Single-layer electric wall broadband SIW slot antenna based on metasurface

Abstract

The invention discloses a single-layer electric wall broadband SIW slot antenna based on a metasurface, which relates to the technical field of antennas, and comprises a dielectric substrate, a first radiating surface and a second radiating surface which are respectively arranged at the top and the bottom of the dielectric substrate, and a slot structure and a transition structure which are coplanar with the first radiating surface, and the single-layer electric wall structure is coplanar with the first radiating surface and the second radiating surface. The metal through holes of the antenna are replaced by the complementary resonance rings, transmission of electromagnetic waves in a channel is achieved by adopting the metasurface structure which is periodically arranged based on the magnetic resonance units on the radiating surface, and compared with an existing substrate integrated waveguide slot antenna, the complementary resonance rings replace the metal through holes, machining is easy, and cost is low.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a single-layer electric wall broadband SIW slot antenna based on a metasurface. Background Art

[0002] Microwave antennas are mainly divided into end-fire, side-fire, slot antennas and other types. Among them, waveguide slot antennas have the advantages of narrow main lobe width, flexible beam scanning and large power capacity. The classic waveguide slot antenna cuts slots on the waveguide wall according to a certain pattern and radiates electromagnetic waves in a form similar to a dipole antenna. The substrate integrated waveguide slot antenna is based on the traditional metal waveguide slot antenna. It uses metal through holes in the dielectric substrate structure and the upper and lower metal surfaces to form a quasi-closed dielectric waveguide structure, realizes the classic metal waveguide function on the dielectric, and radiates electromagnetic waves through the slot. Compared with ordinary waveguide slot antennas, substrate integrated waveguide slot antennas retain the excellent transmission characteristics of dielectric waveguides, and at the same time have the advantages of small size, low profile, low cost, and are very easy to integrate with printed circuit boards. It has been widely used in communications, radars and other fields.

[0003] The easy integration of substrate-integrated waveguide slot antennas can realize the integrated design of antennas and circuits, and has further broad development prospects and more potential practical application value. However, as the communication frequency band develops to higher frequency bands such as millimeter waves, the volume of substrate-integrated waveguides is getting smaller and smaller, which puts higher requirements on the processing accuracy of metallized through holes and waveguide plane flattening technology. There are potential processing errors and local unevenness that lead to performance degradation such as antenna pattern distortion and bandwidth reduction; at the same time, in the integrated design of millimeter wave antennas and circuits, how to simultaneously achieve high-precision drilling, metal injection and PCB surface printing without affecting each other also brings higher processing costs. Therefore, it is still a difficult problem in engineering to realize small-sized substrate-integrated waveguide slot antennas with excellent radiation and bandwidth performance in higher frequency bands such as microwave millimeter waves. Existing studies mostly use the method of optimizing the stepped impedance transformer or optimizing the slot structure to improve the radiation or bandwidth performance of substrate-integrated waveguide slot antennas.

[0004] Chinese patent CN111416206A discloses a substrate integrated waveguide slot antenna, which improves impedance matching by setting a stepped impedance transformer between the feed line and the radiating surface, and introduces a radio frequency connector to optimize the feed line electrical connection method. Chinese patent CN110323569A discloses a substrate integrated waveguide back cavity hexagonal slot antenna, which improves the bandwidth and adjustability of the antenna by changing the back cavity slot to a hexagon. However, it has the following shortcomings: First, the relative bandwidth of the antenna is only 1.42%, and the working bandwidth is not greatly improved; second, the metallized through hole used is still a method of drilling through the dielectric substrate. When the frequency increases and the size decreases, there are problems such as complex process and high cost, which affects the antenna design performance at high working frequency when the process limit is reached. Summary of the invention

[0005] In order to solve the above technical problems, this application proposes the following technical solutions: In the first aspect, an embodiment of the present application provides a single-layer electric wall broadband SIW slot antenna based on a metasurface, comprising: a dielectric substrate, a first radiating surface and a second radiating surface respectively arranged on the top and bottom of the dielectric substrate, a slot structure and a transition structure coplanar with the first radiating surface, and a single-layer electric wall structure coplanar with the first radiating surface and the second radiating surface.

