Waveguide antenna device

Abstract

The invention belongs to the technical field of millimeter wave radars, and particularly relates to a waveguide antenna device which comprises a first metal layer and a second metal layer which are oppositely arranged in a stacked mode, a gap or no gap exists in the connecting face of the two metal layers, one end of an antenna is electrically connected to a first waveguide port with a signal receiving / transmitting function, and the other end of the antenna is electrically connected to a second waveguide port with a signal receiving / transmitting function. The antenna comprises a horizontal waveguide channel and a vertical waveguide channel, a matching branch knot is arranged in the horizontal waveguide channel, a periodic or non-periodic artificial surface plasmon structure is arranged on the outer side of the side wall of the horizontal waveguide channel, and the surface plasmon structure is arranged on the outer side of the side wall of the vertical waveguide channel. The antenna device disclosed by the invention is very suitable for application scenes with requirements on large angles, such as a vehicle-mounted angle radar, and in addition, the antenna scheme disclosed by the invention has very great advantages on assembly tolerance redundancy and cost control during mass production.

Description

Technical Field

[0001] This invention belongs to the field of millimeter-wave radar technology, and specifically relates to a waveguide antenna device. Background Technology

[0002] Millimeter-wave radar has become an indispensable environmental perception sensor for modern automotive advanced driver assistance systems (ADAS) and autonomous driving due to its advantages such as strong anti-interference ability, high detection accuracy, and small size. Among them, millimeter-wave corner radars deployed at the four corners of the vehicle undertake key tasks such as blind spot detection (BSD), lane change assist (LCA), and rear cross traffic alert (RCTA), and their detection performance is directly related to driving safety.

[0003] The effectiveness of corner radar depends heavily on the directivity and coverage of its antenna beam. Ideally, the beam should be able to flexibly and accurately cover high-risk areas to the side and rear of the vehicle, such as adjacent lanes, blind spots of traditional rearview mirrors, and specific oncoming traffic directions at intersections. Currently, mainstream millimeter-wave corner radars generally use a main beam direction set perpendicular to the radar mounting plane (i.e., facing directly to the side).

[0004] However, this standard beam configuration has significant limitations in practical applications: Insufficient coverage and blind spots in specific areas: The coverage of the symmetrical beam pattern is weak in the area immediately behind the rear bumper of the vehicle (near-field blind spot) and targets that cut in at high speed at a small acute angle to the vehicle's axis (such as vehicles changing lanes quickly), which can easily lead to detection delays or missed detections. For example, in lane-changing scenarios, the traditional beam pattern has insufficient side and rear edge detection capability for targets that enter the adjacent lane diagonally from behind the vehicle.

[0005] Performance limitations in key directions: For specific asymmetric directions that require focused monitoring (such as the 30-60 degree area to the side and rear during lane changes), the standard beam struggles to achieve sufficiently high gain and angular resolution in these directions, limiting its ability to accurately distinguish and track close-range, multi-target, or small-sized targets.

[0006] The shortcomings of existing expansion schemes: Although mechanical scanning or complex omnidirectional electronic scanning can expand the field of view, this will significantly increase the system cost, size, power consumption and mechanical failure risk, and the scanning cycle may cause instantaneous missed detection of key targets, which cannot meet the stringent real-time requirements of corner radar. Existing electronic beamforming algorithms (such as FFT-based DBF) mainly optimize wide-angle scanning or symmetrical beams. In terms of generating stable, high-gain main lobes that are significantly deviated from the array normal direction (i.e., "off-beam"), there are problems of algorithm complexity or performance limitations, which is especially challenging in the design of small-size, low-cost corner radars.

[0007] Therefore, overcoming the aforementioned shortcomings of existing millimeter-wave angle radar beam coverage modes without significantly increasing system complexity, cost, and power consumption, especially effectively enhancing the detection capability of key asymmetric areas to the side and rear of vehicles, eliminating near-field blind spots, and suppressing interference, has become a technical bottleneck that urgently needs to be overcome in this field. Summary of the Invention

[0008] In view of the problems raised in the background art above, the object of the present invention is to provide a waveguide antenna device.

