A high-isolation MIMO antenna and communication device

Abstract

This invention discloses a high-isolation MIMO antenna and communication device. The antenna includes a metal ground plane, a dielectric layer, and a radiating patch unit arranged sequentially. The radiating patch unit includes at least two circular radiating patches, which operate in TM mode. 12 In this design, each circular radiating patch has a central slot element, and the slot element consists of at least two spaced slots. The TM of the circular radiating patches of this antenna... 12 The edge of the mode along the H-plane has two natural weak field regions, giving the MIMO antenna placed along the H-plane inherently high isolation performance; the slot element placed in the center of the circular radiating patch not only suppresses TM 12 The E-plane sidelobe radiation of the mode also effectively improves the isolation level of MIMO antennas placed along the E-plane. The self-decoupling technology proposed in this invention can achieve natural high isolation between the E-plane and H-plane of the MIMO antenna without introducing any additional decoupling structure. The antenna structure is simple and compact, which can meet the application requirements of various two-dimensional large-scale MIMO arrays.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wireless communication, and relates to a MIMO antenna and a communication device, in particular to a high-isolation MIMO antenna and a communication device. BACKGROUND

[0002] With the increasing demand of various intelligent terminals for data, the traditional single-receiving and single-transmitting antenna cannot meet the requirements of signal real-time performance and reliability. In recent years, with the rapid development of the fifth generation wireless communication technology (5G), MIMO (Multiple Input-Multiple Output) antenna technology has gradually developed. MIMO antenna is a technology in which multiple transmitting antennas and receiving antennas are used at the transmitting end and receiving end of a signal system, so it is called multiple transmitting antenna and multiple receiving antenna technology. MIMO antenna technology can effectively improve the channel capacity and spectrum utilization, so it has been widely used in various wireless communication and radar systems.

[0003] However, since MIMO antenna is essentially a multi-antenna technology, when two antennas with the same frequency and polarization are close to each other, the mutual coupling of electromagnetic energy between adjacent antennas will deteriorate the performance of the antenna, thereby affecting the normal operation of the entire wireless communication system.

[0004] In order to solve the above technical problems, domestic and foreign researchers have done a lot of research work and proposed various self-decoupling technologies based on mode cancellation, floor weak field construction, etc. Compared with other traditional decoupling technologies, self-decoupling technology does not need to introduce additional parasitic structures, and it can achieve high isolation performance while ensuring simple and compact antenna structure. For example, the document "Weak-field-based self-decoupling patch antennas" (IEEE Transaction on Antennas and Propagation, vol. 68, no. 6, pp. 4208-4217, Jun. 2020. H. Lin, et al.) proposes that by properly adjusting the microstrip feed structure of the antenna, the near-field distribution on the shared floor is reshaped, and high isolation performance of a 1x4 MIMO antenna array is achieved. However, the self-decoupling technology based on floor weak field proposed in the document has relatively strict requirements on the antenna feed structure and the placement position of adjacent antennas, which greatly limits its application in actual engineering. The document "Mutual coupling reduction in MIMO microstrip patch array using TM 10 and TM 02Modes (IEEE Transaction on Antennas and Propagation, vol. 69, no. 11, pp. 7562-7571, Nov. 2021. Q. X. Lai, et al) discloses: by properly adjusting the resonant frequency of TM 10 and TM 02 modes of the rectangular patch antenna, the electric field coupled to the adjacent antenna unit is mutually offset, a specific weak field zero point is generated near the feed point, and the isolation performance of the two-element MIMO antenna array of the E-plane coupling is effectively improved. However, when the coupling mode of the MIMO antenna array is changed to H-plane coupling, the entire decoupling process needs to be redesigned and optimized, that is, the self-decoupling technology based on mode offsetting proposed in the document is only applicable to the decoupling of one-dimensional MIMO antenna arrays, and the application range is limited. In actual applications, large-scale MIMO and phased array antennas are two-dimensional arrays, which can provide better performance indicators and meet more application scenarios.

[0005] Therefore, it is a technical problem to be solved at present to further improve the existing MIMO antenna to improve its isolation. SUMMARY

[0006] To this end, the technical problem to be solved by the present application is that the traditional self-decoupling MIMO antenna is limited in actual applications and cannot meet more application scenarios, so a two-dimensional self-decoupling high-isolation MIMO antenna and a communication device are proposed.

