Low profile wide angle scanning filter phased array antenna

Abstract

This application discloses a low-profile wide-angle scanning filter phased array antenna, relating to phased arrays and antenna technology. The antenna consists of several antenna elements arranged in an array, comprising, from bottom to top, a metal ground plane (3), a dielectric layer (2), and a metal radiating layer (1). The metal radiating layer (1) serves as the radiating structure layer of the antenna element, including a rectangular radiating patch (4) and metal branches (5). A set of symmetrical T-shaped slots (6) are etched on the rectangular radiating patch (4). Metallized vias (7) serve as the feeding structure of the antenna element, penetrating the dielectric plate (2) and forming an electrical connection with the metal radiating layer (1). The low-profile wide-angle scanning filter phased array antenna proposed in this application achieves low-frequency suppression and two-dimensional wide-angle scanning capabilities under a single-layer printed circuit structure, while also possessing the advantages of low profile, simple structure, and low cost.

Description

Technical Field

[0001] This application relates to the fields of phased array and antenna technology, and in particular to a low-profile wide-angle scanning filter phased array antenna. Background Technology

[0002] Phased array antennas achieve beam scanning through phase modulation, offering advantages such as fast response, strong beam controllability, and high precision. In recent years, the rapid development of wireless communication, radar detection, and electronic countermeasures has placed demands on the low profile, wide-angle scanning, and anti-interference capabilities of phased array antennas. However, the scanning range of phased array antennas is often limited by the beamwidth of the element pattern and the mutual coupling effect between elements, making it difficult to meet the requirements of wide-area beam scanning coverage. At large angles, phenomena such as a sharp drop in gain, sidelobe rise, and polarization distortion often occur, restricting system performance. Furthermore, in dense spectrum environments, traditional phased array antennas often rely on external filters to suppress out-of-band interference to improve anti-interference capabilities. The use of external filters introduces additional insertion loss and system complexity, resulting in limited radiation efficiency, increased size and weight, and difficulty in meeting the requirements of high-performance, highly integrated systems. Summary of the Invention

[0003] This application provides a low-profile wide-angle scanning filtered phased array antenna to solve the problems of existing antennas, such as high profile, complex structure, narrow scanning range, and poor anti-interference capability. A low-profile wide-angle scanning filter phased array antenna, wherein the phased array antenna is composed of several antenna elements arranged in a triangular grating array, and each antenna element is arranged in the phased array according to a set element spacing, wherein the horizontal spacing is greater than the vertical spacing. The antenna unit consists of a metal ground plane 3, a dielectric layer 2, and a metal radiating layer 1 from bottom to top. The dielectric substrate 2 has a metal ground plane 3 on one side and a metal radiating layer 1 on the other side. The dielectric substrate 2 is penetrated by a metallized through-hole 7, which serves as the feeding structure for the antenna unit. The metallized through-hole 7 and the metal radiating layer 1 are electrically connected. The metal radiating layer 1 serves as the radiating structure layer of the antenna unit. The metal radiating layer 1 includes a rectangular radiating patch 4 and metal branches 5. A set of symmetrical T-shaped slots 6 are etched on the rectangular radiating patch 4.

[0004] This application proposes a planar single-layer wide-angle scanning filter phased array antenna, which achieves low-frequency suppression and two-dimensional wide-angle scanning capabilities in a single-layer PCB structure, while also having the advantages of low profile, simple structure, and low cost.

