An ultra-wideband angle scanning low-profile phased array antenna

Abstract

The application provides an ultra-wideband and wide-angle scanning low-profile phased array antenna. The antenna unit of the antenna is sequentially provided with a transverse metasurface layer, a transverse radiation layer and a transverse metal floor layer, and is matched with a grounding short-circuit column, a metal feeding column and an SSMP connector; each layer is arranged to form a core structure through specific metal patches, a hollow structure and an asymmetric grounding short-circuit column. The application realizes narrow-edge coupling through the co-planar design of the feeding and the radiation metal layer, combines the capacitive coupling effect of the interdigital metal patch, the impedance matching optimization of the unbalanced grounding short-circuit column and the fusion application of the planar dipole and the tight coupling technology, effectively improves the impedance matching under the ultra-wideband and wide-angle scanning, reduces the active standing wave ratio in the working frequency band, realizes the technical characteristics of low profile, ultra-wideband and wide-angle scanning, and simultaneously has the beam scanning capability of a relative impedance bandwidth of 113%, an E-plane of ±60° and an H-plane of ±45°, low reflection loss and high efficiency.

Description

Technical Field

[0001] This invention belongs to the field of antenna technology, specifically a low-profile phased array antenna with ultra-wide bandwidth angle scanning. Background Technology

[0002] With the rapid development of remote sensing satellites, airborne millimeter-wave radar, and 5G communications, the performance requirements of phased array antennas are evolving towards wider bandwidth, lower profile, higher integration, and higher reliability. Among related technologies, phased array antennas must meet requirements such as ultra-wide bandwidth, ultra-large scanning angle, and miniaturization. Regarding structure, traditional designs often employ multi-layer structures or high-profile elements, resulting in high antenna profiles and large volumes, making them difficult to match scenarios with strict requirements for miniaturization and low profiles. Excessive profiles can also affect system performance, increase wind resistance, and reduce stealth capabilities. Regarding bandwidth, traditional tightly coupled dipole elements often use differential excitation, requiring a balun to convert a 50Ω unbalanced impedance, leading to complex feeder structures, increased circuit volume, limited bandwidth, and low doubling ratios.

[0003] In summary, researching phased array antennas that simultaneously possess ultra-wideband, wide-angle scanning, and low-profile characteristics is of great significance, and this invention addresses these key issues. Summary of the Invention

[0004] The purpose of this invention is to overcome the aforementioned problems of the prior art and provide a low-profile phased array antenna with ultra-wide bandwidth and wide-angle scanning. The antenna element, from top to bottom, consists of a lateral metasurface layer, a lateral radiating layer, and a lateral metal ground plane layer, coupled with grounding short-circuit posts, metal feed posts, and SSMP connectors. Each layer forms the core structure through specific metal patches, hollow structures, and asymmetrical grounding short-circuit post arrangements. The operating frequency band covers 5GHz to 18GHz, and the profile height is 0.141-0.141λ. LOW This invention achieves narrow-side coupling by designing the feed and radiating metal layers in a coplanar manner. Combined with the capacitive coupling effect of the co-toe metal patch, impedance matching optimization of the unbalanced grounding short-circuit post, and the fusion of planar dipole and tight coupling techniques, it effectively improves impedance matching under ultra-wideband and wide-angle scanning, reduces the active VSWR within the operating frequency band, and achieves the technical characteristics of low profile, ultra-wideband, and wide-angle scanning. Simultaneously, it simplifies the manufacturing and assembly process and reduces manufacturing costs. This antenna possesses a relative impedance bandwidth of 113% and beam scanning capabilities of ±60° E-plane and ±45° H-plane, exhibiting low reflection loss and high efficiency. It is suitable for aerospace, automotive, and shipborne applications with stringent requirements for miniaturization and low profile, and shows promising application prospects in communications, radar, and electronic warfare.

