Slot waveguide antenna and radar and automobile with same
By using metal pillars to simulate the sidewalls of a closed waveguide cavity and designing waveguide slots in the slotted waveguide antenna, the energy leakage problem caused by tiny gaps in traditional waveguide antennas is solved, achieving efficient and low-cost antenna performance improvement and array layout optimization.
Patent Information
- Application Number
- CN202511239687.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-01
- Publication Date
- 2026-01-09
AI Technical Summary
Traditional closed waveguide antennas are prone to energy leakage and gain reduction due to tiny gaps during manufacturing, and high-precision processing is expensive, making it difficult to meet the needs of large-scale mass production.
The design employs a slotted waveguide antenna, which simulates the sidewalls of a closed waveguide cavity by arranging rectangular metal pillars on the lower surface of the top plate and opening waveguide slots on the top plate to ensure that electromagnetic waves do not leak. Copper metal pillars and waveguide slots are used to achieve ideal electromagnetic field boundary conditions.
It effectively avoids energy leakage caused by non-closed processing, reduces processing difficulty and cost, improves antenna performance stability and array layout flexibility, and widens the horizontal beam.
Smart Images
Figure CN121307481A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of waveguide antenna technology, and in particular to a slotted waveguide antenna and radar and automobiles having the same. Background Technology
[0002] With the rapid development of technologies such as millimeter-wave radar and 5G communication, the demand for high-performance waveguide antennas is becoming increasingly urgent. Traditional waveguide antennas typically employ a closed metal cavity structure, using the conductive boundaries of the cavity's inner wall to constrain the electromagnetic field and achieve directional radiation.
[0003] Enclosed waveguide cavities require extremely high manufacturing precision, especially in the millimeter-wave band (e.g., 24 GHz, 77 GHz). Tiny gaps (>0.05λ) created during cavity welding or milling can disrupt electromagnetic boundary conditions, leading to energy leakage and a sharp drop in gain. Experimental data shows that when the cavity's non-closed gap reaches 0.1λ, the gain of conventional waveguide antennas decreases by 4-6 dB (“Tolerance Analysis of Millimeter-Wave Cavity Antennas”, Proc. EuCAP, 2021). To circumvent this problem, industry often relies on high-precision manufacturing processes (such as laser welding or electroforming), but these processes are costly and difficult to meet the demands of large-scale mass production. Summary of the Invention
[0004] In view of this, the purpose of the present invention is to provide a slotted waveguide antenna and radar and automobile having the same, so as to solve the above-mentioned technical problems.
[0005] This invention provides a slotted waveguide antenna, comprising a top plate and a bottom plate with a rectangular cross-section. The bottom plate is parallel to the top plate and located below it. A plurality of cuboid metal pillars are fixedly connected to the lower surface of the top plate, forming a rectangular enclosure on the lower surface of the top plate. Each side of the rectangle is composed of a plurality of spaced-apart metal pillars, with at least two rows of pillars corresponding to each side. The center-to-center distance between adjacent metal pillars is less than 1 / 2 of the free-space wavelength, and the air gap is less than 1 / 4 of the free-space wavelength. The top of each metal pillar is fixedly connected to the lower surface of the top plate, and the bottom of each metal pillar is separated from the upper surface of the bottom plate by a gap less than 1 / 4 of the free-space wavelength. A plurality of waveguide slots are formed on the top plate, and a waveguide port is formed in the middle of the bottom plate.
[0006] Optionally, the waveguide slots are formed within a rectangular shape enclosed by the metal pillars, and the length of the waveguide slots is less than 1 / 2 of the waveguide wavelength; the center lines of the waveguide slots are offset from the center line of the lower surface of the top plate.
[0007] Optionally, in the rectangular shape formed by the plurality of metal pillars, the center-to-center spacing and air gap between the metal pillars located on the wide side are both smaller than the center-to-center spacing and air gap between the metal pillars located on the long side, and the distance between the edge of the waveguide slot closest to the metal pillar located on the wide side and the metal pillar located on the wide side is 1 / 4 of the waveguide wavelength.
[0008] Optionally, the long side of the waveguide slot extends in the same direction as the length of the rectangular shape formed by the metal pillars, and the length of the waveguide slot is less than 1 / 2 of the waveguide wavelength.
[0009] Optionally, the narrow side of the waveguide slot is semi-circular, and the radius of the narrow side of the waveguide slot is 1 / 2 of the width of the waveguide slot.
[0010] Optionally, the maximum distance between the long sides of the two waveguide slots with the largest offset from the centerline of the top plate is less than 1.5 mm.
