A wide-narrow beam composite array antenna

Abstract

This application belongs to the field of array antenna technology and relates to an array antenna with a combined wide and narrow beamwidth, including a radiating layer, a waveguide layer, and a feeding layer. The radiating layer includes a first antenna array, a second antenna array, and a third antenna array, each comprising A first antenna elements, B second antenna elements, and C antenna groups, with each antenna group including multiple third antenna elements. All antenna elements are hollow right-hand truncated pyramid structures with symmetrical trapezoidal cross-sections. The connecting surface is the surface where the upper base of the isosceles trapezoid on the antenna element is located. The waveguide layer includes multiple waveguides. Each waveguide has two or more slots, which are spaced apart along the length of the connecting surface. The number of slots is the same for different waveguides in the same antenna array, but the number of slots differs for different waveguides in different antenna arrays. The feeding layer includes multiple feeding channels. This application can achieve the combination of wide and narrow beamwidth characteristics in radar array antennas.

Description

Technical Field

[0001] This application relates to the field of array antenna technology, and in particular to an array antenna that combines wide and narrow beams. Background Technology

[0002] Radar array antennas, also known as phased array antennas, achieve electronic beam scanning by controlling the feed phase (or time delay) of multiple radiating elements in the array, without requiring mechanical antenna rotation. Compared with traditional mechanically scanned radars, radar array antennas have significant advantages such as flexible beam pointing, fast scanning speed, strong multi-target tracking capability, and ease of achieving multi-beam and adaptive null formation. Therefore, they have become a core component of modern radar systems and are widely used in military radar, weather monitoring, autonomous driving, UAV detection, and integrated communication and sensing systems, playing a crucial role in numerous fields.

[0003] Depending on the application scenario and mission requirements, radar systems often need to make a trade-off between the detection airspace range and target resolution capability. Wide beams can cover a large airspace range, which is beneficial for rapid search and wide-area surveillance, but their energy dispersion leads to low gain and insufficient angular resolution. Narrow beams, on the other hand, have high gain, high angular resolution and good anti-jamming capability, but their beam coverage is limited, making it difficult to efficiently complete wide-area search tasks.

[0004] In traditional radar systems, the beamwidth is mainly determined by the aperture size of the antenna array and the operating wavelength. Once the array design is finalized, the beamwidth is fixed, making it difficult to simultaneously achieve both wide-beam coverage search and narrow-beam high-precision tracking in the same radar system.

[0005] In existing technologies, the following approaches are commonly used to achieve wide and narrow beam combining: First, mechanically rotating the antenna to change the beam direction. This method has slow response speed, poor reliability, and difficulty in simultaneously tracking multiple targets, making it difficult to adapt to the dynamic switching requirements of multi-task operations. Second, using a time-division multiplexing operating mode, where the radar operates in wide-beam and narrow-beam modes at different time segments. However, this leads to competition for time resources, making it difficult to meet real-time detection requirements in rapidly changing battlefield environments. Third, using a "wide transmit, narrow receive" staring detection mode, where a wide beam is transmitted to achieve airspace coverage, and the receiver simultaneously forms multiple high-gain narrow beams for reception processing using digital beamforming (DBF) technology. However, this mode still essentially achieves narrow beamforming at the receiver end, while the transmitter can only generate a wide beam, failing to achieve wide and narrow beam combining control at the transmitter end. Furthermore, existing beamforming architectures themselves have technical limitations in balancing wide and narrow beams. Moreover, with the increasing demands for range resolution in radar systems and the growing application of broadband and ultra-wideband signals, the difficulty of wide and narrow beam combining is further exacerbated. Summary of the Invention

[0006] Therefore, it is necessary to provide a wide and narrow beam composite array antenna to address the above-mentioned technical problems, which can realize the composite of wide and narrow beam characteristics of radar array antennas, so as to meet the dual requirements of wide-area search coverage and high-precision target tracking.

[0007] A wide and narrow beam composite array antenna includes, from top to bottom, a radiating layer, a waveguide layer and a feed layer connected in sequence. The radiating layer includes: a first antenna array, a second antenna array, and a third antenna array; the first antenna array includes A first antenna elements, the second antenna array includes B second antenna elements, and the third antenna array includes C antenna groups, each antenna group including multiple third antenna elements; A is an even number, B and C are both odd numbers, and A / 2 > B = C; all antenna elements are hollow right truncated pyramid structures with symmetrical trapezoidal cross-sections, serving as horns; the connecting surface is the plane containing the upper base of the isosceles trapezoid on the antenna element; The waveguide layer includes: multiple waveguides corresponding one-to-one with antenna elements, and the waveguides are connected to the connection surfaces of the corresponding antenna elements; the waveguides are provided with two or more slots that penetrate the waveguides from the radiating layer to the feeding layer, the slots on the same waveguide are distributed at intervals along the length of the connection surface, the number of slots in different waveguides in the same antenna array is the same, and the number of slots in different waveguides in different antenna arrays is different. The feeding layer includes: multiple feeding channels, one corresponding end of each feeding channel is connected to an external input end, and the other corresponding end is connected to the first antenna element, the second antenna element, and the antenna group respectively; The first antenna array, the second antenna array, and the third antenna array serve as a wide-beam receiving array, an ultra-wide-angle receiving array, and a narrow-beam transmitting array, respectively, to achieve the composite wide and narrow beam characteristics of the radar array antenna.

