Multi-fold radiation slot and waveguide antenna

Abstract

The utility model provides a multi-fold radiation slot and a waveguide antenna. The multi-fold radiation slot comprises an upper-layer radiation slot, a transition radiation slot and a lower-layer radiation slot, the upper-layer radiation groove penetrates through the outer surface of the waveguide antenna body, the lower-layer radiation groove is communicated with a waveguide cavity in the waveguide antenna body, and the upper-layer radiation groove and the lower-layer radiation groove are arranged in an offset mode in the direction perpendicular to the top face of the waveguide cavity; and the corresponding side walls of the upper-layer radiation slot and the lower-layer radiation slot are connected through a flat side wall which is obliquely arranged on the transition radiation slot. The multi-fold radiation slot disclosed by the utility model comprises the upper-layer radiation slot, the lower-layer radiation slot and the transition radiation slot, and the upper-layer radiation slot and the lower-layer radiation slot which are arranged in an offset manner are connected through the flat side wall which is obliquely arranged on the transition radiation slot, so that the problems of difficult connection and difficult signal transmission of the upper-layer radiation slot and the lower-layer radiation slot are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of waveguide antennas, and in particular to a multi-fold radiation slot and a waveguide antenna. Background Art

[0002] At present, in the application of vehicle-mounted millimeter-wave radar, waveguide antennas have received more and more attention due to their advantages such as low loss and high isolation. The design of a typical waveguide antenna with a radiation slot is as follows: Figure 2 The waveguide cavity is a structure that extends in a straight line and is closed at the end. The top surface (long side) of the waveguide cavity is provided with a radiation slot that penetrates the waveguide antenna body. The radiation slot is a thin and long radiation gap at the bottom layer, and its upper layer often has a step or horn shape with gradually increasing width. Each radiation slot is a centrally symmetrical structure, and the symmetry centers of multiple radiation slots are staggered and offset with the center plane of the waveguide cavity in sequence.

[0003] This typical waveguide slot antenna design leads to two potential problems due to the staggered arrangement of radiation slots: 1. The amplitudes of the first and second side lobes are high and difficult to suppress; 2. The directions of the highest amplitudes of the first and second side lobes point to the axis side and form an angle with the normal direction of the main lobe, which is difficult to measure and has a negative impact on the detection accuracy of application equipment such as radar.

[0004] After research, it was found that if the upper and lower layers of the radiation slot of the waveguide slot antenna are directly connected through tilt offset, it will affect the performance of the slot antenna and increase the overall size of the radiation slot and the difficulty of processing. Utility Model Content

[0005] In view of the defects in the prior art, the purpose of the utility model is to provide a multi-fold radiation slot and a waveguide antenna.

[0006] A multi-fold radiation slot provided by the utility model comprises: an upper radiation slot, a transition radiation slot and a lower radiation slot;

[0007] The upper radiation slot passes through the outer surface of the waveguide antenna body, the lower radiation slot is connected to the waveguide cavity inside the waveguide antenna body, and the upper radiation slot and the lower radiation slot are offset in a direction perpendicular to the top surface of the waveguide cavity;

[0008] The side walls corresponding to the upper radiation slot and the lower radiation slot are connected through a flat side wall inclined on the transition radiation slot.

[0009] Preferably, the center of the upper radiation slot is located in the longitudinal center plane of the waveguide cavity along the signal transmission direction, and the center of the lower radiation slot is located on both sides of the longitudinal center plane of the waveguide cavity along the signal transmission direction, in a staggered offset arrangement.

[0010] Preferably, one end of the waveguide cavity along the signal transmission direction is a waveguide port P1, and the other end is a closed end S1;

[0011] The multi-fold radiation slots are arranged at intervals along the direction of signal transmission, the center distance between two adjacent multi-fold radiation slots is 1 / 2 waveguide wavelength, and the distance between the last multi-fold radiation slot and the closed end S1 is 1 / 4 waveguide wavelength.

[0012] Preferably, the left and right side surfaces of the upper radiation slot which are perpendicular to the signal transmission direction are inclined toward the center and are in an inverted trapezoidal shape.

[0013] Preferably, the lengths of the lower radiation slot, the transition radiation slot and the upper radiation slot along the signal transmission direction are equal or increase in sequence;

[0014] The widths of the lower radiation slot, the transition radiation slot and the upper radiation slot increase in sequence along a direction perpendicular to the signal transmission direction.

