Spherical conformal 4*4 phased array antenna based on liquid crystal material

Abstract

The invention relates to the technical field of communication, in particular to a spherical conformal 4 * 4 phased array antenna based on a liquid crystal material, and an efficient receiving and transmitting module is responsible for space radiation and echo receiving of electromagnetic waves and contributes a main lobe gain greater than or equal to 13.9 dBi to an array; the support module provides continuous mechanical bearing and electromagnetic shielding for each functional layer to ensure stable impedance; the transmission module constructs a closed strip line channel, sends a radio frequency signal to a probe in a low-loss manner, ensures that the feed amplitudes of 16 paths are consistent, and lays a foundation for realizing low-sidelobe beam scanning; the liquid crystal phase shift feed module regulates and controls the orientation of liquid crystal molecules through voltage, continuously changes the effective dielectric constant of a strip line, completes phase compensation, achieves + / -30-degree electric control scanning, achieves the peak gain fluctuation smaller than or equal to 1.02 dB, is free of mechanical motion and low in power consumption, and remarkably reduces the phase correction and beam forming difficulty of the spherical conformal array. Therefore, the problem of phase error of wave beam arrival plane caused by the surface curvature of the traditional planar antenna is solved.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a 4x4 phased array antenna based on liquid crystal material with a spherical conformal surface. Background Technology

[0002] As a core device in modern communication, phased array antennas can flexibly adjust the feed phase of each element in the array to achieve rapid beam scanning and directional control.

[0003] Traditional phased array antennas mostly employ planar structures, which have limitations in terms of space utilization, aerodynamic shape matching, and omnidirectional coverage. Especially in complex platforms such as aircraft, satellites, or missiles, antennas need to conform to spherical or other curved shells to meet the requirements of conformal design and stealth. In these cases, traditional planar phased arrays are no longer sufficient to meet the practical application requirements.

[0004] While existing curved phased array antennas can partially match the shape of the carrier, they still have the following shortcomings: 1. Limited phase modulation technology: Most existing phase shifters use semiconductor devices, ferroelectric materials, or microelectromechanical systems (MEMS). These solutions often suffer from high cost, high power consumption, complex manufacturing processes, or insufficient phase shift continuity, making them difficult to promote in large-scale arrays. 2. Insufficient flexibility: Traditional phase shifter structures rely heavily on rigid materials and complex circuits, making it difficult to achieve high-precision, large-area arrangement on spherical curved surfaces, thus limiting the overall performance of the antenna.

[0005] Liquid crystal materials, as electrically controllable media with tunable dielectric constants, have been increasingly applied to phase shifter design in recent years. By applying an external bias voltage, the orientation of liquid crystal molecules can change, thereby adjusting their equivalent dielectric constant and achieving continuous and controllable phase adjustment. Current research on liquid crystal phase shifters mainly focuses on planar arrays and cylindrical arrays, while designs for conformal phased array antennas with spherical or curved surfaces are still relatively few. Summary of the Invention

[0006] The purpose of this invention is to provide a 4x4 phased array antenna based on liquid crystal material with spherical conformality, which aims to solve the problem of beam arrival plane phase error caused by the surface curvature of traditional planar antennas.

[0007] To achieve the above objectives, the present invention provides a 4x4 phased array antenna based on liquid crystal material with spherical conformality, comprising 16 radiating elements, wherein each radiating element includes a high-efficiency receiving and transmitting module, a support module, a transmission module, and a liquid crystal phase-shifting feeding module;

[0008] The high-efficiency receiving and transmitting module is disposed on the support module, the transmission module is disposed within the support module, and the liquid crystal phase-shifting power supply module is disposed between the transmission module and the support module.

[0009] The high-efficiency transmitting and receiving module includes a radiating patch and an antenna dielectric board. The radiating patch is disposed on the surface of the antenna dielectric board, and the antenna dielectric board is used to support the radiating patch.

[0010] The liquid crystal phase-shifting power supply module includes a second dielectric substrate, a liquid crystal layer, and a lower power supply port. The liquid crystal layer is embedded in the second dielectric substrate, and the lower power supply port interfaces with an external radio frequency system for inputting or outputting radio frequency signals.

[0011] The support module includes a first metal plate and a second metal plate. The first metal plate is disposed below the antenna dielectric substrate, and the second metal plate is disposed below the second dielectric layer and the liquid crystal layer.