[0005] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0006] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the unit structure of the antenna according to an embodiment of this application; Figure 2 This is a front view of an antenna element according to an embodiment of this application; Figure 3 This is a top view of an antenna element according to an embodiment of this application; Figure 4 This is a schematic diagram of antenna element selection in an embodiment of this application; Figure 5 This is a schematic diagram of the phased array antenna layout according to an embodiment of this application; Figure 6 This is a simulation diagram of the antenna setup for an embodiment of this application. Figure 7 A comparison of beam scanning VSWR for antennas with and without open resonant rings in embodiments of this application; Figure 8 Comparison of gain-frequency curves of antennas with and without T-slots in embodiments of this application; Figure 9 This is the current distribution at the antenna gain zero point in an embodiment of this application; Figure 10 The VSWR of the array elements of the antenna in this embodiment of the application; Figure 11 This is the E-plane radiation pattern of the array element of the antenna in an embodiment of this application; Figure 12 This is the H-plane radiation pattern of the array element of the antenna in an embodiment of this application; Figure 13a , 13b The VSWR of the antenna in this application embodiment during beam scanning in the E-plane and H-plane; Figure 14a , 14b This is the E-plane and H-plane beam scanning pattern of the antenna in this embodiment at 14 GHz; Figure 15a , 15bThe image shows the E-plane and H-plane beam scanning patterns of the antenna in this embodiment at 14.25 GHz. Figure 16a , 16b The image shows the E-plane and H-plane beam scanning patterns of the antenna in this embodiment at 14.5 GHz. Detailed Implementation

[0007] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0008] The low-profile wide-angle scanning filtered phased array antenna in this embodiment includes several antenna elements arranged in a triangular grating array. Each antenna element of the low-profile wide-angle scanning filtered phased array antenna in this embodiment... Figure 1 A three-dimensional schematic diagram of the antenna element structure is shown. Figure 2 The front view of the antenna element structure is shown. Figure 3 A top view of the antenna element structure is shown. (See attached image.) Figure 1 , Figure 3 As shown, the antenna element in this embodiment includes: The dielectric substrate 2 has a metal floor 3 on one side and a metal radiation layer 1 on the other side. In some embodiments, the thickness h of the dielectric substrate 2 is 1.016 mm and the dielectric constant of the dielectric substrate 2 is 2.94.

[0009] A metal radiating layer 1, serving as the radiating structure layer of the antenna element, includes a rectangular radiating patch 4 and metal branches 5. A set of symmetrical T-shaped slots 6 are etched on the rectangular radiating patch 4. In some embodiments, the rectangular radiating patch 4 is located at the center of the metal radiating layer 1. Metal floor 3, on which an antenna feed port is provided; A metallized via 7 serves as the feed structure for the antenna element. The metallized via 7 penetrates the dielectric substrate 2 and forms an electrical connection with the metal radiating layer 1. In a specific example, each antenna element in the phased array is arranged according to a set element spacing based on the vacuum wavelength of the center frequency of the antenna's operating frequency band, wherein the horizontal spacing is greater than the vertical spacing. (Refer to...) Figure 4 , Figure 5 This is a schematic diagram of an exemplary antenna array. Figure 5 As shown, a specific example of a low-profile wide-angle scanning filtered phased array antenna is an 8×8 array.

[0010] Specifically, the antenna is formed by extending antenna elements according to a triangular grating. In one example of this application, the array surface of the phased array antenna is as follows: Figure 5 As shown, the element spacing dx is 12mm along the horizontal direction, which is equivalent to 0.57 , The vacuum wavelength is the center frequency of the antenna's operating band. The element spacing dy along the vertical direction is 10.5 mm, equivalent to 0.50. In the triangular lattice topology, there is a misalignment of dx / 2 between antenna elements in adjacent rows in the vertical direction, where dx is the element spacing in the horizontal direction.

[0011] The number of metallized through holes 7 is 1, the metallized through holes 7 are located between symmetrical T-shaped gaps 6, and the diameter of the metallized through holes 7 is 0.3mm-0.6mm.

