 0.1~0.3mm. The height of both is consistent and equal to the height of the air cavity.

[0009] The active circuit module 5 and the lower driving thin film radiating layer 4 abandon the solder balls, RF connectors, and lead soldering conductive structure, and adopt a seamless LGA planar interconnect structure on a thin film substrate to achieve electrical connection. The seamless LGA interconnect can reduce the high-frequency interconnect path, weaken parasitic RF parameters, reduce high-frequency transmission loss, optimize the interlayer heat conduction path, improve the heat dissipation efficiency of the active chip, realize the flattening and lightweighting of the antenna stack, adapt to airborne vibration and repeated bending conditions, and the detachable interconnect structure facilitates the later antenna maintenance and disassembly. The pad diameter of the seamless LGA interconnect is 0.3~0.5mm, the pad spacing is 0.5~0.8mm, and the interconnect impedance is controlled at 50Ω±2Ω.

[0010] The active circuit module 5 integrates TR components, a power divider network, and an intermediate frequency channel. It is responsible for completing the switching of radio frequency signals for the dual-layer thin-film radiating array, power amplification, amplitude and phase modulation, signal combining and distribution, as well as radio frequency / intermediate frequency signal conversion, filtering, modulation and demodulation processing. Together with the beamforming module 6, it realizes the basic detection and communication functions of antenna directional radiation, echo reception, and beam scanning.

[0011] The beamforming module 6 integrates an analog-to-digital converter (ADC), a digital-to-analog converter (DAC), a field-programmable gate array (FPGA), a digital signal processor (DSP), and an ARM core control chip. The ADC performs analog-to-digital conversion of the received channel's analog intermediate frequency signal, the DAC realizes digital-to-analog reconstruction of the transmitted channel's digital beam signal, the FPGA is responsible for multi-channel signal synchronous acquisition, real-time amplitude and phase weighting, and parallel beamforming calculations, the DSP performs channel amplitude and phase error correction, adaptive anti-interference, and beam algorithm optimization, and the ARM manages the overall machine's command interaction, beam parameter scheduling, and peripheral status monitoring. The beamforming module 6 and the active circuit module 5 are connected point-to-point via a button, replacing traditional low-frequency cables and rigid connectors, eliminating signal interruption faults caused by bending, breakage, and poor contact, and improving the stability of multi-channel signal transmission. The diameter of the button is 0.5~1.0mm, the compression is 30%~50%, and the contact resistance is ≤5mΩ.

[0012] The upper parasitic thin film radiating layer 2 is a passive, unfed integrated coupled radiating structure with no independent feed port or electrical welding points. It relies on a sealed air-filled cavity to receive near-field electromagnetic coupling excitation from the lower driving thin film radiating layer 4 to generate parasitic resonance. In conjunction with the complementary symmetrical gradient slotted topology, it simultaneously achieves antenna gain enhancement, beamforming optimization, and radiation sidelobe suppression. The opening width at the end of the complementary symmetrical gradient slot is 0.5~1.0mm, and the horizontal offset between the starting end of the slot and the feed point of the driving radiating layer is 0.2~0.5mm.

[0013] The upper parasitic thin film radiation layer 2 and the lower driving thin film radiation layer 4 are made of any one of LCP film, PI film, or PET radio frequency-specific flexible polymer film. They have fatigue resistance and repeated bending characteristics, are adaptable to conformal bonding of irregularly shaped carrier surfaces, and have no failure attenuation in cavity structure, antenna impedance coupling, and radio frequency radiation performance under continuous deformation conditions. The thickness of the substrate is 25~75μm, the dielectric constant is 2.9~3.2, and the loss tangent is ≤0.002.

[0014] The surface of the upper parasitic thin film radiating layer 2 is gradient inkjet-printed with several nano-silver microstrip antennas 9, which are arranged in a regular rectangular grid two-dimensional array. The nano-metallurgical formed conductive film can ensure that the conductivity attenuation is ≤3% after 100,000 repeated bending cycles. The total thickness of the entire stacked assembly is ≤2mm, and the relative working bandwidth of the antenna is ≥30%, taking into account ultra-thin and lightweight, wideband radiation, flexible conformal, and high-precision beam scanning performance. The patch length of the nano-silver microstrip antenna 9 is 0.35~0.45 times the free space wavelength of the center frequency of the working frequency band, the width is 0.3~0.4 times, and the array unit spacing is 0.5~0.6 times the wavelength.

[0015] The protective antenna cover 1 completely covers the outer side of the upper parasitic film radiation layer 2. The inner curved surface of the protective antenna cover 1 is precisely matched with the conformal curved surface of the upper parasitic film radiation layer 2. A deformation buffer air gap is reserved between the inner surface of the protective antenna cover 1 and the outer surface of the upper parasitic film radiation layer 2, or it is filled with low-density wave-transparent buffer foam to achieve all-round protection of the internal radiation structure against dust, impact, high and low temperatures, and bending and wear. The thickness of the buffer air gap is 0.2~0.5mm, or the density of the filled low-density wave-transparent buffer foam is 0.03~0.08g / cm³ and the dielectric constant is ≤1.1.

[0016] The positioning and assembly coaxial 7 relies on its own multi-layered structure that runs through the entire phased array antenna, breaking the limitations of traditional phased array antennas where TR components, array circuit boards, shielding cavities, power supply and control boards are layered and independently cooled, have high interlayer thermal resistance, and can only conduct heat on one side. It is a composite heat dissipation solution that combines through-type full-domain axial heat conduction, circumferential heat distribution, and interlayer interface enhanced heat dissipation. This is also the core innovation of this structure compared with conventional phased array heat dissipation solutions such as conventional air cooling, liquid cooling, copper embedding on the substrate, and heat dissipation teeth attached to the shell. This component is not only a structural component for mechanical positioning, coaxial limiting, and layer locking, but also a high thermal conductivity thermal bridge built into the whole device. It directly conducts the concentrated heat flow generated by each heat-generating layer longitudinally, and then achieves rapid heat dissipation and export through its own circumferential heat exchange and interlayer contact heat exchange, solving the problem of heat accumulation from multiple heat sources inside the stacked structure and local hot spot overheating caused by interlayer heat exchange. The use of coaxial positioning and assembly is a design approach that is completely different from the existing phased array antenna technology. It integrates three major functions: mechanical coaxial positioning, multi-layer assembly positioning, and high thermal conductivity thermal bridge into one integrated function. It achieves an innovative design for efficient heat dissipation of phased array antennas without increasing the size, weight, or wiring space of the whole unit, which meets the design requirements of lightweight and miniaturized phased array antennas.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following beneficial effects: Compared to existing technologies, this invention offers multiple advantages: ① No interlayer offset and significantly reduced thermal warpage deformation, improving packaging yield and lifespan; ② A three-dimensional composite heat dissipation path, increasing overall heat dissipation efficiency by over 40%; ③ A single internal stacking structure is compatible with saucer / square top covers and flat / finned middle layers, with a modular and universal design adaptable to different equipment usage needs, expanding the product's applicable scenarios. The hexagonal interconnecting solder balls are arranged symmetrically in a ring, achieving both electrical interconnection and dispersing thermal stress, forming a surrounding circumferential heat dissipation channel, unlike ordinary disordered spherical solder balls; the package top cover and the middle thermally conductive bearing plate are interchangeable in two shapes, and the internal stacking interconnection structure is completely universal, with a single internal structure adaptable to multiple installation scenarios and multi-level heat dissipation requirements, reducing mold development costs; the thermally conductive heat dissipation mesh layer adheres to the top cover to achieve uniform heat distribution throughout the entire area, forming a composite three-dimensional heat dissipation path of "top uniform heat distribution - central axial heat conduction - circumferential distributed heat conduction - bottom radiative heat dissipation" when combined with the central pillar, ring solder balls, and radial finned plates. The drive radiating layer and active module adopt a dedicated seamless LGA interconnect, replacing solder balls and connector soldering structures, which has multiple benefits such as lightweight, heat dissipation, vibration resistance, and disassembly and maintenance: I. Combining rigidity and flexibility, ensuring stability even under deformation, thus overcoming the challenge of stable deformation. This invention employs a hollow support dielectric unit 3 and a circular hollow support structure 8 to form a hollow support assembly, ensuring the stability and non-deformation of the air-filled cavity structure formed by the upper parasitic thin film radiation layer 2 and the lower driving thin film radiation layer 4. The hollow support assembly utilizes a hexagonal rigid load-bearing periodic cell + circular flexible deformation buffer cell staggered coupling locking structure to form a rigid-flexible composite topological support grid. Under arbitrary curved surface conformal bending and repeated bending deformation, the interlayer coupling spacing deviation of the air-filled cavity is strictly controlled within ±0.05mm, ensuring that bending does not change the coupling spacing and flexible deformation does not cause cavity collapse. This overcomes long-standing industry technical biases (that flexibility inevitably leads to deformation and air cavities inevitably collapse). This innovative topological support grid structure, featuring interlocking hexagonal rigid load-bearing cells and circular flexible buffer cells, breaks the traditional misconception that flexible deformation and air cavity structural stability cannot be simultaneously achieved. Under conditions of repeated antenna bending and conformal curved surfaces, the air cavity coupling spacing deviation is strictly controlled within ±0.05mm, achieving dual compatibility between flexible conformal installation and constant electromagnetic performance. This completely solves the pain points of conventional flexible antennas, such as bending collapse and electromagnetic coupling failure. The interlocking hexagonal rigid load-bearing cells and circular flexible buffer cells form a rigid-flexible composite topological grid, achieving high-precision constant spacing locking of the air cavity within ±0.05mm, adapting to high-frequency bending conditions and overcoming the industry pain point of air cavity collapse and offset. The double-layer complementary symmetrical gradient slotted configuration completely eliminates the need for external impedance matching media and transition microstrip lines, enabling the pure air cavity to achieve natural impedance self-matching across the entire frequency band, breaking through the technical bottlenecks of bandwidth and loss control in traditional air antennas. Control architecture: Abandoning rigid RF connections, a dedicated near-field multi-channel phase amplitude synchronous collaborative calibration architecture is built to achieve multi-channel linkage calibration, with beam scanning gain fluctuation locked within ±0.5dB; Process level: Nano-silver gradient overprinting + in-situ low-temperature metallurgical curing process forms an integrated dense metallurgical conductive film, which is different from ordinary inkjet printed conductive layers and significantly improves long-term deformation conductivity stability; Material level: The supporting cells are all hollow and free of metal doping, combined with a gradient wall thickness polyimide honeycomb radome, to achieve integrated wave transmission, protection, and conformal adaptation to complex airborne conditions.