[0009] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: A waveguide antenna device, characterized in that it comprises a first metal layer and a second metal layer; The first metal layer is provided with a radiation port, and the first metal layer is provided with at least one first long slit and a second long slit on each side of the radiation port to suppress surface waves. The second metal layer has a horizontal waveguide channel on its front side and a first waveguide port on its back side. The second metal layer is provided with a vertical waveguide channel that penetrates the second metal layer. One end of the vertical waveguide channel is electrically connected to the first waveguide port, and the other side of the vertical waveguide channel is electrically connected to the beginning of the horizontal waveguide channel. The end of the horizontal waveguide channel is located below the radiation port, and the axis along the signal transmission direction of the horizontal waveguide channel is the AA' line. The first metal layer and the horizontal waveguide channel form a rectangular waveguide transmission line. The radiation port includes a first short rectangular port, a second short rectangular port, a third short rectangular port, and a fourth short rectangular port. The first, second, third, and fourth short rectangular ports are symmetrically distributed along the axis AA' of the signal transmission direction of the horizontal waveguide channel. The vertical projection of the first, second, third, and fourth short rectangular ports is located within the horizontal waveguide channel. Each short rectangular port includes a through portion and a non-through portion. The through portion is disposed on the first metal layer with a thickness of h1 and a width of a1. The non-through portion is disposed on the front side of the first metal layer with a thickness of h2 and a width of a11. The through portion and the non-through portion are tangent to each other along their partial edges. The through portions are symmetrically distributed along the axis AA', and the non-through portions are uniformly located on the same side of the axis AA'. The second metal layer has a periodic or non-periodic artificial surface plasmon structure on the outer side of the sidewall of the horizontal waveguide channel. The artificial surface plasmon structure is achieved by setting periodic or non-periodic etched grooves on the outer side of the sidewall of the horizontal waveguide channel. A protrusion is provided between two adjacent etched grooves, and the protrusion is electrically connected to the outer side of the sidewall of the horizontal waveguide channel.

[0010] Furthermore, the radiation ports may include any number other than four, and each short rectangular port may have a different size, or may be partially the same.

[0011] Further defined, the first long slit and the second long slit are located on both sides of the axis AA', and their vertical projections are located outside the horizontal waveguide channel. The dimensions of the first long slit and the second long slit can be completely identical or different, and their distances from the axis AA' can be equal or unequal. Each long slit includes a through portion and a non-through portion. The through portion penetrates the first metal layer and has a thickness of h1 and a width of w1. The non-through portion is disposed on the front side of the first metal layer and has a thickness of h2 and a width of w2. The through portion and the non-through portion are tangent along their partial edges to form a whole.

[0012] Further, the values ​​of the two h1s and the two h2s can be equal or unequal, and the values ​​of w1s and w2s can be equal or unequal.

[0013] Furthermore, the horizontal waveguide channel is configured in a straight structure, or it may be configured in a curved structure.

[0014] Furthermore, the back side of the second metal layer is also provided with periodic or non-periodic artificial surface plasmon structures around the first waveguide port. The protruding part of the artificial surface plasmon structure is electrically connected to the side wall of the first waveguide port, and the second metal layer is provided with a metal fence around the outer perimeter of the first waveguide port.

[0015] Furthermore, the height of the protrusion can be equal to or different from the sidewall of the horizontal waveguide channel; the width and depth of two adjacent etched grooves can be equal or unequal; and the shape of the protrusion and etched groove can be rectangular, elliptical, semi-circular, triangular, etc.

[0016] Furthermore, the horizontal waveguide channel is provided with a matching stub at the junction of its starting end and the vertical waveguide channel. The matching stub is located on the bottom side of the horizontal waveguide channel and is electrically connected to the bottom side. The starting end of the matching stub extends to the inner side of the vertical waveguide channel, and the end is in the shape of a trumpet or rectangle, etc.

[0017] Further specified, the second metal layer has a first metal wall and a second metal wall on both sides of the end of the horizontal waveguide channel. The first metal wall is located on one side of the end of the horizontal waveguide channel and is at the same height as the horizontal waveguide channel. The length of the first metal wall is equal to, slightly longer than or slightly shorter than the length of the first long slot. The second metal wall is located on the other side of the end of the horizontal waveguide channel and is at the same height as the sidewall of the horizontal waveguide channel. In addition, the length of the second metal wall is slightly shorter than the length of the second long slot and passes through the second long slot vertically upward. The first metal wall can be rectangular or can be a periodic or non-periodic corrugated groove provided on the side of the sidewall near the horizontal waveguide channel. The second metal wall and the radiation port form a beam deflection.