[0005] To achieve the above objectives, the present invention employs the following technical solutions:

[0006] A low-profile phased array antenna with ultra-wide bandwidth and scanning angle is composed of several antenna elements arranged periodically; the antenna element includes, from top to bottom, a transverse metasurface layer, a transverse radiating layer, a transverse metal ground layer, and multiple grounding short-circuit posts and metal feed posts.

[0007] The lateral metasurface layer includes a first dielectric substrate and a grid structure metal patch layer disposed on the upper surface of the first dielectric substrate;

[0008] The transverse radiation layer includes a second dielectric plate, and a first metal layer and a second metal layer respectively disposed on the upper and lower surfaces of the second dielectric plate;

[0009] The metal floor layer includes a third dielectric plate and a third metal layer disposed on the lower surface of the third dielectric plate;

[0010] The multiple grounding short-circuit posts and metal feed posts all penetrate the second dielectric plate and the third dielectric plate.

[0011] Preferably, the grid structure metal patch layer includes multiple parallel transverse strip members and two longitudinal strip members arranged at both ends of each transverse strip member; wherein there are gaps between adjacent transverse strip members.

[0012] Preferably, the first metal layer includes a pair of axially symmetrical radial metal patches connected by a bent metal structure.

[0013] The radiating metal patch has a first notch on the side closest to the other radiating metal patch, and a metal disk is disposed in the first notch, which is connected to a bent metal structure; the radiating metal patch has two second notches on the side furthest from the other radiating metal patch, and the strip-shaped branches of the cross-shaped metal patch are inserted into the two second notches respectively.

[0014] Preferably, the radiating metal patch is a chamfered rectangle, with the chamfered corners distributed at the two apex corners of the radiating metal patch near the other radiating metal patch.

[0015] Preferably, the bent metal structure is in the shape of an "arch" and is used to connect the metal disks on both sides to form a power supply structure.

[0016] Preferably, the second metal layer has a through hole for the metal feed post to pass through, and the metal feed post does not contact the second metal layer.

[0017] Preferably, the third metal layer includes a first metal patch and a second metal patch;

[0018] The first metal patch is a large-area continuous metal with a hollow structure; the second metal patch is located inside the hollow structure of the first metal patch, and there is a gap between them.

[0019] Preferably, the metal feed post is connected to the cross-shaped metal patch and the second metal patch; one end of the grounding short-circuit post is connected to the radiating metal patch and penetrates the second metal layer, and the other end is connected to the first metal patch.

[0020] Preferably, the two radiating metal patches are connected to different numbers of grounding short-circuit posts.

[0021] Preferably, the ultra-wideband low-profile phased array antenna operates in the frequency band of 5GHz to 18GHz and has a profile height of 0.141λ. LOW , λ LOW It is a low-frequency wavelength.

[0022] Based on the above technical solution, the beneficial effects of the present invention are at least as follows:

[0023] 1. This invention achieves the requirement of low antenna profile while reducing processing costs by printing the feed structure and the radiating metal layer on the same layer through narrow-edge coupling (coupling between the cross-shaped metal patch and the radiating metal patch, and on the same layer).

[0024] 2. This invention further improves impedance matching for ultra-wideband, large-angle scanning by arranging unbalanced grounding short-circuit posts, effectively reducing the active VSWR within the operating frequency band.

[0025] 3. By adding a cross-linked metal patch, the present invention utilizes the capacitive coupling between array elements to cancel the equivalent inductance of the reflective ground plane, thereby improving the impedance matching of the ultra-wideband circuit and effectively reducing the active standing wave ratio in the operating frequency band.

[0026] 4. This invention uses planar dipoles and tight coupling technology to enable the unit model to be processed according to the required size, and after processing, it can be directly assembled without welding or other methods. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the array structure of the low-profile phased array antenna with ultra-wide bandwidth scanning in this invention. The array shown in the figure has a size of 10×10.

[0028] Figure 2 This is a schematic diagram of the unit structure of the low-profile phased array antenna with ultra-wide bandwidth scanning in this invention.

