An X-band dual-polarization weather radar array antenna

Abstract

This invention belongs to the field of antenna and microwave technology, and discloses an X-band dual-polarization weather radar array antenna. The antenna array consists of multiple dual-polarized microstrip patch antenna subarrays, with odd-numbered rows and even-numbered rows of dual-polarized microstrip patch antenna subarrays alternately staggered in the azimuth plane, effectively reducing the azimuth sidelobe level and improving detection performance. This invention's antenna array is a subarray-level microstrip patch planar array antenna, achieving modular antenna array design. When the array size changes, there is no need to redesign the subarrays; simply recombining the subarrays achieves ultra-low sidelobes. The power divider network uses an air-dielectric plate microwave power divider to improve antenna efficiency. Furthermore, for antennas of the same size, the cost of this invention's antenna array is significantly lower than that of a traveling wave array slot waveguide antenna.

Description

Technical Field

[0001] This utility model belongs to the field of antenna microwave technology, specifically relating to an X-band dual-polarization weather radar array antenna. Background Technology

[0002] Dual-polarization weather radar acquires microstructural information about meteorological targets by transmitting and receiving horizontally and vertically polarized electromagnetic waves and measuring parameters such as reflection coefficients, differential reflectivity factors, and differential propagation phase shifts of the two polarizations. Commonly used S-band (frequency range: 2GHz–4GHz) and C-band (frequency range: 4GHz–8GHz) weather radars can effectively detect precipitation within a 400km range. Combined with a network of multiple X-band (frequency range: 8GHz–12GHz) radars to fill gaps in low-altitude and small-scale coverage, this not only enables networked observations in large cities, providing comprehensive, three-dimensional, high-timeliness, and high-resolution echo observations, but also allows for lower-altitude monitoring, higher spatiotemporal resolution, more flexible scanning strategies, and richer meteorological products. A network of multiple weather radars requires phased array antennas with high efficiency, low sidelobes, narrow beams, large scanning angles, and good performance consistency in their dual-polarized beams.

[0003] Existing dual-polarized antennas include waveguide traveling-wave slot antennas, waveguide standing-wave slot antennas, reflector antennas, and microstrip patch antennas. Traveling-wave slot antennas suffer from difficulties in achieving highly consistent beam pointing and beam pointing frequency dispersion. Waveguide standing-wave slot antennas have drawbacks such as narrow bandwidth and high manufacturing costs. Reflector antennas rely on mechanical rotation for beam scanning, resulting in slow beam response, low isolation, and limited functionality. Microstrip patch antennas have high dielectric loss, making it difficult to achieve high cross-polarization ratios, and are also costly.

[0004] The utility model patent application No. 2020210792629 filed by the Meteorological Observation Center of the China Meteorological Administration, entitled "A Dual-Polarization Phased Array Antenna and a Dual-Polarization Phased Array Weather Radar," employs multiple dual-polarization row feeds arranged on a horizontal cylindrical support surface to form a horizontal cylindrical dual-polarization microstrip patch antenna, thereby achieving simultaneous transmission and reception of two polarized signals in the horizontal and vertical directions. However, when forming a beam, the cylindrical antenna selects at most half of the antenna, resulting in low gain and limited effective range. Furthermore, the cylindrical antenna is perpendicular to the ground, leading to significant interference and poor signal quality. Therefore, this type of antenna has limited detection capability and cannot meet the ever-increasing detection demands. Moreover, the patent does not mention or optimize its cross-polarization ratio, resulting in poor anti-interference performance, unstable signal quality, and deficiencies in overall performance reliability and application potential.

[0005] Therefore, a novel X-band dual-polarization weather radar array antenna with strong detection capabilities and a high cross-polarization ratio is urgently needed for research. Utility Model Content

[0006] To address the existing technical problems and improve the detection capability and cross-polarization ratio of array antennas, this application provides an X-band dual-polarization weather radar array antenna.

[0007] This application provides an X-band dual-polarization weather radar array antenna, which adopts the following technical solution:

[0008] An antenna array consisting of M×N dual-polarized microstrip patch antenna subarrays in M ​​rows and N columns, where M and N are integers greater than 1; it also includes several row power divider networks, each row power divider network comprising a power divider and an RF cable connected to the power divider.