[0018] Further specifying, the first metal layer can be made by stamping copper plate, or by metallizing the surface of plastic molding, or by CNC process. The second metal layer can be made by CNC process or by metallizing the surface of plastic molding. The first metal layer and the second metal layer are fixed by screwing, riveting or welding.

[0019] The beneficial effects of this invention are as follows: 1. The waveguide deflecting beam antenna of the present invention can effectively reduce manufacturing precision, reduce processing degree, and save processing cost. Moreover, the waveguide antenna has a deflecting beam function, which is very suitable for specific angle detection applications of angle radar.

[0020] 2. The waveguide-biased beam antenna of the present invention is mainly used in the millimeter-wave region (30GHz-300GHz), but the present invention also has advantages in frequencies above 300GHz or below 30GHz. Attached Figure Description

[0021] The present invention can be further illustrated by the non-limiting embodiments given in the accompanying drawings; Figure 1 This is a schematic diagram of the structure of a waveguide antenna device according to an embodiment of the present invention; Figure 2 These are front and rear views of the first metal layer of a waveguide antenna device according to an embodiment of the present invention; Figure 3 This is a detailed view and a cross-sectional view of a long slot in the first metal layer of a waveguide antenna device according to an embodiment of the present invention, wherein the dashed box represents the cross-section; Figure 4 This is a detailed view and a cross-sectional view of a short rectangular opening in the first metal layer of a waveguide antenna device according to an embodiment of the present invention, wherein the dashed box represents the cross-section; Figure 5 The images show a front view and a rear view of a short rectangular opening in the first metal layer of a waveguide antenna device according to an embodiment of the present invention. Figure 6These are front and rear views of the second metal layer of a waveguide antenna device according to an embodiment of the present invention; Figure 7 This is a side view of a waveguide antenna device according to an embodiment of the present invention; Figure 8 This is a perspective structural diagram of a waveguide antenna device according to an embodiment of the present invention; Figure 9 This is an exploded structural diagram of a waveguide antenna device according to an embodiment of the present invention; Figure 10 This is a detailed view of the long slit and short rectangular opening of the first metal layer of a waveguide antenna device according to an embodiment of the present invention after it has been split into two layers. Figure 11 This is a schematic diagram of the overall structure of a waveguide-deflected beam antenna according to an embodiment of the present invention; Figure 12 The above is a schematic diagram of a four-transmitter, four-receiver array antenna structure composed of antenna units provided in Embodiment 1, Embodiment 2, or Embodiment 3 of the present invention. Figure 13 The reflection coefficient of a waveguide-biased beam antenna of a waveguide antenna device according to an embodiment of the present invention; Figure 14 This is a gain radiation pattern of a waveguide antenna device according to an embodiment of the present invention; The symbols for the main components are explained below: First metal layer 1, second metal layer 2; Radiation port 3, first short rectangular port 301, second short rectangular port 302, third short rectangular port 303 and fourth short rectangular port 304; First long gap 41, second long gap 42; 5. Long slit cross section; 6. Short rectangular opening cross section; 7. Horizontal waveguide channel; 8. Vertical waveguide channel; 9. Matching stub; 10. Sidewall; 11. Protrusion; 12. Etched groove; 13. First waveguide opening; 14. Metal fence; 15. First metal wall; 16. Second metal wall; 17. Front side of first metal layer; 18. Back side of first metal layer; 19. Front side of second metal layer; 20. Back side of second metal layer. The upper layer 1a after the first metal layer is split, the lower layer 1b after the first metal layer is split, the upper layer 41a with a long gap after the first metal layer is split, the lower layer 41b with a long gap after the first metal layer is split, the upper layer 301a with a short rectangular opening after the first metal layer is split, and the lower layer 301b with a short rectangular opening after the first metal layer is split. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0023] For waveguide antennas operating at high frequencies, existing waveguide antennas have high requirements for assembly processes, or cannot be manufactured at low cost with the required tolerances, failing to meet the requirements in terms of process and cost. Furthermore, conventional radar antenna beam patterns cannot accurately cover targets to the sides and rear of a vehicle, exhibiting limitations. To solve the above technical problems, according to an embodiment of the present invention, a gapped waveguide deflected beam antenna is proposed, comprising: A first metal layer, a second metal layer, wherein... The first metal layer is provided with a radiation port for signal reception or radiation. In this invention, the radiation port is composed of four short rectangular ports, which penetrate the first metal layer. In addition, long slots are provided on both sides of the radiation port in the first metal layer. One or two long slots are provided on each side of the radiation port along the signal transmission direction. The long slots can be used to suppress surface waves of electromagnetic signals, thereby enhancing the radiation performance of the antenna.

