Low-sidelobe gap waveguide slot antenna based on artificial surface plasmon

Abstract

The utility model discloses a low side lobe gap waveguide slot antenna based on artificial surface plasmon, which comprises a first metal layer and a second metal layer which are oppositely stacked, and a gap is arranged on the joint surface of the two metal layers. One end of the antenna is electrically connected to a first waveguide port having a receiving / transmitting signal, and the other end is connected to the radiation opening as a radiation / receiving end of a radio frequency signal. The antenna comprises a horizontal waveguide channel and a vertical waveguide channel, and a matching branch knot is arranged in the horizontal waveguide channel. And an artificial surface plasmon structure is arranged on the outer side of the side wall of the horizontal waveguide channel. According to the utility model, the artificial surface plasmon structure is arranged, so that when a gap exists between the first metal layer and the second metal layer, electromagnetic energy is bound around the artificial surface plasmon, thereby ensuring that the electromagnetic energy can be completely transmitted along an expected direction. The antenna scheme provided by the utility model has great advantages for assembly tolerance redundancy and cost control during mass production.

Description

TECHNICAL FIELD

[0001] The utility model belongs to technical field, concretely relates to a kind of low side lobe gap waveguide slot antennas based on artificial surface plasmon. BACKGROUND

[0002] In recent years, people have higher and higher requirements on information transmission capacity and quality, and the waveguide antenna of millimeter wave frequency band can meet this requirement. Especially in higher-order intelligent driving system, 4D millimeter wave radar is favored due to multi-channel and all-weather, high-performance advantages.

[0003] However, the traditional waveguide antenna has great difficulty in processing and assembling process, which will increase the cost, cannot meet the needs of process, power capacity, cost, anti-interference strength and other aspects, and is not conducive to wide application. UTILITY MODEL CONTENT

[0004] To solve the problems in the above background art, the utility model aims to provide a kind of low side lobe gap waveguide slot antennas based on artificial surface plasmon.

[0005] To achieve the above technical purpose, the utility model adopts the following technical scheme:

[0006] A kind of low side lobe gap waveguide slot antennas based on artificial surface plasmon, characterized by: including first metal layer and second metal layer;

[0007] The first metal layer is provided with radiation opening and a plurality of long rectangular openings for suppressing surface wave, the second metal layer is provided with horizontal waveguide channel on the surface towards the first metal layer, the first metal layer and the horizontal waveguide channel arranged in the second metal layer form a rectangular waveguide transmission line, the end of the horizontal waveguide channel is vertically projected on the radiation opening of the first metal layer, the second metal layer is provided with vertical waveguide channel at the beginning of horizontal waveguide channel, the back surface of the second metal layer is provided with first waveguide port, and the first waveguide port is connected with the beginning of horizontal waveguide channel through vertical waveguide channel.

[0008] Further limited, the radiation opening includes first short rectangular opening, second short rectangular opening, third short rectangular opening, fourth short rectangular opening and fifth short rectangular opening, the first short rectangular opening, second short rectangular opening, third short rectangular opening, fourth short rectangular opening and fifth short rectangular opening are cross-symmetrically distributed along the axis of horizontal waveguide channel signal transmission direction, and the vertical projection of the five short rectangular openings is located in the horizontal waveguide channel;

[0009] The length and width of the first short rectangular opening and the fifth short rectangular opening are completely consistent, and the first short rectangular opening and the fifth short rectangular opening are located on the same side of the axis of horizontal waveguide channel signal transmission direction, and the distance from the axis is equal.

[0010] The length and width of the second short rectangular opening and the fourth short rectangular opening are completely consistent, and the second short rectangular opening and the fourth short rectangular opening are located on the same side of the axis of the horizontal waveguide channel signal transmission direction and are equal in distance from the axis, the size of the second short rectangular opening and the fourth short rectangular opening is inconsistent with the first short rectangular opening and the fifth short rectangular opening, and is located on different sides of the axis and is also not equal in distance from the axis;

[0011] The length and width of the third short rectangular opening are different from the first short rectangular opening, the second short rectangular opening, the fourth short rectangular opening and the fifth short rectangular opening, and the third short rectangular opening is located on the same side of the axis of the horizontal waveguide channel signal transmission direction as the first short rectangular opening and the fifth short rectangular opening, but the distance from the axis is different.

