Substrate integrated waveguide slot antenna

Abstract

The invention relates to the technical field of antennas, in particular to a substrate integrated waveguide slot antenna which comprises a first metal plate, a first plate body, a second metal plate, a second plate body and a third metal plate which are sequentially connected in a stacked mode in the first direction, and a coaxial probe is arranged on the first metal plate; the first plate body is provided with a first power divider and is also provided with a central through hole for a coaxial probe to pass through. A first coupling gap is formed in the second metal plate; the second plate body is provided with an impedance matching groove; the third metal plate is provided with a plurality of groups of gap units which are distributed in an array; on the basis of the substrate integrated waveguide slot antenna, the antenna is designed into a traveling wave antenna array in a series-feed mode, so that the antenna has the broadband characteristic, and meanwhile, the OSB problem of a series-feed antenna is solved by arranging the slot units arranged in an array.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a substrate integrated waveguide slot antenna. Background Art

[0002] With the rapid development of modern communication technology, especially the continuous advancement of applications such as millimeter wave radar, military radar, satellite communication, 5G and even future 6G communication, communication systems have put forward higher requirements on the performance of antennas. Substrate integrated waveguide slot antennas have been widely used in the above scenarios due to their advantages such as easy integration, high efficiency, compact structure, easy processing, diverse structural forms, low cost, and their antenna arrays can achieve high gain and low sidelobe performance. However, compared with some broadband antennas, the operating bandwidth of substrate integrated waveguide slot antennas is narrower, which limits their application in broadband communication systems.

[0003] The traveling wave antenna array is an antenna system composed of multiple antenna units arranged in a certain pattern, in which the current on each antenna unit is distributed in a traveling wave, that is, the electromagnetic wave fed into it will be in a traveling wave state. The traveling wave antenna array has the advantages of a wide operating frequency band, high directivity, low loss, high efficiency and flexible design. The traveling wave antenna array includes two forms: parallel feeding and series feeding. The feeding network structure of the parallel-fed array is complex, and the overall size of the antenna is large or the cross-section is high; the series-fed array has a simple structure and a small antenna size. Therefore, designing the substrate integrated waveguide slot antenna into a traveling wave antenna array in the form of series feeding can make its structure compact and have wide-band characteristics, which can better meet the requirements of the communication system. Summary of the invention

[0004] The purpose of the present application is to provide a substrate integrated waveguide slot antenna. On the basis of the substrate integrated waveguide slot antenna, it is designed into a traveling wave antenna array in the form of series feeding so that it has a wide-band characteristic. At the same time, a special matching structure is set to solve the OSB problem of the series-fed antenna.

[0005] To achieve the above-mentioned purpose, the present application adopts a substrate integrated waveguide slot antenna, comprising: a first dielectric plate and a second dielectric plate sequentially stacked and connected along a first direction;

[0006] The first dielectric plate comprises a first metal plate, a first plate body and a second metal plate, the first metal plate and the second metal plate are respectively attached to the lower surface and the upper surface of the first plate body, a coaxial probe is provided on a side surface of the first metal plate close to the first plate body, a central through hole for the coaxial probe to pass through is provided on the first plate body, a first power divider is also provided on the first plate body, the first power divider is provided with a plurality of output ports symmetrically arranged along a second direction, and the signal phases of the plurality of output ports are the same, a first coupling slot is provided on the second metal plate, and the first coupling slot is provided corresponding to the output port;

[0007] The second dielectric plate comprises a second plate body and a third metal plate, the third metal plate is attached to the upper surface of the second plate body, a side of the second metal plate away from the first plate body is attached to the second plate body, the second plate body is provided with a plurality of impedance matching slots distributed in an array, the third metal plate is provided with a plurality of groups of slot units distributed in an array, each group of the slot units comprises a radiation slot and two impedance matching slots, the two impedance matching slots are symmetrically arranged on both sides of the radiation slot, and the impedance matching slots are arranged in one-to-one correspondence with the impedance matching slots;

[0008] The first direction is perpendicular to the second direction.

[0009] As a preferred solution, the coaxial probe is arranged on the center line of the first metal plate.

[0010] As a preferred solution, the widths of the plurality of output ports gradually decrease from the middle to both sides along the third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other.

[0011] As a preferred embodiment, a plurality of first through holes and second through holes are provided on the first plate body, metal is affixed to the inner walls of the first through holes and the second through holes, the first through holes and the second through holes are both arranged on the same side of the first plate body, and the second through holes are arranged along the side edge of the first plate body, and the first metal plate, the second metal plate, the first through holes and the second through holes jointly define the first power divider.