[0011] Optionally, the four edges between the top and bottom of the metal column are chamfered, and the four edges at the bottom of the metal column are also chamfered.
[0012] Optionally, the top plate, the bottom plate, and the metal column are made of copper.
[0013] The present invention also provides a radar, including a housing and a slotted waveguide antenna as described above. The housing has at least two parallel slots inside, which are used to fix the top plate and the bottom plate inside the housing, such that the top plate and the bottom plate are spaced apart.
[0014] The present invention also provides a vehicle including the radar described above.
[0015] The beneficial effect of this invention is that by using metal pillars arranged in a rectangular shape in a periodic pattern on the lower surface of the top plate instead of a rectangular waveguide cavity, the phenomenon of energy leakage caused by the cavity not being closed is directly avoided from a manufacturing and processing perspective. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the structure of a slot waveguide antenna according to the present invention.
[0018] Figure 2 This is a schematic diagram of the structure of a slot waveguide antenna according to the present invention from another perspective.
[0019] Figure 3 This is a schematic diagram of the exploded structure of a slot waveguide antenna according to the present invention.
[0020] Figure 4 This is a schematic diagram of the top plate and metal column in a slotted waveguide antenna according to the present invention.
[0021] Figure 5 This is a schematic diagram of the array structure of a slot waveguide antenna according to the present invention.
[0022] Figure 6 This is a schematic diagram of the array explosion structure of a slot waveguide antenna according to the present invention.
[0023] In the picture: Top plate 10, waveguide slot 11; Base plate 20, waveguide port 21; Metal column 30, chamfer 31. Detailed Implementation
[0024] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.
[0025] Unless otherwise explicitly specified and limited, the terms "setup," "installation," and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of these terms based on the specific circumstances.
[0026] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.
[0027] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.
[0028] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.
[0029] like Figures 1 to 4 As shown, this embodiment provides a slotted waveguide antenna, including a top plate 10 and a bottom plate 20 with a rectangular cross-section. The bottom plate 20 is parallel to the top plate 10 and located below it. The top plate 10 and the bottom plate 20 have the same shape and size. The thickness of the top plate 10 is greater than 1 mm to ensure processing accuracy and effectively avoid deformation of the top plate 10, while also providing space for adding additional structures for subsequent optimization. Multiple cuboid metal pillars 30 are fixedly connected to the lower surface of the top plate 10. The top plate 10, bottom plate 20, and metal pillars 30 are made of copper, or the top plate 10 and bottom plate 20 are made of copper, and the metal pillars 30 are made of plastic, with a layer of copper metal covering the outer layer of the metal pillars 30. The multiple metal pillars 30 enclose the lower surface of the top plate 10 in a rectangular shape. The long side of the rectangle is aligned with the length direction of the top plate 10 or bottom plate 20, and the wide side is aligned with the width direction of the top plate 10 or bottom plate 20. Each side of the rectangular shape is composed of multiple spaced metal pillars 30, with at least two parallel rows of metal pillars 30 corresponding to each side. Adjacent metal pillars 30 are equidistant. These adjacent metal pillars 30 can be adjacent within the same row or parallel adjacent pillars outside the same row. The center-to-center distance between adjacent metal pillars 30 is less than half the wavelength of free space, and the air gap is less than one-quarter of the wavelength of free space. Here, the center-to-center distance refers to the distance along the centerline of the metal pillar 30 extending from its top to its bottom. The air gap refers to the distance between the outer walls of adjacent metal pillars 30 facing each other. The top of the metal pillar 30 is fixedly connected to the lower surface of the top plate 10, and the bottom of the metal pillar 30 is separated from the upper surface of the bottom plate 20 by a gap of less than 1 / 4 of the free space wavelength. That is, the metal pillar 30 is located between the top plate 10 and the bottom plate 20, and the top of the metal pillar 30 is connected to the lower surface of the top plate 10, but the bottom of the metal pillar 30 is not connected to the upper surface of the bottom plate 20. Multiple waveguide slots 11 are provided on the top plate 10, and a waveguide port 21 is provided in the middle of the bottom plate 20. Its dimensions meet the standard rectangular waveguide dimensions, and its master mode is TE. 10 In array design, the mode realizes the transition structure between microstrip and waveguide feeding, and also plays a role in impedance matching.
