A dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna

Abstract

The present invention discloses a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna, which is composed of M×N array units arranged periodically, where M≥2 and N≥2. Each array antenna unit comprises a metal floor, two feed ports, two feed baluns, a dielectric substrate, a co-aperture coupled radiation patch, and a wide-angle impedance matching layer. The stacked structure of the antenna is suitable for curved surface conformal design and can be conformal to a cylindrical surface. The dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna provided by this invention has an operating bandwidth covering 4 to 10 GHz when the curvature radius is not less than 100 mm, can achieve ±60° angular scanning of the E-plane and H-plane within the operating frequency band, and has dual-polarization radiation characteristics, and can be used in the multi-function radar aperture of various high-speed and highly maneuverable carrier platforms.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar antennas, relates to a conformal broadband phased array, and in particular to a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna. Background Art

[0002] With the continuous development of integrated electronic systems for high-speed, highly maneuverable platforms, radar systems are required to perform multifunctional functions such as detection, jamming, probing, and communication. The demand for phased array radar antennas with ultra-wideband angular scanning capabilities is becoming increasingly urgent. Antenna performance directly determines the operational quality of the entire platform's communication system. Furthermore, dual-polarization technology has attracted considerable attention in radar applications due to its potential to improve target detection and recognition. Furthermore, in high-speed, highly maneuverable aircraft platforms, conformal antennas can improve the aerodynamics of the airframe without compromising the vehicle's external structure, while also offering greater beam coverage and improved space utilization. This has become a key development trend for radar antennas for future high-speed, highly maneuverable platforms. Therefore, research on dual-polarization, ultra-wideband angular scanning curved array antennas is of great significance in the field of radar antennas.

[0003] Patent CN114759351A discloses an ultra-wideband tightly coupled antenna array for use in special shapes. The antenna includes trapezoidal and square dielectric substrates, a metal floor, and antenna units. It is suitable for some scenarios with relatively special spaces. However, the trapezoidal structure is difficult to apply to curved antennas.

[0004] Patent CN115117608A discloses a tightly coupled ultra-wideband dual-polarized phased array antenna. The antenna has a stacked structure and is easy to conformally design. However, the antenna has many layers, and the metal radiating structures are distributed in different layers. Therefore, after the antenna is conformed, the antenna performance will vary dramatically due to the changes in the curvature radius of different layers. Summary of the Invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna. The curved surface design is easy to realize through the stacked structure, and the metal radiation structure is a single-layer planar structure. The impact on the antenna radiation performance during the curved surface conformal design is small, and it has good application prospects in radar conformal antennas for high-speed and highly maneuverable platforms.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A dual-polarized ultra-wide bandwidth angular scanning tightly coupled curved array antenna, consisting of M×N antenna units periodically arranged and conformally along a cylindrical surface, M≥2, N≥2, characterized in that each antenna unit includes a metal floor block, a dielectric substrate, and a wide-angle impedance matching layer arranged in sequence from the inside to the outside; a co-aperture coupled radiation patch is provided on the upper surface of the dielectric substrate, and the co-aperture coupled radiation patch consists of an X-polarized dipole patch, a Y-polarized dipole patch, and a circular coupling patch; two feed baluns respectively penetrate the lower surface of the metal floor block and are connected to the X-polarized dipole patch and the Y-polarized dipole patch.

[0008] In one embodiment, the co-aperture coupled radiation patch is a planar single-layer structure, with two X-polarized dipole patches and two Y-polarized dipole patches, which are symmetrically distributed around the circular coupling patch and centered, wherein the two X-polarized dipole patches are symmetrical about the Y direction, and the two Y-polarized dipole patches are symmetrical about the X direction, and the antenna unit realizes dual-polarized radiation on the planar single-layer co-aperture coupled radiation patch.

[0009] In one embodiment, the two feed baluns, a first feed balun connects an X-polarized dipole patch and an X-polarized antenna feed port; and a second feed balun connects a Y-polarized dipole patch and a Y-polarized antenna feed port.

