SIW resonant cavity vortex field antenna and device based on coplanar metasurface

Abstract

The invention discloses a coplanar metasurface-based SIW resonant cavity vortex field antenna and equipment, and the antenna comprises a first radiation sheet which is disposed at the top layer, and the first radiation sheet is provided with a first resonant ring with a coplanar metasurface and an annular gap in a surrounding and etching manner; a first dielectric substrate is arranged adjacent to the radiation fins, a plurality of metal probes are arranged in the first dielectric substrate, the first ends of the metal probes are connected with the first radiation fins, and the second ends of the metal probes sequentially penetrate through the first dielectric substrate and the second radiation fins adjacent to the first dielectric substrate and are connected with the second dielectric substrate at the bottom and the feed network; the second radiation sheet is used for etching a second resonant ring opposite to the opening of the first resonant ring in a surrounding manner; and the two groups of resonant rings form a pair of complementary resonant rings. The metasurface structure that the complementary resonant rings are periodically arranged on the radiating surface based on the resonant units is adopted, transmission of electromagnetic waves in the resonant cavity is achieved, compared with an existing substrate integrated waveguide slot antenna, the complementary resonant rings replace metal through holes, machining is easy, and cost is low.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a SIW resonant cavity vortex field antenna and device based on a coplanar metasurface. Background Art

[0002] In recent years, mobile communication technology has shifted to 5G and 6G frequency bands, and modern communication systems have developed rapidly. Improving spectrum resources has become a top priority in communication technology research. Vortex electromagnetic waves are electromagnetic waves with orbital angular momentum, characterized by a spiral shape of the wavefront. The rotational characteristics of this wavefront can be used to encode and transmit multidimensional information. In theory, vortex waves with different modal values ​​are orthogonal to each other, thereby improving the bandwidth of the communication system and the data transmission speed.

[0003] Therefore, OAM antenna technology plays an important role in how to improve spectrum utilization. Commonly used antenna technologies for generating OAM waves mainly include uniform circular arrays, spiral phase plates, and metasurface methods. However, most antennas have large size and complex feeding networks, and cannot meet the miniaturization and integration requirements of the communications field. PCB antennas that are suitable for miniaturization are more likely to deform than traditional antennas due to their small size, and the introduction of processing technologies such as drilling, which affects the electrical performance of the antenna. For example, in Zihan Xu's article in ICEICT 2021, a millimeter-wave small OAM slot excitation antenna with a power-dividing stripline in the middle of the cavity is disclosed. Its miniaturized and low-profile antenna structure is used to meet the design requirements of the millimeter-wave frequency band for integrated interconnection. However, in the millimeter-wave band, due to the reduction in the size of electromagnetic equipment, drilling and metallization technologies become more difficult, and thin PCBs are also easily deformed under mechanical pressure, resulting in deterioration of electromagnetic performance.

[0004] Substrate integrated waveguide (SIW) is a new type of microwave and millimeter wave integrated waveguide technology. It embeds the traditional waveguide structure into the substrate, which can realize highly integrated microwave devices. Its transmission mode is similar to that of rectangular waveguide, and it has the characteristics of high integration, low loss, and high quality factor. The metal through-holes of the substrate integrated waveguide structure can well realize the electric wall effect, so resonant cavity microwave devices can be designed. By introducing the slot leakage wave structure on the resonant cavity, resonant cavity antennas with excellent performance can be further designed. For example, Chinese patent CN107611600A discloses a SIW annular slot antenna that generates dual-mode OAM vortex electromagnetic waves. This application reduces the size of the antenna and improves the compactness and integration of the antenna.

