An all-metal dual-polarized Luneburg lens multi-beam antenna
By using a coverless corrugated plate and a parallel flat plate waveguide structure combined with a waveguide orthogonal mode coupler in an all-metal waveguide lens antenna, multi-beam scanning of a dual-polarization Luneburg lens is achieved, which solves the limitation of single polarization in the existing technology, achieves wide-angle dual-polarization coverage and circular polarization performance, and simplifies the processing and assembly process.
Patent Information
- Application Number
- CN202110640945.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-06-09
- Publication Date
- 2025-10-03
- Estimated Expiration
- 2041-06-09
AI Technical Summary
The existing all-metal waveguide-fed Luneburg lens antenna can only achieve a single polarization refractive index distribution and cannot meet the dual-polarization and multi-beam requirements of 5G communications.
A coverless corrugated plate structure is used to control the phase velocity of the vertical polarization mode, and a parallel plate waveguide structure is used to control the phase velocity of the horizontal polarization mode. Seven groups of waveguide orthogonal mode couplers surrounding the lens are used as the feeding structure to achieve dual-polarization feeding. The phase velocity of the polarization mode is controlled by the distance between the metal plates, and the upper and lower halves of the seven groups of waveguide orthogonal mode couplers are combined to achieve dual-polarization beam scanning.
It realizes independent operation of horizontal polarization and vertical polarization, covers wide-angle multi-beam of not less than -48° to +48°, supports multi-beam coverage of circular polarization, and the integrated design of Luneburg lens and waveguide orthogonal mode coupler feeding structure facilitates processing and assembly.
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Figure CN113381202B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an all-metal dual-polarization Luneburg lens multi-beam antenna, belonging to the technical field of lens antennas. Background Art
[0002] In recent years, 5G communications technology has placed significant demands on multi-beam technology for millimeter-wave antennas. Due to the high cost, high energy loss, and relatively narrow bandwidth of the phase modulation equipment required by phased array and digital multi-beam technologies, passive multi-beam antennas are considered an important alternative for millimeter-wave multi-beam systems. Lens antennas are increasingly being used in multi-beam antennas due to their low cost, wide bandwidth, multi-beam scanning, and simple feed networks. The Luneburg lens is a classic non-uniform lens antenna that exhibits excellent multi-beam performance over a wide angle. This makes Luneburg lens antennas potentially applicable in a wide range of fields, including communications and radar.
[0003] For 5G communication applications, in addition to multi-beam and millimeter wave characteristics, the coverage range and polarization diversity requirements of the fan-shaped beam also need to be considered. In an environment with limited electromagnetic spectrum resources, polarization diversity technology is of great significance to improving the channel capacity and transmission rate of the communication system. Summary of the Invention
[0004] In response to the current situation where existing all-metal waveguide-fed Luneburg lens antennas can only achieve a single polarization refractive index distribution, the present invention proposes an all-metal dual-polarization Luneburg lens multi-beam antenna. While typical Luneburg lenses use a corrugated waveguide structure to control the phase velocity of the vertical polarization mode, the lens antenna proposed in the present invention improves on this by adopting a topless corrugated plate structure to control the phase velocity of the vertical polarization mode. Furthermore, the lens antenna combines a parallel plate waveguide structure to control the phase velocity of the horizontal polarization mode by controlling the distance between the metal plates. The lens antenna uses seven groups of waveguide orthogonal mode couplers surrounding the lens as the feeding structure to achieve dual-polarization feeding, and dual-polarization beam scanning is achieved by selecting different feeding ports.
[0005] To achieve the above object, the present invention adopts the following technical solutions:
[0006] The all-metal dual-polarization Luneburg lens multi-beam antenna includes an upper metal plate A and a lower metal plate B.
[0007] The upper metal plate A includes an upper metal cover plate, metal pillars of varying heights mounted on the surface of the metal cover plate, a choke slot E1, the upper half of seven waveguide orthogonal mode couplers, and through holes and threaded holes for connecting the lower half. The lower metal plate B includes a lower metal cover plate, metal pillars of varying heights mounted on the surface of the metal cover plate, a choke slot E2, the lower half of seven waveguide orthogonal mode couplers surrounding the lens, and threaded holes for fixing.
[0008] The upper part of the seven waveguide orthogonal mode couplers includes seven vertical polarization mode feeding ports of the waveguide orthogonal mode couplers, with an adjacent angular spacing of 16°, and are respectively denoted as V1, V2, V3, V4, V5, V6, and V7; the lower part of the seven waveguide orthogonal mode couplers includes seven waveguide channels and seven horizontal polarization mode feeding ports, with an adjacent angular spacing of 16°, and the seven horizontal polarization mode feeding ports are respectively denoted as H1, H2, H3, H4, H5, H6, and H7; The metal columns of different heights loaded on the surface of the metal cover plate are multiple cylindrical metal columns of different heights. They are variable refractive index periodic structural units that support horizontal polarization mode and vertical polarization mode respectively. They are divided into 9 step rings, and the step rings are numbered 1-9 from the center to the edge. The height of the metal columns inside different step rings, the placement of the metal columns in the step rings, and the spacing between the metal columns in the corresponding step rings in the upper and lower metal plates are controlled to construct the gradient equivalent refractive index distribution required for the two polarizations of the Luneburg lens.