[0008] In one embodiment, the feed channel includes, in sequence, a connection port, a connection segment, a feed line, a transition segment, and a bias resonant cavity, wherein a ridge waveguide is provided in the bias resonant cavity; the feed line, the transition segment, and the bias resonant cavity are disposed in the same plane; The feed line includes one or more bends and has chamfers at the bends. The connecting segment is perpendicular to the plane of the feed line to form an impedance matching structure.

[0009] In one embodiment, the transition segment includes: multiple branches of varying widths; The width of the spur gradually decreases toward the bias resonant cavity, so that the transition section forms a stepped axial structure to form a signal coupling structure with the bias waveguide cavity and the slot.

[0010] In one embodiment, the feed channel connected to the antenna group further includes a power divider network; The power divider network includes multiple 1-to-2 power dividers, which are cascaded to form an input port and multiple output ports. The input port is connected to a transition section, and the output ports are connected to a bias resonant cavity.

[0011] In one embodiment, the waveguide of the first antenna element is provided with a first slot, the waveguide of the second antenna element is provided with b second slots, and the waveguide of the third antenna element is provided with c third slots. a, b, and c are all even numbers, and b, a, and c are distributed in an arithmetic sequence with a common difference of d, where d = 2b.

[0012] In one embodiment, the length direction of the first slot is the same as the length direction of the connecting surface, and all the first slots are symmetrically distributed about the width direction axis of the connecting surface; among the first slots located on the same side of the width direction axis of the connecting surface, the length direction axes of symmetry of adjacent first slots are located on both sides of the length direction axis of the connecting surface.

[0013] In one embodiment, the length direction of the second groove is the same as the length direction of the connecting surface, and all the second grooves are symmetrically distributed about the length direction axis and the width direction axis of the connecting surface.

[0014] In one embodiment, the length direction of the third groove is the same as the length direction of the connecting surface, and all the third grooves are centrally symmetrical about the length direction axis and the width direction axis of the connecting surface; the length direction axis of symmetry of adjacent third grooves is located on both sides of the length direction axis of symmetry of the connecting surface.

[0015] In one embodiment, the center distance of the third slot is greater than both the center distance of the second slot and the center distance of the first slot.

[0016] In one embodiment, the first antenna array includes eight first antenna elements, and each first antenna element has six first slots on its corresponding waveguide. The second antenna array includes three second antenna elements, and each second antenna element has two second slots on its corresponding waveguide. The third antenna array includes three antenna groups, each antenna group includes eight third antenna elements, and each third antenna element has ten third slots on its corresponding waveguide.

[0017] The aforementioned wide and narrow beam composite array antenna is designed with a wide beam receiving array, an ultra-wide viewing angle receiving array, and a narrow beam transmitting array. The corresponding waveguides of different antenna elements adopt different numbers of radiation slots to form differentiated beam widths, which together realize the integrated radiation function of wide and narrow beam composite. Specifically: the wide-beam receiving array forms a medium beamwidth, balancing receiving gain and viewing angle coverage, for detection of the main area; the ultra-wide viewing angle receiving array forms an even wider beamwidth, used to extend the detection viewing angle and eliminate detection blind spots, complementing the wide-beam receiving unit in terms of viewing angle; the narrow-beam transmitting array, as a long-range transmitting array, forms a high-gain, narrow-beam radiation, used for long-range target detection, forming a combined wide- and narrow-beam transmission and reception working mode with the wide beam of the receiving unit; the three arrays are integrated and laid out on the same substrate, operate independently, and have complementary beams, realizing a radar array antenna with wide- and narrow-beam combination and high isolation in the 91.5-93.5GHz frequency band, possessing the combined detection capabilities of no blind spots, wide coverage, and long distance, solving the technical problems of existing radar antennas with single beam form, limited coverage, and low isolation. Attached Figure Description

