A broadband low-profile dual-polarized antenna based on metasurface

Abstract

The application discloses a broadband low-profile dual-polarized antenna based on a metasurface, which comprises, from bottom to top, a metal bottom plate, a first dielectric substrate, a radiation antenna, a second dielectric substrate and a metasurface structure, wherein the radiation antenna comprises a circular radiation antenna body, a cross-shaped hole is arranged in the middle of the circular radiation antenna body, a plurality of fan-shaped holes are arranged on the outer periphery of the cross-shaped hole, and a feeder line connected with the circular radiation antenna body is arranged on the inner edges of the adjacent two fan-shaped holes. The application has the advantages that the bandwidth and gain of the antenna are effectively improved through the introduction of the design of the cross-shaped hole and the fan-shaped hole, the optimization of the feeder line structure, the arrangement of the metal bottom plate and the circular through hole, the combination of the dielectric substrate and the non-metal through hole and the introduction of the metasurface structure and the like.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of mobile communication antennas, in particular to a broadband low-profile dual-polarized antenna based on a metasurface. BACKGROUND

[0002] A microstrip patch antenna is a common antenna design used in wireless communication and microwave fields. In practical applications, the microstrip patch antenna is commonly used in various wireless communication devices, such as Wi-Fi routers, Bluetooth devices, mobile communication devices, and some radars and microwave sensors. In recent years, the microstrip patch antenna has gained a prominent position in the research and development of compact lightweight antennas due to its low profile, ease of manufacture, conformal structure and ease of integration. However, narrow bandwidth and low gain are some major drawbacks of the microstrip patch antenna, which limit their applications.

[0003] In order to overcome the inherent narrow bandwidth and low gain of the patch antenna, several methods have been developed to improve the bandwidth and gain. The Fabry-Perot cavity method increases the gain and bandwidth; however, due to their high profile, these antennas have poor mechanical performance. Antennas with multi-layer stacked substrates and air gap-free designs have relatively high gain and wideband CP characteristics, but due to their high profile and complex structure, they have limitations, and because of the complex structure, the antenna manufacturing difficulty is increased, which leads to an increase in production cost, and is not suitable for large-scale production and promotion. SUMMARY

[0004] The technical problem to be solved by the application is to overcome the above technical defects and provide a broadband low-profile dual-polarized antenna based on a metasurface.

[0005] To solve the above technical problems, the technical solution provided by the application is: a broadband low-profile dual-polarized antenna based on a metasurface, comprising a metal bottom plate, a first dielectric substrate, a radiation antenna, a second dielectric substrate and a metasurface structure arranged in sequence from bottom to top, the radiation antenna comprises a circular radiation antenna body, a cross-shaped hole is arranged in the middle of the circular radiation antenna body, a plurality of fan-shaped holes are arranged on the outer periphery of the cross-shaped hole, and a feed line connected with the circular radiation antenna body is arranged on the inner edges of adjacent two fan-shaped holes.

[0006] Preferably, the cross-shaped hole is composed of a first rectangular hole and a second rectangular hole intersecting with each other, the fan-shaped hole is four, and the cross-shaped hole and the four fan-shaped holes divide the circular radiation antenna body into an inner circular ring part, an outer circular ring part and four rectangular connecting parts for connecting the inner circular ring part and the outer circular ring part.

[0007] The diameter R1 of the outer circular ring part is 32 mm, the width X3 of the outer circular ring part is 2 mm, the diameter R2 of the inner circular ring part is 17 mm, the width D3 of the rectangular connecting part is 4.2 mm, the width D1 of the first rectangular hole is 1.4 mm and the length L1 is 20 mm, and the width D2 of the second rectangular hole is 2 mm and the length L2 is 24 mm.

[0008] Preferably, the feeder line is composed of a rectangular microstrip line and a trapezoidal microstrip line, the length K1 of the rectangular microstrip line is 1.5 mm and the width X1 is 0.8 mm, the length K2 of the bottom of the trapezoidal microstrip line is 2.5 mm and the height X2 of the bottom is

[0009] 1.25 mm.