[0009] Each row of the dual-polarized microstrip patch antenna subarray is connected to the power divider port of the corresponding row of the row power divider network via an RF cable.

[0010] In the antenna array, the dual-polarized microstrip patch antenna subarrays in odd-numbered rows and the dual-polarized microstrip patch antenna subarrays in even-numbered rows are alternately staggered in the azimuth plane, with a staggered distance of half the length of the dual-polarized microstrip patch antenna subarray.

[0011] Furthermore, the dual-polarized microstrip patch antenna subarray includes an upper microwave printed circuit board, a lower microwave printed circuit board, a metal mounting plate, and a dielectric support block. The upper microwave printed circuit board has several circular copper-clad surfaces printed on its upper surface. The lower microwave printed circuit board has copper clad surfaces on both its upper and lower surfaces, with a slot in the upper layer. A feed section and a power divider are located between the upper and lower microwave printed circuit boards. The metal mounting plate is located below the lower microwave printed circuit board and is tightly attached and fixed to it. The dielectric support block is located between the upper and lower microwave printed circuit boards, fixing the upper microwave printed circuit board and locking the distance between them.

[0012] Furthermore, the dual-polarized microstrip patch antenna subarray comprises several dual-polarized microstrip patch antenna elements arranged in an array, each of the dual-polarized microstrip patch antenna elements comprising two orthogonally placed stripline feed segments, corresponding to vertical polarization and horizontal polarization respectively.

[0013] Furthermore, the dual-polarized microstrip patch antenna subarray has two models: Type A antenna subarray and Type B antenna subarray; the Type A antenna subarray is located in the middle of the antenna array, and the Type B antenna subarray is located on both sides of the antenna array; the Type A antenna subarray and the Type B antenna subarray are completely identical in appearance and structure.

[0014] Furthermore, in the type A antenna subarray, the dual-polarized microstrip patch antenna elements in each row have the same amplitude and phase; in the type B antenna subarray, the dual-polarized microstrip patch antenna elements in each row have different amplitudes but the same phase.

[0015] Furthermore, the current amplitude ratios of the B-type antenna subarrays located on both sides of the antenna array are mirror-distributed.

[0016] Furthermore, each of the aforementioned power divider networks consists of one air dielectric plate line microwave power divider and several radio frequency cables, the number of which is equal to the number of dual-polarized microstrip patch antenna subarrays in one row of the antenna array; the ports of the air dielectric plate line microwave power divider are connected to connectors of the same polarization in the same row of the same dual-polarized microstrip patch antenna subarray.

[0017] Furthermore, the power output ratio of the microwave power divider on the air dielectric plate is equal to the Taylor amplitude distribution with a set sidelobe size, and the amplitude gradually decreases from the middle port to both sides, and is symmetrical from left to right.

[0018] The beneficial effects of this utility model are as follows:

[0019] The antenna array of this invention consists of M×N dual-polarized microstrip patch antenna subarrays. The odd-numbered rows of dual-polarized microstrip patch antenna subarrays are alternately staggered with the even-numbered rows of dual-polarized microstrip patch antenna subarrays in the azimuth plane, which effectively reduces the azimuth sidelobe level of the X-band microstrip patch antenna array to below -30dB. With lower sidelobes, the meteorological detection effect is better.

[0020] The antenna array of this invention is a planar array antenna in the form of subarray-level microstrip patches, realizing the modularization of the antenna array. When the array size changes, there is no need to redesign the subarrays; simply recombining the subarrays can achieve ultra-low sidelobes.

[0021] Compared to conventional X-band microstrip patch antennas, this solution improves antenna efficiency by more than 3dB, mainly due to the increased efficiency of the power divider network. Conventional microstrip power dividers have a loss of 4dB (per meter), while this invention uses an air-dielectric plate microwave power divider with a loss of only 1dB, thus improving antenna efficiency by 3dB.

[0022] For antennas of the same size, the cost of the antenna array of this invention is much lower than that of the traveling wave array slot waveguide antenna. Attached Figure Description

[0023] Figure 1 This is a diagram showing the distribution of the dual-polarized microstrip patch antenna subarray of the radar array antenna in Embodiment 1 of this utility model;

[0024] Figure 2This is a schematic diagram of the connection between a row of dual-polarized microstrip patch antenna subarrays and a row power distribution network in Embodiment 1 of this utility model.