[0029] Figure 3 This is a schematic diagram of the lateral metasurface layer of the low-profile phased array antenna with ultra-wide bandwidth and wide-angle scanning in this invention.

[0030] Figure 4 This is a top view of the lateral metasurface layer of the low-profile phased array antenna with ultra-wide bandwidth and wide-angle scanning in this invention.

[0031] Figure 5 This is a schematic diagram of the radiation structure of the low-profile phased array antenna with ultra-wide bandwidth scanning in this invention.

[0032] Figure 6 This is a top view of the radiating structure of the low-profile phased array antenna with ultra-wide bandwidth scanning in this invention.

[0033] Figure 7 This is a diagram of the reflective ground structure of the low-profile phased array antenna with ultra-wide bandwidth scanning in this invention.

[0034] Figure 8 This is a bottom view of the feeding structure of the low-profile phased array antenna with ultra-wide bandwidth scanning in this invention.

[0035] Figure 9 This is a simulation diagram of the active standing wave of the present invention.

[0036] Figure 10 This is the 5GHz beam scanning pattern of a 10*10 antenna array with a low profile and ultra-wide bandwidth scanning in this invention.

[0037] Figure 11 This is a 11GHz beam scanning curve of a low-profile 10*10 antenna array with ultra-wide bandwidth and wide angle scanning in this invention.

[0038] Figure 12 This is a 18GHz beam scanning curve of a low-profile 10*10 antenna array with ultra-wide bandwidth and wide angle scanning in this invention.

[0039] The markings are as follows: 1. Lateral metasurface layer; 11. First dielectric substrate; 12. Grid structure metal patch layer; 2. Lateral radiating layer; 21. Second dielectric substrate; 22. First metal layer; 23. Second metal layer; 221. Radiating metal patch; 222. Cross-toed metal patch; 223. Metal disk; 224. Bent metal structure; 3. Metal floor layer; 31. Third dielectric substrate; 32. Third metal layer; 321. First metal patch; 322. Second metal patch; 4. Grounding short-circuit post; 5. Metal feed post. Detailed Implementation

[0040] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0041] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0043] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0044] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0045] This example provides a low-profile phased array antenna with ultra-wide bandwidth angular scanning operating in the C-band (5~8GHz), X-band (8~12GHz), and Ku-band (12~18GHz), such as... Figure 1 As shown, the array size is 10×10.

[0046] Reference Figure 2 The antenna unit includes, from top to bottom, a transverse metasurface layer 1, a transverse radiating layer 2, a transverse metal ground layer 3, N grounding short-circuit posts 4, and one metal feed post 5. In this embodiment, N=7.

[0047] The lateral metasurface layer 1 includes a first dielectric substrate 11 and a grid structure metal patch layer 12 disposed on the upper surface of the first dielectric substrate 11.

[0048] One embodiment, referred to Figures 3-4 The grid structure metal patch layer 12 includes multiple (ten in this embodiment) parallel horizontal strip members and two vertical strip members arranged at both ends of each horizontal strip member; gaps exist between adjacent horizontal strip members. The two vertical strip members are arranged parallel in the vertical direction, each with a length of 8mm and a width of 0.14mm; the ten horizontal strip members are arranged horizontally, each with a length of 4mm and a width of 0.23mm; all ten horizontal strip members are vertically arranged between the two vertical strip members and are evenly distributed along the length of the vertical strip members. The two ends of each horizontal strip member are printed and connected to the inner sidewalls of the two vertical strip members, and the spacing between adjacent horizontal strip members is equal, together forming a regular grid-like overall structure.

[0049] The transverse radiation layer 2 includes a second dielectric plate 21, and a first metal layer 22 and a second metal layer 23 respectively disposed on the upper and lower surfaces of the second dielectric plate 21.