[0006] In a possible implementation, the transition structure is a trapezoidal structure coplanar with the first radiation surface, located symmetrically in the center of both sides of the first radiation surface, and the transition structure is connected to a microstrip line, and the transition structure is connected to a feed source through the microstrip line.

[0007] In a possible implementation manner, the slot structure is a periodic slot structure based on Floquet's theorem.

[0008] In a possible implementation manner, the units of the periodic slot structure include trapezoidal slots and single slots.

[0009] In a possible implementation, the electric wall structure includes a first resonant ring coplanar with the first radiation surface and a second resonant ring coplanar with the second radiation surface, the first resonant ring and the second resonant ring are both arranged on both sides of the radiation surface, and the resonant ring realizes the transmission of the electromagnetic waves emitted by the feed source inside the dielectric substrate surrounded by the electric walls on both sides, the first radiation surface and the second radiation surface.

[0010] In a possible implementation, the resonant ring is composed of periodically arranged metal ring hollow microstructures, the metal ring hollow microstructures of the first resonant ring and the second resonant ring correspond to each other up and down, the metal ring hollow microstructure of the first resonant ring is located on both sides of the gap structure, and the opening directions of the metal ring hollow microstructures of the first resonant ring and the second resonant ring are opposite.

[0011] In a possible implementation, the shapes of the metal ring hollow microstructure include: triangle and cross.

[0012] In a possible implementation, the triangular metal ring hollow microstructure has a definition of an opening direction, which is an unclosed triangular base; the cross-shaped metal ring hollow microstructure is centrally symmetrical and has no definition of an opening direction; the opening direction of other types of metal ring hollow microstructures depends on whether they have an unclosed base. If there is an opening, the opening directions of the first resonant ring and the second resonant ring are opposite.

[0013] In a possible implementation manner, the dielectric substrate is a rectangular parallelepiped structure filled with dielectric.

[0014] In an embodiment of the present application, the metal through holes of the antenna are replaced with complementary resonant rings. By adopting a metasurface structure based on a periodic arrangement of magnetic resonance units on the radiating surface, the transmission of electromagnetic waves in the channel is realized. Compared with the existing substrate integrated waveguide slot antenna, the complementary resonant ring replaces the metal through hole, which is easy to process and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of a single-layer electric wall broadband SIW slot antenna based on a metasurface provided in an embodiment of the present application, which includes a three-layer cross-sectional view, a top view, and a bottom view from top to bottom; Figure 2 A schematic diagram of an antenna with a triangular ring and a trapezoidal gap provided in an embodiment of the present application; Figure 3 for Figure 2 S11 simulation diagram of the middle antenna; Figure 4 for Figure 2 The radiation pattern of the antenna in the figure; Figure 5 A schematic diagram of an antenna with a cross-shaped ring and trapezoidal slots provided in an embodiment of the present application; Figure 6 for Figure 5 S11 simulation diagram of the middle antenna; Figure 7 for Figure 5 The radiation pattern of the antenna in the figure; Figure 8 A schematic diagram of a triangular ring single-slot antenna provided in an embodiment of the present application; Fig. 9 for Figure 8 S11 simulation diagram of the middle antenna; Fig.10 for Figure 8 The radiation pattern of the antenna in the figure; Fig.11A schematic diagram of a cross-ring single-slot antenna provided in an embodiment of the present application; Fig.12 for Fig.11 S11 simulation diagram of the middle antenna; Fig.13 for Fig.11 The radiation pattern of the antenna in the figure; Fig.14 A schematic diagram of a triangular ring seamless transmission line provided in an embodiment of the present application; Fig.15 for Fig.14 S parameter simulation diagram of the transmission line in the figure; Fig.16 A schematic diagram of a seamless transmission line of a cross-shaped ring provided in an embodiment of the present application; Fig.17 for Fig.16 S-parameter simulation diagram of the transmission line in Figure 2.