[0010] Preferably, the diameter CR1 of the metal bottom plate is 46 mm, and two circular through holes are further arranged at the orthogonal axes of the metal bottom plate, and the diameter P2 of the circular through hole is 3 mm.

[0011] Preferably, two non-metal through holes for connecting the radiating antenna are arranged on the first dielectric substrate, and the positions of the non-metal through holes correspond to the positions of the circular through holes.

[0012] Preferably, the diameter CR1 of the first dielectric substrate is 46 mm, the thickness is 1.6 mm, the material is FR4, the relative dielectric constant is 4.4, and the diameter P1 of the non-metal through hole is 1 mm.

[0013] Preferably, the diameter CR1 of the second dielectric substrate is 46 mm, the thickness is 1.6 mm, the material is FR4, and the relative dielectric constant is 4.4.

[0014] Preferably, the metasurface structure is composed of sixteen circular patches, and the sixteen circular patches are arranged in a 4x4 array.

[0015] Preferably, the diameter CR2 of the circular patch is 6.8 mm, and the spacing S1 between adjacent two circular patches is 0.75 mm.

[0016] Compared with the prior art, the application has the advantages that: compared with the prior art, the application has obvious advantages in the design of a microstrip patch antenna. In view of the problems of narrow bandwidth and low gain of the traditional microstrip patch antenna, the application introduces a cross-shaped hole and a fan-shaped hole design, optimizes the feed line structure, sets a metal bottom plate and a circular through hole, adopts a combination of a dielectric substrate and a non-metal through hole, and introduces a super surface structure and other innovative measures, thereby effectively improving the bandwidth and gain of the antenna. Compared with the high-profile antenna adopting the Fabry-Perot cavity method and the complex structure and production difficulty caused by the multi-layer stacked substrate design, the application realizes more excellent wideband and high efficiency on the basis of maintaining the advantages of low posture, easy manufacturing and integration, is suitable for various wireless communication devices and scenes, especially suitable for the research and production of compact and light antennas, has lower cost and higher cost performance, and is conducive to large-scale production and promotion. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of an embodiment of the application.

[0018] Figure 2 It is a schematic diagram of a super surface structure in an embodiment of the application.

[0019] Figure 3 It is a schematic diagram of a second dielectric substrate structure in an embodiment of the application.

[0020] Figure 4 It is a structural schematic diagram of a radiating antenna in an embodiment of the application.

[0021] Figure 5 It is a schematic diagram of a first dielectric substrate structure in an embodiment of the application.

[0022] Figure 6 It is a schematic diagram of a metal bottom plate structure in an embodiment of the application. Figure 1

[0023] Figure 7 It is a simulation result of the antenna return loss (S11) of the application.

[0024] Figure 8 It is a simulation result of the antenna port reflection coefficient (S22) of the application.

[0025] Figure 9 It is a simulation result of the antenna port isolation (S12) of the application.

[0026] Figure 10 It is a simulation result of the antenna port isolation (S21) of the application.

[0027] Figure 11 It is a far-field radiation pattern of the antenna of the application in the YZ direction at a working frequency of 6GHz.

[0028] ​Figure 12 The far-field radiation patterns of the antenna of the present application in YZ direction at 7GHz operating frequency, respectively;

[0029] Figure 13 The far-field radiation patterns of the antenna of the present application in YZ direction at 8GHz operating frequency, respectively;

[0030] Figure 14 The far-field radiation patterns of the antenna of the present application in YZ direction at 9GHz operating frequency, respectively;

[0031] As shown in the figure: 1, metal base plate, 2, first dielectric substrate, 3, radiation antenna, 4, second dielectric substrate, 5, super surface structure, 6, cross-shaped hole, 7, fan-shaped hole, 8, feed line, 9, first rectangular hole, 10, second rectangular hole, 11, inner circular ring part, 12, outer circular ring part, 13, rectangular connecting part, 14, circular through hole, 15, non-metal through hole, 16, circular patch. DETAILED DESCRIPTION

[0032] The present application will be further described below in conjunction with the accompanying drawings.

