A high-gain, wide-band, high-crossed-pole-ratio ridge waveguide slot antenna array and device

Abstract

The application relates to the technical field of microwave antennas, and particularly discloses a high-gain, wide-band, high-cross-pole-ratio ridge waveguide slot antenna array and device, the structure of the antenna array is as follows: an antenna radiation linear array layer is formed by linear subarray arrays, one linear subarray array is formed by two linear subarray units; a first feed network layer is formed by a plurality of first feed networks corresponding to the linear subarray arrays, a probe insertion structure is arranged in the center, a feed probe is inserted in the interior, the first feed network and the feed probe are non-contact coupled feed; a second feed network layer is formed by a second feed power division network, a second feed power division channel of the second feed network layer corresponds to the first feed network, the feed probe and the second feed power division channel are non-contact coupled feed, and a radio frequency signal port is arranged in the middle of the bottom surface of the second feed power division network layer. The application can reduce the complexity of the feed network, simplify the impedance matching design of the antenna, optimize the standing wave ratio of the antenna, and improve the working bandwidth of the antenna on the basis of guaranteeing the gain performance of the antenna.

Description

Technical Field

[0001] This application relates to the field of microwave antenna technology, specifically to a ridge waveguide slot antenna array and device with high gain, wide bandwidth, and high crossover ratio. Background Technology

[0002] Standing-wave waveguide (SWR) slot antennas radiate electromagnetic waves by creating a series of slots in the waveguide wall and using the standing wave formed by the superposition of incident and reflected waves within the waveguide to excite the slots. They feature high gain, low sidelobes, and a compact structure, making them suitable for radar and communication systems. However, for a specific SWR slot antenna, its physical structure is designed based on a specific center frequency. Only within the vicinity of this center frequency can all slots resonate. When the frequency shifts, the change in wavelength within the waveguide causes a mismatch between the designed slot spacing and the short-circuit termination position and the wavelength, disrupting the resonance condition. Impedance mismatch in the slots accumulates along the waveguide, causing a rapid increase in the overall VSWR of the antenna. This results in a narrow usable operating bandwidth for the SWR slot antenna, typically between 1% and 3%. Maximizing the operating bandwidth of SWR slot antennas is one of the primary goals for engineers.

[0003] In antenna design, a common approach is to combine multiple smaller subarrays to form a large antenna array. Independent feeding of the subarrays reduces impedance mismatch accumulation, thereby increasing the operating bandwidth; and combining multiple subarrays enables co-directional radiation, improving the antenna gain.

[0004] However, as the number of subarrays increases, the feeding network structure becomes more complex, occupying more space resources. This makes it difficult to simultaneously accommodate the layout of both the feeding and impedance matching networks, hindering impedance matching design and ultimately impeding bandwidth optimization. This is especially true when there are specific limitations on antenna size or gain requirements leading to a large number of subarrays, where limited space resources make it difficult to arrange the feeding and impedance matching networks effectively. Furthermore, achieving specific antenna polarization, such as horizontal polarization with high purity, requires careful design of the slot's location, orientation, and structure, further impacting the impedance matching design of the feeding structure.

[0005] In summary, the performance requirements of antenna gain, operating bandwidth, and cross-polarization purity collectively constrain antenna design, and the performance indicators of existing antenna design schemes have bottlenecks. Summary of the Invention

[0006] The purpose of this application is to overcome the shortcomings of the prior art and provide a high-gain, wide-bandwidth, high crossover ratio ridge waveguide slot antenna array. It can reduce the complexity of the feeding network without sacrificing the antenna gain performance, realize the feeding network configuration of the antenna subarray in a limited space, simplify the antenna impedance matching design, optimize the antenna VSWR, and improve the antenna operating bandwidth.

[0007] In a first aspect, this application provides a high-gain, wide-bandwidth, high crossover ratio ridge waveguide slot antenna array, which adopts the following technical solution:

[0008] The antenna array consists of an antenna radiating linear array layer and a feed network layer;

[0009] The antenna radiating array layer consists of 2 arrays. n The array is composed of two parallel linear array units, each of which consists of two parallel linear array units. The bottom surface of the linear array unit is provided with a power feeding coupling slot, and the top surface of the linear array unit is provided with a radiation slot.