[0012] Further limited, the number of radiation openings is one or more, and the odd-numbered short rectangular openings in the radiation openings are located on the same side of the axis, and the even-numbered short rectangular openings are located on the other side of the axis, and the odd-numbered short rectangular openings and the even-numbered short rectangular openings are distributed symmetrically along the axis; the size of the first short rectangular opening, the second short rectangular opening, the third short rectangular opening, the fourth short rectangular opening and the fifth short rectangular opening can also be completely consistent, and the distance from the axis is also the same.

[0013] Further limited, the long rectangular openings are symmetrically arranged on both sides of the radiation openings along the axis, and the distance between the long rectangular openings on both sides and the axis is equal or unequal, and the long rectangular openings on both sides can be arranged in equal length or unequal length, the number of long rectangular openings arranged on both sides of the axis is one or more, and the vertical projection of the long rectangular opening cannot be located in the horizontal waveguide channel.

[0014] Further limited, the horizontal waveguide channel is arranged in a curved structure and can also be arranged in a straight structure, the horizontal waveguide channel and the first metal layer form a complete rectangular waveguide transmission line, and the first metal layer and the second metal layer are in complete electrical connection, or partial electrical connection, or there is a gap.

[0015] Further limited, the first waveguide port and the horizontal waveguide channel are provided with artificial surface plasmon structure on the outer side wall perpendicular to the second metal layer, the artificial surface plasmon structure includes a plurality of grooves arranged on the outer side wall of the horizontal waveguide channel, and a protrusion is arranged between two adjacent grooves; the shape of the protrusion and the groove is rectangular, oval, semicircle or triangle.

[0016] Further limited, the horizontal waveguide channel is provided with a matching stub at the junction with the vertical waveguide channel, the matching stub is arranged on the bottom side of the horizontal waveguide channel and is electrically connected with the bottom side of the horizontal waveguide channel, the beginning end of the matching stub extends into the vertical waveguide channel or extends to the edge of the vertical waveguide channel, and the tail end is provided in a horn structure.

[0017] Further limited, the second metal layer is symmetrically provided with a metal strip on both sides of the radiation opening, the metal strip is provided in a rectangular structure, and the metal strip can also be provided with a corrugated groove on the side wall close to one side of the horizontal waveguide channel, and the distance between the metal strip and the outer side wall of the horizontal waveguide channel is at least 0.3mm.

[0018] Further limited, the long rectangular opening is arranged between the metal strip and the horizontal waveguide channel.

[0019] Further limited, the first metal layer is punched by a copper plate, or is produced by plastic molding, surface metallization or a CNC process, the second metal layer is produced by a CNC process or plastic molding, surface metallization, and the first metal layer and the second metal layer can be fixedly connected through a screwing, riveting or welding process.

[0020] The low side lobe gap waveguide slot antenna based on artificial surface plasmons has the advantages that the manufacturing precision can be effectively reduced, the processing and manufacturing degree is reduced, the processing cost is saved, the waveguide antenna has low lobe, has strong anti-interference ability, has wide working bandwidth and is very suitable for high-frequency application, is mainly used in a millimeter wave region (30GHz-300GHz), but the low side lobe gap waveguide slot antenna based on artificial surface plasmons also has advantages at frequencies higher than 300GHz or lower than 30GHz. BRIEF DESCRIPTION OF DRAWINGS

[0021] The low side lobe gap waveguide slot antenna based on artificial surface plasmons can be further illustrated through the non-limiting embodiments shown in the drawings.

[0022] Figure 1 It is a whole structure schematic view of the low side lobe gap waveguide slot antenna based on artificial surface plasmons.