[0018] II. Low loss in air medium, self-matching for broadband expansion, breaking through performance and technical bottlenecks. The entire process eliminates the solid dielectric substrate, using air as the sole transmission medium for RF coupling, resulting in extremely low dielectric loss. Furthermore, the unique all-air dielectric transitional gradient coupling impedance matching structure overcomes the common problems of existing technologies: dual-layer coupled antennas either suffer from high losses due to the dielectric substrate or suffer from impedance mismatch, narrow bandwidth, and high reflection due to pure air coupling, failing to achieve both low loss and wide bandwidth. The complementary symmetrical gradient slotted coupling topology of the upper and lower thin-film radiating layers enables full-band impedance self-matching without the need for additional impedance matching structures, solving the bottleneck of traditional air-coupled antennas that cannot simultaneously achieve low loss and high bandwidth. The antenna's relative operating bandwidth is no less than 30%, with insertion loss ≤0.8dB, perfectly suited to the high-frequency, high-bandwidth communication requirements of low-Earth orbit satellites. The nano-silver microstrip antenna array 9 of the upper parasitic thin film radiating layer 2 and the RF circuit of the lower driving thin film radiating layer 4 inkjet printed adopt a complementary symmetrical gradient slotted coupling topology of the upper and lower thin film radiating layers. It does not require any dielectric matching layer or impedance transition microstrip line. It achieves natural full-band impedance self-matching by relying solely on the single medium of the air cavity, achieving low loss while significantly widening the bandwidth, breaking through the inherent technical bottleneck of narrow bandwidth of traditional air-coupled antennas.

[0019] III. Nanometallurgical forming process, resulting in long bending resistance, long service life, and stable and durable electrical properties. This invention employs a proprietary metallurgical process involving low-temperature sintering of nano-silver conductive inks, combined with in-situ curing, to replace conventional inkjet printing. This process achieves a high degree of density in both the upper parasitic thin-film radiating layer 2 and the lower driving thin-film radiating layer 4, with conductivity attenuation ≤3% after over 100,000 repeated bending cycles. This effectively solves the problems of easy cracking, high loss, and poor durability associated with traditional conductive layers, making it suitable for the long-term continuous operation of high-precision phased array antennas. The aforementioned proprietary process of in-situ curing and low-temperature metallurgical treatment of multilayer conductive ink films in inkjet printing not only avoids the common problems of existing technologies—poor adhesion, easy cracking upon bending, and high RF loss—making it unsuitable for high-precision phased arrays, but also utilizes a gradient layering inkjet printing process with low-temperature sintering of nano-silver conductive inks combined with in-situ low-temperature curing metallurgical conductivity. This results in a dense nano-metallurgical conductive film structure in the radiating conductive layers, achieving long-term stable RF electrical performance under flexible repeated bending. This delivers durability and RF performance far exceeding that of conventional processes.

[0020] This invention completely replaces the rigid PCB substrate with a flexible thin film substrate. The overall thickness of the antenna is ≤2mm, and the weight is reduced by more than 70% compared with traditional PCB antennas. It has no rigid protrusions and no mechanical servo mechanism. It can be conformally installed on various irregular curved surfaces such as drone skins and vehicle shells, reducing aerodynamic drag and radar cross-section. It has excellent environmental adaptability and installation compatibility.

[0021] V. Simplified process facilitates mass production, reduces costs and increases efficiency, and promotes widespread adoption. The upper parasitic thin film radiation layer 2 and the lower driving thin film radiation layer 4 of this invention are formed by inkjet printing and the supporting structure is prepared by laser cutting. This replaces the complex etching, lamination and electroplating processes of traditional PCBs, greatly simplifying the process flow, improving the yield and material utilization rate, providing a reliable and low-cost manufacturing path for the large-scale industrialization of low-orbit satellite communication terminals, significantly reducing the cost of mass production, and meeting the needs of mass industrialization and popularization of civilian low-orbit satellite communication terminals.

[0022] In summary, this invention breaks through the traditional technical prejudice that "flexibility inevitably leads to deformation and air cavity inevitably leads to failure," and achieves simultaneous consideration of key performance aspects such as ultra-thinness, bendability, low loss, wide bandwidth, and high-precision beam stabilization, providing a systematic solution for the design and application of next-generation flexible conformal antennas. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the exploded structure of the overall thin-film antenna phased array according to the first embodiment of the present invention; Embodiment: The top cover of the package is a UFO arc shape, the middle heat-conducting carrier plate is a planar plate, and the number of interconnecting solder balls is small, which is suitable for low-power small package; Figure 2 shows a second embodiment of the present invention: the top cover of the package is a square flat plate, the middle heat-conducting bearing plate is a radial fin heat sink, and the interconnecting solder balls are densely arranged in a ring, which is suitable for high-power high heat flux density packaging; Figure 3 shows the third embodiment of the present invention: the top cover of the package is a square flat plate, the middle heat-conducting bearing plate is a radial fin heat sink, and the interconnect solder balls adopt a thickened polyhedral hexagonal contour structure, which is suitable for automotive and industrial-grade high-reliability vibration-resistant packaging.

[0024] Figure 4 This is a schematic diagram of an embodiment of a dual-layer coupled thin-film antenna array; Figure 5 This is a schematic diagram of the planar arrangement of the hollow support medium unit and the circular hollow support structure of the present invention; Figure 6 This is a flowchart illustrating the fabrication process of the thin-film phased array antenna of the present invention.

[0025] Explanation of reference numerals in the attached drawings: 1-protective radome, 2-upper parasitic thin film radiating layer, 3-hollow support medium unit, 4-lower driving thin film radiating layer, 5-active circuit module, 6-beamforming module, 7-positioning assembly coaxial, 8-circular hollow support structure, 9-nano silver microstrip antenna, 10-metal thermally conductive carrier plate, 11-inner groove.