[0012] As a preferred solution, a second power divider is further provided on the first plate, the first power divider and the second power divider are symmetrically distributed along the third direction, and the structures of the first and second power dividers are the same, and a second coupling slot is further provided on the second metal plate, and the second coupling slot is arranged corresponding to the output port of the second power divider.

[0013] As a preferred embodiment, a third through hole and a fourth through hole are provided on the second plate body, and metal is affixed to the inner walls of the third through hole and the fourth through hole. The third through hole is distributed in an array in the second plate body, and the fourth through hole is arranged along the peripheral side of the second plate body.

[0014] As a preferred solution, the signal phase difference between the first power divider and the second power divider is 180°.

[0015] As a preferred solution, the widths of the plurality of radiation slots and the plurality of impedance matching slots gradually decrease from the middle position to both sides and are symmetrical about the third direction.

[0016] As a preferred solution, the first metal plate, the first plate body, the second metal plate, the second plate body and the third metal plate are connected by screws.

[0017] As a preferred solution, the substrate integrated waveguide slot antenna is manufactured using a printed circuit board process.

[0018] The substrate integrated waveguide slot antenna provided by the above technical solution has the following beneficial effects compared with the prior art:

[0019] On the one hand, the present application sequentially stacks and connects the first metal plate, the first dielectric plate, the second metal plate, the second dielectric plate and the third metal plate from bottom to top, and sets the coaxial probe on the first metal plate. The coaxial probe transmits the signal to the first dielectric plate through the central through hole on the first plate body, and further transmits it to the output port of the first power divider, and transmits it to the second dielectric plate through the first coupling slot. The signal is transmitted to the impedance matching slot on the third metal plate through the impedance matching slot, and is transmitted to the radiation slot through the impedance matching slot. The energy wave is transmitted from one side of the slot unit to the other side thereof to form a traveling wave, so that the antenna has a wider operating frequency band, that is, it has a wide-band characteristic.

[0020] On the other hand, the slot unit is composed of a radiation slot and two impedance matching slots symmetrically arranged on both sides thereof. The multiple slot units are distributed in an array, and the multiple impedance matching slots correspond one-to-one to the multiple impedance matching slots. The one-to-one corresponding impedance matching slots and impedance matching slots can broaden the impedance bandwidth of the antenna to a certain extent, so that the antenna maintains good impedance matching performance in a wider frequency range, and reduces the influence of the OSB problem on the antenna performance; at the same time, this matching structure will affect the electromagnetic field distribution around the antenna, making it more uniform and stable, reducing energy reflection and scattering caused by electromagnetic field distortion, improving the radiation characteristics of the antenna, and suppressing the OSB problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present application is further described in detail below in conjunction with the accompanying drawings and preferred embodiments, but those skilled in the art will appreciate that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be used as a limitation on the scope of the present application. In addition, unless otherwise specified, the drawings are intended only to conceptually represent the composition or structure of the described objects and may contain exaggerated displays, and the drawings are not necessarily drawn to scale.

[0022] Figure 1 It is a structural schematic diagram of the antenna of the present invention;

[0023] Figure 2 is a schematic diagram of a first dielectric plate of the present invention;

[0024] Figure 3is a schematic diagram of a second dielectric plate of the present invention;

[0025] Figure 4 is a schematic diagram of a third metal plate of the present invention;

[0026] Figure 5 is a line graph of the reflection coefficient of the antenna array of the present invention;

[0027] Figure 6 is the radiation pattern of the antenna of the present invention;

[0028] Wherein: 1. first dielectric plate; 11. first metal plate; 110. coaxial probe; 12. second metal plate; 120. first coupling slot; 121. second coupling slot; 13. first plate body; 130. central through hole; 131. first through hole; 132. second through hole; 133. output port; 134. first power divider; 135. second power divider; 2. second dielectric plate; 21. second plate body; 210. third through hole; 211. fourth through hole; 212. impedance matching slot; 22. third metal plate; 220. slot unit; 221. radiation slot; 222. impedance matching slot. DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0030] In the description of the present application, it should be understood that the terms "front", "rear", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, in the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0031] See also Figure 1-5 , a substrate integrated waveguide slot antenna provided in an embodiment of the present application, comprising: a first dielectric plate 1 and a second dielectric plate 2 sequentially stacked and connected along a first direction;