[0025] Figure 3 This is a cross-sectional view of the dual-polarized microstrip patch antenna subarray of Embodiment 1 of this utility model;

[0026] Figure 4 This is a top view of the dual-polarized microstrip patch antenna subarray of Embodiment 1 of this utility model;

[0027] Figure 5 This is a diagram showing the distribution of the radio frequency input / output ports on the back of the dual-polarized microstrip patch antenna subarray according to Embodiment 1 of this utility model.

[0028] Figure 6 This is a radiation power distribution diagram of a row of patch antenna elements in the A-type antenna subarray in Embodiment 1 of this utility model;

[0029] Figure 7 This is a radiation power distribution diagram of a row of patch antenna elements in the B-type antenna subarray located on the right side of the antenna array in Embodiment 1 of this utility model;

[0030] Figure 8 This is a radiation power distribution diagram of a row of patch antenna elements in the B-type antenna subarray located on the left side of the antenna array in Embodiment 1 of this utility model;

[0031] Figure 9 This is a horizontal beamline diagram of the array antenna according to Embodiment 1 of this utility model;

[0032] Figure 10 This is a diagram of the main polarization and cross-polarization lobe of the dual-polarized microstrip patch antenna subarray according to Embodiment 1 of this utility model;

[0033] Explanation of reference numerals in the attached diagram: 11. Lower microwave printed circuit board; 12. Dielectric support block; 13. Upper microwave printed circuit board; 14. Metal mounting plate; 131. Dual-polarized microstrip patch antenna element; 141. Vertical polarization port; 142. Horizontal polarization port. Detailed Implementation

[0034] The present invention will now be described in further detail.

[0035] This invention provides an X-band dual-polarization weather radar array antenna, which is a planar array antenna in the form of a subarray-level microstrip patch. It includes: an antenna array of M rows and N columns composed of M×N dual-polarized microstrip patch antenna subarrays, where M and N are integers greater than 1; it also includes several row power divider networks, each including a power divider and an RF cable connected to the power divider; each row of dual-polarized microstrip patch antenna subarrays is connected to the power divider port of the corresponding row's power divider network via an RF cable; wherein, in the antenna array, the dual-polarized microstrip patch antenna subarrays in odd-numbered rows are alternately staggered with those in even-numbered rows in the azimuth plane, with a staggered distance equal to half the length of the dual-polarized microstrip patch antenna subarray.

[0036] A dual-polarized microstrip patch antenna subarray is composed of several dual-polarized microstrip patch antenna elements arranged and fed in a specific manner.

[0037] Each row power divider network consists of an air-dielectric plate line microwave power divider and several low-loss RF cables. The number of low-loss RF cables is equal to the number of antenna subarrays in a row of the array antenna. In the final electrical signal flow direction, the ports of one row power divider network connect to connectors of the same polarization within the same row of the same subarray. The number of ports of the air-dielectric plate line microwave power divider is equal to the number of subarrays in its row.

[0038] Example 1:

[0039] The X-band dual-polarization weather radar array antenna of this embodiment includes a 16-row × 12-column antenna array composed of 192 dual-polarized microstrip patch antenna subarrays (e.g., Figure 1 As shown, the X-axis represents the sequence number of the dual-polarized microstrip patch antenna element 131 in the odd-numbered rows of dual-polarized microstrip patch antenna subarrays, the Y-axis represents the sequence number of the dual-polarized microstrip patch antenna element 131 in each column of dual-polarized microstrip patch antenna subarrays, and the 128 row power distribution networks connected to the 192 dual-polarized microstrip patch antenna subarrays. Figure 1In the diagram, A represents a type A antenna subarray, and B represents a type B antenna subarray. Type A and type B antenna subarrays are two models of dual-polarized microstrip patch antenna subarrays. The two models are identical in size and structure, differing only in the printed circuitry on the underlying microwave printed circuit board. The number of antenna subarrays for each model depends on the size of the modular array. In this embodiment, there are 96 type A subarrays and 96 type B subarrays. Type A subarrays are located in the center of the antenna array, while type B subarrays are located on either side. The 192 dual-polarized microstrip patch antenna subarrays are arranged alternately and staggered in the azimuth plane. The distance in the azimuth plane is the length of the dual-polarized microstrip patch antenna subarray, and the distance in the vertical plane is the width of the dual-polarized microstrip patch antenna subarray. The staggered distance of the dual-polarized microstrip patch antenna subarrays is half the length of the dual-polarized microstrip patch antenna subarray; in this embodiment, the staggered distance is 58 mm. In the antenna array, odd-numbered rows and even-numbered rows are alternately staggered. The length of the dual-polarized microstrip patch antenna subarray is equal to twice the horizontal spacing of the dual-polarized microstrip patch antenna elements 131, and the width of the dual-polarized microstrip patch antenna subarray is equal to twice the vertical spacing of the dual-polarized microstrip patch antenna elements 131.