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific implementation examples. The described embodiments are only preferred embodiments of the present invention and not all embodiments. All embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention. Detailed Implementation

[0027] See Figures 1-5 An air-dielectric stacked coupled flexible thin-film phased array antenna includes, from top to bottom, a protective radome 1, an upper parasitic thin-film radiating layer 2, a hollow supporting dielectric unit 3, a circular hollow supporting structure 8, a lower driving thin-film radiating layer 4, an active circuit module 5, a beamforming module 6, and a positioning assembly coaxial 7 that supports the entire flexible thin-film phased array antenna.

[0028] The protective antenna cover 1 is designed with a conformal curved surface structure based on the outer contour of the carrier. It is made of polyimide honeycomb sandwich composite wave-transparent material with low dielectric constant, low loss tangent, high strength and corrosion resistance. The structure and wave-transparent design are integrated through layering, sandwich ratio, wall thickness gradient and structural optimization. It is installed in close contact with the curved surface of the carrier by molding and thermosetting process. The excellent electromagnetic wave penetration characteristics of the material reduce antenna signal insertion loss, reflection and beam distortion. At the same time, the composite sandwich structure plays a role in impact resistance, rain protection and corrosion protection.

[0029] The hollow support assembly is composed of a hollow support dielectric unit 3 and a circular hollow support structure 8, with the circular hollow support structure 8 embedded within the hollow support dielectric unit 3. The hollow support assembly is sandwiched between the upper parasitic thin film radiating layer 2 and the lower driving thin film radiating layer 4. No solid radio frequency solid dielectric substrate is completely eliminated between the two radiating structures; the hollow support assembly alone achieves physical isolation and shaping support for the two radiating layers. Together, they form a sealed, integrated air-filled cavity, which serves as the sole medium for near-field coupling transmission of radio frequency energy between the upper parasitic thin film radiating layer 2 and the lower driving thin film radiating layer 4. The hollow support medium unit 3 of the hollow support component adopts a hexagonal rigid load-bearing periodic cell structure, and the circular hollow support structure 8 of the hollow support component adopts a circular flexible deformation buffer cell structure. The two are interleaved and coupled to form a unique rigid-flexible composite topological support grid structure. Relying on the periodic alternating nesting and cooperation of two different functional cells, the static support stiffness and dynamic deformation adaptability of the overall structure are taken into account. Under the condition of conformal fitting on arbitrary curved surfaces and repeated bending deformation at high frequencies, the deviation of the interlayer electromagnetic coupling spacing of the air dielectric filling cavity is strictly controlled within ±0.05mm. This effectively overcomes the inherent technical contradictions in the industry of deformation collapse and electromagnetic performance failure caused by coupling spacing deviation of traditional flexible air cavity antennas, and realizes that the cavity structure does not collapse and the electromagnetic coupling parameters remain constant under flexible deformation conditions. The upper parasitic thin film radiating layer 2 and the lower driving thin film radiating layer 4 adopt a complementary symmetrical gradient slotted coupling topology configuration with upper and lower alignment and fitting. This design abandons the conventional matching structure of traditional double-layer coupled antennas that require additional impedance matching circuit layers and transition microstrip matching lines. Instead, it achieves full-band RF impedance self-matching by relying solely on a single transmission medium, the air-filled cavity. This breaks through the inherent technical bottleneck of traditional pure air-coupled antennas, which cannot simultaneously achieve low loss and wide operating bandwidth. Both the upper parasitic thin film radiation layer 2 and the lower driving thin film radiation layer 4 adopt a gradient layer inkjet printing process with nano-silver low-temperature sintering conductive ink, combined with an in-situ low-temperature curing metallurgical conduction exclusive molding process. After printing and curing, a dense nano-metallurgical conductive film integrated radiation structure is formed. Unlike the simple molding structure of conventional inkjet printed conductive layers, it can ensure that the conductivity attenuation is ≤3% after more than 100,000 repeated bending deformations of the antenna, and maintain the stability of radio frequency conductivity and radiation characteristics under flexible long-term working conditions. The rigid RF soldering conductive structure (RF circuit connector) between the active circuit module 5 and the lower driving thin film radiating layer 4 is eliminated, and an inter-board LGA interconnect between the flexible thin film and the active circuit substrate is adopted. Using inter-board LGA technology to connect the lower driving thin film radiating layer 4 and the active circuit module 5 substrate eliminates traditional connectors, leads, and solder ball structures, achieving overall flatness and lightweight design. This adapts to the conformal curvature of the flexible film and repeated bending conditions, improving structural reliability under airborne vibration environments. It also shortens the interconnect path, reduces high-frequency parasitic parameters and RF losses, ensures the quality of multi-channel signal transmission, optimizes inter-layer heat conduction paths, improves chip heat dissipation, simplifies assembly processes, and the detachable structure facilitates later inspection and maintenance.

[0030] The active circuit module 5 consists of a TR component, a power divider network, and the main components of the intermediate frequency channel. It completes the transmission and reception switching, power amplification, amplitude and phase distribution, signal allocation or combining, and frequency conversion, filtering, demodulation / modulation processing of the RF signal of the air dielectric stacked coupled flexible thin film antenna, which is composed of the upper parasitic thin film radiating layer 2, the hollow support dielectric unit 3, the circular hollow support structure 8, and the lower driving thin film radiating layer 4. Ultimately, it realizes the directional transmission, echo reception, beam scanning, and signal preprocessing of the antenna array, ensuring the normal detection and communication functions of the phased array antenna.

[0031] The beamforming module 6 is composed of core components including an ADC, DAC, FPGA, DSP, and ARM. The ADC converts the analog intermediate frequency (IF) signal from the receiving channel of the active circuit module 5 into a digital signal. The DAC restores the digital beam signal to the analog IF signal from the transmitting channel of the active circuit module 5. The FPGA is responsible for multi-channel synchronous acquisition of the TR component, real-time digital amplitude and phase weighting, beamforming calculation, and parallel multi-beam generation. The DSP performs complex algorithm processing such as adaptive anti-interference, channel amplitude and phase error correction, and beamforming optimization. The ARM handles command interaction, beam parameter scheduling, peripheral control, and status management for the entire phased array antenna. All components work together to complete core functions such as digital domain beamforming, beam scanning, interference suppression, and array channel calibration. The circuit signal interconnection between the beamforming module 6 and the active circuit module 5 is achieved through point-to-point mating, avoiding problems such as bending and breakage of rigid low-frequency connectors and low-frequency cables, poor contact, and signal interruption.

[0032] The core principle of electronic beam scanning: This antenna achieves electronic beam scanning without mechanical rotation based on the phased array interference principle. The specific process is as follows: Gradient phase difference introduction: The beamforming module 6 sets a linear gradient phase difference for the signal of each radiating element nanosilver microstrip antenna 9 according to the target beam direction. For example, when the beam needs to be deflected in the θ direction, the elements arranged along this direction are set with increasing or decreasing phase offsets in sequence. These phase offsets are finally implemented in the TR component in the active circuit module 5.

[0033] Constructive interference in space: When the electromagnetic waves emitted by the nano-silver microstrip antennas 9 of each radiating unit propagate in the far field space, the initial phase difference and path difference of the nano-silver microstrip antennas 9 of different radiating units cancel each other out, forming constructive interference in the target direction. The signal intensity is superimposed and enhanced to form the main beam. Dynamic beam adjustment: When it is necessary to change the beam direction, the beamforming module 6 adjusts the phase difference combination of each radiating element nanosilver microstrip antenna 9 to change the direction of constructive interference, thereby realizing rapid scanning of the beam in space without rotating the antenna body.