[0033] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0034] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0035] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood through specific circumstances.

[0036] The application provides a broadband low-profile dual-polarized antenna based on a metasurface, as shown in the drawings, comprising, from bottom to top, a metal bottom plate 1, a first dielectric substrate 2, a radiation antenna 3, a second dielectric substrate 4 and a metasurface structure 5, the radiation antenna 3 comprises a circular radiation antenna body, a cross-shaped hole 6 is arranged in the middle of the circular radiation antenna body, a plurality of fan-shaped holes 7 are arranged on the outer periphery of the cross-shaped hole 6, and a feed line 8 connected with the circular radiation antenna body is arranged on the inner edges of adjacent two fan-shaped holes 7. Figure 1 Specifically, as shown in the drawings, the cross-shaped hole 6 is composed of a first rectangular hole 9 and a second rectangular hole 10, the fan-shaped hole 7 is four, and the cross-shaped hole 6 and the four fan-shaped holes 7 divide the circular radiation antenna body into an inner circular ring part 11, an outer circular ring part 12 and four rectangular connecting parts 13 for connecting the inner circular ring part 11 and the outer circular ring part 12, and the metasurface structure 5 is introduced on the top of the second dielectric substrate 4, which can greatly improve the working bandwidth of the antenna. In this embodiment, the cross-shaped hole 6 composed of the first rectangular hole 9 and the second rectangular hole 10 is carefully designed. This structure not only looks beautiful, but more importantly, it optimizes the electromagnetic performance of the antenna. The cross-shaped hole 6 effectively breaks the surface current of the circular radiation antenna body (the radiation antenna 3), thereby reducing the coupling between the antenna ports and improving the port isolation. At the same time, four fan-shaped holes 7 are arranged on the outer periphery of the cross-shaped hole 6. These fan-shaped holes 7 are connected with the circular radiation antenna body through the feed line 8, which not only enhances the radiation ability of the antenna, but also optimizes the antenna pattern. This design enables the antenna to achieve wideband performance while maintaining a low profile, meeting the high requirements of modern wireless communication systems on antenna performance.

[0037] Figure 4 The diameter R1 of the outer circular ring part 12 is 32 mm, the width X3 of the outer circular ring part 12 is 2 mm, the diameter R2 of the inner circular ring part 11 is 17 mm, the width D3 of the rectangular connecting part 13 is 4.2 mm, the width D1 of the first rectangular hole 9 is 1.4 mm and the length L1 is 20 mm, and the width D2 of the second rectangular hole 10 is 2 mm and the length L2 is 24 mm.

[0038] The diameter R1 of the outer circular ring part 12 is 32 mm, the width X3 of the outer circular ring part 12 is 2 mm, the diameter R2 of the inner circular ring part 11 is 17 mm, the width D3 of the rectangular connecting part 13 is 4.2 mm, the width D1 of the first rectangular hole 9 is 1.4 mm and the length L1 is 20 mm, and the width D2 of the second rectangular hole 10 is 2 mm and the length L2 is 24 mm.

[0039] ​In one embodiment, the feed line 8 is composed of a rectangular microstrip line and a trapezoidal microstrip line, the length K1 of the rectangular microstrip line is 1.5 mm and the width X1 is 0.8 mm, the length K2 of the bottom of the trapezoidal microstrip line is 2.5 mm and the height X2 of the bottom is 1.25 mm. In this embodiment, the structure of the feed line 8 is optimized, and a design combining a rectangular microstrip line and a trapezoidal microstrip line is adopted. This design fully considers the requirements of antenna impedance matching and energy transmission. The rectangular microstrip line provides a stable current transmission path, while the trapezoidal microstrip line achieves good matching with the antenna body (radiating antenna 3) by changing the width and length of the microstrip line. This structure not only effectively reduces the physical size of the antenna, but also improves the bandwidth and radiation efficiency of the antenna. In addition, the use of the trapezoidal microstrip line also reduces the electromagnetic interference between the feed line and the antenna, further improving the performance of the antenna.