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

[0008] The first aspect of the present application provides a high-isolation MIMO antenna, which comprises a metal ground plate, a dielectric layer and a radiation patch unit arranged in sequence, the radiation patch unit comprises at least two circular radiation patches, and the circular radiation patches work in TM 12 mode, wherein a slot unit is formed in the center of each circular radiation patch, and the slot unit is composed of at least two spaced-apart slots.

[0009] As a preferred, the slot unit is composed of two spaced-apart rectangular slots, and the two rectangular slots are symmetrically arranged in the center of the circular radiation patch.

[0010] As a preferred, the length of the slot unit is 0.3-0.8 times the diameter length of the circular radiation patch.

[0011] As a preferred, the width of the rectangular slot is less than 1 / 2 of the length.

[0012] As preferred, the radiation patch unit is composed of MxN circular radiation patches, wherein M is a positive integer no less than 1, and N is an even number no less than 2.

[0013] As preferred, when M is no less than 2, the slot units in the circular radiation patches of adjacent rows are arranged in parallel.

[0014] As preferred, the radiation patch unit is composed of 4 circular radiation patches, and the 4 circular radiation patches are arranged in mirror image, forming a 2x2 radiation patch array.

[0015] As preferred, each of the circular radiation patches is connected to the metal ground plate through a feeding mechanism.

[0016] The second aspect of the present application provides a communication device comprising the high-isolation MIMO antenna.

[0017] The above technical solution of the present application has the following advantages compared with the prior art:

[0018] The high-isolation MIMO antenna provided by the present application comprises a metal ground plate, a dielectric layer and a radiation patch unit arranged in sequence, the radiation patch unit comprises at least two circular radiation patches, and the circular radiation patches work in TM 12 mode, wherein a slot unit is formed in the center of each circular radiation patch, and the slot unit is composed of at least two spaced-apart slots. The circular radiation patches of the MIMO antenna work in TM 12 mode, and the TM 12 mode of the circular radiation patches has two natural weak field regions along the edge of the H plane, so that the MIMO antenna has a natural high-isolation performance. Meanwhile, by arranging a slot unit in the center of each circular radiation patch, and by composing the slot unit of at least two spaced-apart slots, the electric field distribution at the two ends of the E plane of the radiation patch is reshaped, and two new weak field regions are constructed, effectively improving the isolation level of the MIMO antenna working in TM 12 mode along the E plane, so that the MIMO antenna simultaneously realizes the natural high-isolation of the E plane and the H plane without introducing any additional decoupling structure, and the antenna structure is simple and compact, which can meet the application of various two-dimensional large-scale MIMO arrays. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to make the content of the present application easier and clearer to understand, the present application will be further described in detail below according to specific embodiments of the present application and in conjunction with the drawings, wherein

[0020] Figure 1 is a structural schematic diagram of the high-isolation MIMO antenna provided by the embodiments of the present application;

[0021] Figure 2is a front view of a high-isolation MIMO antenna provided by an embodiment of the present application;

[0022] Figure 3 is a cross-sectional schematic view of a high-isolation MIMO antenna provided by an embodiment of the present application;

[0023] Figure 4 is a field distribution schematic view of a conventional MIMO antenna arranged along an E plane and operating in a TM 11 mode;

[0024] Figure 5 is a field distribution schematic view of a conventional MIMO antenna arranged along an H plane and operating in a TM 11 mode;

[0025] Figure 6 is a simulation S parameter curve of a conventional MIMO antenna arranged along an E plane and operating in a TM 11 mode;

[0026] Figure 7 is a simulation S parameter curve of a conventional MIMO antenna arranged along an H plane and operating in a TM 11 mode;

[0027] Figure 8 is a field distribution schematic view of a MIMO antenna arranged along an H plane and operating in a TM 12 mode;

[0028] Figure 9 is a simulation S parameter curve of a MIMO antenna arranged along an H plane and operating in a TM 12 mode;

[0029] Figure 10 is a schematic view of a circular patch antenna provided with one slot and operating in a TM 12 mode;

[0030] Figure 11 is a schematic view of a circular patch antenna provided with two slots and operating in a TM 12 mode;

[0031] Figure 12 is an E plane radiation pattern of a circular patch antenna provided with different slot structures and operating in a TM 12 mode;

