A shared-aperture metasurface antenna with high isolation

Abstract

The application discloses a shared-aperture metasurface antenna with high isolation, which comprises a horn feed source and a shared-aperture metasurface patch antenna assembly, and the shared-aperture metasurface patch antenna assembly comprises at least one microwave metasurface patch unit, and each microwave metasurface patch unit comprises at least two reflective array units. The shared-aperture metasurface antenna forms the effect of microwave metasurface antenna and millimeter wave reflective array antenna multiplexing on the side close to the horn feed source, the required compensation phase can be obtained by adjusting the size of the reflective array unit, the independent design of the shared-aperture antenna is realized, the high isolation and stable radiation pattern in the microwave and millimeter wave working frequency bands are realized, the antenna has a large frequency ratio of 1:8.57, the ultra-high isolation of more than 100 dB and 40 dB is realized in the low frequency band and the high frequency band respectively, the microwave metasurface and the millimeter wave reflective array effect of the antenna can be integrated on the same layer of the antenna, the antenna structure is compact, and the antenna profile and cost are effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wireless communication, and relates to an antenna, in particular to a high-isolation shared-aperture metasurface antenna. BACKGROUND

[0002] An antenna is a component for transmitting and receiving free-space electromagnetic waves in a wireless communication system, which is located at the front end of a radio frequency system, and its performance determines whether the communication device can correctly transmit signals. For an antenna system with receiving and transmitting functions, the isolation of the receiving and transmitting ends needs to be ensured, therefore, the working frequency bands of the receiving and transmitting antennas are often different, and in some cases, the working frequencies of the two are quite different. Traditional single-frequency antennas are difficult to meet the requirements of both receiving and transmitting antennas. In addition, with the continuous development of communication technology, communication systems often need to cover multiple frequency bands to meet different needs. In recent years, multi-band antennas have been widely studied and applied. In a large frequency ratio multi-band communication system compatible with microwave and millimeter wave frequency bands, different frequency band antennas need to be designed and combined reasonably.

[0003] Since the gain of an antenna is mainly determined by the area of its radiation aperture, if the radiation structures for different frequency bands occupy different apertures, it is difficult for a communication system containing multiple antennas of different frequency bands to be miniaturized. Since shared-aperture antennas can significantly improve the utilization efficiency of the aperture, they help to integrate and miniaturize communication systems, thus attracting more and more researchers' attention. Shared-aperture antennas can design antennas of different frequency bands in the same aperture, which can effectively reduce the space occupied by the antennas and reduce the complexity of the communication system. In some microwave / millimeter wave large frequency ratio devices, the use of shared-aperture antennas can reduce costs while ensuring transmission speed and reliability, effectively utilizing space and spectrum resources, and being more conducive to realizing multi-band integrated communication systems. Therefore, shared-aperture antennas with large frequency ratios have attracted more and more attention due to their advantages of cost savings, compact structure, high aperture utilization rate, etc., and have been widely used in military, commercial, medical and other fields such as synthetic aperture radar and satellite communication.

[0004] At present, the main ways to realize aperture sharing include aperture sharing of the upper radiation structure and aperture sharing of the lower feeding structure. Since different frequency band antennas must be integrated together to achieve the purpose of multi-band communication in the same aperture, too compact antenna arrangement will lead to increased mutual coupling between different frequency antennas, poor isolation, and sharp deterioration of antenna radiation performance and port performance, which will further affect communication quality. In summary, existing shared-aperture antennas are difficult to meet the requirements of high aperture utilization rate and high port isolation at the same time.

[0005] Therefore, it is necessary to further improve the shared-aperture antennas of the prior art. SUMMARY

[0006] To this end, the technical problem to be solved by the present application is that the existing shared aperture antenna is difficult to meet the requirements of high aperture utilization rate and high isolation, thereby providing a shared aperture metasurface antenna with high aperture utilization rate and isolation.

[0007] To solve the above technical problems, the technical scheme of the present application is as follows:

[0008] The present application provides a shared aperture metasurface antenna with high isolation, which comprises:

[0009] a horn feed source;

[0010] a shared aperture metasurface patch antenna assembly arranged in a spaced manner with the feed source, the shared aperture metasurface patch antenna assembly comprising: a shared aperture metasurface patch, a first dielectric layer, a metal ground plate, and a second dielectric layer arranged in sequence in a direction away from the horn feed source, the metal ground plate being provided with a gap, and the second dielectric layer being connected with a feeding mechanism;

[0011] The shared aperture metasurface patch comprises at least one microwave metasurface patch unit, and each microwave metasurface patch unit comprises at least two reflective array units.