[0040] The physical structure of a dual-polarized microstrip patch antenna subarray is as follows: Figure 3 As shown, the system includes an upper microwave printed circuit board 13, a lower microwave printed circuit board 11, a metal mounting plate 14, and a dielectric support block 12. The upper microwave printed circuit board 13 is a 0.4mm thick FR4 (Flame Retardant Type 4) board with 16 circular copper-clad surfaces printed on its upper surface. The horizontal and vertical spacing of these 16 circular copper-clad surfaces is determined by pre-simulation calculations. The lower microwave printed circuit board 11 is a 1mm thick Arlon CLTE-XT (a ceramic-filled polytetrafluoroethylene (PTFE) composite dielectric material) board with copper cladding on both sides. The upper surface is slit, and the middle section contains the power supply section and a 1:4 power divider. The connector housing is located on the lower copper-clad surface of the board, and the inner conductor passes through the lower microwave printed circuit board 11 and is soldered to the main port of the 1:4 power divider. The metal mounting plate 14 is located below and tightly fixed to the lower microwave printed circuit board 11, serving as structural support. The dielectric support block 12 is located between the upper microwave printed circuit board 13 and the lower microwave printed circuit board 11, and is used to fix the upper microwave printed circuit board 13 and precisely lock the distance between the two.

[0041] In this embodiment, the dual-polarized microstrip patch antenna subarray (including type A antenna subarray and type B antenna subarray) comprises 16 dual-polarized microstrip patch antenna elements 131, such as... Figure 4As shown, a 4×4 antenna array is formed by arranging elements in a 4×4 configuration. The 4×4 antenna array consists of four 1×4 antenna linear arrays. The dual-polarized microstrip patch antenna elements 131 are evenly spaced horizontally and vertically. The azimuth element spacing of the dual-polarized microstrip patch antenna elements 131 is 29mm, and the elevation element spacing is 20mm. In the 1×4 antenna linear array, there are four dual-polarized microstrip patch antenna elements 131 in one row. The four dual-polarized microstrip patch antenna elements 131 are fed by striplines. The four stripline feed segments are connected by a 1:4 stripline power divider. The stripline feed segments and the 1:4 stripline power divider are on the same layer of the printed circuit board. The dual-polarized microstrip patch antenna element 131, i.e., each patch antenna is fed by two orthogonally placed stripline feed sections, and a 1×4 antenna array includes two sets of 1:4 stripline power dividers. Each 1×4 antenna array has two external connectors, corresponding to vertical polarization and horizontal polarization respectively. A 4×4 antenna array has a total of eight external connectors, corresponding to eight RF input / output ports. Each row is composed of two input / output ports formed by the printed circuitry of the lower microwave printed circuit board 11. For example... Figure 5 As shown, each dual-polarized microstrip patch antenna subarray has 8 RF output ports, including 4 vertically polarized ports 141 (corresponding to vertical polarization) and 4 horizontally polarized ports 142 (corresponding to horizontal polarization). The connectors of the ports are SMP type, and are fixed to the metal mounting plate 14 through holes. The inner conductor of the connector is soldered to the printed line of the lower microwave printed circuit board 11.