[0010] In one embodiment, the feeding balun is composed of a coaxial inner core feeding metal column and a grounded short-circuit column.

[0011] In one embodiment, the co-aperture coupled radiation patch is obtained by cutting four circles with a radius of R2 at the four corners of a square metal, etching a circular opening, and etching a gap at the feed balun connected to the co-aperture coupled radiation patch, and the area of ​​the cut circle is π*R2 2 .

[0012] In one embodiment, the dielectric substrate and the wide-angle impedance matching layer are obtained by cutting off four cylinders with a radius of R1 at the four corners of a cube, and the top projection area of ​​the cut cylinders is π*R1. 2 .

[0013] In one embodiment, the antenna units are symmetrical along the angle bisector of ∠XOY.

[0014] In one embodiment, the metal floor block is 1.8 mm thick, the dielectric substrate has a dielectric constant of 2.2 and a thickness of 4.75 mm, and the wide-angle impedance matching layer has a dielectric constant of 4.0 and a thickness of 3 mm. When the radius of curvature of the array antenna is not less than 100 mm, the operating bandwidth covers 4 to 10 GHz, the active voltage standing wave ratio within the operating frequency band is less than 3, the operating mode is dual-polarization, and the dual-polarization antenna can achieve ±60° angular scanning of the E plane and H plane within the working bandwidth.

[0015] The present invention also provides a multifunctional radar, which adopts the dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna. Specifically, the dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna can be installed in the aperture of the multifunctional radar.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The tightly coupled antenna proposed in the present invention adopts a stacked structure, which is easy to conformal design.

[0018] 2. The tightly coupled antenna proposed in the present invention achieves ultra-wideband dual-polarization radiation performance using only a single-layer co-aperture coupled radiation patch.

[0019] 3. The co-aperture coupled radiation patch of the tightly coupled antenna proposed in the present invention is a single-layer planar structure, which can avoid the change of the curvature radius of the multi-layer metal radiation structure when the surface is conformal, thereby affecting the antenna performance. Therefore, the radiation performance of the tightly coupled antenna is stable when the surface is conformally designed.

[0020] This antenna has the advantages of ultra-wideband, wide-angle scanning, dual polarization, and conformal properties, and is suitable for use in multi-function radar systems on high-speed and highly maneuverable carrier platforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the three-dimensional structure of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of the present invention.

[0022] Figure 2 This is a schematic diagram of the three-dimensional structure of the planar units of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of the present invention.

[0023] Figure 3 and Figure 4 The top view is of a planar unit of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of the present invention.

[0024] Figure 5 This is a side view of a planar unit of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of the present invention.

[0025] Figure 6 This is a diagram showing the active voltage standing wave ratio range of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of the present invention.

[0026] Figure 7 This is the E-plane scanning pattern of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of the present invention.

[0027] Figure 8This is the H-plane scanning pattern of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of the present invention.

[0028] In the figure: 1. Metal floor block; 2. Feed balun; 21. Metal post connecting the coaxial inner core feed; 22. Ground short-circuit post; 3. Dielectric substrate; 4. Co-aperture coupled radiation patch; 41. X-polarized dipole patch; 42. Y-polarized dipole patch; 43. Circular coupling patch; 5. Wide-angle impedance matching layer; 6. X-polarized antenna feed port; 7. Y-polarized antenna feed port. DETAILED DESCRIPTION

[0029] In order to make the objects, features and advantages of the present invention more obvious and easy to understand, the invention is further described in detail below with reference to the accompanying drawings and embodiments, but they are not intended to be used as a basis for limiting the invention in any way.

[0030] like Figure 1 As shown, a schematic diagram of the three-dimensional structure of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of this embodiment is obtained by periodically arranging M×N antenna units and conforming them along a cylindrical surface, where M≥2, N≥2. In this embodiment, M=10, N=10.