[0040] In one embodiment, as shown in Figure 6 , the diameter CR1 of the metal base plate 1 is 46 mm, and two circular through holes 14 with a diameter P2 of 3 mm are also provided at the orthogonal axes of the metal base plate 1. The metal base plate 1 serves as the ground plane of the entire antenna, and when the antenna is excited, the metal base plate 1 can reflect electromagnetic waves and produce radiation, thereby increasing the bandwidth and enhancing the directivity of the antenna.

[0041] In one embodiment, as shown in Figure 5 , the first dielectric substrate 2 is provided with two non-metal through holes 15 for connecting the radiating antenna 3, and the positions of the non-metal through holes 15 correspond to the positions of the circular through holes 14. The non-metal through holes 14 serve as channels for connecting the coaxial inner core to the radiating antenna 3. In this embodiment, the metal base plate 1 serves as the ground plane of the antenna and has an important influence on the performance of the entire antenna. By providing the circular through holes 14 on the metal base plate 1, the radiation characteristics of the antenna are adjusted. The circular through holes 14 not only provide the necessary channels for the feed line 8, but also affect the radiation pattern and bandwidth of the antenna by adjusting the position and size of the circular through holes 14. This design enables the antenna to maintain a low profile while achieving high directivity and gain. In addition, the presence of the metal base plate 1 can effectively reflect electromagnetic waves, enhance the radiation ability of the antenna, and improve the performance of the wireless communication system.

[0042] In one embodiment, as shown in Figure 5 , the diameter CR1 of the first dielectric substrate 2 is 46 mm, the thickness is 1.6 mm, the material is FR4, the relative dielectric constant is 4.4, and the diameter P1 of the non-metal through hole 15 is 1 mm, as shown in Figure 3As shown, the diameter CR1 of the second dielectric substrate 4 is 46mm, the thickness is 1.6mm, the material is FR4, and the relative dielectric constant is 4.4. In this embodiment, FR4 is selected as the material of the first dielectric substrate 2 and the second dielectric substrate 4, because FR4 has a lower dielectric constant and loss, and is suitable for making broadband antennas. The diameter and thickness of the first dielectric substrate 2 and the second dielectric substrate 4 are carefully calculated and optimized to ensure that the antenna has the best performance. In addition, the selection of the material and size of the dielectric substrate also takes into account the operating frequency and bandwidth requirements of the antenna, ensuring that the antenna can maintain good performance in a wide frequency band range.

[0043] In one embodiment, as shown in Figure 2 , the metasurface structure 5 is composed of sixteen circular patches 16 arranged in a 4x4 array, the diameter CR2 of the circular patch 16 is 6.8mm, and the spacing S1 between adjacent two circular patches 16 is 0.75mm. It is conceivable that by adding a metasurface structure 5 on top of the antenna, a substrate integrated waveguide structure is formed, which can effectively concentrate field energy within the structure. The electromagnetic coupling feeding method is used for feeding, which directly contacts the radiating antenna and the feed line, and the current is coupled to each other. The feeding structure is composed of two ladder-shaped feed lines. The metasurface structure 5 provides stable energy input for the antenna through electromagnetic coupling feeding, and effectively concentrates field energy within the structure. This design not only improves the radiation efficiency and gain of the antenna, but also enhances the directivity and bandwidth of the antenna. The use of the metasurface structure 5 enables the antenna to maintain a low profile while achieving high-performance wireless communication. In addition, the metasurface structure 5 also has flexible control ability, which can adjust the performance parameters of the antenna according to actual needs to meet the needs of different application scenarios.

[0044] According to the technical solutions described in the above embodiments, the results obtained by using ANSYS HFSS simulation software are used to further explain and illustrate the technical effects of the present application.