[0032] Figure 13 is a field distribution schematic view of a two-unit MIMO antenna provided with one slot and operating in a TM 12 mode;

[0033] Figure 14 is a simulation S parameter curve of a two-unit MIMO antenna provided with one slot and operating in a TM 12The field distribution schematic diagram of the two-unit MIMO antenna provided with two slots in the mode;

[0034] Figure 15 The S parameter simulation curve diagram of the two-unit MIMO antenna provided with one slot in the TM 12 mode;

[0035] Figure 16 The S parameter simulation curve diagram of the two-unit MIMO antenna provided with two slots in the TM 12 mode;

[0036] Figure 17 The field distribution schematic diagram of the high-isolation MIMO antenna provided by the embodiment of the application;

[0037] Figure 18 The simulation S parameter curve diagram of the high-isolation MIMO antenna provided by the embodiment of the application;

[0038] Figure 19 The radiation pattern of the high-isolation MIMO antenna provided by the embodiment of the application;

[0039] Figure 20 The radiation pattern of the high-isolation MIMO antenna provided by the embodiment of the application.

[0040] In the figure, the reference signs are as follows: 1-metal floor; 2-dielectric layer; 3-radiating patch unit; 301-circular radiating patch; 302-slot; 4-feeding mechanism. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the embodiments of the application clearer, the technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some but not all of the embodiments of the application. The components of the embodiments of the application described and shown in the drawings can be arranged and designed in various different configurations.

[0042] In the description of the application, it should be understood that the terms "upper", "lower", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly understood by those skilled in the art, and are only used to facilitate the description of the application and simplify the description, and do not indicate or imply 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 a limitation on the application.

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

[0044] In the description of the present application, it is also necessary to explain that, unless otherwise explicitly specified and limited, the terms "arrange", "mount" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected; 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 present embodiment provides a high-isolation MIMO antenna, please refer to Figures 1-3 , the high-isolation MIMO antenna includes a metal floor 1, a dielectric layer 2 and a radiation patch unit 3 arranged in sequence, wherein the dielectric layer 2 can adopt a dielectric substrate, or as an alternative embodiment, the dielectric layer 2 can also adopt air medium, when the dielectric layer 2 is air medium, the radiation patch unit 3 is connected to the metal floor 1 through a support structure. The radiation patch unit 3 includes at least two circular radiation patches 301, the circular radiation patch 301 works in TM 12 mode, and a slot unit is formed in the center of each circular radiation patch 301, the slot unit is composed of at least two spaced-apart slots 302.

[0047] The high-isolation MIMO antenna provided by the present embodiment includes at least two circular radiation patches 301 in each radiation patch unit, and the circular radiation patch 301 works in TM 12 mode. The conventional patch antenna working in the main mode, the MIMO array placed along the E plane will cause poor isolation of the antenna due to the strong electric field coupling of the patch edge, and the MIMO array placed along the H plane will cause poor isolation of the antenna due to the strong magnetic field coupling of the patch edge. Compared with the conventional patch, the MIMO antenna adopted by the present embodiment uses a circular radiation patch 301 working in TM 12 mode, the TM 12 mode of the circular radiation patch 301 has two natural weak field regions along the edge of the H plane, so that the MIMO antenna array working in TM 12 mode along the H plane has a natural high-isolation performance.

[0048] At the same time, a slot unit is formed in the center of each circular radiation patch 301, and the slot unit is composed of at least two spaced-apart slots 302. Under normal circumstances, in TM 12In this mode, introducing a gap in the center of the circular radiating patch can cut off the reverse current in the middle part, thereby suppressing the radiation of the E-plane sidelobes. However, strong electric field radiation still exists at both ends of the E-plane. In other words, the single gap introduced by the traditional patch antenna cannot solve the problem of mutual coupling on the antenna's E-plane. In this embodiment, by using the aforementioned spaced gaps 302, the electric field distribution at both ends of the antenna's E-plane can be reshaped, constructing two new weak field regions, thereby effectively improving the performance of the antenna placed along the E-plane in TM mode. 12 The isolation level of the MIMO antenna in the mode.