[0005] However, the metallized through holes and RF connectors used in traditional SIW technology are still drilled through the dielectric substrate. When the size is reduced, there are problems such as complex process, high cost, easy deformation, and affecting the antenna design performance at high operating frequencies when the process limit is reached. As the operating frequency increases, the volume of substrate integrated waveguides becomes smaller and smaller, which puts higher requirements on the processing accuracy of metallized through holes and waveguide flattening technology. Summary of the invention

[0006] 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 SIW resonant cavity vortex field antenna based on a coplanar metasurface, comprising: a first radiating plate arranged on the top layer, the first radiating plate surrounding a first resonant ring and annular gap etched with a coplanar metasurface; a first dielectric substrate is arranged adjacent to the radiating plate, a plurality of metal probes are arranged in the first dielectric substrate, a first end of the metal probe is connected to the first radiating plate, and a second end passes through the first dielectric substrate and a second radiating plate adjacent to the first dielectric substrate in sequence and is connected to the second dielectric substrate and a feeding network at the bottom; the second radiating plate etches a second resonant ring opposite to the opening of the first resonant ring, and the two resonant rings form a pair of complementary resonant rings.

[0007] In a possible implementation, the upper surface material of the first radiation plate is a circular radiation plate of metal, which has the first resonant ring, an annular gap and a connecting hole from the outside to the inside, and the metal probe is connected to the first radiation plate through the connecting hole.

[0008] In a possible implementation, the first dielectric substrate has a dielectric constant of 2.2 and a thickness of 2 mm, and the metal probe is inserted therein.

[0009] In a possible implementation manner, the second radiation plate is provided with a through hole, and a diameter of the through hole is larger than a cross-sectional diameter of the metal probe.

[0010] In a possible implementation, the first resonant ring and the second resonant ring are a plurality of rhombus resonant rings that are periodically arranged around a circle, and the diagonal length of the rhombus resonant ring is 2.5 mm.

[0011] In a possible implementation, the distance from the center of the radiation plate to the center of the diamond resonant ring is 18 mm, the distance from the center of the radiation plate to the inner edge of the annular gap is 12 mm, and the gap width is 1 mm; the distance from the center of the radiation plate to the axial center of the metal probe is 9 mm, the diameter of the metal probe is 1 mm, the number of metal probes is 3, and the arc angle between adjacent metal probes is 120°.

[0012] In a possible implementation, the feeding network is disposed on a feeding network dielectric substrate, the radius of the feeding network dielectric substrate is 16 mm, the relative dielectric constant is 2.2, and the thickness is 0.787 mm. The feeding network is a one-to-three feeding network.

[0013] In a possible implementation, an arc is cut off from the feed network dielectric substrate, and the cut surface is set as the feed port excitation.

[0014] In a possible implementation, the three output ports of the feeding network are sequentially increased by 1 / 3 wavelength, so that the phase of the output ports is delayed by 120°.

[0015] In a second aspect, an embodiment of the present application provides a device, including: processor; Memory; A SIW resonant cavity vortex field antenna based on a coplanar metasurface as described in any possible implementation of the first aspect; And a computer program, wherein the computer program is stored in the memory, and the computer program includes instructions, which, when executed by the processor, enable the device to communicate with other electronic devices through the SIW resonant cavity vortex field antenna based on the coplanar metasurface.

[0016] In the embodiment of the present application, the metal through holes of the traditional 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 electric wall effect is well simulated, and the transmission of electromagnetic waves in the resonant cavity is realized. Compared with the existing substrate integrated waveguide slot antenna, the complementary resonant ring that can be achieved by simple etching technology replaces the metal through hole achieved by drilling technology, which is easy to process and low in cost.

[0017] Taking into account the practical application of the antenna, the feeding network structure is directly connected to the metal probe feeding under the small size of the antenna, and each port outputs the same amplitude and a phase difference of 120 degrees, avoiding the direct use of three connectors, thereby simplifying the feeding, reducing the size, and facilitating implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the structure of a SIW resonant cavity vortex field antenna based on a coplanar metasurface provided in an embodiment of the present application; Figure 2 A top view of a SIW resonant cavity vortex field antenna based on a coplanar metasurface provided in an embodiment of the present application; Figure 3 A schematic diagram of the structure of a feeding network provided in an embodiment of the present application; Figure 4 A schematic diagram of the electric field distribution radiated by the antenna provided in an embodiment of the present application; Figure 5 A simulation S parameter diagram provided for an embodiment of the present application; Figure 6 The three-dimensional far-field pattern of the simulated antenna provided in the embodiment of the present application; Figure 7 Provided for the embodiments of this application Figure 6 The two-dimensional far-field patterns of the E-plane and H-plane; Figure 8 A schematic diagram of a device provided in an embodiment of the present application; Figure 1-8 In the symbol, it is represented as: 1-first radiation plate, 2-first resonant ring, 3-annular gap, 4-first dielectric substrate, 5-metal probe, 6-through hole, 7-second radiation plate, 8-second resonant ring, 9-second dielectric substrate, 10-feeding network. DETAILED DESCRIPTION