[0034] The aforementioned air-dielectric stacked coupled flexible thin-film phased array antenna has the following core structural layers from top to bottom: a protective radome 1, an upper parasitic thin-film radiating layer 2, a hollow support dielectric unit 3, a circular hollow support structure 8, a lower driving thin-film radiating layer 4, an active circuit module 5, a beamforming module 6, and a positioning and assembly coaxial structure 7 that supports and assembles the entire flexible thin-film phased array antenna. The upper surface of the upper parasitic thin-film radiating layer 2 is inkjet-printed with a grid array formed by several nano-silver microstrip antennas 9. The lower driving thin-film radiating layer is inkjet-printed with an excitation circuit that matches the grid array. The upper parasitic thin-film radiating layer 2 and the lower driving thin-film radiating layer 4 constitute the core double-layer coupled radiating structure. No PCB or other solid dielectric substrate is placed between these two layers; instead, they are physically isolated and supported by the hollow support component, thus forming a sealed air-dielectric-filled cavity between the two layers. This air medium is the only medium for radio frequency energy coupling and transmission between the two layers. The hollow support assembly is composed of hollow support medium units 3 and circular hollow support structures 8. The hollow support medium unit 3 adopts a hexagonal structure design, is made of rigid expanded polystyrene foam, and has a dielectric constant of 1.02, comparable to pure air, forming a rigid load-bearing periodic cell. The circular hollow support structure 8 is made of ePTFE circular flexible material, with a dielectric constant of 1.01, comparable to pure air, forming a flexible deformation buffer cell. The hollow support medium unit 3 and the circular hollow support structure 8 are nested vertically and periodically alternately arranged in a plane, together forming a composite honeycomb support grid with high structural stability. This structural design precisely defines the spacing between the two radiating layers, ensuring structural parallelism and providing stable mechanical support.

[0035] Both the upper parasitic thin-film radiating layer 2 and the lower driving thin-film radiating layer 4 are printed using inkjet printing technology, directly printing silver-based or copper-based conductive ink onto the surface of the flexible thin-film substrate and curing it. The active circuit module 5 and the lower driving thin-film radiating layer 4 are connected by a seamless LGA (Low-Gas Interconnect). The use of seamless LGA technology to connect the lower driving thin-film radiating layer 4 to the substrate of the active circuit module 5 eliminates traditional connectors, leads, and solder ball structures, achieving overall flatness and lightweight design. This adapts to the conformal design of flexible film surfaces and repeated bending conditions, improving structural reliability under airborne vibration environments. It also shortens interconnection paths, reduces high-frequency parasitic parameters and RF losses, ensuring the quality of multi-channel signal transmission. Furthermore, it optimizes interlayer heat conduction paths, improves chip heat dissipation, simplifies assembly processes, and the detachable structure facilitates later maintenance and repair. The overall antenna assembly thickness can be controlled within 2mm, and it has a relative operating bandwidth of no less than 30%.

[0036] In the following optional embodiments: The aforementioned upper parasitic thin-film radiating layer 2 is a passive coupling structure with no independent feed port or electrical welding connection point. It relies entirely on the near-field electromagnetic coupling excitation between the air-filled cavity and the lower driving thin-film radiating layer 4 to generate a parasitic resonant radiation effect, thereby achieving antenna gain enhancement, beamforming, and sidelobe suppression. The flexible thin-film substrate is a repeatedly bendable flexible polymer film, which can be selected from any of LCP film, PI film, or PET flexible RF film. It can arbitrarily conform to the curved surface of the carrier, achieving conformal mounting of the antenna on the overall curved surface. Furthermore, the structural integrity of the air-filled cavity and the electromagnetic coupling characteristics of the double-layer coupled radiating structure are maintained in the bent state.

[0037] Furthermore, the active circuit module 5 adopts a chip-level packaged die integration + thin-film microcircuit mounting composite process, integrating and securely mounting the TR components, power divider network, and intermediate frequency channel core functional circuits onto the lower driving thin-film radiating layer 4 to achieve RF signal interconnection. This module does not use the traditional rigid PCB board discrete component soldering mode. Relying on the flexible substrate's adaptable deformation structure, all core chip components are integrated using wafer-level chip packaging (WLCSP) ultra-thin packaging technology. Passive RF matching circuits, filter traces, and interconnecting strips are directly formed onto the back substrate of the flexible thin-film substrate using thin-film photolithography deposition technology, achieving overall thinness, flexibility, and integrated assembly.

[0038] Furthermore, the circuit signal interconnection between the beamforming module 6 and the active circuit module 5 is achieved through point-to-point docking of small buttons, avoiding the problems of bending and breaking of rigid low-frequency connectors and low-frequency cables, poor contact, and signal interruption, thereby ensuring the electrical performance indicators of the entire air-laminated flexible thin-film phased array antenna.

[0039] For further details, please refer to [link / reference]. Figure 6 The core method for fabricating the aforementioned air-dielectric stacked coupled thin-film phased array antenna is as follows: S1: Flexible substrate pretreatment. In this specific embodiment, a 25μm thick polyimide (PI) flexible film is selected and subjected to plasma surface cleaning treatment to remove oil and dust and improve the adhesion of the metal layer; the film substrate is cut into a specified array size and divided into two groups: upper substrate and lower substrate.

[0040] S2: Patterning and Metal Fabrication. The patterning and metal fabrication of the upper parasitic thin film radiating layer 2 and the lower driving thin film radiating layer 4 were completed sequentially. First, photosensitive photoresist was uniformly coated onto the substrate surface of the PI film and dried. Second, photolithography was used for exposure and development to form a square radiating patch array pattern. Third, a metal layer with a thickness of 2μm was inkjet printed using a gradient layering inkjet printing process combined with in-situ low-temperature curing metallurgical conductivity-specific molding process using nano-silver low-temperature sintering conductive ink. Fourth, the protective adhesive was peeled off to obtain the upper flexible radiating film with the array of radiating patches, which was then cleaned and dried for later use.

[0041] S3: Fabrication of Flexible Support Frames. Flexible support frames for the upper parasitic thin film radiation layer 2 and the lower driving thin film radiation layer 4 are fabricated. Silicone flexible frames are injection molded using a mold. The internal cavity size of the frame matches the outer contour of the film. Pre-set positioning protrusions on the frame are used for alignment and fixation of the upper and lower films. The frame thickness is consistent with the designed height of the air cavity (1.2 mm).

[0042] S4: Flatten the upper and lower thin film radiation layers respectively. Embed the prepared upper parasitic thin film radiation layer 2 and lower driving thin film radiation layer 4 into the bottom slot of the flexible support frame, and fix them with positioning protrusions to ensure that the film is flat and wrinkle-free.

[0043] S5: Construct an air-dielectric stacked flexible thin-film antenna. The upper parasitic thin-film radiating layer 2, the lower driving thin-film radiating layer 4, and the hollow support assembly (an orderly arranged mesh grid composed of hollow support dielectric unit 3 and circular hollow support structure 8) are tightly stacked to form an air-dielectric stacked flexible thin-film antenna.

[0044] S6: Assemble the RF front-end of the flexible thin-film phased array antenna. The flexible thin-film antenna with air dielectric stacked structure and the active circuit module 5 are interconnected with high precision using LGA packaging. The mechanical bonding and interconnection of RF signals and control signals are completed through a reliable physical pressing process, thus constructing an integrated and lightweight RF transceiver front-end component.

[0045] S7: Complete the fabrication of the air-dielectric stacked coupled thin-film phased array antenna. The phased array antenna RF front-end and beamforming module 6 are interconnected using a button-like interconnection process to achieve high-density, detachable, and seamless assembly. This ensures RF impedance matching and stable transmission of multiple signals while achieving a compact and integrated overall structure, taking into account ease of assembly, electrical reliability, and future module maintainability.

[0046] S8: Performance Testing and Finished Product Packaging. Electrical performance and mechanical reliability tests are conducted on the air-dielectric multilayer coupled thin-film phased array antenna in a microwave anechoic chamber environment. Key test parameters include the phased array antenna's EIRP, system noise, antenna radiation pattern, beam scanning characteristics, and flexible bending durability. After passing all tests, a high-transmittance flexible protective film is attached to the product surface, completing the protective packaging and final fabrication of the antenna.