[0023] Figure 2 It is a first metal layer front view and rear view of the low side lobe gap waveguide slot antenna based on artificial surface plasmons.

[0024] Figure 3 It is a second metal layer front view and rear view of the low side lobe gap waveguide slot antenna based on artificial surface plasmons.

[0025] Figure 4(a) is the first waveguide port view of the low-sidelobe gap waveguide slot antenna based on artificial surface plasmons of the utility model embodiment; Figure 4 (b) is the second waveguide port view of the low-sidelobe gap waveguide slot antenna based on artificial surface plasmons of the utility model embodiment; Figure 4 (a) is the structure diagram of the first waveguide port periphery loading a circle of metal isolation belt;

[0026] Figure 5 (a) is the front view of the vertical waveguide of the utility model embodiment; Figure 5 (b) is the rear view of the vertical waveguide of the utility model embodiment;

[0027] Figure 6 (a) is the front view of the second metal layer of the low-sidelobe gap waveguide slot antenna based on artificial surface plasmons of the utility model embodiment;

[0028] Figure 7 (a) is the first variant diagram of the transmission line in the low-sidelobe gap waveguide slot antenna based on artificial surface plasmons of the utility model embodiment;

[0029] Figure 8 (a) is the second variant diagram of the transmission line in the low-sidelobe gap waveguide slot antenna based on artificial surface plasmons of the utility model embodiment;

[0030] Figure 9 (a) is the third variant diagram of the transmission line in the low-sidelobe gap waveguide slot antenna based on artificial surface plasmons of the utility model embodiment;

[0031] Figure 10 (a) is the front schematic diagram of the eight-transmitting and eight-receiving low-sidelobe gap waveguide slot array antenna based on artificial surface plasmons;

[0032] Figure 11 (a) is the front schematic diagram of the four-transmitting and four-receiving low-sidelobe gap waveguide slot array antenna based on artificial surface plasmons;

[0033] Figure 12 (a) is the reflection coefficient diagram of the low-sidelobe gap waveguide slot antenna based on artificial surface plasmons of the utility model embodiment;

[0034] Figure 13 (a) is the normalized radiation pattern of the low-sidelobe gap waveguide slot antenna based on artificial surface plasmons of the utility model embodiment;

[0035] Figure 14 (a) is the maximum sweep frequency gain in the working frequency band of the low-sidelobe gap waveguide slot antenna based on artificial surface plasmons of the utility model embodiment;

[0036] The main element symbol explanation is as follows:

[0037] First metal layer 1, second metal layer 2;

[0038] Radiation opening 3, first short rectangular opening 301, second short rectangular opening 302, third short rectangular opening 303, fourth short rectangular opening 304, fifth short rectangular opening 305;

[0039] Long rectangular opening 4, horizontal waveguide channel 5, vertical waveguide channel 6, first waveguide port 7, matching stub 8, metal strip 9, protrusion 10, groove 11, metal isolation strip 12, metal column 13, axis AA'. DETAILED DESCRIPTION

[0040] In order for those skilled in the art to better understand the present application, the technical solutions of the present application are further described below in conjunction with the drawings and examples.

[0041] Example one

[0042] In this example one, as shown in the drawings, the low-sidelobe gap waveguide slot antenna based on artificial surface plasmons of the present application comprises a first metal layer 1 and a second metal layer 2. Figure 1 As shown in the drawings, wherein,

[0043] The left side of the first metal layer 1 is a front view, Figure 2 The right side of the first metal layer 1 is a rear view, and the first metal layer 1 is provided with a radiation opening 3 and a plurality of long rectangular openings 4 for suppressing surface waves; the radiation opening 3 forms a port for radiating / receiving signals of the antenna through the short rectangular opening. Figure 2 Figure 2 As shown in the drawings, wherein, The left side of the second metal layer 2 is a front view,