[0032] The first dielectric plate 1 comprises a first metal plate 11, a first plate body 13 and a second metal plate 12, wherein the first metal plate 11 and the second metal plate 12 are respectively attached to the lower surface and the upper surface of the first plate body 13, a coaxial probe 110 is provided on a side surface of the first metal plate 11 close to the first plate body 13, a central through hole 130 is provided on the first plate body 13 for the coaxial probe 110 to pass through, a first power divider 134 is also provided on the first plate body 13, the first power divider 134 is provided with a plurality of output ports 133 symmetrically arranged along a second direction, and the signal phases of the plurality of output ports 133 are the same, a first coupling slot 120 is provided on the second metal plate 12, and the first coupling slot 120 is arranged corresponding to the output port 133;

[0033] The second dielectric plate 2 includes a second plate body 21 and a third metal plate 22, the third metal plate 22 is attached to the upper surface of the second plate body 21, the second metal plate 12 is attached to the second plate body 21 on one side away from the first plate body 13, the second plate body 21 is provided with a plurality of impedance matching slots 212 distributed in an array, the third metal plate 22 is provided with a plurality of groups of slot units 220 distributed in an array, each group of the slot units 220 includes a radiation slot 221 and two impedance matching slots 222, the two impedance matching slots 222 are symmetrically arranged on both sides of the radiation slot 221, and the impedance matching slots 222 are arranged in a one-to-one correspondence with the impedance matching slots 212;

[0034] The first direction is perpendicular to the second direction.

[0035] In this embodiment, screws are preferably used to sequentially stack and connect the first metal plate 11, the first plate body 13, the second metal plate 12, the second plate body 21 and the third metal plate 22, so that the overall structural connection is more stable. On the one hand, in the present application, the signal is emitted from the coaxial probe 110, and the coaxial probe 110 transmits the signal to the first plate body 13 through the central through hole 130, and then the signal flows from the middle of the first plate body 13 to the first power divider 134, and flows to the first coupling slot 120 through the output port 133 of the first power divider 134, so that the signal is transmitted from the first dielectric plate 1 to the second dielectric plate 2, and the signal flows to the radiation slot 221 through the impedance matching slot 212 and the impedance matching slot 222, forming a traveling wave in the second dielectric plate 2, so that the antenna has a wider operating frequency band to meet the requirements of broadband communication systems. On the other hand, please refer to Figure 5Based on the special structure of the slot unit 220, that is, each group of slot units 220 is composed of a radiation slot 221 and two impedance matching slots 222 symmetrically arranged on both sides thereof, the impedance matching slots 222 are arranged one by one corresponding to the impedance matching slots 212, and multiple slot units 220 are distributed in an array. This setting method widens the impedance bandwidth of the antenna to a certain extent. As shown in the reflection coefficient line graph, the reflection coefficient of the antenna is less than -10dB within the frequency range shown in the figure, which means that it can maintain good impedance matching performance within a wider frequency range, solve the OSB (open stopband) problem of the series-fed antenna, and improve the radiation performance of the antenna.

[0036] It is worth noting that the minimum array composed of multiple slot units 220 is a 2×2 matrix, and this array size is the minimum array that can ensure the above-mentioned antenna performance. The matrix size can be appropriately adjusted according to the actual performance requirements of the antenna to enable the antenna to have better performance.

[0037] Furthermore, the coaxial probe 110 is arranged on the center line of the first metal plate 11. On the one hand, it can make the electric field and magnetic field distribution of the signal more uniform and symmetrical during the transmission process, reduce the signal distortion and attenuation caused by position offset, and ensure the quality and stability of the transmitted signal; on the other hand, it helps to better achieve the impedance matching of the coaxial probe 110 and the system where the first metal plate 11 is located, reduce the reflection coefficient, improve the energy transmission efficiency, reduce signal reflection, make more energy be effectively received, and enhance the system performance; in addition, during installation, the center line position is clear and fixed, which is convenient for accurate installation and positioning of the coaxial probe 110, reduces the difficulty and error of installation, improves the consistency and repeatability of the system, and is also conducive to alignment and connection with other boards to ensure the normal operation of the system.

[0038] For further information, see Figure 6 The width of the plurality of output ports 133 gradually decreases from the middle to both sides along the third direction, which can reduce the side lobe level of the antenna H-plane radiation pattern. As shown in the radiation pattern, the side lobe level of the H-plane (dashed line) in the figure is less than -15dB, that is, its side lobe level is low. It is worth noting that the first direction, the second direction and the third direction are perpendicular to each other.