[0031] like Figure 2 The figure shows a schematic diagram of the three-dimensional structure of a planar unit of a dual-polarization ultra-wideband angular scanning tightly coupled curved array antenna according to this embodiment. Each antenna unit of the present invention comprises a metal floor block 1, two feed baluns 2, a dielectric substrate 3, a co-aperture coupled radiation patch 4, a wide-angle impedance matching layer 5, and two feed ports, arranged in sequence from the inside to the outside. The metal floor block 1 is the bottom structure of the antenna unit, that is, the side closest to the center of the circle when the surface is curved. The dielectric substrate 3 is on the upper layer of the metal floor block 1, and the wide-angle impedance matching layer 5 is on the upper layer of the dielectric substrate 3, that is, the side farthest from the center of the circle when the surface is curved.

[0032] A co-aperture coupled radiating patch 4 is mounted on the top surface of the dielectric substrate 3 and consists of an X-polarized dipole patch 41, a Y-polarized dipole patch 42, and a circular coupling patch 43. Two feed baluns 2 extend through the bottom surface of the metal floor panel 1 and connect to the X-polarized dipole patch 41 and the Y-polarized dipole patch 42, respectively. The co-aperture coupled radiating patch 4, serving as the antenna unit radiating structure, is a planar, single-layer structure that conforms to curved surfaces without affecting the antenna's radiation performance.

[0033] The array antenna of the present invention utilizes a laminated structure, which prevents the antenna structure from changing shape when conformally bent, facilitating stable electromagnetic performance during curved surface conformal design. Furthermore, the metal radiating structure is a single-layer planar structure, which minimally impacts the antenna's radiation performance during curved surface conformal design, resulting in stable impedance and radiation performance. Therefore, the laminated structure of the antenna of the present invention is suitable for curved surface conformal design, including conformal to cylindrical surfaces, and has promising application prospects in radar conformal antennas for high-speed, highly maneuverable platforms. For example, it can be installed in the aperture of a multi-function radar, serving as an array antenna for such radars.

[0034] In this embodiment of the present invention, the antenna unit achieves dual-polarized radiation on a planar, single-layer, co-aperture coupled radiating patch 4. Within a co-aperture coupled radiating patch 4, there are two X-polarized dipole patches 41 and two Y-polarized dipole patches 42, symmetrically distributed around the center of a circular coupling patch 43. The two X-polarized dipole patches 41 are symmetrical about the Y direction, i.e., located in the X direction. The two Y-polarized dipole patches 42 are symmetrical about the X direction, i.e., located in the Y direction.

[0035] Through the above structure, the X-polarized dipole patch 41 and the Y-polarized dipole patch 42 work together with the circular coupling patch 43 to achieve X-polarized radiation and Y-polarized radiation, respectively. Therefore, the antenna unit achieves dual-polarized radiation on the planar single-layer co-aperture coupled radiation patch 4.

[0036] In this embodiment of the present invention, the feed balun 2 consists of a coaxial inner core feed metal post 21 and a ground shorting post 22. The two feed baluns 2 are a first feed balun and a second feed balun. The first feed balun connects an X-polarized dipole patch 41 to the X-polarized antenna feed port 6; the second feed balun connects a Y-polarized dipole patch 42 to the Y-polarized antenna feed port 7. Both the X-polarized antenna feed port 6 and the Y-polarized antenna feed port 7 have an input impedance of 50Ω.

[0037] Through the above structure, the antenna port is fed to the dipole radiation patch.

[0038] In the embodiment of the present invention, the dielectric substrate 3 and the wide-angle impedance matching layer 5 are respectively obtained by cutting off four cylinders with a radius of R1 at the four corners of a cube, and the top projection area of ​​the cut cylinders is π*R1 2 .

[0039] With the above structure, the impedance matching of the antenna is improved.

[0040] In the embodiment of the present invention, the co-aperture coupled radiation patch 4 is obtained by cutting four circles with a radius of R2 at the four corners of a square metal, etching a circular opening gap, and etching a gap at the place where the feed balun 2 is connected to the co-aperture coupled radiation patch 4, and the area of ​​the cut circle is π*R22 .