[0045] As shown in Figure 7 , in this embodiment, S11 is less than -10dB in the operating frequency band of 6.15-9.7GHz; as shown in Figure 8 , in this embodiment, S22 is less than -10dB in the frequency band of 6.2-9.65GHz; as shown in Figure 9 , in this embodiment, S12 is less than -15dB in the operating frequency band of 4-11GHz. As shown in Figure 10 , in this embodiment, S21 is less than -15dB in the operating frequency band of 4-11GHz. As shown in Figure 11 , Figure 12 , Figure 13 , Figure 14As shown, the radiation antenna in this embodiment has a far-field radiation pattern in the YZ direction at 6 GHz, 7 GHz, 8 GHz, and 9 GHz operating frequencies with input excitation from the port.

[0046] From the simulation results above, the antenna proposed in this application has a wide operating frequency band, and within the operating frequency band, the port isolation of the antenna is less than -15 dB, which has a wide application prospect in wireless communication.

[0047] Working principle: The antenna design involved in this application aims to achieve high-performance wireless communication through a series of innovative component and structural optimizations. The following is a detailed description of its working principle:

[0048] Firstly, by introducing the design of cross-shaped hole 6 and fan-shaped hole 7, this application successfully optimizes the electromagnetic performance of the antenna. The cross-shaped hole 6 is composed of the first rectangular hole 9 and the second rectangular hole 10, which breaks the surface current of the circular radiation antenna body (radiation antenna 3), thereby reducing the coupling between the antenna ports and improving the port isolation. At the same time, the four fan-shaped holes 7 are distributed around the cross-shaped hole 6, which are connected to the radiation antenna 3 through the feed line 8, enhancing the radiation ability of the antenna and optimizing the directional pattern. This design enables the antenna to maintain a low profile while achieving wideband performance.

[0049] Secondly, the structural optimization of the feed line 8 is the key to improving the performance of the antenna. This application adopts a design combining rectangular microstrip lines and trapezoidal microstrip lines, which not only provides a stable current transmission path for the antenna, but also realizes good matching with the radiation antenna 3 through the width and length changes of the trapezoidal microstrip lines. This design effectively reduces the physical size of the antenna, improves the bandwidth and radiation efficiency, and reduces electromagnetic interference between the feed line and the antenna.

[0050] The metal bottom plate 1, as the ground plane of the antenna, has an important influence on the performance of the antenna. By setting a circular through-hole 14 on the metal bottom plate 1, a necessary channel is provided for the feed line 8, and the radiation pattern and bandwidth of the antenna are affected. The design of the circular through-hole 14 enables the antenna to maintain a low profile while achieving high directivity and gain. In addition, the metal bottom plate 1 can effectively reflect electromagnetic waves, enhancing the radiation ability of the antenna.

[0051] The selection of the first dielectric substrate 2 and the second dielectric substrate 4 is also an important aspect of this application. FR4 material as a dielectric substrate has a low dielectric constant and loss characteristics, which enables the antenna to maintain good performance in a wide frequency band. At the same time, the non-metallic through-hole 15 set on the first dielectric substrate 2 provides a channel for the connection between the feed line 8 and the radiation antenna 3, simplifying the antenna structure, improving stability and reliability.

[0052] Finally, the application introduces a metasurface structure 5 composed of sixteen circular patches 16. This structure provides stable energy input for the antenna through electromagnetic coupling feeding mode, and effectively concentrates field energy in the structure, improving the radiation efficiency and gain of the antenna. The use of the metasurface structure 5 enables the antenna to achieve high-performance wireless communication while maintaining a low profile.

[0053] In summary, through the design of cross-shaped holes and sector-shaped holes, the optimization of the feed line structure, the role of the metal bottom plate and the circular through-hole, the design of the dielectric substrate and the non-metallic through-hole, and the introduction of the metasurface structure, the application realizes excellent performance of the antenna in terms of wideband, low profile, high directivity, and high efficiency. These innovative designs and component selections collectively constitute the working principle of the high-performance wireless communication antenna of the application.