[0010] The power supply network layer includes a first power supply network layer and a second power supply network layer;

[0011] The first feeding network layer is composed of several first feeding networks arranged in an array. The first feeding networks are located below the linear array subarray and correspond to each other. The first feeding network is coupled to two linear array units of the linear array subarray through the feeding coupling gap. A probe insertion structure is provided in the center of the first feeding network. A feeding probe is inserted into the probe insertion structure. The first feeding network and the feeding probe are coupled to each other in a non-contact manner.

[0012] The second power supply network layer is composed of a second power supply power divider network. For any one of the first power supply networks, the second power supply power divider network is provided with a second power supply power divider channel. The power supply probe extends into the second power supply power divider channel and is coupled to the second power supply power divider channel for non-contact power supply, so as to realize the power supply signal connection between the first power supply network layer and the second power supply network layer. The bottom surface of the second power supply power divider network layer is provided with an RF signal port.

[0013] The above technical solution employs a layered feed network structure, where two linear array elements in each subarray share a first feed network. All first feed networks are connected to a second feed power divider network, achieving a total-division coupled feed network. This improves the space utilization of the feed network and reduces the number of slots in a single linear array element while maintaining antenna gain, suppressing long-line effects and facilitating impedance matching optimization. The first feed network is coupled to the linear array elements via feed coupling slots, and the first feed network is connected to the second feed power divider network for signal distribution via feed probes. This simplifies the feed network structure, allowing impedance matching to be designed independently between layers, simplifying impedance matching design and implementation, thereby improving the antenna array's operating bandwidth performance and reducing the antenna's profile height.

[0014] Preferably, the linear array element is a ridge waveguide antenna, and the feed coupling slot is an H-shaped slot. The H-shaped slot has several sets of symmetrically arranged radiating slots on both sides of the top surface projection of the linear array element. Each set of radiating slots consists of two parallelogram slots that are symmetrical about the center line of the length direction of the top surface of the linear array element, forming a V-shaped radiating slot. The opening directions of any two adjacent V-shaped radiating slots are opposite.

[0015] Through the above technical solutions, a wider operating bandwidth and better impedance matching performance can be obtained by using a ridge waveguide antenna; by using an H-shaped feed coupling slot, impedance matching can be achieved through the specific structural design of the H-shaped structure, thus expanding the operating bandwidth; by using a V-shaped radiation slot, the polarization direction can be optimized and high polarization purity can be ensured, thereby reducing the design difficulty of impedance matching of the feed network.

[0016] Preferably, the linear array unit has a power feeding coupling slot on each side of its bottom surface, and the two power feeding coupling slots are symmetrical about the center of the bottom surface.

[0017] By using the above technical solution, feeding coupling slots are opened on both sides of the bottom surface of the linear array unit, and the feed is coupled from both sides. This can shorten the distance from the feed point to the radiation slot, suppress the long-line effect, and provide stronger coupling and richer tuning means, thereby achieving better impedance matching characteristics, wider matching bandwidth and higher design flexibility.

[0018] Preferably, the first feeding network is a ridge waveguide feeding network. The first feeding network has two linear array unit power distribution channels symmetrically arranged for two linear array units. The linear array unit power distribution channels have two power distribution gap power distribution channels symmetrically arranged for two power coupling gaps. The power distribution gap power distribution channels are connected to stepped ridge waveguide feeding channels. The width of the stepped ridge waveguide feeding channels gradually narrows in a stepped manner, with the narrowest section located below the power coupling gap.

[0019] Through the above technical solution, the first feed network with a planar structure feeds two linear array elements of a linear array subarray through the power distribution channel of the linear array element, thus optimizing the spatial layout of the feed network; the two power distribution channels of the feed coupling gap correspond to the two feed coupling gaps, realizing equal amplitude and co-directional feed of the feed coupling gaps on both sides; by adjusting the ridge waveguide feed channel with a stepped width, impedance matching can be achieved and the standing wave ratio can be reduced.

[0020] Preferably, the probe insertion structure includes a probe insertion through hole and a probe connector located on the top surface of the first power supply network layer and covering the probe insertion through hole. The probe connector has a probe mounting blind hole. The diameter of the probe insertion through hole is larger than the diameter of the probe mounting blind hole. The power supply probe is inserted into the probe mounting blind hole and extends downward through the probe insertion through hole into the second power supply power divider channel.