[0047] In an optional implementation, the features of the above structure are further clarified and refined as follows: Regarding the protective radome 1: It is integrally molded from a low dielectric constant, low-loss wave-transmitting composite material, completely covering the upper parasitic thin film radiating layer 2, providing environmental protection against wind and sand, corrosion, and extreme temperatures. An air gap or low-density foam is maintained between its inner surface and the radiating layer, resulting in low wave transmission loss. Furthermore, the structural shape of the protective radome 1 can be matched with the conformal curved surface of the upper parasitic thin film radiating layer 2, and also conformally matched with the platform carrier's external structure.

[0048] Regarding the dual-layer coupled radiation structure: The upper parasitic thin-film radiation layer 2 is a passive coupling structure. It does not have an independent feed port and relies entirely on an air-filled cavity to receive near-field electromagnetic coupling excitation from the lower driving thin-film radiation layer 4, thereby generating parasitic resonant radiation to achieve antenna gain enhancement, beamforming, and sidelobe suppression. The coupling excitation and signal transmission between the two layers do not require any rigid RF soldering or connectors; they are all achieved through near-field coupling via the air medium.

[0049] Regarding the flexible film substrate: It is selected from flexible polymer films such as LCP, PI, or PET, giving the entire antenna the characteristic of being repeatedly bendable. This allows the antenna to be conformally mounted to the curved surfaces of carriers such as drones and vehicles, and the structural integrity of the air-filled cavity and the electromagnetic characteristics of the double-layer coupling are still maintained when bent. Among the domestically produced film substrates, the flexible 6020 (SL) low-shrinkage polyester film produced by Sichuan Dongfang Insulation Materials Co., Ltd. can be selected. This film uses polyethylene terephthalate (PET) as the substrate and is prepared by melt casting and biaxial stretching orientation process. This film substrate has excellent physical and mechanical properties, small thickness tolerance, high transparency, low thermal shrinkage, good surface flatness, and good flexibility.

[0050] Supplement to the implementation principles of key features: Conformal adaptation principle: The flexible thin film substrate's bendability, combined with the multi-layer stacked low-profile structure, allows the antenna to be attached to the surface of curved carriers such as aircraft skin and missile shells, integrating with the carrier and reducing air resistance and radar cross section (RCS). Wideband implementation principle: The main resonant mode of the lower driving thin film radiating layer 4 is superimposed with the parasitic resonant mode of the upper parasitic thin film radiating layer 2 to form multiple resonant frequency points, effectively widening the working bandwidth of the antenna and meeting the needs of multi-band communication. High gain is achieved by the radiation superposition effect of the lower driving thin film radiation layer 4, combined with the directional enhancement effect of the upper parasitic thin film radiation layer 2, concentrating the radiation energy in the main beam direction, greatly improving the directional gain of the phased array antenna array, while suppressing sidelobe interference.

[0051] This embodiment is specifically designed for lightweight data link terminals in low-Earth orbit satellite communication. The antenna adopts a rectangular two-dimensional 16×8 array arrangement, with a total of 128 thin-film antenna elements, operating in the Ku band in a half-duplex mode. The flexible thin-film substrate uses a 50μm thick LCP RF-specific thin film, which has excellent bending durability and low RF loss. The hollow support component is made by laser cutting PC low-loss insulating board. The hexagonal hollow support dielectric unit 3 has a side dimension of 5mm, the circular hollow support structure 8 has a diameter of 4mm, and the support height is precisely controlled to 1.0mm. Together, they form a sealed air dielectric filling cavity, and the coupling spacing deviation is strictly controlled within ±0.05mm. The upper parasitic thin-film radiation layer 2 and the lower driving thin-film radiation layer 4 are prepared by gradient layer inkjet printing process of nano-silver low-temperature sintering conductive ink, and are metallurgically formed by in-situ curing at 120℃. The conductive layer has a linewidth of 0.1mm and has excellent bending and anti-attenuation performance. The active circuit module 5 and the beamforming module 7 are both mounted on the back of the substrate using chip-level packaging integration technology. The overall assembly volume of this embodiment is 178mm×96mm×13mm, and the weight is 0.53kg. The measured relative working bandwidth of the Ku band is 32%, the phased array antenna beam electronic scanning range is ±65°, the RF insertion loss is ≤0.8dB, the weight is reduced by 70% compared with the traditional PCB phased array antenna, the conductivity attenuation after repeated bending of the curved surface is ≤3% after 100,000 cycles, and the gain fluctuation throughout the beam scan is ≤0.5dB. It fully meets the requirements of lightweight, low loss, wide bandwidth, accurate beam tracking and long-term stable operation of civilian low-orbit satellite communication data link terminals.

[0052] Example 2: Low-power miniaturized UFO-shaped curved-surface packaged phased array antenna (corresponding to) Figure 1 ) like Figure 1As shown, this embodiment provides an air-dielectric stacked coupled flexible thin-film phased array antenna, which is designed for low-power, miniaturized radar or satellite communication terminals and has excellent conformal surface capability.

[0053] Overall structure and assembly relationship: The antenna is assembled in a coaxial nested layered manner from top to bottom, specifically including: Protective antenna radome 1: Adapted to the outline of the carrier (such as a spherical radome or a cylindrical equipment shell) and processed into a saucer-shaped arc. It is made of high-strength, corrosion-resistant polyimide honeycomb sandwich composite wave-transparent material with low dielectric constant (ε≈1.05) and low loss tangent (tanδ≤0.002). It is installed tightly against the curved surface of the carrier through a molding and thermosetting process, achieving all-weather protection against impact, rain, and corrosion.

[0054] Upper parasitic thin film radiation layer 2: Located below the protective shield, it has a micro-arc surface structure.

[0055] Hollow support medium unit 3 and circular hollow support structure 8: The two are interleaved and locked together to form a rigid-flexible composite topological support grid. In this embodiment, in order to adapt to the curved surface shape, some hexagonal rigid load-bearing cells 3 undergo adaptive bending, while circular flexible buffer cells 8 provide deformation margin.

[0056] Lower driving thin film radiation layer 4: serves as the bottom radiation surface.

[0057] Active circuit module 5 and beamforming module 6: are mounted on the bottom PCB board.

[0058] Positioning and Assembly Coaxial 7: Penetrating through all layers, ensuring coaxial positioning of the entire unit, while also providing rapid and efficient heat dissipation, ensuring long-term and reliable operation of the phased array antenna.

[0059] Detailed description of key components: Rigid-flexible composite support grid ( Figure 5 ):like Figure 5 As shown, the hollow support medium unit 3 is a hexagonal rigid cell, and the circular hollow support structure 8 is nested within the inner circle of the hexagonal cell or arranged alternately with the hexagonal cell. In this embodiment, the planar ratio of the hexagonal cell to the circular cell is 7:3, forming a composite honeycomb grid. Relying on the periodic nesting and cooperation of the hexagonal rigid load-bearing periodic cell and the circular flexible deformation buffer cell, the structure remains stable under the static load of the antenna-fitting curved surface, while relieving stress during repeated bending at high frequencies.

[0060] The dual-layer coupled radiation layer consists of an upper parasitic thin-film radiation layer 2 and a lower driving thin-film radiation layer 4, which adopt a complementary, symmetrical, gradient-grooved coupling topology with upper and lower alignment. A solid radio frequency solid dielectric substrate is completely eliminated between the two radiation layers; physical isolation and shaping are achieved solely through hollow support dielectric units 3 and circular hollow support structures 8, enclosing a sealed, integrated air-filled cavity. This air-filled cavity serves as the sole medium for radio frequency near-field coupling transmission between the two radiation layers.

[0061] Nano-silver microstrip antenna 9: (e.g.) Figure 4 As shown, several nanometer silver microstrip antennas 9 are printed on the surface of the upper parasitic thin film radiating layer 2 using a gradient inkjet overprinting process, arranged in a regular rectangular grid two-dimensional array. The lower driving thin film radiating layer 4 also has corresponding driving units arranged thereon.

[0062] Preparation process flow (corresponding) Figure 6 ): Substrate pretreatment: A 25 μm thick LCP film was selected as the substrate for the radiation layer.

[0063] Inkjet overprinting and curing: Nano-silver conductive ink is gradient-jet-overprinted onto the lower driving thin film radiating layer 4 to form a driving microstrip antenna array. An in-situ low-temperature curing metallurgical conduction process is used, curing at 80℃ to form a dense nano-metallurgical conductive thin film. The upper parasitic thin film radiating layer 2 is processed in the same manner.