[0044] The right side of the second metal layer 2 is a rear view, and the surface of the second metal layer 2 facing the direction of the first metal layer 1 is provided with a horizontal waveguide channel 5 whose end is perpendicular to the projection of the radiation opening 3, and the other side of the second metal layer 2 opposite to the first metal layer 1 is provided with a first waveguide port 7, wherein the first waveguide port 7 is connected to the beginning of the horizontal waveguide channel 5 through a vertical waveguide channel 6 penetrating the second metal layer 2, and the horizontal waveguide channel 5 provided in the first metal layer 1 and the second metal layer 2 constitutes a rectangular waveguide transmission line. Figure 3 Figure 3 Figure 3 In conjunction with

[0045] and Figure 2 Figure 3 ​​​In the first metal layer 1, the first short rectangular opening 301, the second short rectangular opening 302, the third short rectangular opening 303, the fourth short rectangular opening 304, and the fifth short rectangular opening 305 are formed, and the five short rectangular openings form the ports of the antenna for radiating / receiving signals. The other five short rectangular openings are symmetrically distributed along the axis AA' of the horizontal waveguide channel 5 signal transmission direction, and the vertical projections of the short rectangular openings are located in the horizontal waveguide channel.

[0046] In order to reduce the side lobe level of the antenna pattern in the elevation direction, the positions and sizes of the five short rectangular openings are designed to be different. Specifically, the length and width of the first short rectangular opening 301 and the fifth short rectangular opening 305 are completely consistent, and the first short rectangular opening 301 and the fifth short rectangular opening 305 are located on the same side of the axis AA' of the horizontal waveguide channel 5 signal transmission direction and are equidistant from the axis AA'. The length and width of the second short rectangular opening 302 and the fourth short rectangular opening 304 are completely consistent, and the second short rectangular opening 302 and the fourth short rectangular opening 304 are located on the same side of the axis AA' of the horizontal waveguide channel 5 signal transmission direction and are equidistant from the axis AA'. In addition, the sizes of the second short rectangular opening 302 and the fourth short rectangular opening 304 are different from those of the first short rectangular opening 301 and the fifth short rectangular opening 305, and the second short rectangular opening 302 and the fourth short rectangular opening 304 are located on different sides of the axis AA' and are not equidistant from the axis AA'. The length and width of the third short rectangular opening 303 are also completely different from those of the other four short rectangular openings, and the third short rectangular opening 303 is located on the same side of the axis AA' of the horizontal waveguide channel 5 signal transmission direction as the first short rectangular opening 301 and the fifth short rectangular opening 305, but the third short rectangular opening 303 is not equidistant from the axis AA'.

[0047] The number of radiation openings 3 can be one, two, three, four, six, etc. in addition to the five in the embodiment, and the odd-numbered short rectangular openings in the radiation openings 3 are located on the same side of the axis AA', and the even-numbered short rectangular openings are located on the other side of the axis AA'. In addition, the odd-numbered and even-numbered short rectangular openings are staggered on the two sides of the axis AA'. In addition, if the side lobe level of the antenna pattern in the elevation direction is not high, the sizes of all the short rectangular openings can be completely consistent, and the distances from the axis can also be the same.

[0048] In the first metal layer 1, long rectangular openings 4 are also provided on both sides of the radiation openings 3 along the axis AA', and the long rectangular openings 4 are symmetrically distributed about the axis AA' and are equidistant or not equidistant from the axis AA'. In addition, the long rectangular openings 4 on both sides of the axis AA' can be one, two, etc., and the vertical projections of the long rectangular openings 4 are located between the side walls of the horizontal waveguide channel 5 and the metal strips 9.

[0049] The second metal layer 2 is provided with a horizontal waveguide channel 5 on the side facing the first metal layer 1, the end of the horizontal waveguide channel 5 is opposite to the radiation opening 3 of the first metal layer 1, and the beginning of the horizontal waveguide channel 5 is connected to the first waveguide port 7 through a vertical waveguide channel 6 penetrating the second metal layer 2.

[0050] The horizontal waveguide channel 5 forms a complete rectangular waveguide transmission line with the first metal layer 1, and the first metal layer 1 and the second metal layer 2 can be completely electrically connected, partially electrically connected, or have a gap, and the horizontal waveguide channel 5 can be straight or curved.