[0021] The above technical solution achieves non-contact fixation of the feed probe to the waveguide wall of the first feed network through the probe connector, and enables the feed probe to achieve non-contact coupling feed with the first feed network and the second feed power divider channel respectively. The coupling method is near-field radiation coupling, without physical contact and wear, which has high mechanical reliability. It can also avoid overheating and arc discharge at the contact point, improve power capacity, and is not affected by contact resistance. It can facilitate impedance matching optimization and improve the operating bandwidth.

[0022] Preferably, the power supply probe is an L-shaped probe, consisting of a vertical section and a horizontal section. The vertical and horizontal sections have circular cross-sections with the same diameter. The vertical section is inserted into the probe connector and extends downward through the probe insertion through-hole into the second power supply distribution channel. It then transitions to the horizontal section within the second power supply distribution channel. The impedance matching of the power supply probe is adjusted by adjusting the diameter of the cross-section, the depth of the vertical section extending into the second power supply distribution channel, and the length of the horizontal section.

[0023] The above technical solution achieves wave-to-wave conversion using an L-shaped probe. The length, height, diameter, coupling distance, and other parameters of the L-shaped probe can be adjusted independently. By optimizing the structural dimensions of the L-shaped probe, impedance matching can be flexibly achieved without adding an additional impedance matching network, which simplifies the antenna structure and impedance matching design, and ensures the operating bandwidth under the premise of limiting the space of the feed network.

[0024] Preferably, the end face of the horizontal section of the L-shaped probe is provided with a stepped impedance matching structure.

[0025] By using the above technical solution, a multi-section impedance transformer is formed through the stepped impedance matching structure at the end face, which can achieve a smooth transition of wave-to-wave conversion and maintain good impedance matching over a wider frequency range, thereby expanding the operating bandwidth.

[0026] Preferably, the second power distribution network is a waveguide power distribution network. Each second power distribution channel of the second power distribution network forms a multi-level power distribution network. Several adjacent second power distribution channels form a second power distribution channel group. Two adjacent second power distribution channels or two adjacent second power distribution channel groups of the same level are interconnected through a power distribution interface. Each power distribution interface is provided with a metal partition wall.

[0027] Through the above technical solution, a multi-level power distribution network is constructed through the second power distribution channel to realize the power distribution of each feed point; by setting metal partitions at each power distribution interface and adjusting the size of the metal partitions, the amplitude distribution of each linear array element of the antenna array can be optimized to achieve fine adjustment, thereby optimizing the radiation characteristics such as gain and sidelobes of the array pattern.

[0028] Preferably, a set of metal tuning probes is symmetrically arranged in the two branches of any power divider interface.

[0029] The above technical solution introduces capacitive or inductive reactance by setting a metal tuning probe, thereby changing the electric field vector transmitted in the waveguide, canceling the reactance generated by the feed network itself, and further optimizing impedance matching.

[0030] Secondly, the radar antenna device provided in this application employs the aforementioned ridge waveguide slot antenna array.

[0031] In summary, this application includes at least one of the following beneficial technical effects:

[0032] 1. This application adopts a dual-layer feeding network layer. The first feeding network corresponds to two linear array subarrays. All first feeding networks are connected to the second feeding power divider network layer to form a total-division feeding network structure, which optimizes the spatial layout and improves the space utilization rate, and can meet the spatial arrangement requirements of antenna array.

[0033] 2. This application simplifies the structure of the feed network, reduces the complexity and design difficulty of achieving impedance matching between the radiating layer and the feed layer, as well as between different feed layers, and enables flexible impedance matching by adjusting the structure, thereby expanding the operating bandwidth of the antenna.

[0034] 3. This application can achieve the antenna operating bandwidth design requirements by adjusting the structure and impedance matching design, while meeting the antenna gain and polarization direction requirements, thereby realizing an antenna design that meets the performance requirements in terms of gain, operating bandwidth, polarization direction and polarization purity. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a three-layer ridge waveguide slot antenna array with high gain, wide bandwidth, and high crossover ratio according to an embodiment of this application.

[0036] Figure 2 This is a top view of the antenna radiating linear array layer 1 of a high-gain, wide-bandwidth, high crossover ratio ridge waveguide slot antenna array according to an embodiment of this application.