[0039] Furthermore, the widths of the plurality of radiation slots 221 and the plurality of impedance matching slots 222 gradually decrease from the middle position to both sides, and are symmetrical about the third direction. This arrangement can reduce the sidelobe level of the antenna E-plane radiation pattern. As shown in the radiation pattern, the sidelobe level of the E-plane (solid line) in the figure is less than -15dB, that is, its sidelobe level is low, reducing interference with the main lobe signal and interference with other frequency bands. In a multi-antenna system, it helps to improve the system's anti-interference ability and spectrum utilization.

[0040] It is worth noting that the above settings are based on different requirements for sidelobe levels, and are based on methods such as Taylor distribution and Chebyshev distribution commonly used in array synthesis theory to determine the energy ratio of each output port 133 of the power divider and the energy radiation ratio of different radiation slots 221, thereby setting the width of the output port 133 and the radiation slot 221 accordingly.

[0041] Furthermore, a plurality of first through holes 131 and second through holes 132 are provided on the first plate body 13, and metal is affixed to the inner walls of the first through holes 131 and the second through holes 132. The first through holes 131 and the second through holes 132 are both arranged on the same side of the first plate body 13, and the second through holes 132 are arranged along the side of the first plate body 13. The first metal plate 11, the second metal plate 12, the first through holes 131 and the second through holes 132 jointly define the first power divider 134, and the first through holes 131 and the second through holes 132 define an output port 133 of the first power divider 134. In the present embodiment, eight output ports 133 are provided.

[0042] Further, the second plate body 21 is provided with a third through hole 210 and a fourth through hole 211, the inner peripheral walls of the third through hole 210 and the fourth through hole 211 are affixed with metal, the third through holes 210 are distributed in an array in the second plate body 21, and the fourth through holes 211 are arranged along the peripheral side of the second plate body 21. The third through holes 210 arranged in an array can generate an electromagnetic field with a specific polarization direction, meet the polarization requirements of different communication scenarios, and improve communication quality and anti-interference ability.

[0043] It is worth noting that the metallized through hole, as part of the antenna structure, can adjust the input impedance of the antenna to better match the characteristic impedance of the feeder, and can form a specific waveguide structure to reduce signal reflection, improve signal transmission efficiency and antenna radiation efficiency, and ensure the overall performance of the antenna system. In addition, the second through hole 132 and the fourth through hole 211 are both set to prevent the signal from leaking out of the board and causing energy dissipation.

[0044] Furthermore, a second power divider 135 is also provided on the first plate 13, the first power divider 134 and the second power divider 135 are symmetrically distributed along the third direction, and the first and second power dividers 135 have the same structure, and a second coupling slot 121 is also provided on the second metal plate 12, and the second coupling slot 121 is arranged corresponding to the output port 133 of the second power divider 135. The symmetrical distribution of the first and second power dividers 135 can make the overall structure compact and save the occupied area, and the symmetrical distribution can make the signal maintain better balance during the transmission process, reduce the signal difference caused by different transmission paths, and improve the signal quality and transmission efficiency. In addition, the symmetrical arrangement of the two power dividers can make the signal pass from both sides of the slot unit 220 to the opposite side, respectively, to form a standing wave in the second dielectric plate 2, and ensure that the beam pointing of the antenna array does not change with the frequency.

[0045] Furthermore, the signal phase difference between the first power divider 134 and the second power divider 135 is 180°, realizing differential feeding. On the one hand, it can effectively improve the anti-interference ability of the signal, making the transmitted signal quality higher and more stable; on the other hand, the use of differential feeding can make the radiation field distribution of the antenna more uniform, reduce the radiation zero point and side lobe level, thereby improving the gain and directivity of the antenna, improving the radiation efficiency and coverage of the antenna, and enhancing the performance of the communication system; secondly, the OSB problem of the series-fed antenna has been solved by the above-mentioned matching structure, and by exciting the two symmetrically distributed power dividers with the help of differential feeding, the antenna can obtain a fixed beam.

[0046] Furthermore, the substrate integrated waveguide slot antenna is manufactured using a printed circuit board process. On the one hand, it is convenient to design the antenna into a compact structure, making it easier to integrate it into various miniaturized electronic devices, meeting the requirements of communication equipment for miniaturization and lightness; on the other hand, the process can achieve high processing accuracy, ensure the consistency and stability of antenna performance, and the process has high production efficiency and low cost; in addition, during the manufacturing process using the printed circuit board process, the structure, size, shape and other parameters of the substrate integrated waveguide slot antenna can be easily adjusted and optimized, and the manufactured antenna structure is firm, not easily affected by external factors, and has a longer service life.