[0018] Figure 1 This is a three-dimensional schematic diagram of a wide and narrow beam composite array antenna in one embodiment; Figure 2 This is a top view schematic diagram of a wide and narrow beam composite array antenna in one embodiment; Figure 3 This is a schematic diagram showing the connection of the first antenna element of a wide and narrow beam composite array antenna with the waveguide and feed channel from one perspective in one embodiment. Figure 4 This is a schematic diagram of the connection between the first antenna element of a wide and narrow beam composite array antenna and the waveguide and feed channel from another perspective in one embodiment. Figure 5 This is a schematic diagram showing the connection of the second antenna element of a wide and narrow beam composite array antenna with the waveguide and feed channel from one perspective in one embodiment. Figure 6 This is a schematic diagram showing the connection between the second antenna element of a wide and narrow beam composite array antenna in one embodiment and the waveguide and feed channel from another perspective. Figure 7 This is a schematic diagram showing the connection of the third antenna element of a wide and narrow beam composite array antenna with the waveguide and feed channel from one perspective in one embodiment. Figure 8 This is a schematic diagram showing the connection between the third antenna element of a wide and narrow beam composite array antenna in one embodiment and the waveguide and feed channel from another perspective. Figure 9 This is a schematic diagram of the first slot corresponding to the first antenna element in one embodiment; Figure 10 This is a schematic diagram of the second slot corresponding to the second antenna unit in one embodiment; Figure 11 This is a schematic diagram of the third slot corresponding to the third antenna element in one embodiment; Figure 12 This is a schematic diagram of the feed channel of a wide and narrow beam composite array antenna in one embodiment; Figure 13 This is a schematic diagram of the reflection coefficient of the first antenna array of a wide and narrow beam composite array antenna in one embodiment; Figure 14 This is a schematic diagram of the reflection coefficient of the second antenna array of a wide and narrow beam composite array antenna in one embodiment; Figure 15 This is a schematic diagram of the reflection coefficient of the third antenna array of a wide and narrow beam composite array antenna in one embodiment; Figure 16 This is a schematic diagram of the isolation of the first antenna array of a wide and narrow beam composite array antenna in one embodiment; Figure 17 This is a schematic diagram illustrating the isolation of the second antenna array of a wide and narrow beam composite array antenna in one embodiment. Figure 18 This is a schematic diagram illustrating the isolation of the third antenna array in one embodiment of a wide and narrow beam composite array antenna. Figure 19 The gain pattern of the first antenna array of a wide and narrow beam composite array antenna in one embodiment is shown at 91.5 GHz. Figure 20 The gain pattern of the first antenna array of a wide and narrow beam composite array antenna in one embodiment is shown at 93.5 GHz. Figure 21 The gain pattern of the second antenna array of a wide and narrow beam composite array antenna in one embodiment is shown at 91.5 GHz. Figure 22 The gain pattern of the second antenna array of a wide and narrow beam composite array antenna in one embodiment is shown at 93.5 GHz. Figure 23 The gain pattern of the third antenna array of a wide and narrow beam composite array antenna in one embodiment is shown at 91.5 GHz. Figure 24 This is the gain pattern of the third antenna array of a wide and narrow beam composite array antenna in one embodiment at 93.5 GHz.

[0019] Figure label: First antenna array 11, second antenna array 12, third antenna array 13, antenna group 14; First groove 21, second groove 22, third groove 23; Connection port 31, connection section 32, feeder 33, transition section 34, power divider network 35, bias resonant cavity 36, ridge waveguide 37. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0021] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple sets" means at least two sets, such as two sets, three sets, etc., unless otherwise explicitly specified.

[0022] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0023] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0024] This application provides a wide-narrow beam composite array antenna, such as... Figures 1 to 12 As shown, in one embodiment, it includes a radiating layer, a waveguide layer, and a feeding layer, and the radiating layer, the waveguide layer, and the feeding layer are connected sequentially from top to bottom.

[0025] The radiating layer is used to radiate the radio frequency signal input from the feed layer into free space and form a directional electromagnetic wave beam, including: a first antenna array, a second antenna array, and a third antenna array; the first antenna array includes A first antenna elements, which are distributed in an equally spaced array along the width direction; the second antenna array includes B second antenna elements, which are distributed in an equally spaced array along the width direction; the third antenna array includes C antenna groups, each antenna group including multiple third antenna elements, which are distributed in an equally spaced array along the width direction; A is an even number, B and C are both odd numbers, and A / 2 > B = C; all antenna elements are hollow right truncated pyramid structures with symmetrical trapezoidal cross-sections to serve as horns; the surface where the upper base of the isosceles trapezoid on the antenna element is located is the connecting surface.

[0026] The waveguide layer is used to connect the radiating layer and the feed layer to achieve accurate and stable signal transmission. It includes: multiple waveguides corresponding one-to-one with antenna elements, and the waveguides are connected to the connection surfaces of the corresponding antenna elements; two or more slots are provided on the wide wall surface along the length of the waveguide. The slots are waist-shaped structures that penetrate the waveguide from the radiating layer to the feed layer (i.e., the slot depth is equal to the waveguide wall thickness), and the length of the slots is parallel to the feed transmission direction; the slots on the same waveguide are evenly distributed along the length of the connection surface. The number of slots is the same for different waveguides in the same antenna array, and the number of slots is different for different waveguides in different antenna arrays, so that the antenna has stable radiation characteristics in the operating frequency band.

[0027] The feed layer is used to perform mode conversion and energy transfer on the radio frequency signals output by the front-end equipment before feeding them into the radiation layer. It includes multiple independently arranged feed channels. One corresponding end of each feed channel is connected to an external input terminal, and the other corresponding end is connected to each first antenna element, each second antenna element, and each antenna group. (That is, the number of feed channels is equal to the sum of the number of first antenna elements, second antenna elements, and antenna groups. The feed channels are divided into three parts (i.e., the first part, the second part, and the third part). Each part includes multiple feed channels. The multiple feed channels in the first part are connected one-to-one with the first antenna elements, the multiple feed channels in the second part are connected one-to-one with the second antenna elements, and the multiple feed channels in the third part are connected one-to-one with the antenna groups.)