[0037] Figure 3 This is a schematic diagram of the ridge waveguide cross-section of the linear array unit 11 in the embodiments of this application;

[0038] Figure 4 This is a schematic diagram of the bottom surface of the linear array unit 11 in the embodiments of this application;

[0039] Figure 5 This is a magnified view showing the details of the H-shaped feed coupling gap of the linear array unit 11 in the embodiments of this application;

[0040] Figure 6 This is a schematic diagram of the top surface of the linear array unit 11 in the embodiments of this application;

[0041] Figure 7 This is a top view (including H-shaped feed coupling slots) of the first feed network layer 2 of a high-gain, wide-bandwidth, high crossover ratio ridge waveguide slot antenna array according to an embodiment of this application.

[0042] Figure 8 This is a schematic diagram of the structure of the first power supply network 21 in the embodiments of this application;

[0043] Figure 9 This is an enlarged view showing the detailed probe insertion structure of the first power supply network 21 in this embodiment of the application;

[0044] Figure 10 This is a side view of the first power supply network 21 in an embodiment of this application;

[0045] Figure 11 This is a schematic diagram of the forward structure of an L-shaped feeding probe in an embodiment of this application;

[0046] Figure 12 This is a schematic diagram of the lateral structure of an L-shaped feed probe in an embodiment of this application;

[0047] Figure 13 This is a top view of the second feed network layer 3 of a high-gain, wide-bandwidth, high crossover ratio ridge waveguide slot antenna array according to an embodiment of this application;

[0048] Figure 14This is a side view of the second power distribution network 31 in an embodiment of this application;

[0049] Figure 15 This is a graph showing the antenna standing wave ratio (VSWR) of a high-gain, wide-bandwidth, high crossover ratio ridge waveguide slot antenna array according to an embodiment of this application.

[0050] Figure 16 This is the antenna normal gain curve of a ridge waveguide slot antenna array with high gain, wide bandwidth, and high crossover ratio in an embodiment of this application;

[0051] Figure 17 This is a diagram showing the main polarization and cross-polarization pattern of a high-gain, wide-bandwidth, high cross-polarization ridge waveguide slot antenna array in the low-frequency range, as described in an embodiment of this application.

[0052] Figure 18 This is a diagram showing the main polarization and cross-polarization pattern of a ridge waveguide slot antenna array with high gain, wide bandwidth, and high cross-polarization ratio in the mid-frequency range, as described in an embodiment of this application.

[0053] Figure 19 This is the antenna main polarization and cross-polarization pattern in the high-frequency range of a high-gain, wide-bandwidth, high cross-polarization ratio ridge waveguide slot antenna array according to an embodiment of this application. Detailed Implementation

[0054] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of this application.

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that in the optional embodiments of this application, the object information and other related data involved require the permission or consent of the object when the embodiments of this application are applied to specific products or technologies, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. That is to say, if the embodiments of this application involve data related to the object, it needs to be obtained with the authorization and consent of the object, the authorization and consent of the relevant departments, and in compliance with the relevant laws, regulations, and standards of the country and region. If personal information is involved in the embodiments, the acquisition of all personal information requires the consent of the individual. If sensitive information is involved, the separate consent of the information subject is required, and the embodiments also need to be implemented with the authorization and consent of the object.

[0056] The embodiments of this application will now be described in further detail with reference to the accompanying drawings.

[0057] The embodiments of this application are used to achieve the design requirements of an array antenna, wherein the antenna array dimensions (length*width*height) are 370mm*370mm*25mm; the antenna operating frequency band is X band; the operating bandwidth BW≥12%; the antenna VSWR<1.7 within the operating frequency band; and the antenna array gain G>30dBi.

[0058] Please see Figure 1 To achieve the above performance requirements, this application embodiment selects a ridge waveguide slot antenna array. The specific structure includes an antenna radiating linear array layer 1 composed of ridge waveguide slot antennas and a layered feed network layer, wherein the feed network layer is divided into a first feed network layer 2 and a second feed network layer 3.

[0059] Please see Figure 2 In the embodiments of this application, the antenna radiating linear array layer 1 consists of 32 linear array elements 11 arranged in an array of 2*16 (column*row). Each column of linear array elements 11 is grouped into two rows to form a linear array subarray, sharing a first feed network located in the first feed network layer 2. All first feed networks in the first feed network layer 2 are connected to the second feed power divider network of the second feed network layer 3, and signals are input or output through the radio frequency signal port located in the center of the second feed power divider network.

