MIMO patch antenna and decoupling design method thereof

Abstract

The invention discloses an MIMO patch antenna and a decoupling design method thereof, and relates to the technical field of antenna decoupling, and the antenna comprises a main dielectric substrate, a metal ground and a port antenna module. The metal ground is arranged on the lower surface of the main dielectric substrate, the port antenna module is distributed on the upper surface of the substrate, the port antenna module comprises two parallel and symmetrical radiation units, the two radiation units are rectangular patches, the short edges of the two radiation units are parallel, and the distance between the short edges of the two radiation units is smaller than a preset distance threshold value, so that ultra-narrow distance layout is realized to save space. Each rectangular patch is provided with a feed port, a metal probe which penetrates through the patch is arranged in the middle of each rectangular patch, the bottom of each metal probe is located in the main dielectric substrate, and the frequency band can be expanded to cover the N79 frequency band; a square annular gap and a rectangular gap are further formed in the patch, the capacitor is embedded in the rectangular gap, and the short edge of the rectangular gap coincides with the center of the square annular gap; metal short-circuit columns which penetrate through the patch and the substrate and are connected with the metal ground are arranged at the right-angle and square annular gaps of the patch, so that the port isolation can be improved. According to the antenna, the contradiction between the terminal space and the number of antennas can be relieved, the frequency band coverage and the signal stability are guaranteed, and the high-integration MIMO communication requirement is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of antenna decoupling, in particular to a MIMO patch antenna and a decoupling design method thereof. BACKGROUND

[0002] With the large-scale deployment of the fifth generation mobile communication technology, the Sub-6GHz frequency band has become the mainstream choice for early deployment of 5G. This technology evolution promotes the Multiple Input Multiple Output (MIMO) configuration of mobile terminals to upgrade from 2x2 or 4x4 in the 4G era to 8x8 or even higher specifications, and the number of antennas is doubled. At the same time, the popularity of full-screen, folding screen and other technologies has greatly compressed the internal space of the terminal, and the available space for antenna layout has been greatly reduced, and various components have further occupied the space, resulting in the spacing between antenna units being compressed to a very narrow degree (usually less than 0.1λ) much smaller than half a wavelength.

[0003] Under the condition of extremely narrow spacing, strong near-field coupling effects occur between antenna units, resulting in a significant decrease in port isolation (usually deteriorating by 10-15dB), and also causing impedance mismatch, reduced radiation efficiency, distorted directional pattern, and other problems, ultimately degrading the spatial diversity gain and channel capacity of the MIMO system. And in the Sub-6GHz multi-band operating environment, the coupling characteristics of different frequency bands differ significantly, requiring decoupling technology to have wideband characteristics. Existing decoupling solutions such as defect ground structures and electromagnetic bandgap materials still cannot simultaneously meet the requirements of extremely narrow spacing, low profile, wide operating bandwidth, and high port isolation, becoming a key bottleneck restricting the performance improvement of 5G terminals. Therefore, the industry urgently needs a new type of extremely narrow spacing MIMO antenna suitable for ultra-thin 5G mobile terminals. SUMMARY

[0004] The purpose of the present application is to provide a MIMO patch antenna and a decoupling design method thereof, which can simultaneously meet the requirements of extremely narrow spacing, low profile, wide operating bandwidth, and high port isolation.

[0005] To achieve the above-mentioned purpose, the present application provides the following solutions: In a first aspect, the present application provides a MIMO patch antenna, comprising: a port antenna module, a main dielectric substrate and a metal ground; the port antenna module is arranged on the upper surface of the main dielectric substrate, and the metal ground is arranged on the lower surface of the main dielectric substrate; the port antenna module comprises a first radiation unit and a second radiation unit arranged side by side, and the first radiation unit and the second radiation unit are completely identical in structure and symmetrical to each other; the first radiation unit and the second radiation unit each comprise a rectangular patch, and the short sides of the two rectangular patches are parallel and the distance therebetween is less than a preset distance threshold; for any one of the rectangular patches, a feeding port is arranged on the rectangular patch, and a group of metal probes are arranged in the middle of the rectangular patch, the metal probes penetrate through the rectangular patch, and the bottoms of the metal probes are located in the main dielectric substrate, and the metal probes are used to expand the frequency band of the antenna, so that the frequency band of the port antenna module can cover the N79 frequency band.