[0028] In this embodiment, the feed channel transmits the input electromagnetic signal TE10 wave to the slots on each waveguide. The main TE10 transmission mode is excited inside the waveguide to complete the energy transfer. The slots convert the electromagnetic signal TE10 wave into a quasi-TEM wave, completing the mode conversion. Then, the quasi-TEM wave is radiated into free space through each antenna element. The first antenna array serves as a wide-beam receiving array (achieving stable, high-sensitivity, and wide-coverage reception), the second antenna array serves as an ultra-wide-view receiving array (achieving spatial diversity to fill blind spots and improve isolation, signal-to-noise ratio, and anti-interference capability), and the third antenna array serves as a narrow-beam transmitting array (achieving a balance between high gain and narrow beam). The three arrays work together to regulate the electric field distribution, suppress mutual coupling, and beam deflection, realizing the composite wide and narrow beam characteristics of the radar array antenna. This achieves the complete functions of wide-area coverage, blind spot elimination, and long-range accurate detection, ensuring balanced gain, sidelobes, and beamwidth across the entire frequency band, and improving radiation performance, especially isolation, signal-to-noise ratio, and anti-interference capability. It also reduces electromagnetic crosstalk and performance fluctuations and avoids sidelobe degradation.

[0029] Preferably, the waveguide of the first antenna element is provided with 'a' first slots at intervals, the waveguide of the second antenna element is provided with 'b' second slots at intervals, and the waveguide of the third antenna element is provided with 'c' third slots at intervals; a, b, and c are all even numbers, and b, a, and c are distributed in an arithmetic sequence with a common difference of 'd', where 'd' = 2b. This configuration can simultaneously accommodate ultra-wide-angle reception, standard wide-beam reception, and narrow-beam high-gain transmission, forming a complete composite beam system with smooth transitions and complementary width and narrow beam widths. It balances the beamwidth gradient, improves frequency band characteristics and stable in-phase excitation effect, ensures stable radiation performance across the entire frequency band, and meets electrical performance indicators and engineering feasibility, avoiding reception coverage gaps, increased detection blind zones, impedance mismatch, and overload of the feed network.

[0030] More preferably, the length direction of the first slot is the same as the length direction of the connecting surface, and all the first slots are axially symmetrical about the width direction axis of the connecting surface; among the first slots located on the same side of the width direction axis of the connecting surface, the length direction axes of symmetry of adjacent first slots are located on opposite sides of the length direction axis of the connecting surface. This arrangement, through staggered placement, enables stable equal-amplitude and in-phase excitation and phase balance of the wide-beam receiving array, and ensures stable radiation characteristics of the antenna within the operating frequency band.

[0031] More preferably, the length direction of the second slot is the same as the length direction of the connecting surface, and all the second slots are axially symmetrical about the axis of symmetry in both the length and width directions of the connecting surface. This configuration enables stable equal-amplitude and in-phase excitation and phase balance of the ultra-wide-angle receiving array, and ensures stable radiation characteristics of the antenna within the operating frequency band.

[0032] More preferably, the length direction of the third slot is the same as the length direction of the connecting surface, and all the third slots are centrally symmetrical about the length and width axes of symmetry of the connecting surface; the length axes of symmetry of adjacent third slots are located on both sides of the length axis of symmetry of the connecting surface. This arrangement, through staggered placement, enables stable equal-amplitude and in-phase excitation and phase balance of the narrow-beam transmitting array, and ensures stable radiation characteristics of the antenna within the operating frequency band.

[0033] More preferably, the center distance of the third slot is greater than both the center distance of the second slot and the center distance of the first slot, in order to meet the requirements of long-distance transmission with narrow beam and high gain.

[0034] More preferably, the first antenna array includes 8 first antenna elements, and each first antenna element has 6 first slots on its corresponding waveguide; the second antenna array includes 3 second antenna elements, and each second antenna element has 2 second slots on its corresponding waveguide; the third antenna array includes 3 antenna groups, each antenna group includes 8 third antenna elements, and each third antenna element has 10 third slots on its corresponding waveguide.

[0035] In another embodiment, the feed channel includes, in sequence, a connection port, a connection segment, a feed line, a transition segment, and a bias resonant cavity, wherein the feed line, transition segment, and bias resonant cavity are located in the same plane; the connection port is connected to an external input terminal to receive an external RF excitation signal and input TE10 mode electromagnetic waves; the connection segment is perpendicular to the plane of the feed line; the feed line includes one or more bends and has chamfers at the bends, the radius of which is 1.2 times the width of the feed line; the transition segment has a non-uniform width gradient structure and is connected to the middle of one side of the bias resonant cavity so that the slot is centrally fed; the bias resonant cavity has a cuboid structure with a ridge waveguide to form cutoff characteristics adapted to electromagnetic wave transmission and provide a closed electromagnetic shielding environment. The arrangement of the feed line and the connection segment forms an impedance matching structure, which can optimize the efficient transmission of energy across the entire frequency band, achieve stable beam pointing to zero angle at each frequency point across the entire frequency band without detection blind zones, and simultaneously achieve good impedance matching, eliminate signal reflection and standing wave problems at bends, and effectively reduce signal leakage to significantly improve isolation.

[0036] Preferably, the transition section includes multiple stubs of varying widths; the width of the stubs gradually decreases towards the bias resonant cavity, forming a stepped axial structure with varying cross-sections, thus enabling the transition section to form a signal coupling structure with the bias waveguide cavity and the slot. This configuration, gradually transitioning from the standard width of the feed end to a size adapted to the bias resonant cavity, creates connection paths with varying cross-sections, resulting in a natural impedance matching transition. This avoids signal reflection caused by direct connection and constrains electromagnetic field propagation through the enclosed metal wall structure, preventing signal leakage. Simultaneously, it balances impedance matching and crosstalk suppression, effectively reducing energy loss and optimizing signal transmission efficiency without adding extra structural complexity. It perfectly fits the characteristics of a one-piece metal structure and further enhances the stability and reliability of signal transmission. Combined with the enclosed metal structure, it effectively blocks electromagnetic interference from adjacent channels, ensuring smooth energy transmission between the feed layer and the radiation layer while reducing crosstalk through the physical isolation of the metal wall.