[0064] Supporting mesh molding: Rigid expanded polystyrene hexagonal cell 3 with a dielectric constant of 1.02 and ePTFE circular cell 8 with a dielectric constant of 1.01 are respectively molded using precision injection molding process.

[0065] Layered assembly: A honeycomb rigid-flexible composite support grid is laid on the lower driving thin film radiation layer 4, and then covered with the upper parasitic thin film radiation layer 2.

[0066] Packaging and Interconnection: A molded polyimide honeycomb protective antenna radome 1 is placed on the top layer, and each layer is locked in place by a positioning assembly coaxial cable 7. The bottom active circuit module 5 and the beamforming module 6 are connected via point-to-point mating, replacing traditional low-frequency cables.

[0067] Example 3: High-power, high-heat-flux-density square planar packaged phased array antenna (corresponding to...) Figure 2 ) like Figure 2 As shown, this embodiment provides an air-dielectric stacked coupled flexible thin-film phased array antenna suitable for high-power radar. Compared to Embodiment 1, its main improvements lie in the optimization of the heat dissipation structure and interconnection density.

[0068] Structural features: Encapsulation Top Cover: The protective radome 1 is designed with a square flat top surface with a concave shape, meaning the outer top layer has an inner groove 11, which can be adapted to the payload platform of high-power radar. The protective radome 1 has a composite structure with an inner groove 11 on the outer top layer. The four corners of the square flat surface of the protective radome 1 have built-in rainwater drainage pipes to prevent rainwater accumulation. Compared with traditional solid radomes of the same wall thickness or single hollow radomes, it has multiple technical advantages and core innovations. The inner groove 11 structure maintains the flat aerodynamic shape and overall wave-transmitting profile of the outer surface of the radome, and removes redundant solid materials through the hollow cavity, significantly reducing the antenna's heat output. The overall weight of the radome is reduced, achieving a lightweight design that effectively reduces the load and assembly stress, improving the long-term reliability of the structure. Simultaneously, the inner groove 11 allows for precise control of the local wall thickness gradient of the radome, working in conjunction with the hollow air layer to form a multi-level electromagnetic impedance matching structure. This achieves a smooth impedance transition between free space, the dielectric radome, and the internal space of the antenna, significantly reducing electromagnetic wave incident reflection loss and standing wave interference. It also improves the transmittance, gain, and phase consistency of high-power radar antennas under wide-angle scanning conditions, resolving the technical contradiction of balancing lightweight design and high transmittance performance in traditional radomes. Furthermore, the inner groove 11 within the hollow cavity forms a quasi-reinforced mechanical structure, enhancing the radome's resistance to bending, impact, and deformation without increasing material usage. This effectively suppresses warping deformation under vibration, wind pressure, and alternating high and low temperature environments, ensuring the antenna's shape accuracy and electrical performance stability.

[0069] Intermediate thermally conductive support plate: A square, flat metal thermally conductive support plate 10 is introduced between the protective radome 1 and the upper parasitic thin film radiating layer 2. The metal thermally conductive support plate 10 is internally designed with a radial fin heat dissipation plate structure, which significantly improves the heat conduction capability to the upper radiating layer to cope with the high heat flux density during high-power operation.

[0070] Interconnect solder balls: At the interconnection between the bottom active circuit module 5 and the beamforming module 6, and at the coaxial connection between the positioning and assembly of each layer, densely arranged ring-shaped interconnect solder balls are used (the solder balls are not explicitly shown in the figure, but are described as "densely arranged ring-shaped") to increase the cross-sectional area of ​​the current path, reduce the on-resistance, and improve the high current carrying capacity.

[0071] Working principle and advantages: In this embodiment, due to the increased power and heat generation, the heat generated by the active circuit module 5 is rapidly conducted to the protective radome 1 via the radial fin heat sink type metal heat-conducting bearing plate 10. This heat is then dissipated, allowing it to penetrate to the lower driving thin film radiating layer 4 and the upper parasitic thin film radiating layer 2. This ensures that the two thin film radiating layers are not deformed by high temperatures and can operate stably. Simultaneously, the dense interconnect solder balls ensure the reliability of high-current transmission and prevent connection failures caused by overheating. Other structures, such as the double-layer coupled thin film radiating layer and the rigid-flexible composite support grid, remain consistent with Embodiment 1, ensuring the antenna's high-performance radiation characteristics.

[0072] Example 4: Vehicle-mounted, industrial-grade high-reliability vibration-resistant packaged phased array antenna (corresponding to...) Figure 3 ) like Figure 3 As shown, this embodiment provides an air-dielectric stacked coupled flexible thin-film phased array antenna specifically designed for harsh environments such as automotive and industrial applications. Its core strength lies in improving the mechanical reliability and vibration resistance of the structure.

[0073] Structural features: Encapsulation top cover and thermal conductive support plate: In this embodiment, both the encapsulation top cover and the thermal conductive support plate adopt an integrated design of square flat plate structure. The protective antenna cover 1 is arranged on the outermost side, and the middle thermal conductive support plate is a radial fin heat dissipation plate structure, which is set between the protective antenna cover 1 and the upper parasitic thin film radiation layer 2, and is integrally formed into a whole. The protective antenna cover is made of polyimide honeycomb sandwich composite wave-transparent material, and a high wave-transparent thermal conductive support plate is arranged on the inner side of the antenna cover. While achieving efficient penetration of electromagnetic signals, the overall heat conduction and heat dissipation capacity is improved by relying on the radial fin heat dissipation structure.

[0074] Interconnect solder ball structure: The key improvement in this embodiment is that the bottom interconnect solder balls (located in the active circuit module 5), the beamforming module 6 and the PCB board, and the positioning and assembly coaxial 7 connections between each stack adopt a thickened polyhedral hexagonal profile structure (not shown in detail in the figure, but described as "thickened polyhedral hexagonal profile"). This thickened and multi-faceted contact solder ball design significantly increases the contact area and improves shear strength and tensile strength.

[0075] Reinforced rigid-flexible composite support grid: The materials and structures of the hollow support medium unit 3 and the circular hollow support structure 8 have been specially selected. The rigid unit 3 is made of a higher strength composite material, while the circular unit 8 is made of ePTFE material with excellent fatigue resistance, and the locking structure between the two is designed to prevent slippage.

[0076] Working principle and advantages: In automotive or industrial applications, antennas are exposed to strong random vibrations and shocks. This embodiment effectively resists solder joint breakage and interlayer misalignment caused by vibration through thickened hexagonal interconnect solder balls and reinforced support mesh. Even under high-frequency vibration conditions, the parallelism of the air-filled cavity and the reference coupling spacing can still be firmly locked, ensuring stable and reliable antenna radiation performance and eliminating the potential for breakage and poor contact caused by traditional connectors or thin leads during vibration.

[0077] Example 5: Detailed Implementation of a Dual-Layer Coupled Thin-Film Antenna Array (corresponding to...) Figure 4 , Figure 5 ) This embodiment focuses on the specific implementation details of the dual-layer coupled thin-film antenna array to further illustrate the superiority of the technical solution of the present invention.

[0078] Complementary symmetric gradient slotted topology ( Figure 4 ): like Figure 4 As shown, the coupling region between the upper parasitic thin-film radiating layer 2 and the lower driving thin-film radiating layer 4 features a complementary symmetrical gradient slot structure. Specifically, gradient slot lines are etched on the ground layer or radiating patch of the lower driving thin-film radiating layer 4, while complementary gradient slots are etched at corresponding positions on the upper parasitic thin-film radiating layer 2. The shape and size of these gradient slot lines and slots are determined by 3D electromagnetic simulation software to ensure that the antenna's electrical performance meets user requirements. This structure eliminates the need for an external impedance matching dielectric layer and transition microstrip matching lines in traditional dual-layer coupled antennas. It achieves natural self-matching of RF impedance across the entire operating frequency band by relying solely on the air-filled cavity as a single transmission medium. Simulation and field measurements demonstrate that this design simplifies the antenna stack-up structure, reduces assembly thickness, and achieves excellent impedance matching characteristics in the 10–40 GHz frequency band.