[0019] The present solution is described below in conjunction with the accompanying drawings and specific implementation methods.

[0020] See also Figure 1 The SIW resonant cavity vortex field antenna based on the coplanar metasurface provided in this embodiment adopts a four-layer structure. The whole is based on a circular resonant cavity. The upper surface material of the first layer is metal, which serves as the first radiation plate 1, and includes a first resonant ring 2 and an annular gap 3 etched on the upper coplanar metasurface.

[0021] The second layer is a first dielectric substrate 4 made of Rogers RT 5880, with a dielectric constant of 2.2 and a height of h=2mm. Metal probes 5 are inserted therein. In this embodiment, three metal probes 5 are provided, which are connected to the first radiation sheet 1 on the upper surface, and pass through the first dielectric substrate 4 and the second radiation sheet 7 adjacent to the first dielectric substrate 4 and are connected to the feeding network 9 at the bottom. The second radiation sheet 7 is provided with a through hole 6, and the diameter of the through hole 6 is larger than the cross-sectional diameter of the metal probe 5. The radius of the through hole 6 is set to be larger than the cross-sectional diameter of the metal probe 5 to ensure that it does not contact it, so as to prevent the metal probe 5 from contacting the floor and short-circuiting.

[0022] The third layer is the lower surface, and the metal with the same material as the first radiation plate 1 is used as the second radiation plate 7. The second resonant ring 8 opposite to the opening of the upper surface resonant ring is etched on its circumference. The first resonant ring 2 and the second resonant ring 8 form a pair of complementary resonant rings up and down, and the metal columns are replaced and arranged periodically, that is, a coplanar metasurface, so that the electromagnetic waves are surrounded by the circular resonant cavity and are not leaked. At the same time, holes larger than the cross-sectional diameters of the three metal probes 5 are etched.

[0023] The fourth layer is the feeding network 10, which is arranged on the second dielectric substrate 9. The material of the second dielectric substrate 9 is Rogers RT 5880, with a dielectric constant of 2.2 and a height of 0.787 mm. The feeding network 10 is a Wilkinson feeding network, which is designed in two levels of unequal division and equal division to achieve equal-amplitude feeding. The three outputs increase by approximately one-third of the wavelength in sequence to achieve a 120° phase delay at the feeding points. The Wilkinson feeding network 9 is connected to the radiation patch on the first layer through three coaxial probes to excite TE21 mode electromagnetic waves. Due to the phase delay, a vortex is formed and radiated outward through the annular slot 3.

[0024] See Figure 2 , it can be seen from the top view of the antenna that on the circular first radiation patch 1, from the outside to the inside are the first resonant ring 2, the annular slot 3, and the three probes 5 in sequence. Among them, the resonant ring and the resonant ring opposite to the opening on the lower surface form a complementary resonant ring, which acts as a metal electric wall to prevent electromagnetic waves from leaking from the side of the substrate. The diameter of this circle as the shielding layer is set to d = 2.5 mm, the number of resonant rings around the circumference is n = 50, and the radius of the resonant cavity is the distance from the center of the metal ring to the center of the resonant cavity, set to a = 18 mm. The distance from the center of the resonant cavity to the inner edge of the annular slot 3 is rg = 12 mm, the slot width is g = 1 mm. The distance from the center of the resonant cavity to the centers of the three feeding probes is rf = 9 mm, the diameter of the feeding probe is df = 1 mm, and the arc length between adjacent probes is α = 120°.