[0037] More preferably, the feed channel connected to the antenna group further includes a power divider network. That is, the feed channel connected to the antenna group includes a connection port, a connection section, a feed line, a transition section, a power divider network, and a bias resonant cavity. The power divider network includes multiple 1-to-2 power dividers, which are cascaded to form a multi-stage symmetrical equal-amplitude and equal-phase feed network, symmetrical about the geometric center to ensure the consistency of amplitude and phase of each feed path. The feed network has one input port and multiple output ports. The input port is connected to the transition section, and the output ports are connected to the bias resonant cavity, so as to equally divide (equal amplitude and equal phase distribution) the TE10 wave input from the transition section into multiple TE10 waves with the same amplitude and phase, and stably output them to each bias resonant cavity, thereby exciting each slot to radiate electromagnetic waves. The feed channels of different antenna groups are independent of each other and do not crosstalk, ultimately achieving equal amplitude and in-phase excitation of multiple third antenna elements.

[0038] It should be noted that the overall structure adopts a layered three-dimensional arrangement. The radiating layer, waveguide layer, and feed layer share the same substrate. The radiating layer is located on the upper layer of the substrate (the substrate is a rectangular plate structure, and the upper layer of the substrate includes a first side, a second side, a third side, and a fourth side connected end to end; the first antenna array is adjacent to the first side and spaced apart, and the length direction of the first antenna element is perpendicular to the first side; the second antenna array is adjacent to the second side and spaced apart, and the length direction of the second antenna element is parallel to the second side; the third antenna array is adjacent to the third side and spaced apart, and the length direction of the third antenna element is perpendicular to the third side). The waveguide layer is located on the middle layer of the substrate, and the feed layer is located on the lower layer of the substrate. The overall structure adopts a one-piece molding structure, without using splicing, assembly, or dielectric support, which are prone to electromagnetic leakage. It can directly block electromagnetic wave coupling, surface wave propagation, and cavity crosstalk paths between units physically. The connection port of the feed layer is connected to the board port of the substrate, realizing the transmission and reception of millimeter-wave radar signals.

[0039] It should also be noted that the distance between the first antenna elements, the distance between the second antenna elements, and the distance between the third antenna elements are matched with the equivalent guided wave wavelength of the target frequency band. The slot spacing of the same waveguide is matched with the equivalent guided wave wavelength of the operating frequency band. The size of the slot is matched with the volume of the bias waveguide cavity. The size of the bias resonant cavity is matched with the transmission requirements of the feed signal. The specific matching methods are all existing technologies and will not be elaborated here.

[0040] The aforementioned wide and narrow beam composite array antenna is designed with a wide beam receiving array, an ultra-wide viewing angle receiving array, and a narrow beam transmitting array. The corresponding waveguides of different antenna elements adopt different numbers of radiation slots to form differentiated beam widths, which together realize the integrated radiation function of wide and narrow beam composite. Specifically: the wide-beam receiving array forms a medium beamwidth, balancing receiving gain and viewing angle coverage, for detection of the main area; the ultra-wide viewing angle receiving array forms an even wider beamwidth, used to extend the detection viewing angle and eliminate detection blind spots, complementing the wide-beam receiving unit in terms of viewing angle; the narrow-beam transmitting array, as a long-range transmitting array, forms a high-gain, narrow-beam radiation, used for long-range target detection, forming a combined wide- and narrow-beam transmission and reception working mode with the wide beam of the receiving unit; the three arrays are integrated and laid out on the same substrate, operate independently, and have complementary beams, realizing a radar array antenna with wide- and narrow-beam combination and high isolation in the 91.5-93.5GHz frequency band, possessing the combined detection capabilities of no blind spots, wide coverage, and long distance, solving the technical problems of existing radar antennas with single beam form, limited coverage, and low isolation.

[0041] Specifically, this application has the following beneficial effects: 1. Through core technologies such as "differentiated antenna element array design, differentiated slot array design, impedance matching structure, signal coupling structure, and multi-stage symmetrical power divider feeding", a dual technological breakthrough of wide and narrow beam combination and high isolation has been achieved in the 91.5-93.5GHz frequency band. Compared with the shortcomings of existing radar antennas in the same frequency band, such as narrow impedance matching bandwidth, insufficient channel isolation, single beam form and discrete performance indicators, this application has achieved significant improvements in the three core indicators of impedance matching, channel isolation and beam performance. At the same time, it simplifies the integrated structure of multi-beam antennas, reduces the difficulty of processing and assembly, and greatly improves the engineering adaptability and working stability of the product.

[0042] 2. Regarding impedance matching performance, existing integrated radar antennas in the same frequency band are generally affected by multi-channel coupling, resulting in difficulty in consistently maintaining a |S11| below -12dB, and significant fluctuations in performance within the bandwidth. This application achieves excellent impedance matching and ideal radiation direction across the entire frequency band through precise coupling of the impedance matching structure and the signal coupling structure, ensuring a stable |S11| below -12dB, improving the impedance matching depth, and exhibiting minimal fluctuations in radiation performance across the entire frequency band, resulting in high stability, effectively reducing signal reflection loss, and improving energy transmission efficiency.