[0009] The upper metal plate A and the lower metal plate B are both made of metal materials and adopt an integrated processing technology of all-metal Luneburg lens and waveguide orthogonal mode coupler. During the assembly process, the connection process between the lens part and the feeding structure is omitted, which facilitates mechanical processing and assembly of the overall structure.
[0010] The connection relationship between the various parts of the all-metal dual-polarization Luneburg lens multi-beam antenna is as follows: the upper metal plate A and the lower metal plate B are positioned through two positioning holes, the feed ports of each vertical polarization mode are matched one by one with the waveguide channels of the waveguide orthogonal mode coupler, and then fixed with countersunk screws.
[0011] The working process of the all-metal dual-polarization Luneburg lens multi-beam antenna is as follows: the external waveguide is fixedly connected to the horizontal polarization port of the waveguide orthogonal mode coupler with screws, the horizontally polarized electromagnetic wave is fed by the external waveguide, transmitted to the Luneburg lens antenna part through the waveguide channel, the horizontally polarized electromagnetic wave is converted into a spherical wave through the gradient refractive index transformation and radiated into the free space; the external waveguide is connected to the vertical polarization port of the waveguide orthogonal mode coupler with screws, the vertically polarized electromagnetic wave is fed by the external waveguide, transmitted to the Luneburg lens antenna part through the waveguide channel, the vertically polarized electromagnetic wave is converted into a spherical wave through the gradient refractive index transformation and radiated into the free space.
[0012] The all-metal dual-polarization Luneburg lens multi-beam antenna selects feeding ports at different positions to feed two orthogonally polarized electromagnetic waves to achieve dual-polarization beam scanning. The seven ports H1-H7 and V1-V7 corresponding to horizontal polarization and vertical polarization achieve beam coverage of no less than -48° to +48° within the operating frequency band.
[0013] Beneficial effects
[0014] The all-metal dual-polarized Luneburg lens multi-beam antenna described in the present invention has the following advantages compared to existing wide-angle coverage multi-beam antennas:
[0015] 1. Using the waveguide orthogonal mode coupler feeding structure to achieve independent operation of horizontal polarization and vertical polarization;
[0016] 2. Achieve dual-polarization, wide-angle multi-beam coverage;
[0017] 3. Achieve circularly polarized multi-beam coverage;
[0018] 4. The integrated design of Luneburg lens and waveguide orthogonal mode coupler feeding structure facilitates processing and assembly; BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is an exploded view of the structure of the all-metal dual-polarized Luneburg lens multi-beam antenna according to an embodiment of the present invention;
[0020] Figure 2 : is a schematic structural diagram of an all-metal dual-polarized Luneburg lens multi-beam antenna according to an embodiment of the present invention, wherein Figure 2 (a) is a schematic diagram of the upper metal plate. Figure 2 (b) is a schematic diagram of the lower metal plate;
[0021] Figure 3 1 is a schematic structural diagram of a waveguide orthogonal mode coupler of an all-metal dual-polarization Luneburg lens multi-beam antenna according to an embodiment of the present invention;
[0022] Figure 4 is a return loss curve of the all-metal dual-polarized Luneburg lens multi-beam antenna according to an embodiment of the present invention, wherein Figure 4 (a) is the return loss curve of the horizontal polarization port, Figure 4 (b) is the return loss curve of the vertical polarization port;
[0023] Figure 5 1 is an insertion loss curve of a co-polarization port of the all-metal dual-polarization Luneburg lens multi-beam antenna according to an embodiment of the present invention;
[0024] Figure 6 1 is a cross-polarization port insertion loss curve of the all-metal dual-polarization Luneburg lens multi-beam antenna according to an embodiment of the present invention;
[0025] Figure 7 is the horizontally polarized normalized pattern of the all-metal dual-polarized Luneburg lens multi-beam antenna according to an embodiment of the present invention, wherein Figure 7 (a) is the horizontal polarization E-plane pattern, Figure 7 (b) is the horizontal polarization H-plane pattern;
[0026] Figure 8 is the vertical polarization normalized pattern of the all-metal dual-polarization Luneburg lens multi-beam antenna according to an embodiment of the present invention, wherein Figure 8 (a) is the vertical polarization E-plane pattern, Figure 8 (b) is the vertical polarization H-plane pattern;