[0025] As Figure 3 , as the schematic diagram of the structure of the feeding network 10 from the bottom surface of the antenna, it can be seen that the second resonant ring 8 opposite to the opening on the first layer, the feeding network of the resonant cavity on the second dielectric substrate 9, and the one-to-three feeding network 10 are etched on the third layer. Among them, the radius of the dielectric substrate of the feeding network is rb = 16 mm. In order not to damage the resonant ring structure, rb < a, and an arc is cut off at y = -b / 2, and the cut surface is set as the excitation of the feeding port. The feeding network 10 is designed as a Wilkinson power divider, with the characteristics of equal amplitude and equal phase. Since the antenna requires a 120° phase difference at the output ports, the output ports increase by 1 / 3 wavelength in sequence to make the phase of the output ports delay by 120°.

[0026] As Figure 4 , the HFSS software is used for simulation to obtain the electric field distribution diagram on the surface of the first radiation patch 1 of the antenna. It can be seen that the quasi-TE21 mode is cut and rotated by the slot and radiated outward through the annular slot 3, with a central radiation hole, forming an OAM field distribution with a mode number of 2.

[0027] As Figure 5, HFSS software was used to simulate and obtain the S parameter diagram. The center frequency of the antenna is 10GHz, S11 is -30.42dB, the -10dB bandwidth is between 8.540GHz and 10.766GHz, the bandwidth reaches 2.226GHz, and the relative bandwidth is 22.26%.

[0028] like Figure 6 , HFSS software was used to simulate and obtain the three-dimensional far-field ,pattern. In the process of outward radiation, a hole appears in the center direction, which has the ,characteristics of OAM electromagnetic waves. Figure 7 for Figure 6 The two-dimensional far-field patterns of the E-plane and H-plane.

[0029] It can be seen from the above embodiments that the present application replaces the metal through holes of the traditional antenna with complementary resonant rings, and realizes the transmission of electromagnetic waves in the resonant cavity by adopting a metasurface structure based on a periodic arrangement of magnetic resonance units on the radiating surface. 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.

[0030] The antenna has a four-layer structure design, integrating the SIW resonant cavity and the feeding network in one design. The actual size diameter D=44mm improves compactness and integration. Considering the actual application of the antenna, a one-to-three Wilkinson feeding network is designed under the small size of the antenna. This feeding network structure directly connects the three metal pillars to feed, so that each port outputs the same amplitude and the phase difference is 120 degrees, avoiding the direct use of three connectors, thereby simplifying the feeding, reducing the volume, and facilitating implementation.

[0031] In the present application, the antenna outputs three excitations with the same amplitude and a phase difference of 120 degrees through the feeding network, generates a rotating TE21 mode in the resonant cavity, and then cuts through the annular gap so that the resonant mode radiates from the gap to generate a mode 2 OAM vortex electromagnetic wave beam.

[0032] This application also provides an embodiment of a device, see Figure 8 , the device 10 in this embodiment includes: Processor 101, memory 102 and communication unit 103. Processor 101 is ARM Cortex-M4 or similar products, memory 102 includes Micron MT25QL128ABA1EW9 or similar products, these components communicate through one or more buses, those skilled in the art can understand that the device structure shown in the figure does not constitute a limitation on the embodiments of the present application, it can be a bus structure or a star structure, and can also include more or less components than shown in the figure, or combine certain components, or arrange components differently.

[0033] Among them, the communication unit 103 is the SIW resonant cavity vortex field antenna based on the coplanar metasurface in the above embodiment, so that the device can communicate with other electronic devices.

[0034] The processor 101 is the control center of the device. It uses various interfaces and lines to connect various parts of the entire device. It runs or executes software programs and / or modules stored in the memory 102, and calls data stored in the memory to perform various functions of the device and / or process data. The processor can be composed of an integrated circuit (IC), for example, it can be composed of a single packaged IC, or it can be composed of multiple packaged ICs with the same or different functions. For example, the processor 101 can include only a central processing unit (CPU). In the embodiment of the present application, the CPU can be a single computing core or multiple computing cores.