[0012] The transmission module includes a dielectric substrate, a stripline transmission line, and a probe feed. The dielectric substrate is disposed between the metal plate and the metal plate. The stripline transmission line is disposed above the liquid crystal layer and embedded in the dielectric substrate. The probe feed passes through the dielectric substrate and connects the stripline transmission line and the radiating patch.

[0013] This invention discloses a 4x4 phased array antenna based on liquid crystal material with a spherical conformal design. The high-efficiency transmitting and receiving module is dedicated to the spatial radiation and echo reception of electromagnetic waves. With excellent impedance matching of S11≤-15dB at 16GHz, it contributes a main lobe gain of ≥13.9dBi to the array. The support module provides continuous mechanical support and electromagnetic shielding for each functional layer and also serves as system grounding. Its integrated rigid design eliminates the need for additional supports, reducing weight while suppressing interlayer parasitic coupling and ensuring impedance stability. The transmission module constructs a closed stripline channel, delivering RF signals to the probe with low loss, ensuring consistent amplitude across the 16 feed paths, laying the foundation for low sidelobe beam scanning. The liquid crystal phase-shifting feed module continuously changes the equivalent dielectric constant of the stripline by voltage-controlled liquid crystal molecule orientation, achieving phase compensation and ±30° electrically controlled scanning with peak gain fluctuation ≤1.02dB. It features no mechanical movement, low power consumption, and significantly reduces the difficulty of phase correction and beamforming in spherical conformal arrays. This solves the problem of beam arrival plane phase error caused by the surface curvature of traditional planar antennas. Attached Figure Description

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

[0015] Figure 1 This is a schematic diagram of the array element structure.

[0016] Figure 2 This is a schematic diagram of phase compensation analysis for arrayed signals.

[0017] Figure 3 This invention provides a schematic diagram of a 4x4 phased array antenna based on liquid crystal material with a spherical conformal structure.

[0018] Figure 4 The present invention provides a side view of a 4x4 phased array antenna based on liquid crystal material with a spherical conformal structure.

[0019] Figure 5 The present invention provides a top view of a 4x4 phased array antenna based on liquid crystal material with a spherical conformal structure.

[0020] Figure 6 The return loss coefficient for array element S11.

[0021] Figure 7 , Figure 8 and Figure 9 This shows the radiation pattern of the array antenna at different scanning angles.

[0022] In the diagram: 1-Radiating patch, 2-Antenna dielectric substrate, 3-Metal plate one, 4-Dielectric substrate one, 5-Strip line transmission line, 6-Probe feed, 7-Dielectric substrate two, 8-Liquid crystal layer, 9-Lower feed port, 10-Metal plate two. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0024] Please see Figures 1 to 9 The present invention provides a 4x4 phased array antenna based on liquid crystal material with spherical conformality, comprising 16 radiating elements, wherein the radiating elements include a high-efficiency receiving and transmitting module, a support module, a transmission module and a liquid crystal phase-shifting feeding module;

[0025] The high-efficiency receiving and transmitting module is disposed on the support module, the transmission module is disposed within the support module, and the liquid crystal phase-shifting power supply module is disposed between the transmission module and the support module.

[0026] In this embodiment, the high-efficiency transceiver module is dedicated to the spatial radiation and echo reception of electromagnetic waves. Leveraging its excellent impedance matching of S11≤-15dB at 16GHz, it contributes a main lobe gain of ≥13.9dBi to the array. The support module provides continuous mechanical support and electromagnetic shielding for each functional layer and also serves as the system ground. Its integrated rigid design eliminates the need for additional supports, reducing weight while suppressing interlayer parasitic coupling and ensuring impedance stability. The transmission module constructs a closed stripline channel, delivering RF signals to the probe with low loss, ensuring consistent amplitude across the 16 feed paths, laying the foundation for low sidelobe beam scanning. The liquid crystal phase-shifting feed module continuously changes the equivalent dielectric constant of the stripline by voltage-controlled liquid crystal molecule orientation, achieving phase compensation and ±30° electrically controlled scanning with peak gain fluctuation ≤1.02dB. This process involves no mechanical movement and low power consumption, significantly reducing the difficulty of phase correction and beamforming in spherical conformal arrays. This solves the problem of beam arrival plane phase error caused by the surface curvature of traditional planar antennas.

[0027] Furthermore, the high-efficiency transmitting and receiving module includes a radiating patch 1 and an antenna dielectric board 2. The radiating patch 1 is disposed on the surface of the antenna dielectric board 2, and the antenna dielectric board 2 is used to support the radiating patch 1.