[0012] Preferably, the reflective array unit comprises: a central patch, at least one connecting arm connected to the outer periphery of the central patch, one end of the connecting arm being connected to the central patch and the other end being connected to an outer frame.

[0013] Preferably, the central patch is a rectangular patch, the length and width of the central patch are both 0.023λ-0.058λ, the outer frame is a rectangular outer frame, the length and width of the outer frame are both 0.061λ-0.068λ, the width of the connecting arm is 0.005λ-0.007λ, and the length of the connecting arm is 0.008-0.018λ, wherein λ is the wavelength at the working frequency of the antenna.

[0014] Preferably, the distance between the horn feed source and the shared aperture metasurface patch is 0.75λ-0.85λ, wherein λ is the wavelength at the working frequency of the antenna; the horn feed source comprises a signal input portion, a switching portion, and a horn output portion connected in sequence, the horn output portion is provided with a first opening at one end close to the switching portion, the other end of the horn output portion away from the switching portion is an open end, the plane where the open end is located has an included angle of 23°-27° with the shared aperture metasurface patch; the switching portion is provided with a second opening at a position corresponding to the first opening, the signal input portion has a cavity inside, and the cavity, the second opening, and the first opening are sequentially connected.

[0015] As preferred, the cross-sectional pattern of the first opening and the second opening is rectangular, and the length of the first opening and the second opening is 0.093λ-0.105λ, and the width is 0.047λ-0.058λ; the cross-sectional pattern of the open end is rectangular, the length of the open end is 0.257λ-0.280λ, the width of the open end is 0.187λ-0.222λ, and the height of the horn output part is 0.128λ-0.157λ; the cavity inside the signal input part is a cuboid cavity, the length of the cavity is 0.093λ-0.105λ, the width is 0.047λ-0.058λ, and the height is 0.128λ-0.157λ; the adapter part is a cuboid plate structure, the length of the adapter part is 0.21λ-0.26λ, the width is 0.21λ-0.26λ, and the thickness is 0.014λ-0.021λ; wherein λ is the wavelength at the working frequency of the antenna.

[0016] As preferred, a side wall of the signal input part is provided with a through hole for connecting an external connector, the through hole includes a first through hole, a second through hole and a third through hole arranged in sequence in a direction away from the adapter part, the second through hole communicates with the cavity; the aperture of the first through hole and the third through hole is 0.027λ-0.031λ; the aperture of the second through hole is 0.016λ-0.018λ.

[0017] As preferred, the first dielectric layer is a cuboid plate, the length and width of the first dielectric layer are both 1.167λ-1.283λ, and the thickness is 0.026λ-0.028λ; a first branch is connected around the first dielectric layer, the first branch is provided with a first connecting hole, the cross-sectional pattern of the first branch is rectangular, the length is 0.117λ-0.163λ, and the width is 0.047λ-0.07λ, the aperture of the first connecting hole is 0.029λ-0.041λ; the second dielectric layer is a cuboid plate, the length and width of the second dielectric layer are both 1.167λ-1.283λ, and the thickness is 0.005λ-0.007λ; a second branch is connected around the second dielectric layer, the second branch is provided with a second connecting hole, the cross-sectional pattern of the second branch is rectangular, the length is 0.117λ-0.163λ, and the width is 0.047λ-0.07λ, the aperture of the second connecting hole is 0.029λ-0.041λ, wherein λ is the wavelength at the working frequency of the antenna.

[0018] As preferred, one side of the first dielectric layer is also provided with an avoiding groove, the length of the avoiding groove is 0.187λ-0.233λ, and the width is 0.058λ-0.082λ.

[0019] As preferred, the shared aperture metasurface patch comprises 4 rows and 4 columns of microwave metasurface patch units, each of the shared aperture patch units comprises 4 rows and 4 columns of the reflective array units, the length and width of the shared aperture patch unit are 0.25 lambda-0.26 lambda, and the distance between two adjacent shared aperture patch units is 0.009 lambda-0.014 lambda, wherein lambda is the wavelength at the working frequency of the antenna.