[0015] Preferably, the lower radiation slots are staggered left and right, and the staggered offset conforms to Taylor distribution or Chebyshev distribution.

[0016] Preferably, the width of the upper radiation slot is adjusted according to the radiation direction of the antenna;

[0017] The length and width of the lower radiation slot and the staggered offset between the lower radiation slot and the longitudinal center plane are adjusted according to the antenna array S parameters and radiation efficiency.

[0018] A waveguide antenna provided by the utility model comprises the multi-fold radiation slot.

[0019] A vehicle-mounted radar provided by the utility model comprises the waveguide antenna with multi-fold radiation slots.

[0020] A car provided according to the utility model comprises the above-mentioned vehicle-mounted radar.

[0021] Compared with the prior art, the utility model has the following beneficial effects:

[0022] 1. The multi-fold radiation slot disclosed in the utility model comprises an upper radiation slot, a lower radiation slot and a transition radiation slot. The upper radiation slot and the lower radiation slot which are offset are connected by the flat side wall which is inclined on the transition radiation slot, thus solving the problem of difficulty in connecting the upper radiation slot and the lower radiation slot and difficulty in signal transmission.

[0023] 2. The multi-fold radiation slots disclosed in the utility model have the centers of the upper radiation slots aligned, which can optimize the direction of the side lobes and facilitate the suppression of the side lobe height; the lower radiation slots are staggered left and right, and the misaligned offsets conform to or are close to Taylor distribution or Chebyshev distribution, which is convenient for debugging and realizing the preset standing wave bandwidth and impedance characteristics.

[0024] 3. The transition radiation slot in the utility model plays a role of smooth transition between the upper and lower radiation slots, so that the alternating offset lower radiation slots and the centrally symmetrical upper radiation slots are integrated, ensuring the impedance performance and radiation efficiency of the antenna, and the structural design meets the process requirements of CNC machining or plastic injection molding.

[0025] 4. The width and side inclination of the middle and upper radiation slots of the utility model can be adjusted independently, which is convenient for debugging and achieving the preset antenna radiation directivity technical goals.

[0026] 5. By adopting the multi-fold radiation slot provided by the utility model, the waveguide cavity can be set to a straight cavity shape, which is easier to process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0028] Figure 1 It is a three-dimensional diagram of a waveguide antenna with multi-fold radiation slots in the utility model;

[0029] Figure 2 It is a schematic diagram of an existing waveguide antenna with a radiation slot;

[0030] Figure 3 It is a top view of the waveguide antenna with multi-fold radiation slots in the utility model;

[0031] Figure 4 This is a cross-sectional view of embodiment 1 of the multi-fold radiation slot in the utility model;

[0032] Figure 5 This is a cross-sectional view of Embodiment 2 of the multi-fold radiation slot in the present utility model;

[0033] Figure 6 This is a cross-sectional view of the upper and middle radiation slots of the utility model;

[0034] Figure 7 This is a cross-sectional view of the middle and lower radiation slots of the utility model;

[0035] Figure 8 is a lobe shape distribution diagram of an existing radiation slot waveguide antenna;

[0036] Fig. 9 This is a distribution diagram of the lobe shape of the waveguide antenna with multi-fold radiation slots in the utility model.

[0037] Description of reference numerals:

[0038] Waveguide antenna body 1 Multi-fold radiation slot 3

[0039] Waveguide cavity 2 Second center plane 30

[0040] First center plane 20 Upper radiation slot 31

[0041] Waveguide port P1 Lower radiation slot 32

[0042] Closed end S1 Transition radiation slot 33 DETAILED DESCRIPTION

[0043] The utility model is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the utility model, but do not limit the utility model in any form. It should be pointed out that for those of ordinary skill in the art, several changes and improvements can be made without departing from the concept of the utility model. These all belong to the protection scope of the utility model.

[0044] The utility model provides a multi-fold radiation slot which can be applied to a waveguide antenna. Figure 1 As shown, it includes a waveguide antenna body 1, a waveguide cavity 2 is formed inside the waveguide antenna body 1, and a multi-fold radiation slot 3 is arranged through the waveguide antenna body 1.

[0045] Reference Figure 3-Figure 7 As shown, the waveguide cavity 2 is arranged inside the waveguide antenna body 1. The waveguide cavity 2 is a hollow cavity filled with an electromagnetic wave transmission medium (such as air); its size meets the preset frequency requirements, such as the vehicle radar application frequency band of 76-81GHz. The waveguide cavity 2 extends straight along the Y direction to form an inline cavity. The Y direction is the direction in which the signal is transmitted in the waveguide cavity. One end of the waveguide cavity 2 along the Y direction is the waveguide port P1, and the other end is closed as the closed end S1.