[0028] In this embodiment, the radiating patch 1 is disposed on the surface of the antenna dielectric substrate 2 and is used to generate and radiate electromagnetic waves to achieve efficient transmission or reception of radio frequency signals by the antenna; the antenna dielectric substrate 2 carries the radiating patch 1 and provides a stable dielectric environment to ensure the stability of the operating frequency and radiation characteristics of the radiating patch 1.

[0029] Furthermore, the support module includes a first metal plate 3 and a second metal plate 10. The first metal plate 3 is disposed below the antenna dielectric substrate 2, and the second metal plate 10 is disposed below the second dielectric layer 7 and the liquid crystal layer 8.

[0030] In this embodiment, the first metal plate 3 serves as an isolation and conductive layer in the structure, enhancing the overall mechanical strength of the antenna while controlling the electromagnetic field distribution; the second metal plate 10 is located at the bottom of the structure, providing physical support for the liquid crystal while also providing a voltage applied to the outside of the liquid crystal.

[0031] Furthermore, the transmission module includes a dielectric substrate 4, a stripline transmission line 5, and a probe feed 6. The dielectric substrate 4 is disposed between the metal plate 3 and the liquid crystal layer 8. The stripline transmission line 5 is disposed on the liquid crystal layer 8. The probe feed 6 passes through the dielectric substrate 4 to connect the stripline transmission line 5 and the radiating patch 1.

[0032] In this embodiment, the dielectric substrate 4 serves as a support and electromagnetic characteristic regulator, ensuring antenna structural stability and controllable electromagnetic coupling. The stripline transmission line 5 transmits radio frequency signals and is connected to the probe feed 6 to effectively excite the radiating patch 1. The probe feed 6 penetrates the dielectric substrate 4 and is connected to the stripline transmission line 5 and the radiating patch 1 to excite the radiating patch 1 to generate the required electromagnetic waves. Simultaneously, a semi-circular metal cylinder is inserted at the feed port. This structure ensures that as much energy as possible is transferred from the phase shifter to the patch via the probe, preventing energy radiation into the surrounding space and improving energy transmission efficiency.

[0033] Furthermore, the liquid crystal phase-shifting power supply module includes a second dielectric substrate 7, a liquid crystal layer 8, and a lower power supply port 9. The liquid crystal layer 8 is embedded in the second dielectric substrate 7, and the lower power supply port 9 interfaces with an external radio frequency system for inputting or outputting radio frequency signals.

[0034] In this embodiment, the dielectric substrate 7 further supports the structure and controls the electromagnetic environment, providing physical support for the liquid crystal layer 8; the liquid crystal layer 8, as a tunable dielectric, changes its dielectric constant under the action of an applied bias electric field to achieve antenna beam scanning or phased array control; the feed port 9 interfaces with an external radio frequency system and is used for inputting or outputting radio frequency signals.

[0035] The input signal enters the array element through the lower feed port and is then fed into the stripline via the lower feed port 9 for phase modulation. The liquid crystal in the phase shifter exhibits different dielectric constants under the influence of the external voltage, thereby changing the effective dielectric constant of the stripline transmission line. The modulated signal is then fed onto the radiating patch 1 via the probe feed 6 and radiated to the outside via the patch antenna.

[0036] Due to the influence of spatial curvature, the electromagnetic wave path phase difference between each element inside the antenna array and the reference plane is not the same. The array needs to provide additional phase compensation for the elements at different positions to make up for the path phase difference. Figure 2 As shown, the gray plane is tangent to the sphere, the four black rectangular blocks represent array elements, R represents the radius of the sphere, L represents the path phase to be compensated, Arc represents the arc length from the tangent point to the array element, θ represents the angle corresponding to Arc, d represents the distance between the intersection of the extended line connecting the center of the sphere and the array element and the tangent plane, θ represents the phase to be compensated, and θ represents the wavelength of the signal beam. Based on the above information, it can be deduced that:

[0037]

[0038]

[0039]

[0040] Figures 3 to 5 The overall structure of the designed conformal antenna is shown. The antenna consists of 16 radiating elements, uniformly arranged on a spherical surface with a radius of 140 mm, forming a regular 4×4 array layout. Specifically, the elements are evenly spaced along the longitude and latitude directions of the sphere, ensuring a relatively uniform spacing between the radiating elements and avoiding radiation imbalances caused by irregular arrangements. This arrangement allows the array to maintain a compact structure while achieving both spherical symmetry and array uniformity. Furthermore, the electrical spacing between the elements has been optimized, enabling the array to effectively suppress grating lobe generation within the operating frequency band and ensuring good directivity and beam scanning capability.