[0043] 3. Regarding channel isolation performance, the isolation between adjacent receiving channels of existing integrated radar antennas can typically only reach 20-25dB, and the isolation between transmitting and receiving channels is difficult to exceed 80dB, which easily leads to severe signal crosstalk. This application, through the precise coupling of impedance matching structure and signal coupling structure, blocks the electromagnetic leakage path in three-dimensional space, achieving an order-of-magnitude improvement in isolation performance. The peak isolation of the entire receiving channel exceeds 110dB, far exceeding the upper limit of 80dB of existing products, and the isolation stability is high.

[0044] 4. Regarding radiation performance and beamforming advantages, existing radar antennas in the same frequency band mostly adopt a single-beam design. To achieve wide and narrow beam coverage, multiple independent antennas need to be spliced ​​and integrated, resulting in defects such as large size, low integration, and blind spots in beam connection. This application achieves wide-angle coverage, ultra-wide-angle blind spot filling, and long-distance narrow beam detection within the same antenna aperture through differentiated design of antenna array beamwidth and the number of radiation slots. It realizes the integrated wide and narrow beams, and has a wide beam coverage angle, good directivity and detection accuracy across the entire frequency band, with no detection blind spots. At the same time, it ensures good radiation performance and beamforming advantages, which can meet the application requirements of radar stable detection, accurate positioning, and professional adaptation of transceiver functions across the entire frequency band.

[0045] In one specific embodiment, a conventional waveguide of WR10 specification is used as the feed substrate.

[0046] The radiating layer includes: a first antenna array, a second antenna array, and a third antenna array; the first antenna array includes 8 first antenna elements, the second antenna array includes 3 second antenna elements, and the third antenna array includes 3 antenna groups, each antenna group including 8 third antenna elements.

[0047] The waveguide layer includes 35 waveguides corresponding one-to-one with antenna elements. Among them, 8 waveguides are connected to 8 first antenna elements, 3 waveguides are connected to 3 second antenna elements, 8 waveguides are connected to 8 third antenna elements of the first antenna group, 8 waveguides are connected to 8 third antenna elements of the second antenna group, and 8 waveguides are connected to 8 third antenna elements of the third antenna group. Each first antenna element has 6 first slots on its corresponding waveguide, each second antenna element has 2 second slots on its corresponding waveguide, and each third antenna element has 10 third slots on its corresponding waveguide.

[0048] The feed layer includes 14 feed channels, of which 8 feed channels are connected to 8 first antenna elements, 3 feed channels are connected to 3 second antenna elements, and 3 feed channels are connected to 3 antenna groups. Each feed channel connected to a first antenna element or a second antenna element includes, in sequence, a connection port, a connection segment, a feed line, a transition segment, and a bias resonant cavity. Each feed channel connected to an antenna group includes, in sequence, a connection port, a connection segment, a feed line, a transition segment, a power divider network, and a bias resonant cavity. Each power divider network includes 7 identical 1-to-2 power dividers (mirror-symmetric equal-division power dividers), and the 7 power dividers are cascaded to form one input port and 8... The output port and input port are connected to the transition section of the antenna group. The output port is connected to the 8 bias resonant cavities of the same antenna group to complete the 1 to 8 power distribution (specifically: the input port of the first power divider is connected to the transition section, the two output ports are connected to the input ports of the second and third power dividers respectively, the output port of the second power divider is connected to the input ports of the fourth and fifth power dividers respectively, the output port of the third power divider is connected to the input ports of the sixth and seventh power dividers respectively, and the output ports of the fourth, fifth, sixth and seventh power dividers are connected to the 8 bias resonant cavities respectively).

[0049] Simulation tests were conducted using full-wave electromagnetic simulation software in the 91.5–93.5 GHz frequency band. The reflection coefficient, channel isolation, gain, sidelobe suppression, and beamwidth were verified according to microwave antenna electrical performance testing standards. The results are as follows: Figures 13 to 24 As shown.

[0050] like Figure 13 and Figure 14 As shown, the first and second antenna arrays consistently have |S11| less than -13.6dB within the 91.5-93.5GHz range.

[0051] like Figure 15As shown, the minimum value of the full receiving channel unit |S11| reaches -12.7dB. Compared with existing products, the impedance matching depth is improved by an average of more than 1.6dB, and the performance across the entire frequency band is not significantly fluctuating. This effectively reduces signal reflection loss and improves energy transmission efficiency.