[0042] In the Type A antenna subarray, the four dual-polarized microstrip patch antenna elements 131 in each row have the same amplitude and phase. The radiated power distribution diagram of a row of patch antenna elements in the Type A antenna subarray is shown in the figure below. Figure 6 As shown (where the X-axis represents the sequence number of the dual-polarized microstrip patch antenna element 131 inside the type A antenna subarray, and the Y-axis represents the sequence number of the dual-polarized microstrip patch antenna element 131 inside the type A antenna subarray); the amplitudes of the four dual-polarized microstrip patch antenna elements 131 in each row of the type B antenna subarray are different, but the phases are the same. The current amplitude ratios of the type B antenna subarrays on both sides of the antenna array are mirror-distributed. The radiated power distribution diagram inside the type B antenna subarray located on the right side of the antenna array is shown in the figure. Figure 7 As shown (where the X-axis represents the serial number of the dual-polarized microstrip patch antenna element 131 inside the B-type antenna subarray, and the Y-axis represents the serial number of the dual-polarized microstrip patch antenna element 131 inside the B-type antenna subarray), the current amplitude ratios are 0.8 (left edge element), 0.9, 0.95, and 1; the radiated power distribution diagram inside the B-type antenna subarray located on the left side of the antenna array is shown below. Figure 8As shown (where the X-axis represents the serial number of the dual-polarized microstrip patch antenna element 131 inside the B-type antenna subarray, and the Y-axis represents the serial number of the dual-polarized microstrip patch antenna element 131 inside the B-type antenna subarray), the current amplitude ratios of the B-type antenna subarrays on both sides of the antenna array are mirror-distributed, that is, the current amplitude ratios of the B-type antenna subarray on the right side are 1, 0.95, 0.9, and 0.8 (right edge element).

[0043] In this embodiment, there are 128 row power divider networks, each consisting of one air-dielectric-board line microwave power divider and 96 low-loss RF cables. Each air-dielectric-board line microwave power divider in this embodiment has 12 ports, which connect to connectors of the same polarization within the same row of the dual-polarized microstrip patch antenna subarray. Therefore, the number of ports of the air-dielectric-board line microwave power divider is the same as the number of subarrays in its row. Figure 2 As shown, each row of 12 patch antenna subarrays (a total of 8*12=96 RF input / output ports) is connected by 8 air dielectric board microwave power dividers (12*8=96 splitters) and 96 RF cables. Figure 2 (Each line in the diagram represents 8 RF cables) cascaded. The number of power divider networks is equal to 8 times the number of subarray rows. The air dielectric plate microwave power divider has ultra-low loss characteristics, which can effectively improve the efficiency of the characteristics, with a loss of 1dB. The RF cable is a low-loss RF cable, 1m in length, with a loss of 1dB. The power output ratio of the air dielectric plate microwave power divider is equal to the Taylor amplitude distribution with a set sidelobe size, and the amplitude gradually decreases from the middle port to the sides, and is symmetrical from left to right. In this embodiment, the power output ratio of the air dielectric plate microwave power divider is equal to the Taylor amplitude distribution with a sidelobe size of -35dB, and the amplitude gradually decreases from the middle port to the sides, and is symmetrical from left to right. Its current ratios are as follows: 0.18, 0.31, 0.51, 0.72, 0.90, 1, 1, 0.90, 0.72, 0.51, 0.31.

[0044] The horizontal beamline diagram of the array antenna in this embodiment is as follows: Figure 9 As shown, the antenna gain varies with the horizontal azimuth angle, reflecting the antenna's coverage capability in the horizontal plane. The beamwidth is 1.58°, and the maximum sidelobe level is -34.7 dB, meaning that even the largest sidelobe is more than 34.7 dB weaker than the main beam. This high sidelobe suppression capability gives the array antenna strong anti-interference ability, effectively suppressing interference signals and reducing the probability of false alarms from the radar.