[0049] Compared with traditional self-decoupling techniques, the high-isolation MIMO antenna provided in this embodiment constructs multiple weak-field edge regions by utilizing the field distribution of the antenna body and reshaping the field distribution at both ends of the antenna. Without introducing any additional decoupling structures, it simultaneously achieves decoupling of the antenna's E-plane and H-plane, realizing high isolation between the antenna's E-plane and H-plane, symmetrical high-gain side-firing beams, and high polarization purity. Moreover, the antenna structure is simple and compact, making it suitable for various two-dimensional MIMO antenna array applications.

[0050] In this embodiment, for ease of processing, the metal floor 1 is a rectangular metal plate, and the dielectric layer 2 is a rectangular dielectric substrate. Preferably, the metal floor 1 and the dielectric layer 2 are square plate structures with the same shape and size. Of course, as an alternative implementation, the metal floor 1 and the dielectric layer 2 can also be circular or other polygonal shapes.

[0051] like Figures 1-2 As shown, each slot unit consists of two spaced rectangular slots 302. The two slots 302 extend along the diameter of the circular radiating patch 301 in the x-direction and are symmetrically arranged with respect to the center of the circular radiating patch 301, that is, the two rectangular slots 302 are symmetrically arranged at the center of the circular radiating patch 301. The width of each rectangular slot 302 is less than 1 / 2 of its length.

[0052] The length of the slit unit composed of two slits 302 is 0.3-0.8 times the diameter of the circular radiating patch 301. In this embodiment, the length of the slit unit is preferably 0.6 times the diameter of the circular radiating patch 301.

[0053] To form a well-isolated MIMO antenna array, the radiating patch unit 3 consists of M×N circular radiating patches 301, the size of which can be adjusted according to its operating frequency. Here, M is a positive integer not less than 1, and N is an even number not less than 2. Depending on the requirements, the radiating patch unit 3 can be composed of circular radiating patches 301 with different numbers of rows and columns, such as 1×2, 1×4, 2×2, and 2×4, forming a radiating patch array.

[0054] In this embodiment, the slot units in each circular radiating patch 301 are arranged along the x direction, so that the slot units in each row of circular radiating patches 301 are arranged in parallel when M is greater than or equal to 2.

[0055] As shown in the figure, Figures 1-2 In this embodiment, specifically, the radiating patch unit 3 is composed of 4 circular radiating patches 301, the 4 circular radiating patches 301 form a 2x2 radiating patch array, and adjacent circular radiating patches 301 can be closely arranged (i.e., the minimum spacing can be 0) or arranged with a certain gap.

[0056] In order to supply power to the radiating patch unit 3, each circular radiating patch 301 is further connected to a feeding mechanism 4, one end of the feeding mechanism 4 is connected to the circular radiating patch 301, the other end penetrates the dielectric layer 2 and the metal floor 1 and is connected to the metal floor 1, and then is connected to an external excitation source on the other side of the metal floor 1, forming a feeding structure of the antenna. In this embodiment, the feeding mechanism 4 adopts a feeding probe.

[0057] This embodiment also provides a communication device comprising the high-isolation MIMO antenna described above.

[0058] Experimental Example

[0059] 1. Test the simulation S parameters of the conventional patch MIMO antenna working in TM 11 mode and the simulation S parameters of the MIMO antenna working in TM 12 mode.

[0060] The field distribution diagram of the conventional MIMO antenna working in the main mode (TM 11 mode) is shown in Figures 4-5 , in which Figure 4 is a schematic diagram of two circular radiating patches arranged along the E plane coupling, Figure 5 is a schematic diagram of two circular radiating patches arranged along the H plane coupling. The spacing between the two circular radiating patches is 0.2 mm, so as to better highlight the decoupling effect. As shown in Figure 4 , the electric field near the coupling edge of the two circular radiating patches arranged along the E plane is very strong, resulting in electric coupling, as shown in Figure 5 , the magnetic field near the coupling edge of the two circular radiating patches arranged along the H plane is very strong, resulting in magnetic coupling. Therefore, whether arranged along the E plane or the H plane, the patch antenna working in the main mode (TM 11 mode) will inevitably face very poor isolation effect, affecting the performance of the antenna.