[0020] As preferred, the feeding mechanism is a microstrip feed line, the microstrip feed line is arranged perpendicularly to the slot, the length of the slot is 0.502 lambda-0.548 lambda, and the width is 0.021 lambda-0.026 lambda, the length of the microstrip feed line is 0.758 lambda-0.817 lambda, and the width is 0.017 lambda-0.018 lambda.

[0021] The above technical solution of the present application has the following advantages compared with the prior art:

[0022] The high-isolation shared aperture metasurface antenna provided by the present application comprises a horn feed source and a shared aperture metasurface patch antenna assembly arranged at a distance from the horn feed source, the shared aperture metasurface patch antenna assembly comprises a shared aperture metasurface, a first dielectric layer, a metal ground plate, and a second dielectric layer arranged in sequence in the direction away from the horn feed source, the metal ground plate is provided with a slot, and the second dielectric layer is connected with a feeding mechanism; the shared aperture metasurface comprises at least one microwave metasurface patch unit, and each microwave metasurface patch unit comprises at least two reflective array units. The shared aperture metasurface antenna forms the effect of microwave metasurface antenna and millimeter wave reflective array antenna multiplexing on the side close to the horn feed source, the required compensation phase can be obtained by adjusting the size of the reflective array unit, which has no effect on low-frequency radiation, realizes independent design of the shared aperture antenna, realizes high isolation and stable radiation pattern in the microwave and millimeter wave working frequency bands, has a large frequency ratio of 1:8.57, realizes super-high isolation of more than 100 dB and 40 dB in the low-frequency band and the high-frequency band respectively, and the microwave metasurface effect and the millimeter wave reflective array effect can be integrated in the same layer of the antenna, the antenna structure is compact, the antenna profile and cost are effectively reduced, and the antenna has important value and significance for 5G and subsequent communication systems. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the drawings, in which

[0024] Figure 1 is an exploded schematic view of the high-isolation shared aperture metasurface antenna provided by the embodiment of the present application;

[0025] Figure 2is a side view of a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0026] Figure 3 is a top view of a shared-aperture metasurface patch antenna assembly in a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0027] Figure 4 is a bottom view of a shared-aperture metasurface patch antenna assembly in a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0028] Figure 5 is a structural schematic diagram of a reflective array unit in a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0029] Figure 6 is a structural schematic diagram of a horn feed source in a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0030] Figure 7 is a top view of a horn feed source in a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0031] Figure 8 is a sectional schematic diagram of a horn feed source in a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0032] Figure 9 is a low-frequency reflection coefficient curve of a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0033] Figure 10 is a radiation pattern at 3.4 GHz of a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0034] Figure 11 is a radiation pattern at 3.5 GHz of a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0035] Figure 12 is a radiation pattern at 3.6 GHz of a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0036] Figure 13 is a gain curve at 3.4-3.6 GHz of a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0037] Figure 14 is a high-frequency reflection coefficient curve of a high-isolation shared-aperture metasurface antenna provided by an embodiment of the present application;

[0038] Figure 15is a radiation pattern of a high-isolation shared-aperture metasurface antenna at 30 GHz provided by the embodiment of the present application.

[0039] Figure 16 is a gain curve of a high-isolation shared-aperture metasurface antenna at 30 GHz provided by the embodiment of the present application.

[0040] The figure mark is shown as follows: 1-horn feed source; 11-signal input part; 111-cavity; 112-first through hole; 113-second through hole; 114-third through hole; 12-adapting part; 13-horn output part; 131-first opening; 2-shared-aperture metasurface patch; 21-microwave metasurface patch unit; 211-reflection array unit; 2111-central patch; 2112-connection arm; 2113-outer frame; 3-first dielectric layer; 31-first branch; 32-first connection hole; 33-avoidance groove; 4-metal floor; 41-slit; 5-second dielectric layer; 51-second branch; 52-second connection hole; 6-feeding mechanism. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0042] In the description of the present application, it should be understood that the terms "upper", "lower" and the like indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, or the orientation or positional relationship commonly understood by those skilled in the art, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0043] The "first", "second" and the like of the present application are only used to distinguish in description, and do not have special meanings.