[0045] The main polarization and cross-polarization lobe diagrams of the dual-polarized microstrip patch antenna subarray in this embodiment are as follows: Figure 10As shown, at a frequency of 9.4 GHz, the radiation characteristics of the array antenna of this application are illustrated through two perpendicular cross-sections (Phi=0° and Phi=90°). Marker m1 (0.3000, 14.1560 dBi) identifies the core performance characteristics of the antenna, namely the maximum radiation direction and maximum radiation intensity. Marker m2 (0.5000, -39.4893 dBi) indicates that at an angle of only 0.2° (0.5° - 0.3°) away from the main beam direction, the gain drops by more than 53 dB from its peak (from 14.2 dBi to -39.5 dBi). This demonstrates that the array antenna of this invention has a low cross-polarization level and better radar detection performance. Curve ③ represents the cross-polarization pattern of the azimuth plane of the 1 / 4-row linear array in the subarray, quantifying the cross-polarization components within the azimuth plane. Its low level (especially the deep null -39.5 dBi) ensures that the radar maintains extremely high polarization purity in the azimuth dimension. Curve ② represents the main polarization pattern of the elevation plane of the 1 / 4-row linear array in the subarray, representing the radiation characteristics of the antenna subarray in the elevation plane and describing the change of antenna gain with elevation angle. Curve ① represents the main polarization pattern of the azimuth plane, representing the radiation characteristics of the antenna subarray in the azimuth plane and describing the change of antenna subarray gain with azimuth angle. Curve ④ represents the cross-polarization pattern of the elevation plane of the subarray, quantifying the unwanted radiation components within the elevation plane whose polarization direction is orthogonal to the main polarization. For radar systems, a low cross-polarization level is crucial because a high cross-polarization level can generate false targets, interfere with radar signal processing, and reduce polarization purity, affecting target identification and anti-jamming capabilities. In this embodiment, the curve level is extremely low (<-30 dB), indicating that the subarray polarization purity of this embodiment is high.

[0046] Therefore, the X-band dual-polarization rain-measuring radar microstrip patch array antenna of this application features ultra-low sidelobes and a high cross-polarization ratio, reducing the azimuth sidelobe level of the X-band microstrip patch antenna array to below -30dB. If the azimuth subarray is not misaligned, the maximum azimuth sidelobe is -22dB, and after misalignment, it can reach -35dB, resulting in even lower sidelobes and better meteorological detection performance.

[0047] When the antenna array size changes, there's no need to redesign the subarrays; simply recombine the Type A and Type B antenna subarrays to achieve ultra-low sidelobes. It only requires borrowing subarrays from standard radars and redesigning the power divider network, achieving modular antenna array design and effectively improving radar development efficiency.

[0048] Furthermore, the cost of the array antenna in this application is significantly lower than that of the traveling wave array slot waveguide antenna. The fabrication cost of a standard dual-polarization radar with 64 rows of waveguides is RMB 19,000 per waveguide, totaling RMB 1,216,000. For an antenna of the same size, this solution requires 192 dual-polarized microstrip patch antenna subarrays, 16 air-dielectric plate line microwave power divider groups (each group contains 8 air-dielectric plate line microwave power dividers; each air-dielectric plate line microwave power divider has a 1:12 ratio, corresponding to one polarization direction of one row of dual-polarized microstrip patch antenna elements 131), and 1536 (12*64*2) RF cables. The cost of each dual-polarized microstrip patch antenna subarray is RMB 600, totaling RMB 115,200; the cost of each air-dielectric plate line microwave power divider group is RMB 2,600, totaling RMB 41,600; the cost of each RF cable is RMB 80, totaling RMB 122,880; and the total antenna cost is RMB 279,680. This can save 936,320 yuan.

[0049] Example 2:

[0050] The array antenna of this invention is not limited to the 16×12 size described in Embodiment 1. Based on the same subarray design concept and power divider network architecture, it can be easily expanded to a larger-scale array, such as a 64x48 antenna array.

[0051] For a 64x48 array, it can be viewed as using the 16×12 antenna array in Embodiment 1 as a basic subarray, and then performing higher-level arraying on this basis. Specifically, the 64x48 array can be composed of 4×4 of the aforementioned basic subarrays (i.e., each antenna subarray is a 16×12 element) arranged in a regular pattern. Its power divider network also adopts a multi-stage power divider structure. For example, the first-stage power divider distributes the signal to 4×4 output ports, each port is connected to one of the aforementioned 16×12 basic subarrays, and then the power divider network of the basic subarray itself distributes the signal to its 192 (16×12) patch antenna elements. Those skilled in the art will understand that this expansion method is structurally a simple repetition and stacking of Embodiment 1, and its working principle and the resulting technical effects are exactly the same as those of Embodiment 1.