[0050] One embodiment, referred to Figures 5-6 The first metal layer 22 includes a pair of axially symmetrical radiating metal patches 221 connected by a bent metal structure 224. Specifically, the bent metal structure 224 in this embodiment is "bow" shaped and is an adjustable-length connecting metal wire, serving as a coupling feed section to connect the two metal disks 223 to form a feed structure, thereby realizing signal coupling and energy transfer between the two radiating units.

[0051] The radiating metal patch 221 has a first notch on the side adjacent to another radiating metal patch 221. A metal disk 223 is disposed within the first notch, and the metal disk 223 is connected to the bent metal structure 224. Specifically, in this embodiment, both the first notch and the metal disk 223 are circular, and there is an annular gap between the metal disk 223 and the radiating metal patch 221. The annular gap serves as a ring resonant structure for gap coupling.

[0052] The radiating metal patch 221 has two second notches on the side away from the other radiating metal patch 221. The cross-shaped metal patch 222 has two parallel strip-shaped branches on the side near the current radiating metal patch 221, which are inserted into the two second notches respectively. Specifically, the strip-shaped branches do not contact the radiating metal patch 221, and there is a gap between them. The ends of the strip-shaped branches are connected to an annular transition structure, which is also connected to the antenna ground. The whole structure constitutes an antenna structure with symmetrical radiation characteristics. The outer side of the cross-shaped metal patch 222 of the current antenna element is connected to the outer side of the cross-shaped metal patch 222 of the adjacent antenna element.

[0053] Furthermore, the radiating metal patch 221 is a chamfered rectangle, with the chamfered corners distributed at the two apex corners of the radiating metal patch 221 near the other radiating metal patch 221.

[0054] Furthermore, all metal structures on the first metal layer 22 are coplanar and located in the same conductive metal layer.

[0055] One embodiment, referred to Figure 7 The second metal layer 23 is a large area of ​​continuous metal with a through hole for the metal feed post to pass through. The metal feed post does not contact the second metal layer 23, but eventually contacts the second metal patch 322. N grounding short-circuit posts 4 pass through the second metal layer 23 and contact the first metal patch 321, and the grounding short-circuit posts 4 contact the second metal layer 23.

[0056] The metal floor layer 3 includes a third dielectric plate 31 and a third metal layer 32 disposed on the lower surface of the third dielectric plate 31.

[0057] One embodiment, referred to Figure 8 The third metal layer 32 includes a first metal patch 321 and a second metal patch 322.

[0058] Specifically, the first metal patch 321 is a large-area continuous metal with a hollow structure, including an integrally formed central rectangular hollow and two circular hollows connected to the two ends of the central rectangular hollow. The second metal patch is located within the hollow structure of the first metal patch 321, with a gap between it and the first metal patch 32. It specifically includes an integrally formed circular metal part and a rectangular metal part, with the circular metal part located within one of the circular hollows and the rectangular metal part located within the central rectangular hollow.

[0059] In one embodiment, the grounding short-circuit post 4 and the metal feed post both penetrate the second dielectric substrate 21 and the third dielectric substrate 31. Specifically, in this embodiment, each first metal layer 22 has a grounding short-circuit post 4 connecting the first metal layer 22 and the first metal patch 321 on both sides of the first notch. In one of the first metal layers 22 (in this embodiment, the right-side first metal layer 22), one end of a grounding short-circuit post 4 connects to the radiating metal patch 221, and the other end passes through the second metal layer 23 to connect to the first metal patch 321. Thus, there are three metal short-circuit posts near the signal feed end and two metal short-circuit posts away from the signal feed end, forming an unbalanced feed structure.

[0060] After the cross-toe metal patch 222 of the current antenna element is connected to the cross-toe metal patch 222 of the adjacent antenna element, one end of the two grounding short-circuit posts 4 is connected to the cross-toe metal patch 222, and the other end passes through and connects to the first metal patch 321. In this embodiment, the metal disk 223 located on the right first metal layer 22 is connected to the first metal layer 22 and the second metal patch 322 through the metal feed post.