[0052] like Figure 16 The diagram shows the isolation of the first antenna array. S12 represents the isolation curve between adjacent channels of port 1 and port 2. Port 1 and port 2 are the first group of adjacent feed channels of the array. The coupling is strongest at a low frequency of 90 GHz, approximately -29.5 dB, and gradually weakens as the frequency increases. The coupling is consistently below -28 dB across the entire operating frequency band of 91.5~93.5 GHz, effectively suppressing crosstalk between channels. S23 represents the isolation curve between adjacent channels of port 2 and port 3. Across the entire frequency band, the curve is generally located in the range of -27 to -28 dB, showing better isolation performance than S12. The spatial mutual coupling between adjacent elements is lower, the curve fluctuates gently, and the frequency band consistency is good. S34 represents the isolation curve between adjacent channels of port 3 and port 4. The curve trend is highly consistent with S23, reaching the optimal isolation value of approximately -27.2 dB in the 93~93.5 GHz range. The isolation characteristics of adjacent ports in the middle section of the array are uniform and stable. S45 represents the isolation curve between adjacent channels of ports 4 and 5. Located at the center of the array, the isolation level across the entire frequency band is basically consistent with S34, with a peak isolation close to -27dB and no significant frequency degradation. S56 represents the isolation curve between adjacent channels of ports 5 and 6. The curve closely follows S45, reaching its optimal isolation value near 93GHz. The mutual coupling control level of the ports in the later stages of the array is uniform. S67 represents the isolation curve between adjacent channels of ports 6 and 7. The isolation at high frequencies (93.5~95GHz) deteriorates slightly, but remains better than -27dB within the core operating band, with no significant overall performance degradation. S78 represents the isolation curve between adjacent channels of ports 7 and 8. Its trend perfectly matches that of curve S67. The isolation characteristics of adjacent units at the end of the array are consistent with those in the middle of the array, and the entire array does not exhibit the defect of a sharp drop in isolation performance at both ends.

[0053] like Figure 17The diagram shows the isolation of the linear array on the second day. S12 represents the isolation curve of adjacent channels between port 1 and port 2; the coupling is strongest at the low frequency end of 90GHz, with a value of approximately -27.5dB; the coupling trough (optimal isolation) is reached near 90.5GHz, with a value of approximately -28dB; the coupling in the 91~92GHz band increases slightly and stabilizes at around -27dB; after 92GHz, it decreases slowly and gradually; the isolation is consistently better than 26dB throughout the entire operating frequency band, the overall fluctuation of the curve is small, and the frequency band isolation consistency is good. S23 represents the isolation curve of adjacent channels between port 2 and port 3; the coupling degree at the low frequency of 90GHz is higher than that of S12, with the lowest value close to -28.2dB; a coupling peak appears at 91GHz, approximately -26.5dB; within the core operating frequency band of 91.5~93GHz, the curve closely matches S12, and the isolation level is basically the same; the coupling deteriorates slightly after 93GHz, but does not exceed -26.5dB throughout.

[0054] like Figure 16 and Figure 17 As shown, the channel isolation of the first antenna array and the second antenna array is greater than 26.6dB and 26.4dB respectively, which is 1.4-6.6dB higher than that of existing integrated antennas. The two curves are highly overlapping, indicating that the mutual coupling characteristics of the units in the two adjacent ports of the array are uniform, and the structural decoupling design has a consistent suppression effect on different adjacent channels.

[0055] like Figure 18 The diagram shows the isolation of the third antenna array. S12 represents the isolation curve between adjacent channels of port 1 and port 2, and S23 represents the isolation curve between adjacent channels of port 2 and port 3. The peak isolation of the entire receiving channel exceeds 110dB, far exceeding the upper limit of 80dB for existing products, completely solving the multi-channel crosstalk problem. In addition, no additional isolation components are required. Compared with the traditional external isolation structure, this simplifies the product structure, reduces the complexity of processing and assembly, and improves production efficiency by about 25%.

[0056] like Figure 19 and Figure 20 As shown, the first antenna array has a gain greater than 17.3dB and a sidelobe suppression greater than 16dB within the 91.5-93.5GHz range. The 3dB horizontal beamwidths are 45°-52° and 46°-51°, respectively, and the vertical beamwidths are uniformly 11°-12°. The first null position is stable at 13°-16°. Compared with existing conventional wide-beam antennas, the gain is improved by an average of 2.1dB and the sidelobe suppression is improved by more than 3dB.

[0057] like Figure 21 and Figure 22As shown, the linear array gain on the second day is greater than 12.8dB, and the 3dB horizontal cross-section beamwidth exceeds 60°, achieving full-view reception without blind spots and making up for the shortcomings of insufficient view coverage of existing wide-beam antennas.

[0058] like Figure 23 and Figure 24 As shown, the third antenna array has a gain greater than 26.7dB, and the 3dB horizontal and vertical beamwidths are both 7°-8°. Compared with existing narrow-beam antennas in the same frequency band, the gain is improved by more than 3.5dB, and the beam directivity is stronger. The first null position is stable at 8°-9°, achieving accurate detection at long distances.

[0059] As can be seen from the above analysis, the first antenna array, the second antenna array, and the third antenna array all have good and stable impedance matching performance within the operating frequency band. The isolation between each element of the receiving antenna and between the transmitting and receiving channels is high, which can effectively suppress crosstalk between channels. In terms of radiation performance, the first antenna array has high gain and good sidelobe suppression level, with moderate horizontal beamwidth and stable vertical beamwidth, which can achieve wide-angle high-gain reception. The second antenna array has a wider beam, which can achieve ultra-wide-angle coverage to eliminate detection blind spots. The third antenna array has higher gain and narrower beamwidth, with good sidelobe suppression, which can achieve accurate detection at long distances.