[0052] Example 3:

[0053] Similarly, for a 120×96 array, the size of the basic subarrays can be flexibly chosen. For example, a 15×12 subarray can be selected as a basic subarray, and then 8×8 basic subarrays can be used to form the overall 120×96 array. The power distribution network also adopts a matching multi-level design. It should be noted that the division of the basic subarrays is not unique; as long as its arrangement and design principles are consistent with the core idea of ​​this utility model, it should fall within the protection scope of this utility model.

[0054] Although the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the present invention. Any equivalent changes or modifications made without departing from the spirit and scope of the present invention are also within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the content defined in the claims of this application.

Claims

1. An X-band dual-polarization weather radar array antenna, characterized in that, include: An antenna array consisting of M×N dual-polarized microstrip patch antenna subarrays in M ​​rows and N columns, where M and N are integers greater than 1; it also includes several row power divider networks, each row power divider network comprising a power divider and an RF cable connected to the power divider. Each row of the dual-polarized microstrip patch antenna subarray is connected to the power divider port of the corresponding row's power divider network via an RF cable; In the antenna array, the dual-polarized microstrip patch antenna subarrays in odd-numbered rows and the dual-polarized microstrip patch antenna subarrays in even-numbered rows are alternately staggered in the azimuth plane, with a staggered distance of half the length of the dual-polarized microstrip patch antenna subarray.

2. The X-band dual-polarization weather radar array antenna according to claim 1, characterized in that, The dual-polarized microstrip patch antenna subarray includes an upper microwave printed circuit board (13), a lower microwave printed circuit board (11), a metal mounting plate (14), and a dielectric support block (12). The upper microwave printed circuit board (13) has several circular copper-clad surfaces printed on its upper surface. The lower microwave printed circuit board (11) has copper clad surfaces on both its upper and lower surfaces, with a slit in the upper layer. The upper microwave printed circuit board (13) and the lower microwave printed circuit board (11) are connected by a feed section and a power divider. The metal mounting plate (14) is located below the lower microwave printed circuit board (11) and is tightly attached to it. The dielectric support block (12) is located between the upper microwave printed circuit board (13) and the lower microwave printed circuit board (11), fixing the upper microwave printed circuit board (13) and locking the distance between the upper microwave printed circuit board (13) and the lower microwave printed circuit board (11).

3. The X-band dual-polarization weather radar array antenna according to claim 1, characterized in that, The dual-polarized microstrip patch antenna subarray includes several dual-polarized microstrip patch antenna elements (131) arranged in an array. Each dual-polarized microstrip patch antenna element (131) contains two orthogonally placed stripline feed segments, corresponding to vertical polarization and horizontal polarization, respectively.

4. The X-band dual-polarization weather radar array antenna according to claim 1, characterized in that, The dual-polarized microstrip patch antenna subarray comes in two types: Type A antenna subarray and Type B antenna subarray. The Type A antenna subarray is located in the middle of the antenna array, and the Type B antenna subarray is located on both sides of the antenna array. The Type A antenna subarray and the Type B antenna subarray are identical in appearance and structure.

5. The X-band dual-polarization weather radar array antenna according to claim 4, characterized in that, The dual-polarized microstrip patch antenna elements (131) in each row of the type A antenna subarray have the same amplitude and phase; the dual-polarized microstrip patch antenna elements (131) in each row of the type B antenna subarray have different amplitudes but the same phase.

6. The X-band dual-polarization weather radar array antenna according to claim 5, characterized in that, The current amplitude ratios of the B-type antenna subarrays located on both sides of the antenna array are mirror-distributed.

7. The X-band dual-polarization weather radar array antenna according to claim 1, characterized in that, Each of the aforementioned row power divider networks consists of one air dielectric plate line microwave power divider and several radio frequency cables, the number of radio frequency cables being equal to the number of dual-polarized microstrip patch antenna subarrays in one row of the antenna array; the ports of the air dielectric plate line microwave power divider are connected to connectors of the same polarization in the same row of the same dual-polarized microstrip patch antenna subarray.

8. The X-band dual-polarization weather radar array antenna according to claim 7, characterized in that, The power output ratio of the microwave power divider on the air dielectric plate is equal to the Taylor amplitude distribution with a set sidelobe size. The amplitude gradually decreases from the middle port to both sides and is symmetrical from left to right.

Images