[0061] Furthermore, in this embodiment, the overall dimensions of the low-profile phased array antenna are 90mm (length) × 84mm (width) × 7mm (height). The thickness of the first dielectric substrate 11 is 2mm, the thickness of the second dielectric substrate 21 is 3.9mm, and the thickness of the third dielectric substrate 31 is 1mm. All of them are made of materials with a dielectric constant of 2.65.

[0062] Furthermore, in this embodiment, the metal patch is preferably a copper-clad patch.

[0063] The following describes the working principle of unbalanced power supply:

[0064] Generally, small common-mode current components do not have a destructive impact on antenna port matching. However, common-mode currents between adjacent elements can couple, and at certain frequencies, when the coupling path reaches half the wavelength, cavity resonance occurs. The electric field cannot radiate into free space, leading to a short circuit at the antenna element ports, a phenomenon known as common-mode resonance. The formula for calculating the common-mode resonant frequency is as follows:

[0065] (1)

[0066] Among them, D x With D y Let be the coupling paths of the phased array elements in the x and y directions, respectively. Let c0 be the speed of light in free space. This is the relative permittivity of the dielectric substrate. Adding grounding short-circuit post 4 reduces the common-mode coupling path D. x D y This involves shifting the common-mode resonant point to higher frequencies to increase the antenna's frequency bandwidth.

[0067] Preferably, the coupling feed structure composed of the metal disk 223 and the bent metal structure 224 adopts a narrow-side coupling structure with the antenna. The formula for calculating the coupling line length is as follows:

[0068] (2)

[0069] (3)

[0070] (4)

[0071] Where Lf is the length of the coupled feed structure, c0 is the speed of light in free space, and f is the antenna frequency. The wavelength in free space is represented by n, and the harmonic order is represented by n. Indicates the waveguide wavelength. The effective dielectric constant is represented by . In order to reduce the antenna profile height and antenna complexity, a narrow-side coupled feed structure is adopted. The feed line length must meet the requirements of formula (2)-(3). Therefore, a bent metal structure 224 is adopted to meet the feed line length requirements.

[0072] Furthermore, the introduction of the interdigitated metal patch 222 increases the antenna E-plane coupling, which can eliminate feed blinding and increase the E-plane scanning angle.

[0073] Preferably, to further reduce the antenna profile height, the bottom feed of the antenna element adopts a CPWG (composed of a first metal patch 321 and a second metal patch 322). The impedance calculation formula for the microstrip feed and CPWG is as follows:

[0074] (7)

[0075] (8)

[0076] Where Z0 is the characteristic impedance of a conventional transmission line, e ff Where is the dielectric constant of the substrate, W0 is the standard microstrip feed linewidth, W1 is the linewidth of the CPWG transmission line (composed of the first metal patch 321 and the second metal patch 322), h is the dielectric thickness of the conventional transmission line, and g is the gap width between the CPWG transmission line and the coplanar ground on both sides (i.e., the first metal patch 321). From formulas (7) and (8), it can be seen that at a 50Ω impedance, for the same linewidth, the CPWG requires less dielectric thickness than the microstrip feed line, which is more advantageous for reducing the antenna profile width.

[0077] Figure 9The figure shows the simulation results of the active standing wave ratio (VSWR) of an ultra-wide bandwidth angular scanning low-profile phased array antenna element. As can be seen from the figure, this antenna element possesses a relative impedance bandwidth of 113% and beam scanning capabilities of ±60° E-plane and ±45° H-plane, exhibiting low reflection loss and high efficiency; its profile is only 0.141λ. LOW , λ LOW It operates at low frequency wavelengths and features a low-profile physical structure. This antenna element possesses excellent performance characteristics such as ultra-wideband, wide-angle scanning, low profile, and high efficiency.