[0044] In the description of the present application, it should be understood that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] Embodiment

[0046] The embodiment provides a high-isolation shared aperture metasurface antenna, please refer to Figures 1-8 The high-isolation shared aperture metasurface antenna comprises a horn feed source 1 and a shared aperture metasurface patch antenna assembly which is arranged at intervals from the horn feed source 1, and the shared aperture metasurface patch assembly comprises: a shared aperture metasurface patch 2, a first dielectric layer 3, a metal floor 4 and a second dielectric layer 5 which are sequentially and layerwisely arranged in a direction away from the horn feed source 1, the metal floor 4 is provided with a gap 41, and the second dielectric layer 5 is connected with a feeding mechanism 6 which is arranged correspondingly to the gap 41. Wherein, the shared aperture metasurface patch 2 comprises at least one microwave metasurface patch unit 21, and each microwave metasurface patch unit 21 comprises at least two reflective array units 211.

[0047] The high-isolation shared aperture metasurface antenna provided by the embodiment realizes the composite structure of the microwave metasurface antenna and the millimeter wave reflective array antenna in the shared aperture metasurface patch 2, wherein the microwave metasurface antenna function is realized by coupling and feeding of the feeding mechanism 6 and the gap 41, the millimeter wave reflective array antenna function is realized by beam reflection of the horn feed source 1 by the reflective array unit 211, the required compensation phase can be obtained by adjusting the size of the reflective array unit 211, and the size of the reflective array unit 211 has no influence on the overall size of the microwave metasurface patch unit, so that the low-frequency radiation effect is not affected, the independent design of the shared aperture antenna is realized, and then the number of elements and the frequency ratio of the antenna can be adjusted. Therefore, the shared aperture metasurface antenna provided by the embodiment realizes high-isolation and stable radiation pattern in the microwave frequency band and the millimeter wave working frequency band. The antenna has a large frequency ratio of 1:8.57, and more than 100dB and 40dB of super-high isolation is realized in the low-frequency band and the high-frequency band respectively, the antenna has little influence on each other when working in different frequency bands. And the microwave metasurface antenna and the millimeter wave reflective array antenna are combined in the most surface layer of the antenna, the reflective array antenna unit is embedded in the microwave metasurface antenna, and the profile and cost of the antenna are effectively reduced.

[0048] Wherein, the shared aperture metasurface patch 2 and the metal floor 4 can be made of copper material.

[0049] Please refer to Figure 5In the embodiment, the reflective array unit 211 specifically comprises: a center patch 2111, as shown in the figure, the center patch 2111 is a rectangular patch, the length and the width are both 0.023λ-0.058λ, preferably in the embodiment, the center patch 2111 is a square patch, and the side length is preferably 0.035λ, in the embodiment, λ is all the wavelength at the working frequency of the antenna, and the working frequency is 3.5GHz. The center patch 2111 is connected with a connecting arm 2112 around respectively, the connecting arm 2112 is preferably connected to the middle line position of the four edges of the center patch 2111, the cross-sectional shape of the connecting arm 2112 is a rectangle, the width is 0.005λ-0.007λ, preferably 0.006λ in the embodiment, and the length is 0.008λ-0.018λ, preferably 0.013λ in the embodiment. One end of the connecting arm 2112 is connected to the center patch 2111, and the other end is connected to an outer frame 2113, in the embodiment, the outer frame 2113 is a rectangular outer frame formed by surrounding a metal strip, the length and the width of the outer periphery are both 0.061λ-0.068λ, preferably 0.064λ in the embodiment, and the width of the metal strip is half of the width of the connecting arm 2112, that is, the width of the metal strip is 0.003λ in the embodiment, and it can be calculated from the above that the length of the connecting arm 2112 is 0.0115λ in the embodiment. In order to make the microwave metasurface patch unit 21 compact in structure, two adjacent reflective array units 211 share a metal strip of the outer frame 2113. Among them, the size of the center patch 2111 can be adjusted, and the function of obtaining a compensation phase is realized by adjusting the size of the center patch 2111, thereby realizing the independent design of the shared aperture antenna. The above structure of the reflective array unit 211 is obtained by digging a hollow groove on the metal patch, that is, a hollow design is made on the outer periphery of the center patch 2111 with a predetermined size, and the connecting arm 2112 and the outer frame 2113 structure are obtained. Thus, the form of the reflective array unit 211 embedded in the microwave metasurface patch is realized, the antenna profile is reduced, the antenna volume is reduced, and the cost is reduced.