[0060] Please see Figure 3The linear array element 11 adopts a ridge waveguide design. The ridge waveguide slot antenna has a significantly lower main mode cutoff frequency than the rectangular waveguide for the same cross-sectional size, thus avoiding the inconvenience caused by the excessive size of the rectangular waveguide. The ratio of the higher-order mode cutoff frequency to the main mode cutoff frequency is also larger in the ridge waveguide, resulting in a wider operating bandwidth than the rectangular waveguide. Furthermore, the characteristic impedance of the ridge waveguide is relatively low, typically between 20Ω and 100Ω, closer to the impedance of commonly used transmission lines such as coaxial lines and microstrip lines, facilitating impedance matching and further optimizing bandwidth performance. In the embodiments of this application, the outer wall width of the ridge waveguide is D1 = 9.9mm, the inner wall width is D2 = 8.9mm, the ridge height is H = 6mm, and the ridge width is D3 = 2.1mm.

[0061] Please see Figure 4 and Figure 5 A H-shaped feed coupling slot 111 is symmetrically formed on both sides of the bottom surface of the linear array element 11 for coupling feed with the first feed network. The dimensions of the two parallel sides and the middle connecting side of the H-shaped feed coupling slot 111 can be adjusted to flexibly regulate impedance characteristics, better achieve impedance matching, and improve energy transmission efficiency. The coupling region of the two parallel sides of the H-shaped structure can achieve coupling on both sides of the ridge of the ridge waveguide, resulting in a larger coupling region. Furthermore, the middle connecting side can form synergistic coupling, enhancing the energy coupling strength between the feed network and the linear array element. Simultaneously, the coupling characteristics are less affected by the external environment, resulting in higher stability. The multi-segment structure of the H-shaped slot can generate multiple resonant points. By optimizing the dimensions of the H-shaped structure to bring the resonant points closer together, the operating bandwidth of the antenna can be effectively extended. In the embodiments of this application, the length Lh1 of the two parallel sides of the H-shaped feed coupling slot 111 is 8.6 mm, and the width Bh1 is 2.6 mm. The length Lh2 of the connecting side is 2.8 mm, and the width Bh2 is 0.8 mm.

[0062] Please see Figure 6The H-shaped feed coupling slot 111 of the linear array element 11 has several sets of symmetrically arranged radiation slots on both sides of the top surface projection of the linear array element 11. Each set of radiation slots consists of two parallelogram slots 112 symmetrical about the center line of the length direction of the top surface of the linear array element, forming a V-shaped radiation slot. The opening directions of any two adjacent V-shaped radiation slots are opposite. In the embodiments of this application, the angle between the hypotenuse of the two parallelogram slots 112 and the axis of the linear array element is 60° or 120°, the slot width is 2.6 mm, and the depth is 5 mm. The two parallelogram slots 112 with a certain angle can effectively cancel the cross-polarization component, which can make the ratio of the main polarization to the cross-polarization in the normal direction of the antenna array ≥70dB, and the polarization purity is extremely high. By changing the angle of the V-shaped radiation slots, the radiation pattern can be adjusted within a wide range, which is especially suitable for scenarios requiring specific directivity, such as directional communication and radar detection. By adjusting the structural dimensions and angles of the parallelogram slots, resonant points can be brought closer together and superimposed, thereby widening the antenna's operating bandwidth. The V-shaped radiating slot can also achieve flexible designs for linear, elliptical, or even circular polarization by adjusting the length ratio and angle of the two parallelogram slots 112, adapting to communication scenarios with different polarization requirements. The V-shaped slot, through angle design, can achieve multi-resonance characteristics within a limited space without adding extra slot length. Compared to the combination of multiple independent conventional slots, it is more compact, which is beneficial for the miniaturization and array integration of waveguide antennas.

[0063] It should be noted that, since the antenna in this embodiment simplifies the design of the feed network structure and facilitates the arraying of a larger number of linear array elements, the antenna gain performance requirements can be met by using a smaller number of radiating slots on a single linear array element. In this embodiment, only 8 sets of V-shaped radiating slots are provided on the top surface of the linear array element 11, with each feed coupling slot corresponding to 4 sets of V-shaped radiating slots. Reducing the number of radiating slots on a single linear array element 11 can avoid impedance mismatch and bandwidth narrowing caused by an increase in the number of radiating slots, and can also avoid complex mutual coupling and pattern deterioration caused by too many radiating slots.

[0064] Based on the design of the antenna radiating linear array layer 1 in the embodiments of this application, the feed network structure of the embodiments of this application will be described in detail.