[0016] Figure 1-17 In the symbol, it is represented as: 1- dielectric substrate, 2- first radiation surface, 3- second radiation surface, 4- slot structure, 5- transition structure, 6- electric wall structure, 7- microstrip line. DETAILED DESCRIPTION

[0017] The present solution is described below in conjunction with the accompanying drawings and specific implementation methods.

[0018] See also Figure 1 The single-layer electric wall broadband SIW slot antenna based on a metasurface provided in an embodiment of the present application comprises: a dielectric substrate 1, which is a rectangular parallelepiped structure filled with dielectric. A first radiation surface 2 and a second radiation surface 3 are respectively arranged on the top and bottom of the dielectric substrate 1, a slot structure 4 and a transition structure 5 coplanar with the first radiation surface 2, and a single-layer electric wall structure 6 coplanar with the first radiation surface 2 and the second radiation surface 3.

[0019] Among them, the transition structure 5 in this embodiment is a trapezoidal structure coplanar with the first radiation surface 2, located symmetrically in the center of both sides of the first radiation surface 2, and the transition structure 5 is connected to a microstrip line 7, and the transition structure 5 is connected to the feed source through the microstrip line 7.

[0020] The slot structure 4 is a periodic slot structure 4 based on Floquet's theorem. In this embodiment, units of the periodic slot structure 4 include trapezoidal slots and single slots.

[0021] When the periodic slot structure 4 described in this embodiment exists, the embodiment is a SIW slot antenna design. If the slot structure 4 is removed, that is, there is no slot structure, the embodiment is a SIW transmission line design. The introduction and comparison of the transmission line design is intended to illustrate that the single-layer electric wall design based on the metasurface introduced in the present invention is also applicable to the transmission line structure.

[0022] The electric wall structure 6 includes a first resonant ring coplanar with the first radiation surface 2 and a second resonant ring coplanar with the second radiation surface 3. The first resonant ring and the second resonant ring are both arranged on both sides of the radiation surface. The resonant ring realizes the transmission of the electromagnetic waves emitted by the feed source inside the dielectric substrate 1 surrounded by the electric walls 6 on both sides, the first radiation surface 2 and the second radiation surface 3. The resonant ring is composed of periodically arranged metal ring hollow microstructures. The metal ring hollow microstructures of the first resonant ring and the second resonant ring correspond to each other up and down. The metal ring hollow microstructure of the first resonant ring is located on both sides of the gap structure 4, and the opening directions of the metal ring hollow microstructures of the first resonant ring and the second resonant ring are opposite. In this embodiment, the shapes of the metal ring hollow microstructures include: triangle and cross, of course, not limited to the above two structures.

[0023] The distance between each group of trapezoidal slots or single slots in the slot structure 4 ranges from 0.3 wavelengths to 1.2 wavelengths, and the number is M, where M is greater than or equal to 3. The number of M is positively correlated with the antenna gain, so the actual designed M value is related to the required gain index range.

[0024] The first resonant ring and the second resonant ring of the single-layer electric wall structure 6 have a distance range of 0.1 wavelength to 0.5 wavelength on the same side of the adjacent and coplanar resonant rings, and the number is N. The number N is positively correlated with the value of M, and N is greater than M. At the same time, the degree to which N is greater than M needs to ensure that the distance between the first gap and the Mth gap in the gap structure 4 and the junction of the transition structure 5 and the first radiation surface 2, respectively, is in the range of 0.3 wavelength to 1.2 wavelength.

[0025] Several single-layer electric wall broadband SIW slot antennas based on metasurfaces are described below as schematic examples.

[0026] See also Figure 2 , Figure 2 In the metasurface-based single-layer electric wall broadband SIW slot antenna, the unit of the periodic slot structure is a trapezoidal slot, and the metal ring hollow microstructure of the resonant ring is a triangle.