[0024] A horizontal waveguide channel is provided on the front side of the second metal layer, with the end of the horizontal waveguide channel facing the radiation port of the first metal layer. In addition, a metal wall is provided on the outside of the end of the horizontal waveguide channel.

[0025] According to another aspect of the invention, an artificial surface plasmon structure is further provided on the outer sidewall of the horizontal waveguide channel. This structure is composed of alternating periodic or non-periodic protrusions and grooves, and the protrusions are electrically connected to the outer sidewall of the horizontal waveguide channel. Furthermore, the beginning of the horizontal waveguide channel is connected to a first port through a vertical channel penetrating the second metal layer. The first waveguide port is used to connect to the transmitting or receiving end of the radio frequency chip. Example

[0026] In this first embodiment, see Figure 1 This is a schematic diagram of the waveguide-biased beam antenna structure according to Embodiment 1 of the present invention, which includes two parts: a first metal layer 1 and a second metal layer 2.

[0027] like Figure 2 These are the front and rear views of the first metal layer in Embodiment 1, wherein... Figure 2 (a) is a front view of the first metal layer. Figure 2 (b) is a rear view of the first metal layer, which is provided with a radiation port 3 and long slots 41 and 42 that can suppress surface waves; the radiation port 3 includes four short rectangular ports (301-304), which form the ports for radiating / receiving signals of the antenna.

[0028] See Figure 2 The four short rectangular ports are symmetrically distributed along the axis AA' of the horizontal waveguide channel signal transmission direction.

[0029] like Figure 4The four short rectangular openings are represented separately by short rectangular opening 301 for the purpose of analyzing their characteristics. Each short rectangular opening consists of two parts: one is a portion that penetrates the first metal layer, with a thickness of h1 and a width of a1; the other is a portion that does not penetrate the first metal layer, with a thickness of h2 and a width of a11, and these two portions are tangent along their partial edges. The sizes of h1 and h2 can be equal or unequal; the size of a1 is always greater than the size of a11; the sum of h1 and h2 is equal to the thickness h of the first metal layer.

[0030] The portions of the short rectangular opening that penetrate the first metal layer are staggered along the axis AA', while the portions that do not penetrate the first metal layer are uniformly located on the same side of the axis AA'.

[0031] Figure 5 (a) A front view of the short rectangular opening 301 is given. Figure 5 (b) A rear view of the short rectangular opening 301 is given. In different embodiments, the size of each short rectangular opening may be different or may be partially the same.

[0032] The radiation port given in this embodiment includes four short rectangular ports. Of course, the number of short rectangular ports can be any number other than the four in this invention.

[0033] like Figure 3 In this embodiment, the long gap in the middle, Figure 4 The long slot is one of the long slots 41 and 42 in the first metal layer.

[0034] The dimensions of the different long slits can be completely identical or inconsistent, and their distances from the axis AA' can be equal or unequal. Furthermore, each long slit consists of two parts: one is a portion penetrating the first metal layer, with a thickness of h1 and a width of w1; the other is a portion not penetrating the first metal layer, with a thickness of h2 and a width of w2, and these two parts are tangent along their partial edges to form a single unit. The h1 and h2 of the long slits are also the h1 and h2 of the four short rectangular openings. Therefore, the sizes of h1 and h2 can be equal or unequal; the size of w1 is always greater than the size of w2; the sum of h1 and h2 is equal to the thickness h of the first metal layer.