[0065] Please see Figure 7 The first feed network 21 of the first feed network layer 2 corresponds one-to-one with the linear array subarray, forming a 2*8 (column*row) array, using a ridge waveguide form with a height of 2.2mm. One first feed network 21 corresponds to two linear array elements 11 of one linear array subarray.

[0066] Compared to the technical solution of power-sharing coupling power supply for a linear array unit by a power supply network, the embodiment of this application uses a first power supply network to couple power supply for two linear array units 11 of a linear array subarray. This can greatly reduce the number of first power supply networks required and make full use of the space between adjacent rows of linear array units 11 in the same column. This provides convenience for the subsequent access of the first power supply network to the second power supply power-sharing network while improving the space utilization rate.

[0067] Please see Figures 8 to 10 The first feed network 21 has two linear array unit power distribution channels 211 symmetrically arranged for each of the two linear array units. The linear array unit power distribution channels 211 also have two feed coupling slot power distribution channels 212 symmetrically arranged for each of the two H-shaped feed coupling slots. The feed coupling slot power distribution channels 212 connect to a stepped ridge waveguide feed channel 213. The width of the stepped ridge waveguide feed channel 213 gradually narrows in a stepped manner, with the narrowest section located below the H-shaped feed coupling slot. By adjusting the structural dimensions of the planar stepped ridge waveguide feed channel, impedance matching between the first feed network and the linear array units can be achieved, optimizing the VSWR, while also occupying less space and reducing the antenna profile height.

[0068] A probe insertion structure is provided in the center of the first power supply network, including a probe insertion through-hole 214 and a probe connector 215 located on the top surface of the first power supply network layer and covering the probe insertion through-hole. The probe connector 215 has a probe mounting blind hole, and the diameter of the probe insertion through-hole 214 is larger than the diameter of the probe mounting blind hole. An L-shaped power supply probe 216 is inserted into the probe mounting blind hole through a connecting section. The connection method can be a threaded connection or an interference fit. The L-shaped power supply probe 216 passes downward through the probe insertion through-hole 214 and enters the range of the second power supply network layer.

[0069] It should be noted that although the probe insertion structure has a certain height, its vertical projection lies within the mounting gap between two adjacent linear array elements 11 arranged side-by-side. Therefore, a space can be provided within the antenna radiating linear array layer 1 to accommodate the probe insertion structure without affecting the arrangement of the linear array elements 11. This structure can fully utilize the space of the mounting gap, improving space utilization.

[0070] The above structure enables the L-shaped feed probe 216 to connect the first feed network layer and the second feed network layer in a non-contact, suspended manner, achieving non-contact coupling feed to both the first and second feed power divider networks. Non-contact feed coupling eliminates the need for physical contact, reducing wear, avoiding contact resistance, facilitating impedance matching adjustment, expanding bandwidth, and eliminating the need for redundant impedance matching networks, thus simplifying the antenna structure and saving space.

[0071] More specifically, the L-shaped feed probe 216 consists of a vertical section and a horizontal section, both of which have circular cross-sections of the same diameter. The vertical section is inserted into the probe connector 215 and extends downward through the probe insertion through-hole 214 into the second feed network layer, where it transitions to the horizontal section. The L-shaped feed probe 216 optimizes the standing wave ratio (VSWR) by adjusting the diameter of its cross-section, the depth of the vertical section into the second feed network layer, and the length of the horizontal section to achieve impedance matching. In the embodiments of this application, the diameter of the L-shaped feed probe 216 is ￠=2mm, and the depth of the probe into the second feed network layer is 8mm. The L-shaped feed probe is suitable for the multi-layer structure of the embodiments of this application, can flexibly adapt to different inter-layer distances, and achieves energy transfer through non-contact coupling, effectively avoiding the inter-layer connection problems caused by direct feeding and enhancing the freedom of structural design.

[0072] In another embodiment, please refer to Figure 11 and Figure 12 The horizontal section of the L-shaped feed probe 216 has a stepped impedance matching structure on its end face. The stepped impedance matching structure forms a multi-section impedance transformer, which can achieve a smooth transition of wave-to-wave conversion and maintain good impedance matching over a wider frequency range, thereby expanding the operating bandwidth.

[0073] Please see Figure 13 and Figure 14 The second feed network layer 3 consists of a second feed power divider network 31, which is waveguide-shaped and 11mm high. For each first feed network, the second feed power divider network 31 has a second feed power divider channel 311. An L-shaped feed probe 216 extends into the second feed power divider channel 311 and performs non-contact coupling feed, thus connecting the feed signals of the first and second feed network layers. The distance from each second feed power divider channel 311 to the RF signal port 312 located at the center of the bottom surface of the second feed power divider network layer is equal, ensuring that the signals transmitted by each second feed power divider channel 311 have the same phase.