[0041] Figure 6 The performance evaluation of the designed array element is presented. As shown in the figure, within the dielectric constant range of 2.5 to 3.3, the reflection coefficient S11 at 16 GHz is better than -15 dB, which is significantly better than the commonly used -10 dB threshold, indicating that the antenna has excellent impedance matching performance.

[0042] Figures 7 to 9 The radiation patterns of the array antenna at different scanning angles are shown. Based on the patterns, the main lobe gains at -30°, 0°, and +30° are 13.96 dBi, 14.98 dBi, and 14.1 dBi, respectively, all exceeding the project's minimum gain requirement of 12 dBi. This not only demonstrates the antenna's ability to maintain high radiation efficiency across the entire scanning range but also indicates that gain performance is almost unaffected during beam scanning. Beam scanning is achieved through electronic phase control of each phase-shifting unit. Specifically, this is achieved by adjusting the bias voltage to change the dielectric constant of the liquid crystal layer 8, thus controlling the signal phase without mechanical movement, thereby improving the system's reliability and reconfigurability. Throughout the scanning process, peak gain fluctuations are controlled within 1.02 dB, fully demonstrating the high efficiency and stability of liquid crystal phase-shifting technology.

[0043] Beneficial effects:

[0044] (1) Improved surface adaptability: By applying reconfigurable elements to the spherical curved surface platform, the antenna array can better fit the curved surface installation environment, avoiding the radiation pattern distortion and performance degradation problems that occur when traditional planar antennas are installed on curved surfaces.

[0045] (2) Improved electromagnetic performance: Stable impedance matching and beam control capabilities were achieved on the spherical platform, ensuring that the antenna can maintain high gain and good radiation efficiency under complex curved surface conditions.

[0046] (3) Enhanced system flexibility: The antenna can be installed and applied in a variety of curved platforms, expanding its scope of application and improving the feasibility of the system in aerospace, shipborne, vehicle-mounted and other scenarios.

[0047] (4) Reduce engineering difficulty and cost: Through the integrated design of structure and function, additional mechanical compensation or complex support structures are reduced, thereby simplifying system integration and reducing overall manufacturing and deployment costs.

[0048] The above-disclosed embodiments are merely preferred embodiments of the spherical conformal 4x4 phased array antenna based on liquid crystal material of the present invention. Of course, they should not be construed as limiting the scope of the present invention. Those skilled in the art can understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A 4x4 phased array antenna based on liquid crystal material with a spherical conformal surface, characterized in that, It includes 16 radiating array elements, each of which comprises a high-efficiency receiving and transmitting module, a support module, a transmission module, and a liquid crystal phase-shifting feeding module; The high-efficiency receiving and transmitting module is disposed on the support module, the transmission module is disposed inside the support module, and the liquid crystal phase shifting power supply module is disposed between the transmission module and the support module.

2. The spherical conformal 4x4 phased array antenna based on liquid crystal material as described in claim 1, characterized in that, The high-efficiency transmitting and receiving module includes a radiating patch and an antenna dielectric board. The radiating patch is disposed on the surface of the antenna dielectric board, and the antenna dielectric board is used to support the radiating patch.

3. The spherical conformal 4x4 phased array antenna based on liquid crystal material as described in claim 2, characterized in that, The liquid crystal phase-shifting power supply module includes a second dielectric substrate, a liquid crystal layer, and a lower power supply port. The liquid crystal layer is embedded in the second dielectric substrate, and the lower power supply port interfaces with an external radio frequency system for inputting or outputting radio frequency signals.

4. The spherical conformal 4x4 phased array antenna based on liquid crystal material as described in claim 3, characterized in that, The support module includes a first metal plate and a second metal plate. The first metal plate is disposed below the antenna dielectric substrate, and the second metal plate is disposed below the second dielectric layer and the liquid crystal layer.

5. The 4x4 phased array antenna based on liquid crystal material with spherical conformality as described in claim 4, characterized in that, The transmission module includes a dielectric substrate, a stripline transmission line, and a probe feed. The dielectric substrate is disposed between the metal plate and the metal plate. The stripline transmission line is disposed above the liquid crystal layer and embedded in the dielectric substrate. The probe feed passes through the dielectric substrate and connects the stripline transmission line and the radiating patch.

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