[0027] Figure 9 is the horizontally polarized multi-beam pattern of the all-metal dual-polarized Luneburg lens multi-beam antenna according to an embodiment of the present invention, wherein Figure 9 (a) is the horizontal polarization multi-beam pattern at 28 GHz, Figure 9 (b) is the horizontal polarization multi-beam pattern at 30 GHz, Figure 9 (c) is the horizontally polarized multi-beam pattern at 32 GHz;
[0028] Figure 10 is the vertically polarized multi-beam pattern of the all-metal dual-polarized Luneburg lens multi-beam antenna according to an embodiment of the present invention, wherein Figure 10 (a) is the vertical polarization multi-beam pattern at 28 GHz, Figure 10 (b) is the vertical polarization multi-beam pattern at 30 GHz, Figure 10 (c) is the vertically polarized multi-beam pattern at 32 GHz;
[0029] Figure 11 axial ratio and radiation pattern of the circularly polarized beam characteristics of the all-metal dual-polarized Luneburg lens multi-beam antenna at 30 GHz according to an embodiment of the present invention;
[0030] Figure 12 1 is a circular polarization axial ratio curve of each port of the all-metal dual-polarization Luneburg lens multi-beam antenna according to an embodiment of the present invention. DETAILED DESCRIPTION
[0031] In order to better illustrate the purpose and advantages of the present invention, the following is a further detailed description of an all-metal dual-polarized Luneburg lens multi-beam antenna of the present invention in conjunction with the accompanying drawings and embodiments.
[0032] Example
[0033] The structure of this embodiment is as follows Figure 1 This embodiment includes an upper metal plate A and a lower metal plate B.
[0034] The upper metal plate A includes an upper metal cover plate, metal pillars of varying heights mounted on the surface of the metal cover plate, a choke slot E1, the upper half of seven waveguide orthogonal mode couplers, and through holes and threaded holes for connecting the lower half. The lower metal plate B includes a lower metal cover plate, metal pillars of varying heights mounted on the surface of the metal cover plate, a choke slot E2, the lower half of seven waveguide orthogonal mode couplers surrounding the lens, and threaded holes for fixing.
[0035] The upper half of the seven waveguide orthogonal mode couplers includes seven vertical polarization mode feed ports of the waveguide orthogonal mode couplers, with adjacent angular spacing of 16 degrees, and are respectively denoted as V1, V2, V3, V4, V5, V6, and V7; the lower half of the seven waveguide orthogonal mode couplers includes seven waveguide channels and seven horizontal polarization mode feed ports, with adjacent angular spacing of 16 degrees, and the seven horizontal polarization mode feed ports are respectively denoted as H1, H2, H3, H4, H5, H6, and H7; the metal pillars of different heights loaded on the surface of the metal cover plate are multiple cylindrical metal pillars of different heights, which are variable refractive index periodic structural units that support horizontal polarization mode and vertical polarization mode respectively. They are divided into 9 step rings, and the step rings are numbered 1-9 from the center to the edge. The height of the metal pillars between different rings, the spacing between the upper and lower metal pillars at different placement positions, and the gradient effect refractive index distribution required for the two polarizations of the Luneburg lens are controlled.
[0036] All parts of this embodiment are made of metal materials.
[0037] Figure 4 The test results of the return loss of the horizontally polarized port and the vertically polarized port in this embodiment show that the return loss is less than -10 dB in the frequency band of 28 GHz to 32 GHz. Due to the symmetry of the structure, ports 1 to 4 represent the performance of all ports.
[0038] Figure 5 The test results of the mutual coupling characteristics between the co-polarized ports in this embodiment show that the isolation between the horizontally polarized ports is higher than 10 dB, and the isolation between the vertically polarized ports is higher than 15 dB.
[0039] Figure 6 This is the test result of the mutual coupling characteristics of the cross-polarization ports of this embodiment. The isolation between different polarization ports of the same waveguide orthogonal mode coupler is higher than 40 dB.
[0040] The antenna manufactured in this embodiment was tested in a microwave darkroom. The horizontal polarization normalized radiation patterns at 28 GHz, 30 GHz, and 32 GHz were as follows: Figure 7 As shown, the vertical polarization normalized radiation patterns at 28GHz, 30GHz, and 32GHz are as follows Figure 8 As shown, the horizontally polarized E-plane radiation pattern is a narrow beam radiation pattern with a 3dB beamwidth of 19.4°, the horizontally polarized H-plane radiation pattern is a wide beam radiation pattern with a 3dB beamwidth of 86.7°, the vertically polarized H-plane beam is a narrow beam radiation pattern with a 3dB beamwidth of 14.5°, and the vertically polarized E-plane radiation pattern is a wide beam radiation pattern with a 3dB beamwidth of 77.4°.