[0078] Figures 10 to 12 These are beam scan patterns of an ultra-wideband, angle-scanning, low-profile phased array antenna at frequencies of 5 GHz, 11 GHz, and 18 GHz. The horizontal axis represents the scanning angle, i.e., the angle between the scanning pattern and the positive Z-axis in the antenna coordinate system; the vertical axis represents the antenna gain. The figures show beam scan patterns for E-plane theta = 0°, 15°, 30°, 45°, and 60°, and H-plane theta = 0°, 15°, 30°, and 45°. The figures demonstrate that the antenna array achieves a scanning range of 60° in the E-plane and 45° in the H-plane.

[0079] The above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Those skilled in the art can modify, innovate, or apply the claims and drawings to other technical fields. However, it should be noted that all modifications to the present invention should be included within the patent protection scope of the present invention.

Claims

1. A low-profile phased array antenna with ultra-wide bandwidth and angular scanning, comprising a plurality of antenna elements arranged periodically; characterized in that, The antenna unit includes, from top to bottom, a transverse metasurface layer (1), a transverse radiating layer (2), a transverse metal ground layer (3), and multiple grounding short-circuit posts (4) and metal feed posts (5). The lateral metasurface layer (1) includes a first dielectric plate (11) and a grid structure metal patch layer (12) disposed on the upper surface of the first dielectric plate (11). The transverse radiation layer (2) includes a second dielectric plate (21), and a first metal layer (22) and a second metal layer (23) respectively disposed on the upper and lower surfaces of the second dielectric plate (21). The metal floor layer (3) includes a third medium plate (31) and a third metal layer (32) disposed on the lower surface of the third medium plate (31). The multiple grounding short-circuit posts (4) and metal feed posts (5) all penetrate the second dielectric plate (21) and the third dielectric plate (31).

2. The antenna according to claim 1, characterized in that, The grid structure metal patch layer (12) includes multiple parallel horizontal strip members and two longitudinal strip members arranged at both ends of each horizontal strip member; there are gaps between adjacent horizontal strip members.

3. The antenna according to claim 1, characterized in that, The first metal layer (22) includes a pair of axially symmetrical radial metal patches (221) connected by a bent metal structure (224); The radiating metal patch (221) has a first notch on the side closer to the other radiating metal patch (221), and a metal disk (223) is disposed in the first notch. The metal disk (223) is connected to the bent metal structure (224). The radiating metal patch (221) has two second notches on the side away from the other radiating metal patch (221), and the strip-shaped branches of the cross-shaped metal patch (222) are inserted into the two second notches respectively.

4. The antenna according to claim 3, characterized in that, The radiant metal patch (221) is a chamfered rectangle, with the chamfered corners distributed at the two apex corners of the radiant metal patch (221) on the side closest to the other radiant metal patch (221).

5. The antenna according to claim 3, characterized in that, The bent metal structure (224) is in the shape of an "arch" and is used to connect the two metal disks (223) to form a power supply structure.

6. The antenna according to claim 1, characterized in that, The second metal layer (23) has a through hole for the metal feed post (5) to pass through, and the metal feed post (5) does not contact the second metal layer (23).

7. The antenna according to claim 3, characterized in that, The third metal layer (32) includes a first metal patch (321) and a second metal patch (322); The first metal patch (321) is a large area of ​​continuous metal with a hollow structure; the second metal patch (322) is located inside the hollow structure of the first metal patch (321) and there is a gap between it and the first metal patch (32).

8. The antenna according to claim 7, characterized in that, The metal feed post (5) is connected to the cross-shaped metal patch (222) and the second metal patch (322); one end of the grounding short-circuit post (4) is connected to the radiating metal patch (221) and passes through the second metal layer (23), and the other end is connected to the first metal patch (321).

9. The method according to claim 7, characterized in that, The two radiating metal patches (221) are connected to different numbers of grounding short-circuit posts (4).

10. The method according to claim 1, characterized in that, The ultra-wideband low-profile phased array antenna operates in the frequency band of 5GHz to 18GHz and has a profile height of 0.141λ. LOW , λ LOW It is a low-frequency wavelength.

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