[0051] In order to reduce assembly tolerance and cost, a periodic or non-periodic artificial surface plasmon structure is arranged on the outer side of the side wall of the horizontal waveguide channel 5 perpendicular to the horizontal plane of the second metal layer 2. This structure can confine the transmitted electromagnetic energy in the horizontal waveguide channel 5 when there is a gap between the first metal layer 1 and the second metal layer 2, and make the electromagnetic signal transmit in the desired direction.

[0052] The artificial surface plasmon structure is realized by etching periodic or non-periodic grooves 11 on the outer side of the side wall of the horizontal waveguide channel 5, and the protrusions 10 between adjacent grooves are electrically connected to the outer side of the side wall of the horizontal waveguide channel 5.

[0053] The height of the protrusions 20 perpendicular to the horizontal plane of the second metal layer 2 can be equal to or not equal to the height of the side wall of the horizontal waveguide channel 5; the width and depth of adjacent grooves 11 can be equal or not equal.

[0054] Metal strips 9 are further arranged at the end of the horizontal waveguide channel 5 and on both sides of the radiation opening 3, wherein the metal strips 9 are symmetrically distributed on both sides of the radiation opening 3 about the axis AA'; the metal strips 9 can be rectangular, or can be provided with periodic or non-periodic corrugated grooves on one side close to the side wall of the horizontal waveguide channel 5, and the metal strips 9 are kept at least 0.3 mm away from the outer side of the side wall of the horizontal waveguide channel 5; the vertical projection of the long rectangular opening 4 is located between the metal strips 9 and the side wall of the horizontal waveguide channel 5. In this way, the metal strips 9 and the long rectangular opening 4 can suppress surface waves, thereby improving the radiation performance of the antenna.

[0055] The first waveguide port 7 is further arranged on the second metal layer 2, which is located on the side opposite to the first metal layer 1, and a periodic or non-periodic artificial surface plasmon structure is arranged around the first waveguide port 7. The protrusions 10 of the artificial surface plasmon structure are partially electrically connected to the side wall of the first waveguide port 7, and the height of the protrusions 10 can be equal to or not equal to the height of the side wall of the first waveguide port 7, and the shapes of adjacent grooves 11 can be the same or different.

[0056] Whether it is the outer side of the horizontal waveguide channel 5 or the outer side of the first waveguide port 7, the shape of the protrusions 10 and grooves 11 contained in the artificial surface plasmon structure can be rectangular, elliptical, semi-circular, triangular, etc.

[0057] To improve antenna performance, a matching stub 8 is provided at the junction of the beginning of the horizontal waveguide channel 5 and the vertical waveguide channel 6. The matching stub 8 is located on the bottom side of the horizontal waveguide channel 5 and is electrically connected to the bottom side. The beginning of the matching stub 8 extends into the vertical waveguide channel 6 or to the edge of the vertical waveguide channel 6, and the end is horn-shaped.

[0058] This invention relates to a low-sidelobe gap waveguide slot antenna based on artificial surface plasmon resonances (ASPRINGS), which can also be configured in an array, such as a four-transmitter, four-receiver configuration (e.g.,...). Figure 11 As shown), eight launches and eight returns (as shown) Figure 10 The array shown also employs a two-layer structure, namely the first metal layer 1 and the second metal layer 2.

[0059] Figure 4 Detailed diagrams of the first waveguide port 7 in Embodiment 1 are provided, in which... Figure 4 (a) shows that the outer side of the first waveguide port 7 is an artificial surface plasmon structure, while Figure 4 (b) then in Figure 4 Based on (a), a metal isolation strip 12 is set at a certain distance on the outside of the artificial surface plasmon structure. In addition to the one ring shown in the figure, the number of rings of the metal isolation strip 12 can also be two rings, three rings, etc. This can better prevent energy leakage caused by the gap between the PCB and the waveguide antenna. In addition, the vertical waveguide channel 6 in Embodiment 1 is a double-ridge waveguide structure.