[0050] To form the multiplexing effect of the microwave metasurface antenna and the millimeter wave reflectarray antenna, the shared-aperture metasurface patch 2 is a patch array formed by arranging a plurality of microwave metasurface patch units 21. In this embodiment, the shared-aperture metasurface patch 2 includes 4 rows and 4 columns of microwave metasurface patch units 21. Adjacent microwave metasurface patch units 21 are arranged with a spacing distance of 0.009λ-0.014λ, and preferably 0.011λ in this embodiment. Each microwave metasurface patch unit 21 is formed by arranging a plurality of reflectarray units 211. In this embodiment, the microwave metasurface patch unit 21 preferably includes 4 rows and 4 columns of reflectarray units 211, and adjacent two reflectarray units 211 share one side of the outer frame 2113. Of course, as a variable implementation, the number of rows and columns of reflectarray units 211 in the microwave metasurface patch unit 21 can also be other values, and the specific arrangement can be calculated according to the phase calculation formula. The number of rows and columns of microwave metasurface patch units 21 in the shared-aperture metasurface patch 2 can also use other values. In this embodiment, specifically, since each microwave metasurface patch unit 21 includes 4 rows and 4 columns of reflectarray units 211, the microwave metasurface patch unit 21 has a square structure, and the length and width are both 1.006λ-1.118λ, and preferably 1.056λ in this embodiment.

[0051] Please refer to Figures 6-8 In this embodiment, the specific structure of the horn feed source 1 is as follows: the horn feed source 1 includes a signal input part 11, an adapter part 12, and a horn output part 13 connected in sequence, and the horn output part 13 is arranged towards the shared-aperture metasurface patch 2. The horn output part 13 is provided with a first opening 131 at one end close to the adapter part 12, and the other end away from the adapter part 12 is an open end. The size of the open end is larger than that of one side of the first opening 131, thereby forming a horn-shaped structure. The adapter part 12 is provided with a second opening at a position corresponding to the first opening, and the second opening is adjacent to and penetrates through the first opening. The signal input part 11 has a cavity 111 inside, and the cavity 111, the second opening, and the first opening 131 are connected in sequence. The shape and size of the first opening 131 and the second opening are the same, and the cross-sectional shape of both is a rectangle. The length of the rectangular opening is 0.093λ-0.105λ, and preferably 0.10λ in this embodiment. The width of the rectangular opening is 0.047λ-0.058λ, and preferably 0.052λ in this embodiment. The cross-sectional shape of the open end is also a rectangle. The length inside the open end is 0.257λ-0.280λ, and preferably 0.265λ in this embodiment. The width inside the open end is 0.187λ-0.222λ, and preferably 0.205λ in this embodiment. The length of the horn output part 13 is 0.257λ-0.280λ, and preferably 0.265λ in this embodiment. The width of the horn output part 13 is 0.187λ-0.222λ, and preferably 0.205λ in this embodiment. Figure 7As can be seen, in the embodiment, the cross-sectional shape of the horn output part 13 of the horn feed source 1 is an isosceles trapezoid with a narrow bottom and a wide top, and the whole is a hollow trapezoidal platform structure. The height of the horn output part 13 is 0.128λ-0.157λ, and preferably 0.136λ in the embodiment. The wall thickness of the horn output part 13 is 0.021λ-0.026λ, and preferably 0.023λ in the embodiment. The open end of the horn output part 13 is arranged towards and close to the shared-aperture super-surface patch 2. The distance between the open end of the horn output part 13 and the shared-aperture super-surface patch 2 is 0.75λ-0.85λ, and preferably 0.8λ in the embodiment. As shown in FIG. 1, the plane on which the open end of the horn output part 13 is located is arranged obliquely relative to the shared-aperture super-surface patch 2. The included angle between the two is 23°-27°, and preferably 25° in the embodiment. Figure 2

[0052] The cross-sectional shape of the signal input part 11 is a rectangle. The cavity 111 inside the signal input part 11 is a cuboid cavity. The length and width of the cavity 111 are the same as the size of the first opening 131. The length is 0.093λ-0.105λ, and preferably 0.10λ in the embodiment. The width is 0.047λ-0.058λ, and preferably 0.052λ in the embodiment. The height is 0.128λ-0.157λ, and preferably 0.138λ in the embodiment. The height refers to the distance from one end close to the adapter part 12 to the other end away from the adapter part 12.

[0053] The adapter part 12 is a cuboid plate structure. The length is 0.21λ-26λ, the width is 0.21λ-0.26λ, and the thickness is 0.014λ-0.021λ. In the embodiment, the length of the adapter part 12 is 0.24λ, the width is 0.24λ, and the thickness is 0.018λ.