[0041] Through the above structure, the design of the co-aperture coupled radiation patch 4 is realized in a very small space, and dual-polarization radiation can be achieved.

[0042] In the embodiment of the present invention, the antenna unit is symmetrical along the angular bisector of ∠XOY, that is, the structure is symmetrical along the plane that forms an angle with the center of the XOZ plane and the YOZ plane. This is done to maintain consistent dual-polarization radiation intensity.

[0043] In this embodiment of the present invention, the antenna unit's metal floor block 1 is an aluminum alloy block with a thickness of 1.8 mm. The antenna unit's dielectric substrate 3 is F4b with a dielectric constant of 2.2 and a thickness of 4.75 mm. The antenna unit's wide-angle impedance matching layer 5 is made of 8200 resin with a dielectric constant of 4.0 and a thickness of 3 mm.

[0044] The array antenna of the present invention has an operating bandwidth covering 4 to 10 GHz when the curvature radius is not less than 100 mm, and an average active voltage standing wave ratio within the operating frequency band is less than 3. The operating mode is dual-polarization. Within the operating bandwidth, the dual-polarization antenna can achieve ±60° angular scanning of the E-plane and H-plane, and has dual-polarization radiation characteristics. It can be used in the multi-function radar aperture of various high-speed and high-mobility carrier platforms.

[0045] like Figure 3-Figure 5 As shown, the planar unit structure dimensions of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna in this embodiment are shown in Table 1.

[0046] Table 1

[0047] structure <![CDATA[W0]]> <![CDATA[W1]]> <![CDATA[W2]]> <![CDATA[W3]]> <![CDATA[R1]]> <![CDATA[R2]]> Dimensions (mm) 11 0.2 0.2 1.5 4.2 4.6 structure <![CDATA[R3]]> <![CDATA[R4]]> <![CDATA[H1]]> <![CDATA[H2]]> <![CDATA[H3]]> Dimensions (mm) 1.4 0.4 1.8 4.75 3

[0048] Wherein: W0 is the side length of the square metal floor block 1, W1 is the annular gap width between the X-polarization and Y-polarization dipole patches 41 and 42 and the circular coupling patch 43, W2 is the gap width between the X-polarization dipole patch 41 and the Y-polarization dipole patch 42, W3 is the horizontal distance between the center of the coaxial inner core feeding metal post 21 and the center of the ground short-circuit post 22, R1 is the radius of the four identically cut corners of the dielectric substrate 3 and the wide-angle impedance matching layer 5, R2 is the radius of the four identically cut corners of the co-aperture coupling radiation patch 4, R3 is the radius of the co-aperture coupling radiation patch 4, R4 is the radius connecting the coaxial inner core feeding metal post 21 and the ground short-circuit post 22, H1 is the thickness of the metal floor block 1, H2 is the thickness of the dielectric substrate 3, and H3 is the thickness of the wide-angle impedance matching layer 5.

[0049] The effects of the present invention can be further illustrated with reference to simulation results:

[0050] like Figure 6The figure shows the active voltage standing wave ratio (VSWR) range for a dual-polarization, ultra-wideband, angularly scanned, tightly coupled curved array antenna according to this embodiment. The active voltage standing wave ratio (VSWR) curves for all ports in this co-curved array antenna are within the shaded range. Therefore, the active voltage standing wave ratios (VSWRs) of all ports in the curved array antenna are less than 3 in the 4-10 GHz frequency band, and the antenna's operating bandwidth is 4-10 GHz.

[0051] like Figure 7 As shown, the E-plane scanning pattern of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of the present invention is shown. The gain reduction of the curved array antenna within the 60° scanning range of the E-plane is less than 3.5dB.

[0052] like Figure 8 As shown, the H-plane scanning pattern of a dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of the present invention is shown. The gain reduction of the curved array antenna within the 60° scanning range of the H-plane is less than 3.5dB.