[0060] Example 2

[0061] like Figure 6 As shown,

[0062] Compared to Embodiment 1, Embodiment 2 also has a two-layer structure, namely a first metal layer 1 and a second metal layer 2. The first metal layer 1 in Embodiment 2 is the same as the first metal layer 1 in Embodiment 1. The second metal layer 2 in Embodiment 2 differs from the second metal layer 2 in Embodiment 1 in two ways: First, the vertical waveguide channel 6 in Embodiment 1 has a double-ridge structure, while in Embodiment 2, the structure of the vertical waveguide channel 6 changes from a double-ridge structure to a rectangular structure. Second, the starting end of the matching branch 8 in Embodiment 1 coincides with one of the double ridges of the vertical waveguide channel 6 in the vertical projection, while in Embodiment 2, the starting end of the matching branch 8 extends to the inside of the rectangular vertical waveguide channel. Apart from these two differences, the other designs are consistent with Embodiment 1.

[0063] The outer side of the first waveguide port 7 in Embodiment Two is provided with a metal isolation strip 12 on the outer side of the artificial surface plasmon structure at a certain distance, like Figure 5 (b), the number of turns of the metal isolation strip 12 can be one turn, two turns, etc. Figure 5 Figure 4 (b), the number of turns of the metal isolation strip 12 can be one turn, two turns, etc.

[0064] The assembly and working principle of the first metal layer 1 and the second metal layer 2 in Embodiment Two are consistent with those in Embodiment One.

[0065] Embodiment Three

[0066] As shown in Figure 6 Embodiment Three and the first two embodiments both adopt a two-layer structure design, and the first metal layer 1 is consistent with the first two embodiments, and the only difference is that the metal strip 9 on the surface of the second metal layer 2 in Embodiment Three is different from that in other embodiments, specifically, in Embodiment One, the metal strip 9 is provided with periodic or aperiodic grooves 11 on one side close to the side edge of the horizontal waveguide channel 5, while in Embodiment Three, the metal strip 9 is a regular rectangular metal strip.

[0067] Figure 7 is the first variant of all embodiments of the utility model, wherein Figure 7 (a) is to load periodic or aperiodic metal columns 13 above the side wall of the horizontal waveguide channel 5, in this case, the first metal layer 1 and the second metal layer 2 are designed without gap, Figure 7 (b) is to load periodic or aperiodic metal columns 13 above the protrusions 10 electrically connected with the side wall of the horizontal waveguide channel 5, the first metal layer 1 and the second metal layer 2 of this structure are also designed without gap;

[0068] Figure 8 is the second variant of all embodiments of the utility model, wherein Figure 8 (a) is a side view of the second variant, Figure 8 (b) is an oblique view of the second variant, the first metal layer 1 and the second metal layer 2 of this structure can be designed without gap or with gap, when the first metal layer 1 and the second metal layer 2 have gap, the electromagnetic energy will be bound by the artificial surface plasmon structures and the metal isolation strips on both sides of the horizontal waveguide channel 5, so as to ensure the transmission of electromagnetic energy in the desired direction.

[0069] Figure 9 is the third variant of all embodiments of the utility model, wherein Figure 9 (a) is a side view of the third variant, Figure 9 ​(b) is a perspective view of the third variant, the artificial surface plasmon structure is located on the inner side of the horizontal waveguide channel 5 side wall and is electrically connected with the side wall, and the metal column 13 is electrically connected above the protrusion 10 of the artificial surface plasmon structure, the first metal layer 1 and the second metal layer 2 of this structure can be designed without a gap or with a gap, when the first metal layer 1 and the second metal layer 2 have a gap, the electromagnetic energy will be bound by the artificial surface plasmon structures on both sides of the horizontal waveguide channel and the metal isolation belt, so as to ensure that the electromagnetic energy is transmitted in the desired direction.