[0054] In order to realize the function of inputting signals to the signal input part 11, one side wall of the signal input part 11 is also provided with a through hole for connecting an external connector. In the embodiment, the external connector is preferably a high-frequency connector. The through hole includes a first through hole 112, a second through hole 113, and a third through hole 114 arranged in sequence in the direction away from the adapter part 12. The second through hole 113 communicates with the cavity 111, and the first through hole 112 and the third through hole 114 do not communicate with the cavity 111. The hole diameter of the first through hole 112 and the third through hole 114 is the same, which is 0.027λ-0.031λ, and preferably 0.029λ in the embodiment. The hole diameter of the second through hole 113 is 0.016λ-0.018λ, and preferably 0.017λ in the embodiment. The distance from the center of the second through hole 113 to the adapter part 12 is 0.093λ-0.117λ, and preferably 0.112λ in the embodiment.

[0055] ​In this embodiment, the material of the horn feed source 1 can be aluminum.

[0056] As shown in Figure 1 , Figure 3 In this embodiment, the first dielectric layer 3 is a cuboid dielectric plate, the length and width of which are both 1.167λ-1.283λ, and in this embodiment, the length and width of the first dielectric layer 3 are both preferably 1.202λ, and the thickness thereof is 0.026λ-0.028λ, and in this embodiment, it is preferably 0.027λ. The first dielectric layer 3 adopts F4BTMS220 plate material with a dielectric constant (ε r ) of 2.1-2.3. In order to facilitate the assembly of the antenna with other structures, the periphery of the first dielectric layer 3 is also connected with first branches 31, and first connecting holes 32 are formed on the first branches 31, which are used for assembling nylon screws, and in order to achieve stable connection with other structures, two first branches 31 are connected at the outer side of each edge of the first dielectric layer 3, and the cross-sectional shape of the first branches 31 is rectangular, the length thereof is 0.117λ-0.163λ, and in this embodiment, it is preferably 0.141λ, and the width thereof is 0.047λ-0.07λ, and in this embodiment, it is preferably 0.056λ.

[0057] In order to facilitate the feeding of the low-frequency connector in the later stage, one side edge of the first dielectric layer 3 is also provided with a avoiding slot 33, which is in the shape of a “door”, the length thereof is 0.187λ-0.233λ, and in this embodiment, it is preferably 0.212λ, and the width thereof is 0.058λ-0.082λ, and in this embodiment, it is preferably 0.075λ, and the avoiding slot 33 is arranged between the two first branches 31 on one side of the first dielectric layer 3.

[0058] The second dielectric layer 5 is also a cuboid plate, and in order to make the antenna structure compact and symmetrical, the length and width of the second dielectric layer 5 are the same as those of the first dielectric layer 3, both of which are 1.167λ-1.283λ, and in this embodiment, the length and width of the second dielectric layer 5 are both preferably 1.202λ, and the thickness thereof is 0.005λ-0.007λ, and in this embodiment, it is preferably 0.006λ. The second dielectric layer 5 can also adopt F4BTMS220 plate material with a dielectric constant (ε r ) of 2.1-2.3. Corresponding to the first branches 31 on the periphery of the first dielectric layer 3, the periphery of the second dielectric layer 5 is connected with second branches 51, and second connecting holes 52 are formed on the second branches 51, which are also used for assembling nylon screws, and two second branches 51 are connected at the outer side of each edge of the second dielectric layer 5, and the cross-sectional shape of the second branches 51 is rectangular, the length thereof is 0.117λ-0.163λ, and in this embodiment, it is preferably 0.141λ, and the width thereof is 0.047λ-0.07λ, and in this embodiment, it is preferably 0.056λ.

[0059] To feed the microwave metasurface patch unit, in the embodiment, the feeding mechanism 6 adopts a microstrip feed line, the width of the microstrip feed line can match 50 ohms, as shown in Figure 4 The feeding mechanism 6 is a rectangular microstrip feed line, which extends from the edge of the second dielectric layer 5 to the gap 41, and the feeding mechanism 6 is vertically arranged with the gap 41, and the microstrip feed line is coupled with the gap 41 for feeding. The gap 41 is arranged at the central position of the metal ground plate 4, and is parallel to a group of edges of the metal ground plate 4, and the gap 41 has a rectangular structure. The length and width dimensions of the microstrip feed line have a greater impact on the impedance matching of the antenna. In order to achieve good matching effect, the length of the gap 41 is 0.502λ-0.548λ, and in the embodiment, it is preferably 0.525λ, and the width is 0.021λ-0.026λ, and in the embodiment, it is preferably 0.023λ. The length of the feeding mechanism 6 is 0.758λ-0.817λ, and in the embodiment, it is preferably 0.786λ, and the width is 0.017λ-0.018λ, and in the embodiment, it is preferably 0.0175λ.