[0030] The slotted waveguide antenna provided in this embodiment simulates the four inner cavity sidewalls of a closed waveguide antenna by forming a rectangular shape with multiple metal pillars 30 enclosing the lower surface of the top plate 10. The spacing between adjacent metal pillars 30 is designed to ensure no electromagnetic wave leakage, forming an ideal magnetic conductor PMC boundary condition. Compared to current closed waveguide antennas, the slotted waveguide antenna provided in this embodiment eliminates performance degradation and energy dissipation caused by manufacturing issues while ensuring no energy leakage and meeting performance requirements. Compared to traditional rectangular waveguides, using periodically arranged metal pillars 30 to simulate sidewalls reduces the necessity for complete surface-to-surface contact due to layering, and is more friendly to array layout, providing greater spatial flexibility and significantly reducing the impact of incomplete contact on antenna performance.
[0031] For waveguide slots 11, multiple waveguide slots 11 are formed on the top plate 10, and the multiple waveguide slots 11 are located within a rectangular shape enclosed by multiple metal pillars 30. The waveguide slots 11 are roughly elongated, with the long side of the waveguide slot 11 aligned with the length direction of the top plate 10 or the bottom plate 20, and the narrow side aligned with the width direction of the top plate 10 or the bottom plate 20. Considering manufacturing tolerances, the width of the waveguide slot 11 is at least 0.5 mm, and the length of the waveguide slot 11 is less than half the waveguide wavelength. The multiple waveguide slots 11 have the same shape and size, and the length of the waveguide slot 11 is about half the waveguide wavelength. Considering edge effects, the actual length will be slightly less than half the waveguide wavelength. Therefore, the length of the waveguide slot 11 is less than half the waveguide wavelength. The centerlines of multiple waveguide slots 11 are offset from the centerline of the lower surface of the top plate 10, meaning the centerlines of the waveguide slots 11 and the centerline of the lower surface of the top plate 10 are not on the same straight line. By controlling the offset of the waveguide slots 11 relative to the centerline of the lower surface of the top plate 10, the radiation intensity and phase of each waveguide slot 11 are controlled by the amount of offset, thus achieving the desired radiation pattern. To ensure the balance of amplitude and sidelobe levels, the offset must satisfy a Chebyshev distribution or a Taylor distribution.
[0032] Meanwhile, the narrow side of the waveguide slot 11 is semi-circular, and the radius of the narrow side of the waveguide slot 11 is half the width of the waveguide slot 11. This reduces the processing difficulty of the waveguide slot 11, as it is difficult to form a regular rectangle during processing. Therefore, by configuring the narrow side of the waveguide slot 11 as semi-circular, it is easier to control the error value within the maximum error value.
[0033] Furthermore, compared to the two waveguide slots 11 with the largest offset from the centerline of the lower surface of the top plate 10, the maximum distance between the long sides of the two waveguide slots 11 is less than 1.5 mm. The maximum distance between the long sides of the two waveguide slots 11 is the distance between the long sides of the two waveguide slots 11 that are offset in opposite directions from the centerline of the top plate 10, which is the distance between the long sides of the two waveguide slots 11 closest to the edge of the top plate 10. By controlling the maximum distance between the long sides of the waveguide slots 11 to within 1.5 mm, the horizontal beam of the waveguide antenna can be widened to a greater extent.
[0034] Furthermore, in the rectangular shape formed by the multiple metal pillars 30, the metal pillars 30 located on the wider side not only simulate a closed cavity but also need to simulate the short-circuit end of the closed cavity. Therefore, in this embodiment, in the rectangular shape formed by the multiple metal pillars 30, the center-to-center spacing and air gap between the metal pillars 30 located on the wider side are both smaller than those between the metal pillars 30 located on the longer side. That is, in the metal pillars 30 located on the longer side, the center-to-center spacing between adjacent metal pillars 30 is less than 1 / 2 the wavelength of free space, while in the metal pillars 30 located on the wider side, the center-to-center spacing between adjacent metal pillars 30 needs to be even smaller. In the metal pillars 30 located on the longer side, the air gap is less than 1 / 4 the wavelength of free space, while in the metal pillars 30 located on the wider side, the air gap between adjacent metal pillars 30 needs to be even smaller. Furthermore, the distance between the edge (narrow side) of the waveguide slot 11 closest to the metal pillar 30 located on the wider side and the metal pillar 30 located on the wider side is 1 / 4 the wavelength of the waveguide. This prevents electromagnetic wave leakage and achieves a short circuit. In this embodiment, the metal pillars 30 located on the wider side have three rows.
[0035] Furthermore, in this embodiment, the length of the metal column 30 (from the top to the bottom of the metal column 30) is 1 / 4 of the wavelength of free space. Chamfers 31 are formed at the four edges between the top and bottom of the metal column 30, and chamfers 31 are also formed at the four edges at the bottom of the metal column 30, which facilitates processing.