[0070] The working frequency band applied to the vehicle-mounted millimeter wave radar is generally 76-81GHz, and in the Figure 12 The simulation reflection coefficient diagram of the artificial surface plasmon-based low-sidelobe gap waveguide slot antenna of embodiment one is given, from Figure 12 It is known that the reflection coefficient bandwidth with-10dB as the benchmark is from 74.5-82GHz, realizing a working bandwidth of 7.5GHz, and the working bandwidth is much larger than the working bandwidth 76-81GHz of the millimeter wave radar, which leaves a bandwidth redundancy for the frequency deviation caused by the tolerance of actual processing and manufacturing.

[0071] Figure 13 The antenna normalized radiation pattern of embodiment one is given, and it can be seen that the sidelobe level of the antenna radiation pattern in the elevation direction is lower than-20dB, which provides strong anti-interference capability for the 4D millimeter wave radar to detect the target in the elevation direction. Figure 14 The sweep frequency maximum gain in the working frequency band 76-81GHz of the vehicle-mounted millimeter wave radar is given, that is, the gain of the artificial surface plasmon-based low-sidelobe gap waveguide slot antenna of the utility model in the entire frequency band is excellent.

[0072] The above embodiments only exemplarily illustrate the principle and effect of the utility model, and are not used to limit the utility model. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and category of the utility model. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the utility model should be covered by the claims of the utility model.

Claims

1. An artificial surface plasmon based low side lobe gap waveguide slot antenna, characterized by: The first metal layer (1) and the second metal layer (2) are provided; The first metal layer (1) is provided with a radiation opening (3) and a plurality of long rectangular openings (4) for suppressing surface waves, the second metal layer (2) is provided with a horizontal waveguide channel (5) on the surface facing the first metal layer (1), the first metal layer (1) and the horizontal waveguide channel (5) provided in the second metal layer (2) form a rectangular waveguide transmission line, the end of the horizontal waveguide channel (5) is vertically projected on the radiation opening (3) of the first metal layer (1), the second metal layer (2) is provided with a vertical waveguide channel (6) at the beginning of the horizontal waveguide channel (5), and the back surface of the second metal layer (2) is provided with a first waveguide port (7) connected with the beginning of the horizontal waveguide channel (5) through the vertical waveguide channel (6).

2. The low side-lobe gap waveguide slot antenna based on artificial surface plasmons according to claim 1, wherein: The radiation opening (3) includes a first short rectangular opening (301), a second short rectangular opening (302), a third short rectangular opening (303), a fourth short rectangular opening (304) and a fifth short rectangular opening (305), the first short rectangular opening (301), the second short rectangular opening (302), the third short rectangular opening (303), the fourth short rectangular opening (304) and the fifth short rectangular opening (305) are symmetrically distributed along the axis (AA') of the signal transmission direction of the horizontal waveguide channel (5), and the vertical projections of the five short rectangular openings are located in the horizontal waveguide channel (5); The length and width of the first short rectangular opening (301) and the fifth short rectangular opening (305) are completely consistent, and the first short rectangular opening (301) and the fifth short rectangular opening (305) are located on the same side of the axis (AA') of the signal transmission direction of the horizontal waveguide channel (5) and have equal distances from the axis (AA'); The length and width of the second short rectangular opening (302) and the fourth short rectangular opening (304) are completely consistent, and the second short rectangular opening (302) and the fourth short rectangular opening (304) are located on the same side of the axis (AA') of the signal transmission direction of the horizontal waveguide channel (5) and have equal distances from the axis (AA'), the size of the second short rectangular opening (302) and the fourth short rectangular opening (304) is different from that of the first short rectangular opening (301) and the fifth short rectangular opening (305), and they are located on different sides of the axis (AA') and have different distances from the axis (AA'); The length and width of the third short rectangular opening (303) are different from those of the first short rectangular opening (301), the second short rectangular opening (302), the fourth short rectangular opening (304) and the fifth short rectangular opening (305), and the third short rectangular opening (303) is located on the same side of the axis (AA') of the signal transmission direction of the horizontal waveguide channel (5) as the first short rectangular opening (301) and the fifth short rectangular opening (305), but has a different distance from the axis (AA').