[0046] The top and bottom surfaces of the waveguide cavity 2 are wide-side planes, and the left and right side surfaces are narrow-side planes. The top surface of the waveguide cavity 2 is the top surface of the waveguide cavity H surface, the bottom surface of the waveguide cavity 2 is the bottom surface of the waveguide cavity H surface, and the left and right side surfaces are the two E surfaces of the waveguide cavity. The first central plane 20 is a plane passing through the waveguide cavity 2 along the Y direction and perpendicular to the X direction, that is, the longitudinal central plane of the waveguide cavity 2 along the signal transmission direction, and the X direction is a direction perpendicular to the two side surfaces of the waveguide cavity.

[0047] The multi-fold radiation slots 3 are distributed on the waveguide antenna body 1, and the multi-fold radiation slots 3 penetrate the waveguide antenna body 1 along the Z direction, which is the direction perpendicular to the top surface (or bottom surface) of the waveguide cavity, and are connected to the waveguide cavity 2 at the top surface of the waveguide cavity 2; multiple multi-fold radiation slots 3 are distributed at intervals along the Y direction, and conform to or are close to Taylor distribution or Chebyshev distribution, that is, the center spacing between two adjacent multi-fold radiation slots 3 is close to 1 / 2 waveguide wavelength, and the distance between the last multi-fold radiation slot 3 and the closed end S1 is close to 1 / 4 waveguide wavelength.

[0048] The multi-fold radiation slot 3 includes an upper radiation slot 31, a lower radiation slot 32 and a transition radiation slot 33. The upper radiation slot 31 penetrates the top surface of the waveguide antenna body 1 upward along the Z direction, is distributed at intervals along the Y direction, and conforms to or is close to the Taylor distribution or Chebyshev distribution, that is, the center spacing between two adjacent upper radiation slots 31 is close to 1 / 2 of the waveguide wavelength, and the distance between the last upper radiation slot 31 and the closed end S1 is close to 1 / 4 of the waveguide wavelength; the center of each upper radiation slot 31 is aligned with the first center plane 20 and arranged in a straight line; the left and right sides of the upper radiation slot 31 can be set to a certain angle of inclination, forming an inverted trapezoidal shape. The width of the upper radiation slot 31 can be used as the main debugging parameter for adjusting the radiation directivity of the antenna array.

[0049] The lower radiation slot 32 penetrates the top surface of the waveguide cavity 2 downward along the Z direction, and the lower radiation slot 32 is spaced apart along the Y direction and conforms to or is close to the Taylor distribution or the Chebyshev distribution, that is, the center spacing between two adjacent lower radiation slots 32 is close to 1 / 2 of the waveguide wavelength, and the distance between the last lower radiation slot 32 and the closed end S1 is close to 1 / 4 of the waveguide wavelength. A second central plane 30 is arranged parallel to the YOZ plane direction, and the center of the lower radiation slot 32 is located in the second central plane 30. The second central plane 30 is parallel to the first central plane 20, and the second central plane 30 of each lower radiation slot 32 is staggered on the left and right sides of the first central plane 20. The length, width, and offset of the second central plane 30 and the first central plane 20 of the lower radiation slot 32 can be used as the main debugging parameters for adjusting the S parameters and radiation efficiency of the antenna array. In a preferred embodiment, the left and right sides of the lower radiation slot can be set to a certain angle of inclination in a positive trapezoidal shape or an inverted trapezoidal shape.

[0050] The transitional radiation slot 33 is located between the upper radiation slot 31 and the lower radiation slot 32, and smoothly connects the lower opening of the upper radiation slot 31 and the upper opening of the lower radiation slot 32. The side walls corresponding to the upper radiation slot 31 and the lower radiation slot 32 are connected by the flat side walls inclined on the transitional radiation slot 33.

[0051] In one embodiment, the upper radiation slots 31 are symmetrically arranged about the first plane, and the lower radiation slots 33 are symmetrically arranged about the second plane, and the first plane and the second plane are parallel to the XOZ plane; the upper radiation slots 31 are symmetrically arranged about the third plane, and the lower radiation slots 33 are symmetrically arranged about the fourth plane, and the third plane and the fourth plane are parallel to the YOZ plane.

