Waveguide antenna and radar

Abstract

The application provides a waveguide antenna and radar, comprising: a twist waveguide connecting two rectangular waveguide slot arrays through a separator, and a horn opening; the rectangular waveguide slot array comprises: a special-shaped rectangular waveguide cavity; a slot array is arranged on the surface of the special-shaped rectangular waveguide cavity and is arranged at intervals, and is arranged in a length direction of the special-shaped rectangular waveguide cavity and is located on a straight line; and the horn opening is connected to the special-shaped rectangular waveguide cavity and covers the slot array. Different from a traditional slot design, the variant structure design makes the radiation slot vertically arranged, and the direction of an electric field is changed by using a twist waveguide design principle. The design structure makes the design and arrangement of the waveguide antenna simpler.

Description

[0001] This application claims the following patent applications as prior art:

[0002] Application Number: 202311097056.9

[0003] Application date: 2023-08-28

[0004] Application Title: Waveguide Antenna and Radar Technical Field

[0005] This invention relates to the field of electromagnetic wave antenna technology, specifically to a waveguide antenna and radar. Background Technology

[0006] Most existing millimeter-wave radar waveguide antennas are arranged vertically upwards using a power divider structure. From design to manufacturing, this process requires at least three substrate layers to achieve the antenna's functionality. For example, patent document CN113471687A discloses a three-layer millimeter-wave substrate integrated waveguide antenna, including a bottom substrate, an intermediate substrate, and a top substrate. The bottom substrate has a substrate integrated waveguide planar magic-T structure and two first power dividers; the intermediate substrate has two second power dividers; the top substrate has a second feed coupling slot and an antenna radiation array. Patent document CN113745833A discloses a waveguide antenna and signal transmission device with at least four layers, including: a first substrate with a waveguide port; a second substrate, the first substrate forming a stacked structure with a transmission waveguide; at least one intermediate substrate, the stacked structure forming a signal transmission path, the signal transmission path having an input port and several output ports, and several power dividers connecting the input and output ports; and an antenna substrate. In summary, traditional millimeter-wave radars have complex structures and are difficult to deploy. At the same time, traditional power dividers are expensive and have complex manufacturing processes, which do not meet the requirements of mass production at this stage. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a waveguide antenna and radar.

[0008] A waveguide antenna according to the present invention includes:

[0009] Twisted waveguide 1 connects two rectangular waveguide arrays 5 via separator 3;

[0010] The rectangular waveguide array 5 includes:

[0011] Irregular rectangular waveguide cavity;

[0012] The slot array 2 is formed on the surface of the irregular rectangular waveguide cavity, and is arranged at intervals with each other. It is arranged along the length direction on the irregular rectangular waveguide cavity and is located in a straight line.

[0013] The horn opening 4 is connected to the irregular rectangular waveguide cavity and covers the slot array 2.

[0014] Furthermore, the torsional waveguide 1 includes:

[0015] A longitudinal rectangular waveguide transmission line 11 with a cross-sectional height-to-width ratio of 2:1 is connected in series at the end of the longitudinal rectangular waveguide transmission line 11 with a transverse rectangular waveguide transmission line 13 of the same size but with a cross-sectional height-to-width ratio of 1:2. The transverse rectangular waveguide transmission line 13 is perpendicular to the long side of the longitudinal rectangular waveguide transmission line 11 and has the same top surface height. This allows the direction of the electromagnetic wave electric field to be twisted by 90 degrees after entering from the longitudinal rectangular waveguide transmission line 11 and then being connected to the transverse rectangular waveguide transmission line 13. Impedance matching is performed using an impedance matching block 12 to reduce standing waves and reflections. The transverse rectangular waveguide transmission line 13 is placed at the center of symmetry of the two irregular rectangular waveguide cavities and is perpendicular to them.

[0016] Furthermore, the rectangular waveguide array includes:

[0017] Irregularly shaped rectangular waveguide cavity and / or straight rectangular waveguide cavity;

[0018] The slot array 2 is formed on the surface of the irregular rectangular waveguide cavity and / or the straight rectangular waveguide cavity, and is arranged at intervals with each other. It is arranged along the length direction on the irregular rectangular waveguide cavity and / or the straight rectangular waveguide cavity, and is located on different straight lines.

[0019] The horn opening 4 is connected to the irregular rectangular waveguide cavity and / or the straight rectangular waveguide cavity, respectively covering each of the slot arrays 2.

[0020] Furthermore, the irregular rectangular waveguide cavity includes spaced-apart functional segments 51 and transition segments 52;

[0021] The slot array 2 is formed in the functional section 51;

[0022] The adjacent functional segments 51 are not on the same axis.

[0023] Furthermore, the irregular rectangular waveguide cavity has a wavy, curved shape.

[0024] Furthermore, the odd-numbered functional segments 51 and the even-numbered functional segments 51 are arranged alternately and connected by transition segments 52 to form a wavy, curved shape.

[0025] Furthermore, each slot in the slot array 2 is rectangular, and its length direction is the same as that of the rectangular waveguide array 5.