[0053] In summary, the dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna of the present invention can conformally fit on a cylindrical surface. When the radius of curvature is not less than 100 mm, the operating bandwidth can cover 4 to 10 GHz. Within the operating bandwidth, large angular scanning of ±60° on the E-plane and H-plane can be achieved, and it has dual-polarization radiation characteristics, and can be used in the multi-function radar aperture of various high-speed and high-mobility carrier platforms.

[0054] The above is a detailed introduction to the dual-polarization ultra-wideband angular scanning tightly coupled curved array antenna provided by the present invention, and the principles and implementation methods of the present invention are explained and implemented using detailed structural design parameters. The description of the above embodiments is only intended to help understand the method and core concept of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna, comprising M×N antenna elements arranged periodically and conformally along a cylindrical surface, M ≥ 2, N ≥ 2, characterized in that: Each antenna unit comprises a metal floor plate (1), a dielectric substrate (3) and a wide-angle impedance matching layer (5) arranged in sequence from the inside to the outside; a common-aperture coupling radiation patch (4) is arranged on the upper surface of the dielectric substrate (3), and the common-aperture coupling radiation patch (4) is composed of an X-polarized dipole patch (41), a Y-polarized dipole patch (42) and a circular coupling patch (43); two feeding baluns (2) are respectively connected to the X-polarized dipole patch (41) and the circular coupling patch (43) through the lower surface of the metal floor plate (1). ) and a Y-polarized dipole patch (42); the co-aperture coupled radiation patch (4) is a planar single-layer structure, with two X-polarized dipole patches (41) and two Y-polarized dipole patches (42), which are symmetrically distributed around the circular coupling patch (43), wherein the two X-polarized dipole patches (41) are symmetrical about the Y direction, and the two Y-polarized dipole patches (42) are symmetrical about the X direction, and the antenna unit realizes dual-polarized radiation on the planar single-layer co-aperture coupled radiation patch (4).

2. The dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna according to claim 1, characterized in that: In the two feeding baluns (2), the first feeding balun connects an X-polarized dipole patch (41) and an X-polarized antenna feeding port (6); and the second feeding balun connects a Y-polarized dipole patch (42) and a Y-polarized antenna feeding port (7).

3. The dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna according to claim 2, characterized in that: The feeding balun (2) is composed of a coaxial inner core feeding metal column (21) and a grounding short-circuit column (22).

4. The dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna according to claim 1, 2 or 3, characterized in that: The co-aperture coupled radiation patch (4) is obtained by cutting off four circles with a radius of R2 at the four corners of a square metal, etching a circular opening gap, and etching a gap at the place where the feed balun (2) is connected to the co-aperture coupled radiation patch (4), and the area of ​​the cut circle is π*R2 2 .

5. The dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna according to claim 1, characterized in that: The dielectric substrate (3) and the wide-angle impedance matching layer (5) are respectively obtained by cutting off four cylinders with a radius of R1 at the four corners of a cube, and the top projection area of ​​the cut cylinders is π*R1 2 .

6. The dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna according to claim 1, characterized in that: The antenna units are symmetrical along the angle bisector of ∠XOY.

7. The dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna according to claim 1, characterized in that: The metal floor block (1) has a thickness of 1.8 mm, the dielectric substrate (3) has a dielectric constant of 2.2 and a thickness of 4.75 mm, and the wide-angle impedance matching layer (5) has a dielectric constant of 4.0 and a thickness of 3 mm.

8. The dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna according to claim 1, characterized in that: The array antenna has a working bandwidth of 4 to 10 GHz when the curvature radius is not less than 100 mm. The active voltage standing wave ratio in the working frequency band is less than 3. The working mode is dual polarization. The dual polarization antenna can achieve ±60° angular scanning in the E and H planes within the working bandwidth.

9. A multifunctional radar using the dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna according to claim 1, wherein the dual-polarization ultra-wide bandwidth angular scanning tightly coupled curved array antenna is installed in the aperture of the multifunctional radar.

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