[0035] like Figure 6 , is the second metal layer in Example 1, wherein Figure 6 (a) is the front side of the second metal layer. Figure 6 (b) shows the back side of the second metal layer. From Figure 6 (a) It can be seen that a horizontal waveguide channel is provided on the front side of the second metal layer, from Figure 6(b) It can be seen that a first waveguide port is provided on the back side of the second metal layer. In addition, a vertical waveguide channel is provided through the second metal layer, wherein one end of the vertical waveguide channel is electrically connected to the first waveguide port, and the other end is electrically connected to the beginning of the horizontal waveguide channel. The first metal layer and the horizontal waveguide channel are stacked one on top of the other to form a rectangular waveguide transmission line.

[0036] The beginning of the horizontal waveguide channel on the front side of the second metal layer is connected to one end of the vertical waveguide channel and connected to the first waveguide port. Its end is located below the radiation port, and the axis along the signal transmission direction of the horizontal waveguide channel is the AA' line.

[0037] Horizontal waveguide channels can be straight or curved. The outer sidewalls of horizontal waveguide channels are provided with periodic or non-periodic artificial surface plasmon structures.

[0038] Artificial surface plasmon structures are achieved by setting periodically or non-periodically etched grooves on the outer sidewall of a horizontal waveguide channel, with protrusions between adjacent grooves electrically connected to the outer sidewall of the horizontal waveguide channel.

[0039] The height of the protrusion can be the same as or different from the sidewall of the horizontal waveguide channel; the width and depth of adjacent grooves can be equal or unequal. The shape of the protrusion and groove can be rectangular, elliptical, semi-circular, triangular, etc.

[0040] like Figure 6 (b) A first waveguide port on the back side of the second metal layer is surrounded by periodic or non-periodic artificial surface plasmon structures. The protruding portion of this artificial surface plasmon structure is electrically connected to the sidewall of the first waveguide port, and its height can be the same as or different from the sidewall of the first waveguide port. At the same time, the shapes of adjacent grooves can be the same or different. In addition, a metal fence is also provided around the first waveguide port.

[0041] like Figure 6 (a) A matching stub is provided at the junction of the beginning of the horizontal waveguide channel and the vertical waveguide channel, wherein: the matching stub is located on the bottom side of the horizontal waveguide channel and is electrically connected to the bottom side; the beginning of the matching stub extends to the inner side of the vertical waveguide channel, and the end is in the shape of a horn or a rectangle, etc. Metal walls are provided on both sides of the end of the horizontal waveguide channel in the second metal layer, wherein: the first metal wall is located on one side of the end of the horizontal waveguide channel and is at the same height as the horizontal waveguide channel, and the length of the first metal wall is equal to, slightly longer than or slightly shorter than the length of the first long slot; the second metal wall is located on the other side of the end of the horizontal waveguide channel and is at the same height as the side wall of the horizontal waveguide channel, and the length of the second metal wall is slightly shorter than the length of the second long slot, and passes through the second long slot vertically upward; the first metal wall can be rectangular, or it can be a periodic or non-periodic corrugated groove provided on the side of the side wall near the horizontal waveguide channel.

[0042] Figure 7 A side view of Embodiment 1 is provided. Figure 8 A perspective view of Embodiment 1 is provided. The elongated slits 41 and 42 are located on either side of axis AA', and their vertical projections lie outside the horizontal channel. The shapes of the second metal wall and the radiating aperture allow for antenna beam deflection.

[0043] When the first and second metal layers are stacked one on top of the other, there may be a gap, a partial gap, or a seamless connection between them. Since the outer sidewall of the horizontal waveguide channel has an artificial surface plasmon structure, there is no energy leakage. Example

[0044] like Figure 9 This is an exploded view of the waveguide deflection beam structure in Example 2.

[0045] Compared to Embodiment 1, Embodiment 2 also has a two-layer structure, namely a first metal layer and a second metal layer. The second metal layer in Embodiment 2 is the same as the second metal layer in Embodiment 1, but the first metal layer in Embodiment 2 is different from the first metal layer in Embodiment 1. Specifically, the first metal layer in Embodiment 1 is separated by a boundary with thicknesses h1 and h2, so that the first metal layer becomes two layers with the thickness of the upper layer being h1 and the thickness of the lower layer being h2.

[0046] therefore, Figure 3 and Figure 4 The long slit and short rectangular opening in the original form become, as in the second embodiment of this invention. Figure 10 The shape. Figure 3 The portion of the medium-length slit that does not penetrate the first metal layer becomes Figure 10 41a, which penetrates the first metal layer, and Figure 3 The portion that penetrates the first metal layer becomes Figure 10 41b in the middle. Figure 4 The portion of the short rectangular opening that does not penetrate the first metal layer becomes Figure 10 301a, which penetrates the first metal layer, and Figure 3 The portion that penetrates the first metal layer becomes Figure 10 301b in the middle.