[0026] Furthermore, the separator 3 is located on the opposite side of the transverse rectangular waveguide transmission line 13 and maintains a preset interval distance. The separator 3 completely separates the two rectangular waveguide arrays 5 within its length range. The separator 3 and the transverse rectangular waveguide transmission line 13 are on the same axis in the length direction.

[0027] The signal input to the transverse rectangular waveguide transmission line 13 is divided equally in power at the thin film separator 3, with the phase remaining unchanged, and then fed into the two rectangular waveguide arrays 5 respectively.

[0028] Furthermore, the horn opening 4 has a horn-shaped structure, and the small end of the horn-shaped structure is connected to the irregular rectangular waveguide cavity.

[0029] A radar according to the present invention includes the waveguide antenna described above.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1) The structure of the present invention makes the design of waveguide slot antennas simpler and easier to arrange, and ensures that the antenna gain can be maintained during the electric field turning process, with good sidelobe level suppression and effective impedance bandwidth.

[0032] 2) The structural design of the separator in this invention enables this antenna to still have the equal division effect brought by the power divider without the need for a traditional power divider, making the subsequent slot array design simpler.

[0033] 3) The design of the horn opening structure in this invention avoids the weakness of thin metal materials that cannot increase the distance in the normal height, and can effectively match the air impedance and increase the effective gain of the antenna.

[0034] 4) Compared with traditional waveguide slot antennas, the present invention significantly reduces manufacturing costs and meets the requirements of mass production. Attached Figure Description

[0035] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0036] Figure 1 This is a top view of an embodiment of the present invention;

[0037] Figure 2 This is a perspective view of an embodiment of the present invention;

[0038] Figure 3 This is a perspective view of the second embodiment of the present invention;

[0039] Figure 4 This is a top view of the second embodiment of the present invention;

[0040] Figure 5 This is a perspective view of the third embodiment of the present invention;

[0041] Figure 6 This is a top view of the third embodiment of the present invention;

[0042] Figure 7 This is a partially enlarged view of the present invention. Detailed Implementation

[0043] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0044] Example 1

[0045] like Figure 3 and Figure 4 As shown, the waveguide antenna provided in this embodiment includes:

[0046] A twisted waveguide 1 connects two irregularly shaped rectangular waveguide arrays via a separator 3. In a typical design, the two irregularly shaped rectangular waveguide cavities are placed symmetrically at 180 degrees. The irregularly shaped rectangular waveguide array includes: an irregularly shaped rectangular waveguide cavity 5 and a slot array 2. The slot array 2 has multiple slots, spaced apart on the surface of the irregularly shaped rectangular waveguide cavity, arranged along the length of the cavity in a straight line. Since the twisted waveguide 1 is mounted on a substrate, the waveguide antenna of this invention requires only two layers to be implemented, resulting in a simple and easy-to-design structure.

[0047] like Figure 7 As shown, the irregular rectangular waveguide cavity has a wavy, curved shape, but other curved shapes are also possible; this invention does not limit this. In this invention, the irregular rectangular waveguide cavity includes spaced-apart functional segments 51 and transition segments 52. The slot array 2 is located in the functional segment 51, with a center offset from the axis of the irregular rectangular waveguide cavity by a certain distance. Odd-numbered and even-numbered functional segments 51 are arranged alternately and connected by the transition segment 52 to form a wavy, irregular rectangular waveguide cavity. Through this irregular cavity design, the slot array 2 can be arranged in a straight line; and by adjusting the distance between the center plane of the functional segment 51 and the center plane of the slot 2, the magnitude of the coupling power of each slot can be adjusted, thereby achieving a Taylor distribution of the power of each slot in the slot array 2, and ultimately optimizing the radiation performance of the slot antenna (including but not limited to: antenna gain, half-power azimuth angle, half-power elevation angle, sidelobe level, etc.).

[0048] The horn opening 4 is connected to the irregular rectangular waveguide cavity. The horn opening 4 has a horn-shaped structure, with its small end connected to the irregular rectangular waveguide cavity and covering a slot. Each slot is rectangular, with its length aligned with the length of the rectangular waveguide array 5. The use of the horn opening 4 effectively optimizes the impedance matching between the slot and the air, increasing the effective gain of the waveguide slot antenna.

[0049] This embodiment utilizes a variant of the slotted waveguide cavity structure to arrange the radiating slots vertically, differing from traditional slot designs. It also employs the twisted waveguide design principle to alter the electric field propagation direction. This design simplifies the design and deployment of the waveguide antenna, optimizing manufacturing processes and reducing costs.

[0050] In a practical example based on the present invention, a rectangular waveguide of model BJ900 / WR10 was used, with standard dimensions of 2.54mm for the long side and 1.27mm for the short side. Based on multiple simulation iterations, the reasonable dimensions of the separator (3) were obtained as follows: 0.6-1.2mm for width and 0.8-1.5mm for length.