[0012] In some embodiments, the rectangular radiating patch 4 has a long side l1 of 4.5mm-6mm and a short side l2 of 3.5mm-5mm. In a specific example, the long side l1 of the rectangular radiating patch 4 is 5.4mm and the short side l2 is 4.2mm. The diameter of the metallized via 7 is 0.4mm. The antenna simulation settings in this example are as follows: Figure 6 As shown. The simulation settings in this application adopt the master-slave boundary structure in ANSYS HFSS software. For the feasibility of the simulation, it is necessary to ensure that the boundary environment on the corresponding master-slave boundary is consistent when establishing the master-slave boundary. In the embodiment of this application, the array is truncated. Figure 6 Simulations are performed on the units within the antenna array. Simultaneously, since the antenna units are periodically extended according to a triangular grating, such as... Figure 4 , Figure 5 As shown, its array topology along the vertical direction can be regarded as a staggered superposition of rectangular grid arrays. In the phased array layout, two pairs of staggered master-slave boundaries can be set along the vertical dimension to achieve a dx / 2 stagger between adjacent units along the vertical direction, while a pair of master-slave boundaries are set along the horizontal direction.

[0013] Figure 1 Metal branches 5, extending along the triangular grid of the unit structure, form a set of open metal rings placed alternately between adjacent units in the vertical direction, such as... Figure 4 , Figure 5As shown. In this example, the horizontal side length l4 of metal stub 5 is 2.9 mm, the opening size l5 is 1.05 mm, the vertical side length l6 is 0.85 mm, and the width w3 is 0.2 mm. The open metal ring is a resonant structure composed of bent metal stubs, which has strong frequency selectivity and subwavelength characteristics. It is suitable for compact planar single-layer antenna structures and can optimize impedance matching during wide-angle scanning to achieve wide-angle beam scanning with low gain drop in phased array antennas. The comparison of VSWR of the antenna in 60° vertical beam scanning before and after loading the open resonant ring is shown below. Figure 7 As shown, after loading the open-circuit resonator, the VSWR during wide-angle scanning drops below 3.4, and the impedance matching during wide-angle scanning is optimized.

[0014] like Figure 1 As shown, the T-shaped slot 6 is symmetrically etched along the centerline on the upper and lower sides of the patch. The T-shaped slot 6 serves as a filtering structure, introducing a gain zero outside the passband of the antenna. The T-shaped structure can increase its equivalent electrical length through lateral stubs, and the filtering performance of the antenna can be adjusted by changing the size of the T-shaped slot. The equivalent electrical length of the T-shaped slot 6 is related to the frequency corresponding to the antenna gain zero, and is 0.2. .in This is the operating wavelength corresponding to the frequency where the gain zero point is located.

[0015] In some embodiments, the T-shaped slit 6 has a slit width w1 of 0.15 mm, a slit length l3 of 3.2 mm, and a terminal T-shaped branch width w2 of 0.8 mm.

[0016] The gain-frequency curve of the antenna is as follows: Figure 8 As shown in Figure 9, after introducing the T-slot, the antenna exhibits a zero gain at 12.4 GHz, and its out-of-band rejection is higher than 15.7 dB in the 10.5 GHz-12.75 GHz range. The current distribution at the zero gain is shown in Figure 9. At 12.4 GHz, the current distribution is around the T-slot, with approximately equal current amplitudes on both sides and opposite directions, thus canceling each other out. Therefore, the antenna gain is suppressed near this frequency.

[0017] The antenna standing wave in this embodiment is, for example... Figure 10 As shown, the antenna exhibits a VSWR of less than 2 in the 13.9 GHz–14.5 GHz range. The E-plane and H-plane radiation patterns of the antenna array elements at 14.25 GHz are shown in Figures 11 and 12, respectively. It is evident that the array element gain at the center frequency is 5.4 dBi, and the cross-polarization is below -50 dBi.

[0018] The antenna beam scanning performance of the embodiments of this application, such as Figures 13a to 16bAs shown. Among them, Figure 13a and Figure 13b , which are the standing wave ratios at different scanning angles when the antenna is scanning the beam in the E-plane and H-plane, respectively. Figure 14a and Figure 14b These are the radiation patterns of the antenna at different scanning angles when it performs beam scanning at 14 GHz along the E and H planes within a range of ±60°. Figure 15a and Figure 15b These are the radiation patterns of the antenna at 14.25 GHz, along the E-plane and H-plane, within a range of ±60°, at different scanning angles. Figure 16a and Figure 16b The figures show the radiation patterns of the antenna at 14.5 GHz, along the E and H planes, within a ±60° range, at different scanning angles. It can be seen that the antenna achieves ±60° two-dimensional beam scanning within the 14 GHz-14.5 GHz range, with a VSWR below 3.4 during wide-angle scanning. The scanning gain drop of the antenna within the ±60° range is below 3.9 dB at 14 GHz, below 3.5 dB at 14.25 GHz, and below 3.5 dB at 14.5 GHz. These results demonstrate that the antenna of the present invention possesses two-dimensional, low-gain-drop wide-angle scanning capability.