[0074] More specifically, in the embodiments of this application, the 16 second power distribution channels 311 of the second power distribution network 31 form a three-level power distribution network. Two adjacent second power distribution channels 311 form a first-level second power distribution channel group, which is connected through a first-level power distribution interface; two adjacent first-level second power distribution channel groups form a second-level second power distribution channel group, which is connected through a second-level power distribution interface; two second-level second power distribution channel groups form a third-level second power distribution channel group, which is connected through a third-level power distribution interface; two third-level power distribution interfaces are interconnected, and a radio frequency signal port 312 is provided in the center of the power distribution channel.

[0075] A metal partition 313 is provided at each power divider interface, which makes the power divider channel at the power divider interface concave and narrow. By setting the length, width and specific location of the metal partition, the amplitude distribution of each linear array element of the antenna array can be optimized, thereby optimizing the radiation characteristics such as gain and sidelobes of the array pattern.

[0076] Furthermore, a set of metal tuning probes 314 are symmetrically arranged in the two branches of any power divider interface. The metal tuning probes 314 introduce capacitive or inductive reactance to increase disturbance, change the electric field vector transmitted in the waveguide, and cancel the reactance generated by the network itself, so that the total impedance is close to the matching state, which can further reduce the standing wave ratio and improve the bandwidth.

[0077] The specific manufacturing method of a high-gain, wide-bandwidth, high crossover ratio ridge waveguide slot antenna array according to an embodiment of this application is as follows:

[0078] The antenna array is divided into three layers: the first layer is the antenna radiating linear array layer 1, the second layer is the first feed network layer 2, and the third layer is the second feed network layer 3.

[0079] The three-layer structure was fabricated from aluminum sheets using a high-precision CNC machining center. Furthermore, to ensure accurate welding and assembly after each layer is machined, high-precision positioning pins were added to each layer.

[0080] The antenna radiating array layer, the first feed network layer, and the second feed network layer, which have been processed as described above, are cleaned and assembled using positioning pins.

[0081] The assembled semi-finished antennas are then welded together using a vacuum furnace brazing process to form a ridge waveguide slot antenna array. Vacuum aluminum brazing is a high-precision connection process for brazing aluminum alloys in a vacuum environment. It is suitable for aluminum and aluminum alloy parts that require high strength, high airtightness, and good surface quality, and has the advantages of high connection quality, excellent surface quality, strong adaptability, and good precision control.

[0082] Finally, the ridge waveguide slot antenna array is subjected to surface conductive oxidation or surface silver or gold plating to ensure the stability of the antenna's electrical and structural performance, thus completing the assembly of the ridge waveguide slot antenna array.

[0083] Please see Figure 15-19 The performance of the high-gain, wide-bandwidth, and high crossover ratio ridge waveguide slot antenna array of the embodiments of this application will be described.

[0084] Figure 15 The antenna VSWR curves at different radio frequency reference frequencies show that the antenna array of this application embodiment has a VSWR of <1.7 and a relative bandwidth BW of ≥12.24% in the frequency range of 9.2GHz to 10.4GHz.

[0085] Figure 16 The antenna normal gain curves at different RF reference frequencies show that the antenna normal gain G of the antenna array in this embodiment of the application is greater than 31 dBi in different frequency ranges.

[0086] Figure 17 - Figure 19 The image shows the antenna radiation pattern of the antenna array in this application at different frequencies. It can be seen that the antenna can achieve a high crossover ratio in different frequency bands.

[0087] In another embodiment, this application provides a radar antenna device that employs the ridge waveguide slot antenna array described in the above embodiments. It should be noted that in the implementation of a specific radar antenna device, the number of linear array elements and the array arrangement can be expanded according to space conditions and antenna device performance requirements.