[0061] Figures 6-7 The simulation S parameters of the MIMO antenna working in the main mode (TM 11 mode) are shown in Figure 6The simulated S parameter curve of the MIMO antenna placed along the E plane, Figure 7 The simulated S parameter curve of the MIMO antenna placed along the H plane. It can be seen from the figure that, due to the working in the TM 11 mode, there is a strong electric field distribution along the edge of the circular radiation patch along the E plane, resulting in strong electric coupling, so the isolation of the two antennas is only 5.3 dB; there is a strong magnetic field distribution along the edge of the patch along the H plane, resulting in strong magnetic coupling, so the isolation of the two antennas is only 7.1 dB. The above results verify that, without introducing decoupling structure, when two main mode antennas are close to each other, strong energy coupling will be generated.

[0062] The field distribution diagram of the MIMO antenna working in the TM 12 mode is shown in Figure 8 , which is a schematic diagram of two circular radiation patches arranged along the H plane. It is found that, the circular radiation patch working in the TM 12 mode has a natural weak field region at both ends along the H plane, that is, the position simultaneously presents very weak electric field and magnetic field distribution, which is very beneficial to the H plane decoupling of the MIMO antenna array. Figure 8 For the two-element MIMO antenna arranged along the H plane, both antenna elements work in the TM 12 mode. It can be seen that, when the MIMO array is arranged along the H plane, there is a weak field region near the coupling edge of the adjacent antennas, and almost no mutual coupling between the energies is generated, so the natural decoupling effect can be achieved.

[0063] The simulated S parameter curve of the MIMO antenna arranged along the H plane and working in the TM 12 mode is shown in Figure 9 . It can be seen from the figure that, due to the TM 12 mode having a natural weak field region at both ends along the H plane, an isolation higher than 25 dB can be achieved in the working frequency band without introducing any decoupling structure.

[0064] 2. The E plane radiation pattern of the circular patch antenna without setting a slot, with one slot and with two slots.

[0065] The structure diagram of the circular patch antenna with one slot and two slots arranged at intervals and working in the TM 12 mode is shown in Figure 10 and Figure 11 , respectively. The E plane radiation pattern of the circular patch antenna with different slot structures is shown in Figure 12 .

[0066] The conventional TM 12The E-plane radiation pattern of the mode-circular patch antenna has a high side lobe level, which not only disperses the energy of the main lobe but also reduces the anti-interference ability of the antenna. By means of the slot loading technology, TM 12 The high side lobe problem of the mode-circular patch antenna has been well solved. As can be seen from Figure 12 , before the slot loading, the E-plane radiation pattern of the antenna has a very high side lobe, and the side lobe level is as high as about 5dBi, which leads to a reduction in the main lobe gain and a narrowing of the beam; after the introduction of the traditional single slot loading scheme, the side lobe radiation of the antenna is effectively suppressed, the side lobe level is reduced to about -5dBi, and the main lobe gain and beam width are also improved; after the single slot is ingeniously separated into two slots, the side lobe level is further reduced to -10dBi, and the main lobe beam is also widened.

[0067] 3. S parameter simulation curves of the two-unit MIMO antenna with different slot loading schemes

[0068] Figure 13 Fig. 1 is a schematic diagram of the field distribution of a two-unit MIMO antenna with a rectangular slot arranged in the center of a circular radiating patch, Figure 14 Fig. 2 is a schematic diagram of the field distribution of a two-unit MIMO antenna with two rectangular slots arranged at intervals in the center of a circular radiating patch, Figure 13 Figure 14 In the MIMO antenna shown in the figures, the circular radiating patch works in the TM 12 mode. It is found that the TM 12 mode circular patch antenna along the E-plane has a strong electric field distribution at both ends, and when the two antennas are close to each other, a strong energy coupling is generated, which affects the performance of the antenna. On the contrary, the double slot loading scheme described in the embodiments of the present application is introduced at the middle position of the TM 12 mode circular patch, which significantly reduces the electric field intensity of the patch along the E-plane at both ends, generates two new weak field regions, and is beneficial to the E-plane decoupling of the TM 12 mode circular patch antenna.

[0069] Figures 15-16 Figs. 3 and 4 are respectively the S parameter simulation curve of the two-unit MIMO antenna with a rectangular slot and the S parameter simulation curve of the two-unit MIMO antenna with two rectangular slots described in the embodiments of the present application. It can be seen that the MIMO antenna units loaded with a single slot generate a strong energy mutual coupling, and the isolation is only 12dB; after the introduction of the double slot loading scheme described in the embodiments of the present application, the coupling between the antenna units is effectively suppressed, and the isolation is improved to 21.6dB.