[0006] For any one of the rectangular patches, a square ring-shaped slot and a rectangular slot are arranged in the rectangular patch near the center of the wide side of the other rectangular patch; a capacitor is arranged in the rectangular slot, one short side of the rectangular slot and one side of the square ring-shaped slot are coincided in the middle, and the other short side of the rectangular slot is away from the other rectangular patch; for any one of the rectangular patches, a metal short-circuit column is arranged at each of the two right angles of the rectangular patch adjacent to the other rectangular patch and in the square ring-shaped slot, so as to improve the isolation between the feeding ports of the two rectangular patches; the metal short-circuit column penetrates through the rectangular patch and the main dielectric substrate, and is connected with the metal ground.

[0007] Optionally, the number of the metal short-circuit columns arranged at the two right angles of the rectangular patch adjacent to the other rectangular patch can be multiple, so as to further improve the isolation between the feeding ports of the two rectangular patches.

[0008] Optionally, the capacity of the capacitor is 3pF, and the preset distance threshold is 0.2mm.

[0009] Optionally, the radii of the metal short-circuit columns arranged at the two right angles of the rectangular patch and in the square ring-shaped slot are different.

[0010] Optionally, the length of the rectangular patch is 30mm, and the width of the rectangular patch is 19.4mm; the outer side length of the square ring-shaped slot is 1mm, and the inner side length of the square ring-shaped slot is 0.6mm; the length of the rectangular slot is 1mm, and the width of the rectangular slot is 0.6mm.

[0011] Optionally, the distances between the metal probes in the group of metal probes arranged in the middle of the rectangular patch are not all the same.

[0012] Optionally, the number of the metal probes is 4, the distances between the metal probes are 6mm, 4mm and 6mm respectively, and the radius of each metal probe is 0.35mm.

[0013] Optionally, the main dielectric substrate adopts Rogers RT / duroid 5880 material, the relative dielectric constant is 2.2, and the loss tangent is 0.009; the metal ground and the port antenna module adopt metal materials.

[0014] Optionally, the number of the port antenna modules can be multiple, and the port antenna modules form a large-scale MIMO patch antenna array, and the edges of the port antenna modules are not more than the edges of the main dielectric substrate.

[0015] In a second aspect, the present application provides a decoupling design method of the MIMO patch antenna, comprising the following steps: The coaxial feeding mode is adopted, and the feeding ports are arranged on the two rectangular patches respectively to directly feed the port antenna module.

[0016] For any rectangular patch, a group of metal probes are arranged in the middle of the rectangular patch, so that the frequency band of the port antenna module can cover the N79 frequency band.

[0017] For any rectangular patch, a square ring-shaped slot and a rectangular slot are arranged in the middle of the rectangular patch close to the center of the wide edge of the other rectangular patch.

[0018] For any rectangular patch, a metal short-circuit column is arranged at each of the two right angles adjacent to the other rectangular patch.

[0019] For any rectangular patch, a capacitor is arranged in the rectangular slot of the rectangular patch, and a metal short-circuit column is arranged in the square ring-shaped slot of the rectangular patch.

[0020] According to the specific embodiments provided by the present application, the following technical effects are disclosed: The application provides a MIMO patch antenna and a decoupling design method thereof. In the antenna, a metal ground is directly laid on the lower surface of a main dielectric substrate without additional slits, zero-clearance characteristics can be achieved, and the internal space layout requirements of ultra-thin and full-screen mobile terminals can be perfectly met. By limiting the distance between two rectangular patches of a port antenna module, the occupied space between the radiation units is greatly compressed, the core contradiction between the multiplication of the number of 5G / 6G terminal antennas and the high compression of the internal space is effectively alleviated, and the antenna deployment density is improved. A group of metal probes are arranged in the middle of the rectangular patch. Through the design of penetrating the patch and being limited at the bottom of the main dielectric substrate, the antenna operating frequency band can be accurately expanded, the N79 frequency band of 5G can be completely covered by the port antenna module, the antenna impedance matching characteristics can be optimized, and signal reflection loss can be reduced. A combined structure of a square ring-shaped slot and a rectangular slot embedded with a capacitor is arranged in the rectangular patch. The antenna near-field electromagnetic distribution can be actively controlled, the near-field coupling strength between adjacent patches can be weakened, and the antenna current path can be optimized to assist in widening the operating bandwidth. In addition, a metal short-circuit column is arranged at each of the two right angles between the rectangular patch and another rectangular patch and in the square ring-shaped slot. Through the reliable grounding design of penetrating the patch-substrate-connection metal ground, the coupling signal transmission between adjacent patches can be further inhibited, the isolation between the two feeding ports can be improved to more than 20 dB, which is much better than the traditional design. At the same time, the metal short-circuit column can enhance the electromagnetic stability of the antenna structure, reduce the influence of external interference on the antenna pattern, avoid the degradation of the MIMO system space diversity gain caused by the pattern distortion, and protect the channel capacity. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0022] Figure 1 A structural schematic diagram of a MIMO patch antenna according to an embodiment of the present application is provided.