[0079] Planar arrangement of rigid-flexible composite support mesh Figure 5 ): like Figure 5 As shown, the hollow support dielectric unit 3 and the circular hollow support structure 8 are arranged in a periodic nested pattern on the plane. Specifically, a circular flexible unit 8 is placed at the center of a hexagonal rigid unit 3, or hexagonal and circular units are arranged alternately in a specific close-packing pattern. This arrangement ensures uniform mechanical support and consistent dielectric properties in any direction. When the array is subjected to external force and bends, the circular unit 8 undergoes elastic deformation to absorb strain energy, while the hexagonal unit 3 maintains its basic geometric structure. This ensures that the spacing deviation of the air cavity is strictly controlled within ±0.05mm, eliminating the defects of deformation collapse and interlayer coupling spacing offset in traditional flexible air cavity antennas.

[0080] Gradient inkjet overprinting of nano-silver microstrip antennas: On the surface of the upper parasitic thin film radiating layer 2, the nano-silver microstrip antenna 9 is printed using gradient inkjet overprinting technology. The specific process is as follows: first, a thinner layer of silver paste is sprayed to form a seed layer; then, a thicker layer of silver paste is overprinted in three stages, with low-temperature curing performed after each overprint. The final nano-silver microstrip antenna 9 patch has a length of 0.4 times the free-space wavelength of the center frequency of the operating band, a width of 0.35 times, and an array element spacing of 0.55 times the wavelength. This gradient overprinting process results in minimal conductivity attenuation after repeated bending (≤3% attenuation after 100,000 bends), and the overall film layer is dense with low radio frequency loss.

[0081] Experiment Example 1: Comparative Test of Locking Accuracy of Interlayer Spacing in Air Cavities Test objective: To verify the ability of the "rigid-flexible composite topology support grid" of this invention to control the interlayer coupling spacing under deformation conditions compared with traditional flexible air cavity antennas.

[0082] Test method: According to IEC 62047-43:2024 "Electrical characteristics test method after cyclic bending deformation of flexible microelectromechanical devices", the antenna under test is conformally mounted on a cylindrical carrier with a curvature radius R=80~200mm. A laser displacement sensor (resolution 0.1μm) is used to monitor the air cavity distance between the upper parasitic thin film radiation layer and the lower driving thin film radiation layer in real time at 64 sampling points of the array. The distance deviation Δh under two working conditions, static conformal and dynamic bending (1Hz sinusoidal bending, amplitude ±15°), is recorded.

[0083] Control group design: Comparative Example 1 (DP1): Traditional plastic support air cavity flexible array - using Φ1mm POM plastic cylinders evenly distributed for support, with a spacing of 15mm, and the rest of the structure is the same as in this embodiment (without rigid-flexible composite mesh).

[0084] Comparative Example 2 (DP2): Solid LCP Flexible Phased Array - No air cavity, upper and lower radiating layers use solid LCP (ε=3.0, thickness 0.1mm) as dielectric substrate, conventional microstrip coupling.

[0085] Embodiment of the present invention (Ex1): a hexagonal rigid cell with a side length of 5mm, a circular flexible cell with a diameter of 3.2mm (0.64 times the inscribed circle), and a cell height of 1.0mm are used.

[0086] Test results: Analysis and effect demonstration: The *Journal of Electronics*, in its article "Performance Analysis of Transmission Pattern of Flexible Conformal Arrays," points out that when the element spacing shrinkage ratio α = 0.95 (i.e., Δh ≈ 5% of the center spacing), the mutual coupling leakage jumps from 0.088 to 0.89, resulting in main lobe distortion and sidelobe elevation. The article "Analysis of the Influence of Bowl-Shaped Deformation of Phased Array Antennas on Their Radiation Performance" further indicates that the gain significantly deteriorates when the Z-axis deviation reaches λ / 20. At a center frequency of 10 GHz (λ = 30 mm), λ / 20 = 1.5 mm, and λ / 200 = 0.15 mm—while this invention, under dynamic bending of 10... 5 Under the combined operation of secondary and thermal cross-contamination, Δh is still locked at ±0.05mm (≈λ / 600@10GHz, ≈λ / 200@30GHz), which is 8 to 13 times better than Comparative Example 1 (plastic support) and completely avoids the problem of dielectric ε drift compared to the solid LCP scheme.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An air-dielectric stacked coupled flexible thin-film phased array antenna, comprising: The positioning and assembly coaxial (7) serves as a coaxial limiter and assembly positioning mechanism for the entire stacked structure, and the protective radome (1), upper parasitic thin film radiating layer (2), hollow support dielectric unit (3), lower driving thin film radiating layer (4), active circuit module (5), beamforming module (6), and circular hollow support structure (8) are assembled and formed by coaxial nesting and stacking from top to bottom via the positioning and assembly coaxial (7), characterized in that: The protective antenna cover (1) is adapted to the shape of the carrier by processing a conformal curved surface structure. It is made of polyimide honeycomb sandwich composite wave-transparent material with low dielectric constant, low loss tangent, and high strength corrosion resistance. Through the optimization of the integrated structure of the layup arrangement, sandwich ratio, and wall thickness gradient, the shell structure protection and low electromagnetic wave transmission are integrated and formed. It is installed with the carrier curved surface by molding and thermosetting process. The antenna signal insertion loss, reflection and beam distortion are reduced by the sandwich composite structure. At the same time, the whole machine is protected against impact, rain and corrosion in all weather conditions. The honeycomb sandwich core layer thickness is 2~5mm, the upper and lower skin thickness is 0.1~0.3mm, the layup angle is 0° / 90° orthogonal cross layup, and the wall thickness gradient rate is 0.05~0.15mm / cm along the curvature radius of the curved surface. The hollow support medium unit (3) and the circular hollow support structure (8) are interleaved and locked to form a rigid-flexible composite topological support grid, forming a flexible deformation adaptive air cavity constant spacing locking structure. Relying on the periodic nesting and cooperation of hexagonal rigid load-bearing periodic cells and circular flexible deformation buffer cells, the static load-bearing stiffness and dynamic bending deformation adaptability of the antenna are taken into account. Under the conditions of conformal antenna surface and repeated high-frequency bending, the electromagnetic coupling spacing deviation between air medium filling cavity layers can be controlled and locked within ±0.05mm. The side length of the hexagonal rigid load-bearing periodic cell is 3~8mm, the diameter of the circular flexible deformation buffer cell is 0.6~0.8 times the diameter of the inscribed circle of the hexagon, and the height of both types of cells is 0.8~1.2mm, which corresponds to 1 / 4 of the free space wavelength of the center frequency of the antenna operating frequency band. The upper parasitic thin film radiation layer (2) and the lower driving thin film radiation layer (4) adopt a complementary symmetrical gradient slotted coupling topology configuration with upper and lower alignment and fitting. The external impedance matching dielectric layer and transition microstrip matching line of the traditional double-layer coupled antenna are eliminated. The single transmission medium of the cavity is filled with air dielectric, which realizes the natural self-matching of RF impedance in the entire working frequency band, simplifies the antenna stack-up structure and reduces the assembly thickness. The complementary symmetrical gradient slot is an exponentially gradient slot line. The slot line length is 0.4 to 0.6 times the free space wavelength of the center frequency, and the slot line width is exponentially gradient from 0.1 mm to 1.5 mm with a gradient exponent of 0.5 to 1.

0. The upper parasitic thin film radiation layer (2) and the lower driving thin film radiation layer (4) are both printed by gradient layer inkjet printing of nano-silver low-temperature sintering conductive ink, combined with in-situ low-temperature curing metallurgical conduction exclusive molding process, forming a dense nano-metallurgical conductive thin film integrated radiation structure; the number of gradient layer inkjet printing layers is 4 to 6, the thickness of each layer after drying is 0.5 to 1 μm, the total conductive film thickness is 2 to 6 μm, the low-temperature sintering temperature is 120 to 180℃, and the holding time is 30 to 60 min; The beamforming module (6) and the lower driving thin film radiating layer (4) abandon rigid radio frequency welding and external connector connection structure, and build an air near-field multi-channel phase amplitude synchronous collaborative calibration array control architecture. The radio frequency phase and amplitude of each thin film antenna unit channel are independently controlled and multi-channel linkage calibration is realized. High-precision electronic scanning of the beam is completed by relying on spatial electromagnetic wave interference. The gain fluctuation of the beam scanning is controlled within ±0.5dB throughout the process. The multi-channel linkage calibration adopts the least squares iterative algorithm with a calibration period of 10ms. After calibration, the phase error of each channel is ≤1° and the amplitude error is ≤0.1dB.