[0070] 4. Simulation S parameter curve and radiation pattern of the high-isolation MIMO antenna described in the embodiments of the present application.

[0071] ​A field distribution diagram of the MIMO antenna with a 2x2 circular radiating patch array provided by the embodiment of the present application is shown in FIG. 3. As can be seen from the diagram, there are multiple edge weak field regions constructed, and the TM Figure 17 As can be seen from the diagram, the electric coupling and the magnetic coupling of the adjacent antennas are effectively inhibited due to the multiple edge weak field regions constructed, and a natural high isolation is achieved, with an isolation of more than 20dB within the working frequency band. 12 The TM 12 The TM 12 As can be seen from the diagram, the electric coupling and the magnetic coupling of the adjacent antennas are effectively inhibited due to the multiple edge weak field regions constructed, and a natural high isolation is achieved, with an isolation of more than 20dB within the working frequency band.

[0072] A simulation S parameter curve of the MIMO antenna with a 2x2 circular radiating patch array provided by the embodiment of the present application is shown in FIG. 4. As can be seen from the diagram, the electric coupling and the magnetic coupling of the adjacent antennas are effectively inhibited due to the multiple edge weak field regions constructed, and a natural high isolation is achieved, with an isolation of more than 20dB within the working frequency band. Figure 18

[0073] Figures 19-20 Radiation patterns of the MIMO antenna with a 2x2 circular radiating patch array provided by the embodiment of the present application are shown in FIG. 5, and FIG. 6, due to the symmetry of the structure, Figure 19 and Figure 20 FIG. 5 and FIG. 6 respectively show the radiation patterns of two circular radiating patches 301 of the 2x2 MIMO antenna provided by the embodiment of the present application, and due to the mirror symmetry of the four circular radiating patches, two of them are taken as examples for testing in the present embodiment, with the solid line in the diagram being the radiation pattern of the main polarization and the dotted line being the radiation pattern of the cross polarization. As can be seen, the radiation beams of the two circular radiating patch antennas are radiated towards the positive direction, with a peak gain of 10.7dBi. In addition, due to the multiple edge weak field regions constructed, the MIMO antenna achieves a natural two-dimensional decoupling without introducing additional decoupling structures and under the condition of a compact size and structure, and maintains a symmetrical radiation pattern and a polarization purity of more than 30dB. It is worth pointing out that each TM 12 The TM

[0074] Obviously, the above embodiments are merely example for clearly illustrating but not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments need not and can not be enumerated. The obvious changes or variations derived from the above description are still within the protection scope of the present application.

Claims

1. A high-isolation MIMO antenna, characterized in that, The antenna comprises a metal ground plate, a dielectric layer and a radiation patch unit arranged in sequence, the radiation patch unit comprises at least two circular radiation patches working in TM 12 mode, wherein a slot unit is arranged in the center of each circular radiation patch, the slot unit comprises two rectangular slots arranged at intervals, the two rectangular slots are symmetrically arranged in the center of the circular radiation patch, the two rectangular slots extend along the diameter of the circular radiation patch in the x direction and are symmetrically arranged with respect to the center of the circular radiation patch; the length of the slot unit is 0.3-0.8 times the diameter of the circular radiation patch.

2. The high-isolation MIMO antenna of claim 1, wherein, The width of the rectangular slot is less than 1 / 2 of the length.

3. The high-isolation MIMO antenna according to claim 1 or 2, characterized in that, The radiation patch unit is composed of MxN circular radiation patches, wherein M is a positive integer not less than 1, and N is an even number not less than 2.

4. The high-isolation MIMO antenna of claim 3, wherein, When M is not less than 2, the slot units in the circular radiation patches of adjacent rows are arranged in parallel.

5. The high-isolation MIMO antenna of claim 4, wherein, The radiation patch unit is composed of 4 circular radiation patches, and the 4 circular radiation patches are arranged in mirror image to form a 2x2 radiation patch array.

6. The high-isolation MIMO antenna of claim 5, wherein, Each of the circular radiation patches is connected to the metal ground plate through a feeding mechanism.

7. A communication device, characterized by A high-isolation MIMO antenna comprising any one of claims 1-6.

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