[0047] To sum up, the substrate integrated waveguide slot antenna provided in this embodiment adopts the form of series feeding to design the multi-layer substrate integrated waveguide slot antenna into a traveling wave antenna array, so that it has a wide-band characteristic. At the same time, by arranging a plurality of slot units 220 structures arranged in an array on the third metal plate 22, the OSB problem of the series-fed antenna is better solved.

[0048] This specification discloses the present application with reference to the accompanying drawings, and also enables those skilled in the art to implement the present application, including making and using any device or system, using suitable materials, and using any combined method. The scope of the present application is defined by the technical solution for protection, and includes other examples that occur to those skilled in the art. As long as such other examples include structural elements that are not different from the literal language of the technical solution for protection, or such other examples contain equivalent structural elements that are not substantially different from the literal language of the technical solution for protection, such other examples should be considered to be within the scope of protection determined by the technical solution for protection of the present application.

Claims

1. A substrate integrated waveguide slot antenna, characterized in that: include: A first dielectric plate and a second dielectric plate sequentially stacked and connected along a first direction; The first dielectric plate comprises a first metal plate, a first plate body and a second metal plate, the first metal plate and the second metal plate are respectively attached to the lower surface and the upper surface of the first plate body, a coaxial probe is provided on a side surface of the first metal plate close to the first plate body, a central through hole for the coaxial probe to pass through is provided on the first plate body, a first power divider is also provided on the first plate body, the first power divider is provided with a plurality of output ports symmetrically arranged along a second direction, and the signal phases of the plurality of output ports are the same, a first coupling slot is provided on the second metal plate, and the first coupling slot is provided corresponding to the output port; The second dielectric plate comprises a second plate body and a third metal plate, the third metal plate is attached to the upper surface of the second plate body, a side of the second metal plate away from the first plate body is attached to the second plate body, the second plate body is provided with a plurality of impedance matching slots distributed in an array, the third metal plate is provided with a plurality of groups of slot units distributed in an array, each group of the slot units comprises a radiation slot and two impedance matching slots, the two impedance matching slots are symmetrically arranged on both sides of the radiation slot, and the impedance matching slots are arranged in one-to-one correspondence with the impedance matching slots; The first direction is perpendicular to the second direction.

2. The substrate integrated waveguide slot antenna according to claim 1, characterized in that: The coaxial probe is arranged on the center line of the first metal plate.

3. The substrate integrated waveguide slot antenna according to claim 1, characterized in that: The widths of the plurality of output ports gradually decrease from the middle to both sides along the third direction, wherein the first direction, the second direction and the third direction are perpendicular to each other.

4. The substrate integrated waveguide slot antenna according to claim 3, characterized in that: A plurality of first through holes and second through holes are provided on the first plate body, and metal is affixed to the inner peripheral walls of the first through holes and the second through holes. The first through holes and the second through holes are both arranged on the same side of the first plate body, and the second through holes are arranged along the side edge of the first plate body. The first metal plate, the second metal plate, the first through holes and the second through holes jointly define the first power divider.

5. The substrate integrated waveguide slot antenna according to claim 4, characterized in that: A second power divider is also provided on the first plate, the first power divider and the second power divider are symmetrically distributed along the third direction, and the first and second power dividers have the same structure. A second coupling gap is also opened on the second metal plate, and the second coupling gap is arranged corresponding to the output port of the second power divider.

6. The substrate integrated waveguide slot antenna according to claim 5, characterized in that: The second plate body is provided with a third through hole and a fourth through hole, the inner peripheral walls of the third through hole and the fourth through hole are affixed with metal, the third through holes are distributed in an array in the second plate body, and the fourth through holes are arranged along the peripheral side of the second plate body.

7. The substrate integrated waveguide slot antenna according to claim 5, characterized in that: The signal phase difference between the first power divider and the second power divider is 180°.

8. The substrate integrated waveguide slot antenna according to claim 1, characterized in that: The widths of the plurality of radiation slots and the plurality of impedance matching slots gradually decrease from the middle position to both sides and are symmetrical about the third direction.

9. The substrate integrated waveguide slot antenna according to claim 1, characterized in that: The first metal plate, the first plate body, the second metal plate, the second plate body and the third metal plate are connected by screws.

10. The substrate integrated waveguide slot antenna according to any one of claims 1 to 9, characterized in that: The substrate integrated waveguide slot antenna is manufactured by adopting a printed circuit board process.

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