[0054] The above describes the application and its embodiments, which are not limiting, and the drawings shown are only one of the embodiments of the application, and the actual structure is not limited thereto. In summary, if a person of ordinary skill in the art is inspired thereby, without departing from the spirit of the application, without creative design, similar structural modes and embodiments to the technical solution should belong to the protection scope of the application.

Claims

1. A broadband low-profile dual-polarized antenna based on metasurface, characterized in that, It comprises a metal bottom plate (1), a first dielectric substrate (2), a radiation antenna (3), a second dielectric substrate (4) and a metasurface structure (5) arranged in turn from bottom to top, the radiation antenna (3) comprises a circular radiation antenna body, the middle part of the circular radiation antenna body is provided with a cross-shaped hole (6), the outer periphery of the cross-shaped hole (6) is provided with a plurality of fan-shaped holes (7), and the inner edges of adjacent two fan-shaped holes (7) are both provided with a feed line (8) connected with the circular radiation antenna body. The cross-shaped hole (6) is composed of a first rectangular hole (9) and a second rectangular hole (10), the fan-shaped hole (7) is four, and the cross-shaped hole (6) and the four fan-shaped holes (7) divide the circular radiation antenna body into an inner circular ring part (11), an outer circular ring part (12) and four rectangular connecting parts (13) for connecting the inner circular ring part (11) and the outer circular ring part (12). The diameter R1 of the outer circular ring part (12) is 32mm, and the width X3 of the outer circular ring part (12) is 2mm, the diameter R2 of the inner circular ring part (11) is 17mm, the width D3 of the rectangular connecting part (13) is 4.2mm, the width D1 of the first rectangular hole (9) is 1.4mm and the length L1 is 20mm, the width D2 of the second rectangular hole (10) is 2mm and the length L2 is 24mm.

2. The metasurface-based wideband low-profile dual-polarized antenna according to claim 1, wherein, The feed line (8) is composed of a rectangular microstrip line and a trapezoidal microstrip line, the length K1 of the rectangular microstrip line is 1.5mm and the width X1 is 0.8mm, the length K2 of the trapezoidal microstrip line is 2.5mm and the height X2 of the bottom edge is 1.25mm.

3. The ultra-surface-based wideband low-profile dual-polarized antenna according to claim 1, wherein, The diameter CR1 of the metal bottom plate (1) is 46mm, and the metal bottom plate (1) is also provided with two circular through holes (14) at the orthogonal axis, and the diameter P2 of the circular through hole (14) is 3mm.

4. The metasurface-based wideband low-profile dual-polarized antenna according to claim 3, wherein, The first dielectric substrate (2) is provided with two non-metal through holes (15) for connecting the radiation antenna (3), and the positions of the non-metal through holes (15) correspond to the positions of the circular through holes (14).

5. The metasurface-based wideband low-profile dual-polarized antenna according to claim 4, wherein, The diameter CR1 of the first dielectric substrate (2) is 46mm, the thickness is 1.6mm, the material is FR4, the relative dielectric constant is 4.4, and the diameter P1 of the non-metal through hole (15) is 1mm.

6. The metasurface-based wideband low-profile dual-polarized antenna according to claim 1, wherein, The diameter CR1 of the second dielectric substrate (4) is 46mm, the thickness is 1.6mm, the material is FR4, and the relative dielectric constant is 4.

4.

7. The metasurface-based wideband low-profile dual-polarized antenna according to claim 1, wherein, The metasurface structure (5) is composed of sixteen circular patches (16), and the sixteen circular patches (16) are arranged in a 4×4 array.

8. The metasurface-based wideband low-profile dual-polarized antenna according to claim 7, wherein, The diameter CR2 of the circular patch (16) is 6.8mm, and the spacing S1 between adjacent two circular patches (16) is 0.75mm.

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