[0060] The high-isolation shared-aperture metasurface antenna provided by the embodiment overcomes the technical problems of the conventional shared-aperture antenna, such as multiple layers, low isolation, complex manufacturing process, and high cost. The shared-aperture metasurface patch 2 has the functions of the microwave metasurface antenna and the millimeter wave reflective array antenna at the same time. The composite function is integrated in the top layer of the antenna, which is simple and compact, and effectively reduces the antenna profile and cost.

[0061] Experimental example

[0062] 1. The low-frequency reflection coefficient curve of the high-isolation shared-aperture metasurface antenna provided by the test embodiment is shown in Figure 9 .

[0063] As can be seen from the figure, in the frequency band of 3.2-3.68 GHz (14%), the S 11 of the high-isolation shared-aperture metasurface antenna is less than -10 dB, and the isolation between the two ports of the antenna is less than -100 dB at low frequency.

[0064] 2. The radiation pattern of the high-isolation shared-aperture metasurface antenna provided by the test embodiment at 3.4 GHz, 3.5 GHz, and 3.6 GHz is shown in Figures 10-12 .

[0065] As can be seen from the figure, the high-isolation shared-aperture metasurface antenna provided by the embodiment realizes very stable directional patterns in the copper band.

[0066] 3. The gain curve of the high-isolation shared-aperture metasurface antenna provided by the test embodiment is shown in Figure 13 .

[0067] As can be seen from the figure, the gain of the antenna in the passband can reach 9dBi, and the highest gain can reach 11.45dBi.

[0068] 4. The high-frequency reflection coefficient simulation curve of the high-isolation shared-aperture metasurface antenna provided by the test example is shown in the following figure. Figure 14

[0069] As can be seen from the figure, in the frequency range of 28-32GHz, the S 11 parameters of the antenna are less than -10dB, and the isolation of the two ports of the antenna is less than -40dB at high frequencies.

[0070] 5. The radiation pattern and gain curve of the high-isolation shared-aperture metasurface antenna provided by the test example at 30GHz are shown in the following figure. Figures 15-16

[0071] As can be seen from the figure, the highest simulation gain of the antenna at 30GHz can reach 24.4dBi, and the calculated aperture efficiency is 26%.

[0072] The above test examples show that the high-isolation shared-aperture metasurface antenna provided by the embodiments of the present application realizes an impedance bandwidth of -10db in the range of 3.2-3.68GHz (13.95%), realizes a peak gain of 11.45dBi at 3.5GHz, and has a stable directional pattern. In the upper frequency band, the antenna can work in the frequency range of 28-30GHz, and can realize a peak gain of 24.4dBi at 30GHz, with an aperture efficiency of 26%. The ultra-high isolation of the lower frequency band and the upper frequency band is more than 100dB and 40dB, respectively. The shared-aperture metasurface antenna can be used in 5G and subsequent communication systems, especially in communication systems that require high isolation.

[0073] Obviously, the above embodiments are merely examples for clarity and do not limit the embodiments. Based on the above description, those skilled in the art can make other different forms of changes or modifications. Here, all embodiments need not and cannot be exhausted. The obvious changes or modifications derived therefrom are still within the protection scope of the present application.​​

Claims

1. A high-isolation shared-aperture metasurface antenna, characterized in that: include: Speaker feed; A shared aperture metasurface patch antenna assembly is spaced apart from the feed source, comprising: a shared aperture metasurface patch, a first dielectric layer, a metal floor, and a second dielectric layer stacked sequentially in a direction away from the horn feed source, the metal floor having a gap therein, and the second dielectric layer being connected to a feeding mechanism; The shared aperture metasurface patch includes at least one microwave metasurface patch unit, and each of the microwave metasurface patch units includes at least two reflective array units; the reflective array unit includes: a central patch, the periphery of the central patch is connected to at least one connecting arm, one end of the connecting arm is connected to the central patch, and the other end is connected to an outer frame; the central patch is a rectangular patch, and the outer frame is a rectangular outer frame.