[0052] The widths of the lower radiation slot 32, the transitional radiation slot 33 and the upper radiation slot 31 in the X direction are increased successively. The lengths of the lower radiation slot 32, the transitional radiation slot 33 and the upper radiation slot 31 in the Y direction are equal or increased successively.

[0053] The waveguide antenna 1 is made of metal or plastic with a conductive layer on the surface. The waveguide antenna 1 can be divided into an upper and lower structure and processed separately; the metal material can be processed by casting, 3D printing or CNC processing, and the plastic material can be processed by injection molding, 3D printing or CNC processing and then coated with a metal layer on the surface. The upper and lower structures can be connected by screwing, bonding or welding.

[0054] like Figure 8 The figure shows the lobe shape distribution diagram of a typical radiating slot waveguide antenna. It can be seen that the first side lobe and the second side lobe are suppressed to a certain extent in the normal direction of the antenna (Theta = 0°), but their maximum amplitudes are on both sides of the deviation from the normal direction, which can still have an adverse effect on the detection accuracy of the radar. Fig. 9 This is a lobe shape distribution diagram of an embodiment of the utility model. It can be seen that the first side lobe and the second side lobe are effectively suppressed regardless of the normal direction or the axial direction.

[0055] The utility model also discloses a vehicle-mounted radar, which includes the waveguide antenna with multi-fold radiation slots. The utility model also discloses a car, which is equipped with the vehicle-mounted radar.

[0056] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0057] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other at will.

Claims

1. A multi-fold radiation slot, characterized in that: include: An upper radiation slot (31), a transition radiation slot (33) and a lower radiation slot (32); The upper radiation slot (31) penetrates the outer surface of the waveguide antenna body (1), the lower radiation slot (32) is connected to the waveguide cavity (2) inside the waveguide antenna body (1), and the upper radiation slot (31) and the lower radiation slot (32) are offset in a direction perpendicular to the top surface of the waveguide cavity (2); The side walls corresponding to the upper radiation slot (31) and the lower radiation slot (32) are connected via a flat side wall inclined on the transition radiation slot (33).

2. The multi-fold radiation slot according to claim 1, characterized in that: The center of the upper radiation slot (31) is located in the longitudinal center plane of the waveguide cavity (2) along the signal transmission direction, and the center of the lower radiation slot (32) is located on both sides of the longitudinal center plane of the waveguide cavity (2) along the signal transmission direction, and is arranged in a staggered offset manner.

3. The multi-fold radiation slot according to claim 1, characterized in that: One end of the waveguide cavity (2) along the signal transmission direction is a waveguide port P1, and the other end is a closed end S1; The multi-fold radiation slots (3) are arranged at intervals along the direction of signal transmission, the center distance between two adjacent multi-fold radiation slots (3) is 1 / 2 of the waveguide wavelength, and the distance between the last multi-fold radiation slot (3) and the closed end S1 is 1 / 4 of the waveguide wavelength.

4. The multi-fold radiation slot according to claim 1, characterized in that: The upper radiation slot (31) has two left and right side surfaces perpendicular to the signal transmission direction and arranged tilted toward the center, forming an inverted trapezoidal shape.

5. The multi-fold radiation slot according to claim 1, characterized in that: The lengths of the lower radiation slot (32), the transition radiation slot (33) and the upper radiation slot (31) along the signal transmission direction are equal or increase in sequence; The widths of the lower radiation slot (32), the transition radiation slot (33) and the upper radiation slot (31) increase in sequence along a direction perpendicular to the signal transmission direction.

6. The multi-fold radiation slot according to claim 1, characterized in that: The lower radiation slots (32) are arranged in a left-right staggered manner, and the staggered offset conforms to Taylor distribution or Chebyshev distribution.

7. The multi-fold radiation slot according to claim 1, characterized in that: The width of the upper radiation slot (31) is adjusted according to the radiation direction of the antenna; The length and width of the lower radiation slot (32) and the staggered offset between the lower radiation slot (32) and the longitudinal center plane are adjusted according to the antenna array S parameter and radiation efficiency.

8. A waveguide antenna, characterized in that: The method comprises the multi-fold radiation slot according to any one of claims 1 to 7.

9. A vehicle-mounted radar, characterized in that: It comprises the waveguide antenna with multi-fold radiation slot as claimed in claim 8.

10. An automobile, characterized in that: Including the vehicle-mounted radar as described in claim 9.

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