[0035] The memory 102 is used to store the execution instructions of the processor 101. The memory 102 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0036] When the execution instructions in the memory 102 are executed by the processor 101, the device 100 initiates a communication task according to the instructions, thereby using the SIW resonant cavity vortex field antenna based on the coplanar metasurface to communicate with the electronic device that needs to communicate.

[0037] 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.

[0038] 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 SIW resonant cavity vortex field antenna based on a coplanar metasurface, characterized in that: include: A first radiating plate is arranged on the top layer, and the first radiating plate surrounds a first resonant ring and annular gap etched with a coplanar metasurface; a first dielectric substrate is arranged adjacent to the radiating plate, and a plurality of metal probes are arranged in the first dielectric substrate, wherein a first end of the metal probe is connected to the first radiating plate, and a second end of the metal probe passes through the first dielectric substrate and a second radiating plate adjacent to the first dielectric substrate in sequence and is connected to the second dielectric substrate and a feeding network at the bottom; a second resonant ring is etched around the second radiating plate and is opposite to the opening of the first resonant ring, and the two groups of resonant rings form a pair of complementary resonant rings.

2. The SIW resonant cavity vortex field antenna based on coplanar metasurface according to claim 1, characterized in that: The upper surface material of the first radiation piece is a circular radiation piece of metal, which has the first resonant ring, annular gap and reserved connection hole position from outside to inside, and the metal probe is connected to the first radiation piece through the reserved connection hole position.

3. The SIW resonant cavity vortex field antenna based on coplanar metasurface according to claim 1, characterized in that: The relative dielectric constant of the first dielectric substrate is 1.1-4.4, the thickness is 0.5-4 mm, and the metal probe is inserted therein.

4. The SIW resonant cavity vortex field antenna based on coplanar metasurface according to claim 1, characterized in that: The second radiation plate is provided with a through hole, and the diameter of the through hole is larger than the cross-sectional diameter of the metal probe.

5. The SIW resonant cavity vortex field antenna based on coplanar metasurface according to claim 1, characterized in that: The first resonant ring and the second resonant ring are a plurality of rhombus-shaped resonant rings arranged in a periodic manner and arranged around a circle, and the diagonal length of the rhombus-shaped resonant ring is 1-7.5 mm.

6. The SIW resonant cavity vortex field antenna based on coplanar metasurface according to claim 5, characterized in that: The distance from the center of the radiation plate to the center of the diamond resonant ring is 16-20mm, the distance from the center of the radiation plate to the inner edge of the annular gap is 11-13mm, and the gap width is 0.5-2mm; the distance from the center of the radiation plate to the axial center of the metal probe is 5-10mm, the diameter of the metal probe is 0.5-2mm, and the arc angle between adjacent metal probes is 360° / N, where N is the number of metal probes.

7. The SIW resonant cavity vortex field antenna based on coplanar metasurface according to claim 6, characterized in that: The feeding network is arranged on the lower surface of the second dielectric substrate, the radius of the second dielectric substrate is 14-18 mm, the relative dielectric constant is 1.4-4.4, the thickness is 0.5-4 mm, and the feeding network is a one-to-N feeding network.

8. The SIW resonant cavity vortex field antenna based on coplanar metasurface according to claim 7, characterized in that: An arc is cut off from the second dielectric substrate to which the feeding network is attached, and the cut surface is set as the feeding port excitation.

9. The SIW resonant cavity vortex field antenna based on coplanar metasurface according to claim 7 or 8, characterized in that: The N output ports of the feeding network are sequentially increased by 1 / N wavelength, so that the output port phase is delayed by 360° / N.

10. A device, characterized in that: include: processor; Memory; The SIW resonant cavity vortex field antenna based on a coplanar metasurface as described in any one of claims 1 to 9; And a computer program, wherein the computer program is stored in the memory, and the computer program includes instructions, which, when executed by the processor, enable the device to communicate with other electronic devices through the SIW resonant cavity vortex field antenna based on the coplanar metasurface.

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