2. The high-isolation shared-aperture metasurface antenna according to claim 1, characterized in that: The length and width of the central patch are both 0.023λ-0.058λ, the length and width of the outer frame are both 0.061λ-0.068λ, the width of the connecting arm is 0.005λ-0.007λ, and the length of the connecting arm is 0.008λ-0.018λ, where λ is the wavelength at the antenna operating frequency.

3. The high-isolation shared-aperture metasurface antenna according to claim 1, characterized in that: The spacing between the horn feed and the shared aperture metasurface patch is 0.75λ-0.85λ, where λ is the wavelength at the antenna operating frequency; the horn feed includes a signal input part, a adapter part and a horn output part connected in sequence, and the horn output part is provided with a first opening at one end close to the adapter part, and the horn output part is provided with an open end at one end away from the adapter part, and the plane where the open end is located has an angle of 23°-27° with the shared aperture metasurface patch; the adapter part is provided with a second opening at a position corresponding to the first opening, and the signal input part has a cavity inside, and the cavity, the second opening and the first opening are connected in sequence.

4. The high-isolation shared-aperture metasurface antenna according to claim 3, characterized in that: The cross-sectional figures of the first opening and the second opening are both rectangular, and the lengths of the first opening and the second opening are both 0.093λ-0.105λ and the widths are both 0.047λ-0.058λ; the cross-sectional figure of the open end is rectangular, the length of the open end is 0.257λ-0.280λ, the width of the open end is 0.187λ-0.222λ, and the height of the speaker output portion is 0.128λ-0.157λ ; The cavity inside the signal input part is a rectangular cavity, the length of the cavity is 0.093λ-0105λ, the width is 0.047λ-0.058λ, and the height is 0.128λ-0.157λ; the adapter part is a rectangular plate structure, the length of the adapter part is 0.21λ-0.26λ, the width is 0.21λ-0.26λ, and the thickness is 0.014λ-0.021λ; wherein λ is the wavelength at the antenna operating frequency.

5. The high-isolation shared-aperture metasurface antenna according to claim 4, characterized in that: A through hole for connecting an external connector is provided on one side wall of the signal input portion. The through holes include a first through hole, a second through hole, and a third through hole arranged sequentially in a direction away from the adapter portion, and the second through hole is connected to the cavity; the apertures of the first through hole and the third through hole are both 0.027λ-0.031λ; the aperture of the second through hole is 0.016λ-0.018λ.

6. The high-isolation shared-aperture metasurface antenna according to claim 1, characterized in that: The first dielectric layer is a rectangular plate, the length and width of the first dielectric layer are both 1.167λ-1.283λ, and the thickness is 0.026λ-0.028λ; the first dielectric layer is connected to the first branch node on all sides, and the first branch node is provided with a first connection hole. The cross-section of the first branch node is a rectangle, the length is 0.117λ-0.163λ, the width is 0.047λ-0.07λ, and the aperture of the first connection hole is 0.029λ-0.041λ; the second dielectric layer is A rectangular plate, wherein the length and width of the second dielectric layer are both 1.167λ-1.283λ, and the thickness is 0.005λ-0.007λ; the second dielectric layer is connected to a second branch on all four sides, and the second branch is provided with a second connection hole. The cross-section of the second branch is rectangular, with a length of 0.117λ-0.163λ and a width of 0.047λ-0.07λ. The aperture of the second connection hole is 0.029λ-0.041λ, where λ is the wavelength at the antenna operating frequency.

7. The high-isolation shared-aperture metasurface antenna according to claim 6, characterized in that: A avoidance groove is further provided on one side of the first dielectric layer. The avoidance groove has a length of 0.187λ-0.233λ and a width of 0.058λ-0.082λ.

8. The high-isolation shared-aperture metasurface antenna according to claim 1, characterized in that: The shared aperture metasurface patch includes 4 rows and 4 columns of shared aperture patch units, each of the shared aperture patch units includes 4 rows and 4 columns of reflective array units, the length and width of the shared aperture patch unit are both 0.25λ-0.26λ, and the distance between two adjacent shared aperture patch units is 0.009λ-0.014λ, where λ is the wavelength at the antenna operating frequency.

9. The high-isolation shared-aperture metasurface antenna according to claim 1, characterized in that: The feeding mechanism is a microstrip feeder, which is arranged perpendicular to the slot. The slot has a length of 0.502λ-0.548λ and a width of 0.021λ-0.026λ. The microstrip feeder has a length of 0.758λ-0.817λ and a width of 0.017λ-0.018λ.

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