[0027] See also Figure 3 , Figure 3 The S11 results show that Figure 2The antenna in the system not only meets a certain broadband requirement (the frequency range where S11 is below -10dB is 18.67 GHz-20.95 GHz), but also pays more attention to the low reflection of individual frequency points. For example, the S11 values ​​at 20.32 GHz and 20.50 GHz are both below -30 dB.

[0028] See also Figure 4 , Figure 4 The E-plane directional diagram in Figure 2 The antenna achieves high-gain radiation performance, with a typical maximum gain of 14.5 dBi at 20.3 GHz, a main lobe direction of -13 degrees, and a 3dB beamwidth angle of 4.9 degrees.

[0029] See also Figure 5 , Figure 5 In the metasurface-based single-layer electric wall broadband SIW slot antenna, the unit of the periodic slot structure is a trapezoidal slot, and the metal ring hollow microstructure of the resonant ring is a cross shape.

[0030] See also Figure 6 , Figure 6 The S11 results show that Figure 5 The antenna in the test focuses more on broadband performance. The frequency ranges where the S11 value is lower than -10 dB are 33.46 GHz-34.00 GHz and 34.70 GHz-37.14 GHz, and the lowest S11 value is around -15dB.

[0031] See also Figure 7 , Figure 7 The E-plane directional diagram in Figure 5 The antenna achieves high-gain radiation performance, with a typical maximum gain of 13.4 dBi at 34.0 GHz, a main lobe direction of 7 degrees, and a 3dB beamwidth angle of 2.9 degrees.

[0032] See also Figure 8 , Figure 8 In the metasurface-based single-layer electric wall broadband SIW slot antenna, the unit of the periodic slot structure is a single slot, and the metal ring hollow microstructure of the resonant ring is a triangle. Figure 8 The antenna in the example uses a single slot, and its antenna radiation performance is not as good as the trapezoidal slot design ( Figure 2 ), which is reflected in a slight decrease in gain value, but the structure is simple and easy to process.

[0033] See also Fig. 9 , Fig. 9 The S11 results show that Figure 8The antenna in the system not only meets certain broadband requirements (the frequency range where S11 is below -10dB is 18.85 GHz-20.73 GHz), but also pays more attention to low reflection at certain frequencies. For example, the S11 value at 19.90 GHz is -47.21 dB.

[0034] See also Fig.10 , Fig.10 The E-plane directional diagram in Figure 8 The antenna achieves high-gain radiation performance, with a typical maximum gain of 11.8dBi at 20.0GHz, a main lobe direction of -20 degrees, and a 3dB beamwidth angle of 5.3 degrees.

[0035] See also Fig.11 , Fig.11 In the metasurface-based single-layer electric wall broadband SIW slot antenna, the unit of the periodic slot structure is a single slot, and the metal ring hollow microstructure of the resonant ring is a cross shape. Fig.11 The antenna in the example uses a single slot, and its antenna radiation performance is not as good as the trapezoidal slot design ( Figure 5 ), which is reflected in the enlargement of the side lobes, but the structure is simple and easy to process.

[0036] See also Fig.12 , Fig.12 The S11 results show that Fig.11 The antenna pays more attention to broadband performance. The frequency range where the S11 value is lower than -10dB is 33.24GHz-38.00 GHz, and the lowest S11 value is around -20dB.

[0037] See also Fig.13 , Fig.13 The E-plane directional diagram in Fig.11 The antenna achieves high-gain radiation performance, with a typical maximum gain of 13.5dBi at 34.0GHz, a main lobe direction of 15 degrees, and a 3dB beamwidth angle of 4.0 degrees.

[0038] See also Fig.14 , Fig.14 based on Figure 2 and Figure 8 In the antenna design, the hollow metal ring microstructure of the resonant ring is triangular, but the periodic slot structure is removed. At this time, the antenna structure can be transformed into a transmission line structure.