[0041] Figure 9 The horizontally polarized multi-beam radiation pattern tested in this embodiment at 28 GHz, 30 GHz, and 32 GHz, since the adjacent angular spacing of the seven groups of feeding ports is 16°, the covered beam angles are 0°, ±16°, ±32°, and ±48°.
[0042] Figure 10 This example shows the vertically polarized multi-beam pattern tested at 28 GHz, 30 GHz, and 32 GHz, covering beam angles of 0°, ±16°, ±32°, and ±48°. At a center frequency of 30 GHz, the dual-polarization Luneburg lens achieved scanning losses of less than 1.1 dB for both horizontal and vertical polarization at various angles.
[0043] Figure 11 The axial ratio and narrow beam pattern test results for this embodiment at 30 GHz were obtained by setting the power ratio and feed phase difference between horizontal and vertical polarization to achieve circularly polarized radiation. With an axial ratio of less than 3 dB as the standard, the narrow beam pattern achieves circular polarization within a ±10° range, while the wide beam pattern achieves circular polarization beam coverage within a ±32° range.
[0044] Figure 12 The test results of the circular polarization bandwidth characteristics of each port in this embodiment show that good circular polarization multi-beam performance is maintained in the range of 28.9 GHz to 31.2 GHz.
[0045] The above descriptions are only preferred embodiments of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should fall within the scope of the claims of the present invention.
Claims
1. An all-metal dual-polarized Luneburg lens multi-beam antenna, characterized by: It includes an upper metal plate A and a lower metal plate B; The upper metal plate A includes an upper metal cover plate, metal pillars of different heights loaded on the surface of the metal cover plate, a choke slot E1, the upper half of seven groups of waveguide orthogonal mode couplers, and through holes and threaded holes for connecting the lower half; the lower metal plate B includes a lower metal cover plate, metal pillars of different heights loaded on the surface of the metal cover plate, a choke slot E2, the lower half of seven groups of waveguide orthogonal mode couplers surrounding the lens, and threaded holes for fixing; The upper part of the seven waveguide orthogonal mode couplers includes seven vertical polarization mode feeding ports of the waveguide orthogonal mode couplers, with an adjacent angular spacing of 16°, and are respectively denoted as V1, V2, V3, V4, V5, V6, and V7; the lower part of the seven waveguide orthogonal mode couplers includes seven waveguide channels and seven horizontal polarization mode feeding ports, with an adjacent angular spacing of 16°, and the seven horizontal polarization mode feeding ports are respectively denoted as H1, H2, H3, H4, H5, H6, and H7; The metal columns of different heights loaded on the surface of the metal cover plate are multiple cylindrical metal columns of different heights. They are variable refractive index periodic structural units that support horizontal polarization mode and vertical polarization mode respectively. They are divided into 9 step rings, and the step rings are numbered 1-9 from the center to the edge. The height of the metal columns inside the different step rings, the placement of the metal columns in the step rings, and the spacing between the metal columns in the corresponding step rings in the upper and lower metal plates are controlled to construct the gradient equivalent refractive index distribution required for the two polarizations of the Luneburg lens. The upper metal plate A and the lower metal plate B are both made of metal materials and adopt an integrated processing technology of all-metal Luneburg lens and waveguide orthogonal mode coupler. During the assembly process, the connection process between the lens part and the feeding structure is omitted, which facilitates mechanical processing and assembly of the overall structure.
2. The all-metal dual-polarization Luneburg lens multi-beam antenna according to claim 1, characterized in that: The connection relationship between the various parts of the all-metal dual-polarization Luneburg lens multi-beam antenna is as follows: the upper metal plate A and the lower metal plate B are positioned through two positioning holes, the feed ports of each vertical polarization mode are matched one by one with the waveguide channels of the waveguide orthogonal mode coupler, and then fixed with countersunk screws.
3. The all-metal dual-polarization Luneburg lens multi-beam antenna according to claim 1, characterized in that: Feed ports at different positions are selected to feed two orthogonally polarized electromagnetic waves to achieve dual-polarization beam scanning. The seven ports H1-H7 and V1-V7 corresponding to horizontal polarization and vertical polarization achieve beam coverage of no less than -48° to +48° within the operating frequency band.
4. The all-metal dual-polarized Luneburg lens multi-beam antenna according to claim 1, characterized in that: The all-metal dual-polarization Luneburg lens multi-beam antenna sets the power ratio and feeding phase difference of horizontal polarization and vertical polarization to achieve circular polarization multi-beam coverage.
5. The all-metal dual-polarization Luneburg lens multi-beam antenna according to claim 1, characterized in that: The all-metal dual-polarization Luneburg lens multi-beam antenna operates in the microwave and millimeter wave frequency band.