[0060] In summary, the aforementioned array antenna exhibits excellent full-band performance consistency within the 91.5-93.5 GHz frequency band, with good impedance matching and high isolation among its elements, enabling hierarchical detection capabilities. It integrates wide-beam reception, ultra-wide-angle reception, and long-distance narrow-beam transmission, effectively solving problems such as single beam, limited coverage, insufficient isolation, and easy beam drift inherent in traditional antennas. It achieves stable beamwidth and no detection blind spots across the entire frequency band, successfully realizing the design goals of wide and narrow beam combining and high isolation. This ensures beam radiation consistency across the wide bandwidth and avoids the possibility of beam main lobe distortion, pointing deviation, and coverage angle contraction. It meets the application requirements of modern millimeter-wave radar for stable detection and blind-spot-free coverage, and is widely applicable to industries such as radar detection, wireless sensing, aerospace, security monitoring, and communication systems, especially millimeter-wave radar systems with high requirements for detection range, coverage, and anti-interference performance.

[0061] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended application documents.

Claims

1. A wide-narrow beam composite array antenna, characterized in that, It includes, from top to bottom, the following layers connected in sequence: radiation layer, waveguide layer, and feed layer; The radiating layer includes: a first antenna array, a second antenna array, and a third antenna array; the first antenna array includes A first antenna elements, the second antenna array includes B second antenna elements, and the third antenna array includes C antenna groups, each antenna group including multiple third antenna elements; A is an even number, B and C are both odd numbers, and A / 2 > B = C; all antenna elements are hollow right truncated pyramid structures with symmetrical trapezoidal cross-sections, serving as horns; the connecting surface is the plane containing the upper base of the isosceles trapezoid on the antenna element; The waveguide layer includes: multiple waveguides corresponding one-to-one with antenna elements, and the waveguides are connected to the connection surfaces of the corresponding antenna elements; the waveguides are provided with two or more slots that penetrate the waveguides from the radiating layer to the feeding layer, the slots on the same waveguide are distributed at intervals along the length of the connection surface, the number of slots in different waveguides in the same antenna array is the same, and the number of slots in different waveguides in different antenna arrays is different. The feeding layer includes: multiple feeding channels, one corresponding end of each feeding channel is connected to an external input terminal, and the other corresponding end is connected to the first antenna element, the second antenna element, and the antenna group respectively; each feeding channel includes: a connection port, a connection segment, a feed line, a transition segment, and a bias resonant cavity connected in sequence, and the connection port is connected to the external input terminal; The first antenna array, the second antenna array, and the third antenna array serve as a wide-beam receiving array, an ultra-wide-angle receiving array, and a narrow-beam transmitting array, respectively, to achieve the composite wide and narrow beam characteristics of the radar array antenna.

2. The wide and narrow beam composite array antenna according to claim 1, characterized in that, The bias resonant cavity is provided with a ridge waveguide; the feed line, transition section and bias resonant cavity are arranged in the same plane; The feed line includes one or more bends and has chamfers at the bends. The connecting segment is perpendicular to the plane of the feed line to form an impedance matching structure.

3. The wide and narrow beam composite array antenna according to claim 2, characterized in that, The transition section includes: multiple branches of varying widths; The width of the spur gradually decreases toward the bias resonant cavity, so that the transition section forms a stepped axial structure to form a signal coupling structure with the bias resonant cavity and the slot.

4. The wide and narrow beam composite array antenna according to claim 3, characterized in that, The feed channels connected to the antenna array also include: a power divider network; The power divider network includes multiple 1-to-2 power dividers, which are cascaded to form an input port and multiple output ports. The input port is connected to a transition section, and the output ports are connected to a bias resonant cavity.

5. A wide-narrow beam composite array antenna according to any one of claims 1 to 4, characterized in that, The first antenna element has a first slot on its corresponding waveguide, the second antenna element has b second slots on its corresponding waveguide, and the third antenna element has c third slots on its corresponding waveguide. a, b, and c are all even numbers, and b, a, and c are distributed in an arithmetic sequence with a common difference of d, where d = 2b.

6. The wide-narrow beam composite array antenna according to claim 5, characterized in that, The length direction of the first slot is the same as the length direction of the connecting surface, and all the first slots are symmetrically distributed about the width direction axis of the connecting surface; among the first slots located on the same side of the width direction axis of the connecting surface, the length direction axes of symmetry of adjacent first slots are located on both sides of the length direction axis of the connecting surface.

7. The wide-narrow beam composite array antenna according to claim 6, characterized in that, The length direction of the second groove is the same as the length direction of the connecting surface, and all the second grooves are symmetrically distributed about the length direction axis and the width direction axis of the connecting surface.

8. The wide-narrow beam composite array antenna according to claim 7, characterized in that, The length direction of the third groove is the same as the length direction of the connecting surface, and all the third grooves are centrally symmetrical about the length direction axis and the width direction axis of the connecting surface; the length direction axis of symmetry of adjacent third grooves is located on both sides of the length direction axis of symmetry of the connecting surface.

9. A wide-narrow beam composite array antenna according to claim 8, characterized in that, The center distance of the third groove is greater than both the center distance of the second groove and the center distance of the first groove.

10. A wide-narrow beam composite array antenna according to claim 9, characterized in that, The first antenna array includes eight first antenna elements, and each first antenna element has six first slots on its corresponding waveguide. The second antenna array includes three second antenna elements, and each second antenna element has two second slots on its corresponding waveguide. The third antenna array includes three antenna groups, each antenna group includes eight third antenna elements, and each third antenna element has ten third slots on its corresponding waveguide.

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