[0039] See also Fig.15 , Fig.15 The S11 results show that Fig.14The transmission line not only meets a certain broadband requirement (the frequency range where S11 is lower than -10dB is 18.37 GHz-19.13 GHz and 19.42 GHz-20.06 GHz), but also pays more attention to the low reflection of individual frequency points. For example, the S11 value at 18.69 GHz is -45.10 dB.

[0040] See also Fig.16 , Fig.16 based on Figure 5 and Fig.11 In the antenna design, the hollow microstructure of the metal ring of the resonant ring is cross-shaped, but the periodic slot structure is removed, and the antenna structure can be transformed into a transmission line structure.

[0041] See also Fig.17 , Fig.17 The S11 results show that Fig.16 The transmission line pays more attention to broadband performance. The frequency range where the S11 value is lower than -10dB is 34.35GHz-44.14GHz, and the lowest S11 value is around -35dB.

[0042] In this embodiment, Figure 2 and Figure 5 The antenna in the example uses a trapezoidal slot, which is Figure 8 and Fig.11 The single slot of the antenna in the figure is biased towards better radiation performance.

[0043] Figure 2 and Figure 8 The hollow microstructure of the metal ring of the antenna resonant ring is triangular. Figure 5 and Fig.11 The hollow metal ring microstructure of the antenna resonant ring is in a cross shape. The triangular design tends to achieve broadband performance near 20 GHz, and pays more attention to the low reflection coefficient of individual frequency points. The cross design tends to achieve wider broadband performance near 35 GHz. Fig.14 and Fig.16 The same applies to transmission line design.

[0044] In the embodiments of the present application, "at least one" refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0045] The above is only a specific implementation of the present application. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. The protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A single-layer electric wall broadband SIW slot antenna based on a metasurface, characterized in that: include: A dielectric substrate, a first radiation surface and a second radiation surface respectively arranged on the top and bottom of the dielectric substrate, a gap structure and a transition structure coplanar with the first radiation surface, and a single-layer electrical wall structure coplanar with the first radiation surface and the second radiation surface.

2. The single-layer electric wall broadband SIW slot antenna based on a metasurface according to claim 1, characterized in that: The transition structure is a trapezoidal structure coplanar with the first radiation surface, and is located symmetrically in the middle of both sides of the first radiation surface. The transition structure is connected to a microstrip line, and the transition structure is connected to a feed source through the microstrip line.

3. The single-layer electric wall broadband SIW slot antenna based on a metasurface according to claim 2, characterized in that: The slot structure is a periodic slot structure based on Floquet's theorem.

4. The single-layer electric wall broadband SIW slot antenna based on a metasurface according to claim 3, characterized in that: The units of the periodic slot structure include trapezoidal slots and single slots.

5. The single-layer electric wall broadband SIW slot antenna based on a metasurface according to claim 1, characterized in that: The electric wall structure includes a first resonant ring coplanar with the first radiation surface and a second resonant ring coplanar with the second radiation surface. The first resonant ring and the second resonant ring are both arranged on both sides of the radiation surface. The resonant rings realize the transmission of electromagnetic waves emitted by the feed source inside the dielectric substrate surrounded by the electric walls on both sides, the first radiation surface and the second radiation surface.

6. The metasurface-based single-layer electric wall broadband SIW slot antenna according to claim 5, characterized in that: The resonant ring is composed of periodically arranged metal ring hollow microstructures, the metal ring hollow microstructures of the first resonant ring and the second resonant ring correspond to each other up and down, the metal ring hollow microstructure of the first resonant ring is located on both sides of the gap structure, and the opening directions of the metal ring hollow microstructures of the first resonant ring and the second resonant ring are opposite.

7. The metasurface-based single-layer electric wall broadband SIW slot antenna according to claim 6, characterized in that: The shapes of the metal ring hollow microstructure include: triangle and cross.

8. The single-layer electric wall broadband SIW slot antenna based on a metasurface according to claim 1, characterized in that: The dielectric substrate is a rectangular parallelepiped structure filled with dielectric.

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