[0036] like Figure 5 and Figure 6 As shown, Figure 5 and Figure 6 The array configuration of the slot waveguide antenna provided in this embodiment is such that the top plates 10 of multiple slot waveguide antennas are integrated into one plate, and the bottom plates 20 of multiple slot waveguide antennas are integrated into one plate.
[0037] In summary, the slotted waveguide antenna provided in this embodiment, compared with the traditional rectangular waveguide, uses periodically arranged metal pillars 30 to simulate the sidewalls, which reduces the necessity of complete surface-to-surface contact caused by layering, and is more friendly to array layout, with more room for array arrangement, greatly reducing the impact of antenna performance degradation caused by incomplete contact, and significantly widening the horizontal beam of the waveguide antenna.
[0038] This embodiment also provides a radar, including a housing and a slotted waveguide antenna as described above. The housing has at least two parallel slots inside, which are distributed vertically within the housing. The top plate 10 and the bottom plate 20 are respectively mounted in the slots through their edges. The slots are used to fix the top plate 10 and the bottom plate 20 in the housing, so that the top plate 10 and the bottom plate 20 are spaced apart, thereby maintaining a distance between the metal pillar 30 on the lower surface of the top plate 10 and the upper surface of the bottom plate 20.
[0039] This embodiment also provides a vehicle including the radar described above.
[0040] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A slot waveguide antenna, characterized in that: The system includes a top plate (10) and a bottom plate (20) with a rectangular cross-section. The bottom plate (20) is parallel to the top plate (10) and located below the top plate (10). A plurality of cuboid metal columns (30) are fixedly connected to the lower surface of the top plate (10). The plurality of metal columns (30) enclose the lower surface of the top plate (10) in a rectangular shape. Each side of the rectangular shape is composed of a plurality of spaced metal columns (30), and at least two rows of metal columns are provided for each side. (30), the center-to-center distance between adjacent metal pillars (30) is less than 1 / 2 of the free space wavelength, and the air gap is less than 1 / 4 of the free space wavelength; the top of the metal pillar (30) is fixedly connected to the lower surface of the top plate (10), and the bottom of the metal pillar (30) is separated from the upper surface of the bottom plate (20) by a gap of less than 1 / 4 of the free space wavelength; multiple waveguide slots (11) are provided on the top plate (10), and a waveguide port (21) is provided in the middle of the bottom plate (20).
2. The slotted waveguide antenna according to claim 1, characterized in that: The multiple waveguide slots (11) are formed within a rectangular shape enclosed by the multiple metal pillars (30), and the length of the waveguide slots (11) is less than 1 / 2 of the waveguide wavelength; the center lines of the multiple waveguide slots (11) are offset from the center line of the lower surface of the top plate (10).
3. The slotted waveguide antenna according to claim 2, characterized in that: In the rectangular shape formed by the plurality of metal pillars (30), the center-to-center spacing and air gap between the metal pillars (30) located on the wide side are smaller than the center-to-center spacing and air gap between the metal pillars (30) located on the long side, and the distance between the edge of the waveguide slot (11) closest to the metal pillar (30) located on the wide side and the metal pillar (30) located on the wide side is 1 / 4 of the waveguide wavelength.
4. The slotted waveguide antenna according to claim 2, characterized in that: The long side of the waveguide slot (11) extends in the same direction as the length of the rectangular shape enclosed by the metal pillar (30), and the length of the waveguide slot (11) is less than 1 / 2 of the waveguide wavelength.
5. The slotted waveguide antenna according to claim 4, characterized in that: The narrow side of the waveguide slot (11) is semi-circular, and the radius of the narrow side of the waveguide slot (11) is 1 / 2 of the width of the waveguide slot (11).
6. The slot waveguide antenna according to claim 4, characterized in that: The maximum distance between the long sides of the two waveguide slots (11) with the largest offset from the center line of the top plate (10) is less than 1.5 mm.
7. The slotted waveguide antenna according to claim 1, characterized in that: The metal column (30) has chamfers (31) formed at the four edges between the top and bottom, and the metal column (30) has chamfers (31) formed at the four edges at the bottom.
8. The slot waveguide antenna according to claim 1, characterized in that: The top plate (10), the bottom plate (20), and the metal column (30) are made of copper.
9. A radar, characterized in that: The device includes a housing and a slotted waveguide antenna as described in any one of claims 1-8. The housing has at least two parallel slots inside, which are used to fix the top plate (10) and the bottom plate (20) inside the housing, and the top plate (10) and the bottom plate (20) are spaced apart.
10. A car, characterized in that: Including the radar as described in claim 9.