[0047] The first metal layer is divided into two parts, which are connected from top to bottom by screws. Example

[0048] like Figure 11 These are the front and rear views of the second metal layer of the waveguide-biased beam antenna in Embodiment 3. Both Embodiment 3 and Embodiment 1 employ a two-layer structure design, with the first metal layer identical to the first embodiment. The only difference lies in the second metal layer: in Embodiment 3, the vertical waveguide channel in the second metal layer is changed from the double-ridged waveguide in Embodiment 1 to a rectangular waveguide.

[0049] Figure 12 A four-transmitter, four-receiver antenna array is provided based on the antenna elements in the three embodiments described above. Of course, other numbers of array antennas can also be formed using the antenna elements in the three embodiments described above.

[0050] The operating frequency band for automotive millimeter-wave radar is generally 76-81 GHz, while... Figure 13 The simulated reflection coefficient diagram of the gap waveguide-biased beam antenna of Embodiment 1 is given. Figure 13 It is known that the reflection coefficient bandwidth based on -10dB is 74.8-82GHz, achieving a working bandwidth of 7.2GHz. Moreover, the working bandwidth is much larger than the working bandwidth of millimeter-wave radar (76-81GHz), which leaves bandwidth redundancy for frequency offset caused by actual manufacturing tolerances.

[0051] Figure 14 The antenna gain radiation pattern of Example 1 is given. It can be seen that the sidelobe level of the antenna radiation pattern in the elevation direction is below -18dB, which provides strong anti-jamming capability for millimeter-wave radar to detect targets in the elevation direction. In the azimuth direction, the maximum gain is located at 45°, which provides strong antenna gain for angle radar to detect targets to the side and rear. At the same time, the gain in the -75° direction is also higher than 2dBi, ensuring the detection of close-range targets at large angles.

[0052] The first metal layer 1 can be made by stamping copper plate, or by metallizing the surface of plastic after molding, or by CNC process; the second metal layer 2 can be made by CNC process, or by metallizing the surface of plastic after molding. The first metal layer 1 and the second metal layer 2 can be fixed by screwing, riveting or welding.

[0053] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A waveguide antenna device, characterized in that: It includes a first metal layer (1) and a second metal layer (2); The first metal layer (1) is provided with a radiation port (3), and the first metal layer (1) is provided with at least one first long slit (41) and a second long slit (42) on each side of the radiation port (3) to suppress surface waves. The front side (19) of the second metal layer (2) is provided with a horizontal waveguide channel (7), and the back side (20) of the second metal layer (2) is provided with a first waveguide port (13). The second metal layer (2) is provided with a vertical waveguide channel (8), which penetrates the second metal layer (2). One end of the vertical waveguide channel (8) is electrically connected to the first waveguide port (13), and the other side of the vertical waveguide channel (8) is electrically connected to the beginning of the horizontal waveguide channel (7). The end of the horizontal waveguide channel (7) is located below the radiation port (3), and the axis along the signal transmission direction of the horizontal waveguide channel (7) is the AA' line. The first metal layer (1) and the horizontal waveguide channel (7) constitute a rectangular waveguide transmission line. The radiation port (3) includes a first short rectangular port (301), a second short rectangular port (302), a third short rectangular port (303), and a fourth short rectangular port (304). The first short rectangular port (301), the second short rectangular port (302), the third short rectangular port (303), and the fourth short rectangular port (304) are symmetrically distributed along the axis AA' of the signal transmission direction of the horizontal waveguide channel (7). The first short rectangular port (301), the second short rectangular port (302), the third short rectangular port (303), and the fourth short rectangular port (304) are symmetrically distributed along the axis AA' of the signal transmission direction of the horizontal waveguide channel (7). 3) The vertical projection of the fourth short rectangular aperture (304) is located in the horizontal waveguide channel (7). Each short rectangular aperture includes a through portion and a non-through portion. The through portion is set on the first metal layer (1) with a thickness of h1 and a width of a1. The non-through portion is set on the front side (17) of the first metal layer (1) with a thickness of h2 and a width of a11. The through portion and the non-through portion are tangent to each other along their partial edges. The through portions are symmetrically distributed along the axis AA', and the non-through portions are uniformly located on the same side of the axis AA'. The second metal layer (2) has a periodic or non-periodic artificial surface plasmon structure on the outside of the sidewall (10) of the horizontal waveguide channel (7). The artificial surface plasmon structure is achieved by setting periodic or non-periodic etching grooves (12) on the outside of the sidewall (10) of the horizontal waveguide channel (7). A protrusion (11) is provided between two adjacent etching grooves (12), and the protrusion (11) is electrically connected to the outside of the sidewall (10) of the horizontal waveguide channel (7).