[0088] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "a" or "an," and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising," "including," and similar terms mean that the elements or objects preceding "comprising" encompass the elements or objects listed following "comprising" or "including," and their equivalents, but do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A high-gain, wide-band, high-cross-polarization ridge waveguide slot antenna array, comprising an antenna array layer and a feed network layer, characterized in that: The antenna radiation line array layer is composed of 2 n arrayed line array subarrays, each of which is composed of two parallel line array units, the bottom surface of the line array unit is provided with a feed coupling gap, and the top surface of the line array unit is provided with a radiation gap. the feed network layer comprises a first feed network layer and a second feed network layer; the first feed network layer is composed of a plurality of first feed networks arranged in an array, each first feed network is located below and corresponds to one of the array of linear array elements, and each first feed network is coupled to feed two linear array elements through the feed coupling slots; a probe insertion structure is arranged in the center of the first feed network, and a feed probe is inserted into the probe insertion structure; the first feed network and the feed probe are non-contact coupled to feed; the first feed network is a ridge waveguide feed network, and the first feed network is symmetrically provided with two linear array element power division channels corresponding to two linear array elements; the linear array element power division channel is symmetrically provided with two feed coupling slot power division channels corresponding to two feed coupling slots; the feed coupling slot power division channel is connected to a stepped ridge waveguide feed channel, and the width of the stepped ridge waveguide feed channel gradually narrows in a stepped manner, and the narrowest section is located below the feed coupling slot; the second feed network layer is composed of a second feed power division network, and the second feed power division network is provided with a second feed power division channel corresponding to any one of the first feed networks; the feed probe is inserted into the second feed power division channel and is non-contact coupled to feed, thereby realizing the connection of the feed signals of the first feed network layer and the second feed network layer; and a radio frequency signal port is arranged in the middle of the bottom surface of the second feed power division network.

2. The high-gain, wide-band, high-cross-polarization-ratio slotted ridge waveguide antenna array of claim 1, wherein, the linear array element is a ridge waveguide antenna, and the feed coupling slot is an H-shaped slot; the H-shaped slot is symmetrically provided with a plurality of groups of radiation slots on both sides of the top surface projection of the linear array element; each group of radiation slots is composed of two parallelogram slots symmetric about the center line of the length direction of the top surface of the linear array element, forming a V-shaped radiation slot; and the opening directions of any two adjacent V-shaped radiation slots are opposite.

3. The high-gain, wide-band, high-cross-polarization-ratio slotted ridge waveguide antenna array of claim 1, wherein, one feed coupling slot is arranged on each side of the bottom surface of the linear array element, and the two feed coupling slots are symmetric about the center of the bottom surface.

4. The high-gain, wide-band, high-cross-polarization-ratio slotted ridge waveguide antenna array of claim 1, wherein, the probe insertion structure comprises a probe insertion through-hole and a probe connector arranged on the top surface of the first feed network layer and covering the probe insertion through-hole; the probe connector is provided with a probe mounting blind hole; the aperture of the probe insertion through-hole is larger than the aperture of the probe mounting blind hole; and the feed probe is inserted and fixed in the probe mounting blind hole and extends downward through the probe insertion through-hole into the second feed power division channel.

5. The high-gain, wide-band, high-cross-polarization-ratio slotted ridge waveguide antenna array of claim 4, wherein, the feed probe is an L-shaped probe composed of a vertical section and a horizontal section; the cross sections of the vertical section and the horizontal section are circular with the same diameter; the vertical section is inserted into the probe connector and extends downward through the probe insertion through-hole into the second feed power division channel, and then transitions to the horizontal section in the second feed power division channel; and the feed probe is adjusted in impedance matching by adjusting the diameter of the cross section, the depth of the vertical section inserted into the second feed power division channel, and the length of the horizontal section.

6. The high-gain, wide-band, high-crosspolarization-ratio slotted ridge waveguide antenna array of claim 5, wherein, the end surface of the horizontal section of the L-shaped probe is provided with a stepped impedance matching structure.

7. The high-gain, wide-band, high-cross-polarization-ratio slotted ridge waveguide antenna array of claim 1, wherein, The second feeding power division network is a waveguide power division network, each second feeding power division channel of the second feeding power division network forms a multi-stage feeding power division network, a plurality of adjacent second feeding power division channels form a second feeding power division channel group, and adjacent two second feeding power division channels or adjacent two second feeding power division channel groups at the same stage are connected to each other through a power division interface, and each power division interface is provided with a metal partition wall.

8. The high-gain, wide-band, high-cross-polarization-ratio slotted ridge waveguide antenna array of claim 7, wherein, A set of metal tuning probes is symmetrically arranged in two branches of any one power division interface.

9. A radar antenna device, characterized by The ridge waveguide slot antenna array according to any one of claims 1-8.

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