[0023] Figure 2 A structural schematic diagram of a first radiation unit in a MIMO patch antenna according to an embodiment of the present application is provided.

[0024] Figure 3 A sectional view of a main dielectric substrate in a MIMO patch antenna according to an embodiment of the present application is provided.

[0025] Figure 4 A layout schematic diagram of a MIMO patch antenna array according to another embodiment of the present application is provided.

[0026] Figure 5 A flow chart of a decoupling design method of a MIMO patch antenna provided for another embodiment of the present application.

[0027] Figure 6 A curve graph of scattering parameters of a MIMO patch antenna varying with frequency provided for another embodiment of the present application.

[0028] Figure 7 A curve graph of envelope correlation coefficients of a MIMO patch antenna varying with frequency provided for another embodiment of the present application.

[0029] Figure 8 A curve graph of efficiency of a MIMO patch antenna varying with frequency provided for another embodiment of the present application.

[0030] Reference signs: 1: main dielectric substrate; 2: metal ground; 3: port antenna module; 4-1: first radiating element; 4-2: second radiating element; 5: feeding port; 6: metal probe; 7: square ring-shaped slot; 8: rectangular slot; 9: capacitor; 10: metal shorting post. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] In order to make the above objectives, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0033] A MIMO patch antenna provided by the embodiments of the present application, in an exemplary embodiment, as shown in FIG. 1, comprises a main dielectric substrate 1, a metal ground 2 and a port antenna module 3. In this embodiment, the main dielectric substrate 1 is made of Rogers RT / duroid 5880 material, with a relative dielectric constant of 2.2 and a loss tangent of 0.009; the metal ground 2 and the port antenna module 3 are made of metal material. Figure 1

[0034] The port antenna module 3 is arranged on the upper surface of the main dielectric substrate 1, and the metal ground 2 is arranged on the lower surface of the main dielectric substrate 1; the port antenna module 3 comprises a first radiating element 4-1 and a second radiating element 4-2 arranged side by side, and the first radiating element 4-1 and the second radiating element 4-2 are completely identical in structure and symmetrical to each other; as shown in FIG. 2, the first radiating element 4-1 and the second radiating element 4-2 are both square ring-shaped slots 7, and the square ring-shaped slots 7 are arranged on the metal ground 2.​Figure 1 and Figure 2 As shown in FIG. 4, the first radiating unit 4-1 and the second radiating unit 4-2 each include a rectangular patch, and the short sides of the two rectangular patches are parallel and the distance between the two short sides is less than a preset distance threshold. In the embodiment, the preset distance threshold is 0.2 mm.

[0035] In order to make the bandwidth of the MIMO patch antenna more optimal, for any rectangular patch, a feeding port 5 is arranged on the rectangular patch, and a group of metal probes 6 is arranged in the middle of the rectangular patch, as shown in FIG. 5. Figure 3 As shown in FIG. 5, the metal probes 6 penetrate the rectangular patch and the bottom is located in the main dielectric substrate 1. The metal probes 6 are used to expand the frequency band of the antenna, so that the frequency band of the port antenna module 3 can cover the N79 frequency band. The distance between the metal probes 6 and the wide side of the rectangular patch is 8 mm, and the length of the metal probes 6 is 2 mm. The length of the metal probes 6 cannot be changed at will, and within a certain range, it will affect the working bandwidth of the antenna. The increase or decrease of the length will shorten the working bandwidth of the antenna, so as to not meet the requirement of the working bandwidth of the antenna and not improve the antenna isolation.

[0036] For any rectangular patch, a square ring-shaped slot 7 and a rectangular slot 8 are arranged in the rectangular patch near the center of the wide side of the other rectangular patch; a capacitor 9 is arranged in the rectangular slot 8. In the embodiment, the capacity of the capacitor 9 is 3 pF, and the capacitor 9 is located on the transverse center line of the two rectangular patches. One short side of the rectangular slot 8 and one side of the square ring-shaped slot 7 are coincident, and the other short side of the rectangular slot 8 is away from the other rectangular patch. The capacitance value of the capacitor 9 cannot be changed at will, and its change has an important influence on the performance of the antenna. For example, when the capacitance value of the capacitor 9 decreases and is not 0, the working bandwidth of the antenna will be slightly shortened, and the antenna isolation will not be affected; when the capacitance value of the capacitor 9 is 0, the antenna isolation will be deteriorated, and the working bandwidth of the antenna will not be affected; when the capacitance value of the capacitor 9 increases, the working bandwidth of the antenna will be greatly shortened, and the antenna isolation will not be affected.