3. The low side-lobe gap waveguide slot antenna based on artificial surface plasmons according to claim 2, wherein: The number of the radiation openings (3) is one or more, and the odd-numbered short rectangular openings in the radiation openings (3) are located on the same side of the axis (AA'), the even-numbered short rectangular openings are located on the other side of the axis (AA'), and the odd-numbered short rectangular openings and the even-numbered short rectangular openings are distributed in cross symmetry along the axis (AA'). The sizes of the first short rectangular opening (301), the second short rectangular opening (302), the third short rectangular opening (303), the fourth short rectangular opening (304), and the fifth short rectangular opening (305) can also be completely consistent, and the distances from the axis are also the same.

4. The low side-lobe gap waveguide slot antenna based on artificial surface plasmons according to claim 3, wherein: The long rectangular openings (4) are symmetrically arranged on both sides of the radiation openings (3) along the axis (AA'), and the distances between the long rectangular openings (4) on both sides and the axis (AA') are equal or unequal. The long rectangular openings (4) on both sides can be arranged in equal length or unequal length. The number of the long rectangular openings (4) arranged on both sides of the axis (AA') is one or more, and the vertical projection of the long rectangular opening (4) cannot be located in the horizontal waveguide channel (5).

5. The artificial surface plasmon based low side lobe gap waveguide slot antenna according to claim 4, wherein: The horizontal waveguide channel (5) is arranged in a curved structure and can also be arranged in a straight structure. The horizontal waveguide channel (5) and the first metal layer (1) form a complete rectangular waveguide transmission line, and the first metal layer (1) and the second metal layer (2) are in complete electrical connection, partial electrical connection, or have a gap.

6. The artificial surface plasmon based low side lobe gap waveguide slot antenna according to claim 5, wherein: The first waveguide port (7) and the horizontal waveguide channel (5) are provided with an artificial surface plasmon structure on the outer side wall perpendicular to the second metal layer (2). The artificial surface plasmon structure includes a plurality of grooves (11) arranged on the outer side wall of the horizontal waveguide channel (5), and a protrusion (10) is arranged between two adjacent grooves (11). The shape of the protrusion (10) and the groove (11) is rectangular, elliptical, semicircular, or triangular.

7. The artificial surface plasmon based low side lobe gap waveguide slot antenna according to claim 6, wherein: The horizontal waveguide channel (5) is provided with a matching stub (8) at the junction with the vertical waveguide channel (6). The matching stub (8) is arranged on the bottom side of the horizontal waveguide channel (5) and is in electrical connection with the bottom side of the horizontal waveguide channel (5). The beginning end of the matching stub (8) extends into the vertical waveguide channel (6) or extends to the edge of the vertical waveguide channel (6), and the end is arranged in a horn structure.

8. The artificial surface plasmon based low side lobe gap waveguide slot antenna according to claim 7, wherein: The second metal layer (2) is symmetrically provided with a metal strip (9) on both sides of the radiation opening (3). The metal strip (9) is arranged in a rectangular structure. The metal strip (9) can also be provided with a corrugated groove on the side wall close to the horizontal waveguide channel (5). The distance between the metal strip (9) and the outer side wall of the horizontal waveguide channel (5) is at least 0.3 mm.

9. The artificial surface plasmon based low side lobe gap waveguide slot antenna according to claim 8, wherein: The long rectangular opening (4) is arranged between the metal strip (9) and the horizontal waveguide channel (5).

10. The artificial surface plasmon based low side lobe gap waveguide slot antenna according to claim 9, wherein: The first metal layer (1) is made by punching copper plate, or made by plastic molding and surface metallization, or made by CNC process, the second metal layer (2) is made by CNC process, or made by plastic molding and surface metallization, the first metal layer (1) and the second metal layer (2) can be fixedly connected by screwing, riveting or welding process.

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