2. The waveguide antenna device according to claim 1, characterized in that: The radiation port (3) may include any number other than four, and the size of each short rectangular port may be different or partially the same.

3. The waveguide antenna device according to claim 2, characterized in that: The first long slit (41) and the second long slit (42) are located on both sides of the axis AA', and their vertical projection is outside the horizontal waveguide channel (7). The dimensions of the first long slit (41) and the second long slit (42) can be completely the same or different, and their distances from the axis AA' can be equal or unequal. Each long slit includes a through part and a non-through part. The through part penetrates the first metal layer (1) with a thickness of h1 and a width of w1. The non-through part is set on the front side (17) of the first metal layer (1) with a thickness of h2 and a width of w2. The through part and the non-through part are tangent along their partial edges to form a whole.

4. A waveguide antenna device according to claim 3, characterized in that: The values ​​of h1 and h2 can be equal or unequal, and the values ​​of w1 and w2 can be equal or unequal.

5. A waveguide antenna device according to claim 4, characterized in that: The horizontal waveguide channel (7) is arranged in a straight structure, and the horizontal waveguide channel (7) can also be arranged in a curved structure.

6. A waveguide antenna device according to claim 5, characterized in that: The back side (20) of the second metal layer (2) is also provided with periodic or non-periodic artificial surface plasmon structures around the first waveguide port (13). The protruding part of the artificial surface plasmon structure is electrically connected to the side wall of the first waveguide port (13). The second metal layer (2) is provided with a metal fence (14) around the outer perimeter of the first waveguide port (13).

7. A waveguide antenna device according to claim 6, characterized in that: The height of the protrusion (11) can be equal to or different from the sidewall (10) of the horizontal waveguide channel (7). The width and depth of two adjacent etching grooves (12) can be equal or different. The shape of the protrusion (11) and the etching groove (12) can be rectangular, elliptical, semicircular, triangular, etc.

8. A waveguide antenna device according to claim 7, characterized in that: The horizontal waveguide channel (7) is provided with a matching stub (9) at the junction of its beginning and the vertical waveguide channel (8). The matching stub (9) is located on the bottom side of the horizontal waveguide channel (7) and is electrically connected to the bottom side. The beginning of the matching stub (9) extends to the inner side of the vertical waveguide channel (8), and the end is in the shape of a trumpet or a rectangle.

9. A waveguide antenna device according to claim 8, characterized in that: The second metal layer (2) has a first metal wall (15) and a second metal wall (16) on both sides of the end of the horizontal waveguide channel (7). The first metal wall (15) is located on one side of the end of the horizontal waveguide channel (7) and is at the same height as the horizontal waveguide channel (7). The length of the first metal wall (15) is equal to or slightly longer than the length of the first long slot (41). The second metal wall (16) is located on the other side of the end of the horizontal waveguide channel (7) and is at the same height as the side wall of the horizontal waveguide channel (7). In addition, the length of the second metal wall (16) is slightly shorter than the length of the second long slot (42) and passes through the second long slot (42) vertically upward. The first metal wall (15) can be rectangular or can be a periodic or non-periodic corrugated groove (12) provided on one side of the side wall (10) near the horizontal waveguide channel (7). The second metal wall (16) forms a beam deflection with the radiation port (3).

10. A waveguide antenna device according to claim 9, characterized in that: The first metal layer (1) can be made by stamping copper plate, or by metallizing the surface of plastic after molding, or by CNC process. The second metal layer (2) can be made by CNC process, or by metallizing the surface of plastic after molding. The first metal layer (1) and the second metal layer (2) are fixed by screwing, riveting or welding.

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