[0019] The antenna of this application achieves low-frequency suppression and two-dimensional wide-angle scanning capabilities in a single-layer PCB structure, while also having the advantages of low profile, simple structure, and low cost, solving the problems of existing antennas such as high profile, complex structure, narrow scanning range, and poor anti-interference capability.

[0020] The antenna of this application is based on printed circuit technology, uses a single-layer dielectric, operates in the 14GHz-14.5GHz frequency band, and has a profile height of only 0.048λ0 (λ0 is the vacuum wavelength corresponding to the center frequency of the antenna's operating frequency band). This antenna simultaneously achieves two-dimensional ±60° beam scanning in the 14GHz-14.5GHz range and low-frequency out-of-band suppression in the 10.5GHz-12.75GHz range. Specifically, the gain loss of the ±60° beam scanning is less than 3.9dB, and the out-of-band suppression level is higher than 15.7dB. The radiation efficiency of this antenna within its operating frequency band is higher than 96.25%.

[0021] It should be noted that, in the embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0022] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0023] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims. All of these forms are within the protection scope of this application.

Claims

1. A low-profile wide-angle scanning filtered phased array antenna, characterized in that, The phased array antenna is composed of several antenna elements arranged in a triangular grating array. Each antenna element is arranged in the phased array according to a set element spacing, wherein the horizontal spacing is greater than the vertical spacing. The antenna unit consists of a metal ground plane (3), a dielectric layer (2), and a metal radiating layer (1) from bottom to top. The dielectric substrate (2) has a metal ground plane (3) on one side and a metal radiating layer (1) on the other side. The dielectric substrate (2) is penetrated by a metallized via (7), which serves as the feeding structure for the antenna unit. The metallized via (7) and the metal radiating layer (1) are electrically connected. The metal radiating layer (1) serves as the radiating structure layer of the antenna unit. The metal radiating layer (1) includes a rectangular radiating patch (4) and metal branches (5). A set of symmetrical T-shaped slots (6) are etched on the rectangular radiating patch (4).

2. The low-profile wide-angle scanning filtered phased array antenna as described in claim 1, characterized in that, Within each antenna element, the metal stubs (5) are arranged at all corners of the metal radiating layer (1) and at a set of opposite sides.

3. The low-profile wide-angle scanning filtered phased array antenna as described in claim 1, characterized in that, The T-slot (6) introduces a zero-gain point to the antenna in the low-frequency stopband. The equivalent electrical length of the T-slot (6) is related to the frequency corresponding to the zero-gain point of the antenna and is 0.

2. ,in This is the operating wavelength corresponding to the frequency where the gain zero point is located.

4. The low-profile wide-angle scanning filter antenna as described in claim 1, characterized in that, The dielectric substrate (2) has a thickness h of 1.016 mm and a dielectric constant of 2.

94. The rectangular radiating patch (4) has a long side l1 of 5.4 mm and a short side l2 of 4.2 mm. The diameter of the metallized through hole (7) is 0.4 mm.

5. The low-profile wide-angle scanning filtered phased array antenna as described in claim 1, characterized in that, The antenna elements are arranged in the phased array with a horizontal spacing of 12 mm and a vertical spacing of 10.5 mm.

6. The low-profile wide-angle scanning filtered phased array antenna as described in claim 5, characterized in that, The phased array antenna has a dx / 2 misalignment between adjacent rows of antenna elements in the vertical direction, where dx is the element spacing in the horizontal direction.

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