2. The air-dielectric stacked coupled flexible thin-film phased array antenna according to claim 1, characterized in that: The hollow support medium unit (3) and the circular hollow support structure (8) are combined to form a hollow support assembly. The hollow support assembly is sandwiched between the upper parasitic thin film radiation layer (2) and the lower driving thin film radiation layer (4). The solid radio frequency solid dielectric substrate is completely removed between the two radiation layers. The two thin film radiation layers are physically isolated and shaped only through the hollow support assembly. The two surround and seal an integrated air dielectric filling cavity, and the air dielectric filling cavity is the only medium for radio frequency near-field coupling transmission between the two radiation layers. The hollow support medium unit (3) is a hexagonal rigid load-bearing periodic cell, integrally made of rigid expanded polystyrene with a dielectric constant of 1.

02. The circular hollow support structure (8) is a circular flexible deformation buffer cell embedded in the inner circle of the hexagonal cell, integrally made of ePTFE flexible material with a dielectric constant of 1.

01. The two types of cells are arranged in a planar periodic combination to form a mesh grid. Both types of cells are hollow through-structures, without metal fillers or metal inserts, avoiding the disturbance of the cavity electromagnetic field by the metal structure, minimizing the additional radio frequency loss of the support structure, and matching the low-loss transmission characteristics of pure air. The area ratio of the hexagonal cell to the circular cell is 60%~75%:25%~40%, and the cell arrangement period is 5~10mm.

3. The air-dielectric stacked coupled flexible thin-film phased array antenna according to claim 2, characterized in that: The hollow support medium unit (3) and the circular hollow support structure (8) are precisely nested coaxially and arranged in a uniform alternating plane to form a composite honeycomb rigid-flexible coupling support grid. The hexagonal rigid load-bearing periodic cell bears the static stacked load of the whole machine, and the circular flexible deformation buffer cell releases the high-frequency bending deformation stress. The bidirectional collaborative locking of the parallelism of the air medium filling cavity and the reference coupling distance ensures the integrity of the cavity structure and the constant coupling parameters under deformation conditions. The wall thickness of the hexagonal cell is 0.2~0.5mm, and the wall thickness of the circular cell is 0.1~0.3mm. The height of the two cells is consistent and equal to the height of the air cavity.

4. The air-dielectric stacked coupled flexible thin-film phased array antenna according to claim 1, characterized in that: The active circuit module (5) and the lower driving thin film radiating layer (4) abandon the solder ball, RF connector, and lead wire soldering conduction structure, and adopt a thin film substrate seamless LGA planar interconnect structure to realize electrical connection; the seamless LGA interconnect can reduce the high-frequency interconnect path, weaken parasitic RF parameters, reduce high-frequency transmission loss, optimize the interlayer heat conduction path, improve the heat dissipation efficiency of active chip, realize the flattening and lightweighting of antenna stack, adapt to airborne vibration and repeated bending conditions, and the detachable interconnect structure facilitates the later antenna maintenance and disassembly; the pad diameter of the seamless LGA interconnect is 0.3~0.5mm, the pad spacing is 0.5~0.8mm, and the interconnect impedance is controlled at 50Ω±2Ω.

5. The air-dielectric stacked coupled flexible thin-film phased array antenna according to claim 4, characterized in that: The active circuit module (5) integrates the TR component, power divider network, and intermediate frequency channel. It is responsible for completing the switching of radio frequency signal transmission and reception of the dual-layer thin film radiation array, power amplification, amplitude and phase modulation, signal combining and distribution, as well as radio frequency / intermediate frequency signal conversion, filtering, modulation and demodulation processing. It works with the beamforming module (6) to realize the antenna directional radiation, echo reception, beam scanning basic detection and communication functions.

6. The air-dielectric stacked coupled flexible thin-film phased array antenna according to claim 1, characterized in that: The beamforming module (6) integrates ADC, DAC, FPGA, DSP, and ARM core control chips. The ADC completes the analog-to-digital conversion of the receiving channel's analog intermediate frequency signal, the DAC realizes the digital-to-analog restoration of the transmitting channel's digital beam signal, the FPGA is responsible for multi-channel signal synchronous acquisition, real-time amplitude and phase weighting, and parallel beamforming calculation, the DSP performs channel amplitude and phase error correction, adaptive anti-interference, and beam algorithm optimization, and the ARM manages the overall machine instruction interaction, beam parameter scheduling, and peripheral status monitoring. The beamforming module (6) and the active circuit module (5) are connected point-to-point through a button, replacing traditional low-frequency cables and rigid connectors, eliminating signal interruption faults caused by bending, breakage, and poor contact, and improving the stability of multi-channel signal transmission. The diameter of the button is 0.5~1.0mm, the compression is 30%~50%, and the contact resistance is ≤5mΩ.

7. The air-dielectric stacked coupled flexible thin-film phased array antenna according to claim 1, characterized in that: The upper parasitic thin film radiation layer (2) is a passive, unfed integrated coupled radiation structure with no independent feed port or electrical welding point. It relies on the sealed air medium-filled cavity to receive near-field electromagnetic coupling excitation from the lower driving thin film radiation layer (4) to generate parasitic resonance. With the complementary symmetric gradient slot topology, it simultaneously realizes antenna gain improvement, beamforming optimization, and radiation sidelobe suppression. The opening width at the end of the slot line of the complementary symmetric gradient slot is 0.5~1.0mm, and the horizontal offset between the starting end of the slot line and the feed point of the driving radiation layer is 0.2~0.5mm.

8. The air-dielectric stacked coupled flexible thin-film phased array antenna according to claim 1, characterized in that: The substrates of the upper parasitic thin film radiation layer (2) and the lower driving thin film radiation layer (4) are selected from any one of LCP film, PI film, and PET radio frequency special flexible polymer film, which have fatigue resistance and repeated bending characteristics, adapt to the conformal bonding of irregular carrier curved surfaces, and have no failure attenuation of cavity structure, antenna impedance coupling, and radio frequency radiation performance under continuous deformation conditions; the substrate thickness is 25~75μm, the dielectric constant is 2.9~3.2, and the loss tangent is ≤0.

002.

9. The air-dielectric stacked coupled flexible thin-film phased array antenna according to claim 1, characterized in that: The surface of the upper parasitic thin film radiation layer (2) is gradient inkjet printed with several nano-silver microstrip antennas (9), and the several nano-silver microstrip antennas (9) are arranged in a rectangular grid two-dimensional array; the nano-metallurgical formed conductive film can ensure that the conductivity attenuation is ≤3% after 100,000 repeated bending of the antenna; the total thickness of the whole machine stacked assembly is ≤2mm, and the relative working bandwidth of the antenna is ≥30%; the patch length of the nano-silver microstrip antenna (9) is 0.35~0.45 times the free space wavelength of the center frequency of the working frequency band, the width is 0.3~0.4 times, and the array unit spacing is 0.5~0.6 times the wavelength.

10. The air-dielectric stacked coupled flexible thin-film phased array antenna according to claim 1, characterized in that: The protective radome (1) fully covers the outer side of the upper parasitic film radiation layer (2). The inner curved surface of the protective radome (1) is precisely matched with the conformal curved surface of the upper parasitic film radiation layer (2). A deformation buffer air gap is reserved between the inner surface of the protective radome (1) and the outer surface of the upper parasitic film radiation layer (2), or it is filled with low-density wave-transparent buffer foam to achieve all-round protection of the internal radiation structure against dust, impact, high and low temperatures, and bending and wear. The thickness of the buffer air gap is 0.2~0.5mm, or the density of the filled low-density wave-transparent buffer foam is 0.03~0.08g / cm³ and the dielectric constant is ≤1.1.

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