[0051] In other embodiments, such as Figure 5 , Figure 6 As shown, the length of the irregular rectangular waveguide array is not fixed, which allows for the setting of more or fewer slots and the connection of more or fewer horn openings 4 to obtain antenna performance (such as azimuth, elevation, gain, sidelobe level, etc.) to meet different application requirements.

[0052] Example 2

[0053] like Figure 1 , Figure 2 As shown, the waveguide antenna provided in this embodiment includes:

[0054] A twisted waveguide 1 connects two linear rectangular waveguide arrays via a separator 3. The linear rectangular waveguide arrays include: a linear rectangular waveguide cavity and a slot array 2. The slot array 2 has multiple slots, which are spaced apart on the surface of the linear rectangular waveguide cavity and arranged along the length of the linear rectangular waveguide cavity on different straight lines.

[0055] The horn opening 4 is connected to the linear rectangular waveguide cavity. The horn opening 4 has a horn-shaped structure, and the small end of the horn-shaped structure is connected to the linear rectangular waveguide cavity, covering a slit. Each slit is rectangular, and its length direction is the same as the length direction of the rectangular waveguide array 5.

[0056] Example 3

[0057] The waveguide antenna provided in Example 1 utilizes a twisted waveguide, an irregular rectangular waveguide, a straight slot arrangement, and a horn opening structure design. By utilizing the torsion of the electric field, the waveguide antenna can achieve a 1x4, 1x6, or 1x8 antenna subarray structure layout under a single power distribution.

[0058] The designs in Examples 1, 2, and 3 can realize high-performance waveguide antenna designs, which can be widely used in current 77GHz vehicle-mounted millimeter-wave radar applications, 4D imaging radar and 4D front radar, 4D corner radar, weather monitoring radar, and traffic radar.

[0059] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, 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 this application.

[0060] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A waveguide antenna, characterized in that, include: A twisted waveguide (1) is connected to two rectangular waveguide arrays (5) through a separator (3) and is located on the opposite side of the separator (3); The rectangular waveguide array (5) includes: Irregular rectangular waveguide cavity; The slot array (2) is formed on the surface of the irregular rectangular waveguide cavity, and is arranged at intervals with each other. It is arranged along the length direction on the irregular rectangular waveguide cavity and is located in a straight line. Multiple horn openings (4) are connected to the irregular rectangular waveguide cavity, covering the slot array (2). The two irregularly shaped rectangular waveguide cavities are placed symmetrically at 180 degrees. The waveguide antenna has a two-layer structure.

2. The waveguide antenna according to claim 1, characterized in that, The torsional waveguide (1) includes: A longitudinal rectangular waveguide transmission line (11) with a cross-sectional height-to-width ratio of 2:1 is connected in series at the end of the longitudinal rectangular waveguide transmission line (11) with a transverse rectangular waveguide transmission line (13) of the same size but with a cross-sectional height-to-width ratio of 1:

2. The transverse rectangular waveguide transmission line (13) is perpendicular to the long side of the longitudinal rectangular waveguide transmission line (11) and has the same top surface height. This allows the direction of the electromagnetic wave electric field to be transmitted from the longitudinal rectangular waveguide transmission line (11) to the transverse rectangular waveguide transmission line (13), which is then twisted by 90 degrees. An impedance matching block (12) is used for impedance matching to reduce standing waves and reflections. The transverse rectangular waveguide transmission line (13) is placed at the symmetrical center of the two irregular rectangular waveguide cavities and is perpendicular to them.

3. The waveguide antenna according to claim 1, characterized in that, The irregular rectangular waveguide cavity includes spaced-apart functional segments (51) and transition segments (52). The slot array (2) is located in the functional section (51); The adjacent functional segments (51) are not on the same axis.

4. The waveguide antenna according to claim 1, characterized in that, The irregular rectangular waveguide cavity has a wavy, curved shape.

5. The waveguide antenna according to claim 3, characterized in that, The odd-numbered functional segments (51) and even-numbered functional segments (51) are arranged alternately and connected by transition segments (52) to form a wavy, curved shape.

6. The waveguide antenna according to claim 1, characterized in that, Each slot in the slot array (2) is rectangular, and its length direction is the same as that of the rectangular waveguide array (5).

7. The waveguide antenna according to claim 2, characterized in that, The separator (3) is located on the opposite side of the transverse rectangular waveguide transmission line (13) and maintains a preset interval distance. The separator (3) completely separates the two rectangular waveguide arrays (5) within its length range. The separator (3) and the transverse rectangular waveguide transmission line (13) are on the same axis in the length direction. The signal input to the transverse rectangular waveguide transmission line (13) is divided into equal power at the thin film separator (3) with no change in phase, and then fed into the two rectangular waveguide arrays (5) respectively.

8. The waveguide antenna according to claim 1, characterized in that, The horn opening (4) has a horn-shaped structure, and the small end of the horn-shaped structure is connected to the irregular rectangular waveguide cavity.

9. A radar, characterized in that, Includes the waveguide antenna as described in claim 1.

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