[0037] In the embodiment, the length of the rectangular patch is 30 mm, and the width is 19.4 mm; the outer side length of the square ring-shaped slot 7 is 1 mm, and the inner side length of the square ring-shaped slot 7 is 0.6 mm; the length of the rectangular slot 8 is 1 mm, and the width of the rectangular slot 8 is 0.6 mm.

[0038] For any rectangular patch, a metal short-circuit column 10 is arranged at two right angles of the rectangular patch adjacent to the other rectangular patch and in the square ring-shaped slot 7, so as to improve the isolation between the feeding ports 5 of the two rectangular patches; as shown in FIG. 6, the metal short-circuit column 10 penetrates the rectangular patch and the main dielectric substrate 1 and is connected with the metal ground 2. Figure 3

[0039] ​As an optional embodiment, the number of metal shorting posts 10 arranged at the two right angles of the rectangular patch adjacent to another rectangular patch can be multiple to further improve the isolation between the feed ports 5 of the two rectangular patches. The distance between the metal shorting posts 10 arranged at the two right angles of the rectangular patch can be changed accordingly, so that the isolation of the port antenna module 3 can be flexibly adjusted as needed.

[0040] For example, increasing the number of metal shorting posts 10 can further improve the isolation of the port antenna module 3, but reducing the number of metal shorting posts 10 or reducing to 0 will deteriorate the isolation of the port antenna module 3, and does not affect the working bandwidth of the antenna; increasing the distance of the metal shorting posts 10 can improve the isolation of the port antenna module 3, but shortening the distance of the metal shorting posts 10 will deteriorate the isolation of the port antenna module 3, and does not affect the working bandwidth of the antenna.

[0041] In an exemplary embodiment of the present application, the metal shorting posts 10 arranged at the two right angles of the rectangular patch have different radii from the metal shorting posts 10 arranged in the square ring-shaped slot 7. The first metal shorting posts 10 arranged at the two right angles of the rectangular patch are 0.19 mm away from the wide side of the rectangular patch, and the radii are all 0.15 mm. The second metal shorting posts 10 arranged in the square ring-shaped slot 7 are 1.63 mm away from the wide side, and the radii are all 0.27 mm.

[0042] As an optional embodiment, in order to make the bandwidth of the MIMO patch antenna more optimal, the spacing distances of the metal probes 6 arranged in the middle of the rectangular patch are not all the same. In an exemplary embodiment, the number of metal probes 6 is 4, the distances between the metal probes 6 are 6 mm, 4 mm and 6 mm respectively, and the radius of each metal probe 6 is 0.35 mm.

[0043] In the present embodiment, the size of the main dielectric substrate 1 is 100 mm x 40 mm x 2.6 mm, the thickness of the rectangular patch of the port antenna module 3 arranged thereon and the thickness of the metal ground 2 thereunder can be ignored, and the profile height of the designed extremely narrow spacing MIMO antenna is only 2.6 mm.

[0044] As an expandable embodiment, the number of port antenna modules 3 can be multiple and form a large-scale MIMO patch antenna array, and the edges of each port antenna module 3 do not exceed the edges of the main dielectric substrate 1. As shown in Figure 4 two port antenna modules 3, four radiation units form a MIMO patch antenna array, and the positions of the feed ports 5 of each port antenna module can be adaptively adjusted so that the entire MIMO patch antenna array is symmetric about the central axis in the horizontal direction or the vertical direction.

[0045] Based on the same inventive concept, the embodiment of the present application also provides a decoupling design method of MIMO patch antenna. In an exemplary embodiment, as shown in Figure 5 the method comprises the following steps: A1, using a coaxial feeding mode, a feeding port 5 is arranged on each of the two rectangular patches to directly feed the port antenna module 3.

[0046] A2, for any rectangular patch, a group of metal probes 6 is arranged in the middle of the rectangular patch, so that the frequency band of the port antenna module 3 can cover the N79 frequency band. When the metal probe 6 is not placed, the frequency band of the port antenna module 3 is lower and cannot completely cover the N79 frequency band.

[0047] A3, for any rectangular patch, a square ring-shaped slot 7 and a rectangular slot 8 are arranged in the middle of the rectangular patch close to the center of the wide side of the other rectangular patch.

[0048] A4, for any rectangular patch, a metal shorting post 10 is arranged at each of the two right angles adjacent to the other rectangular patch. After arranging a group of metal shorting posts 10 along the right angle side of the rectangular patch, the isolation of the port antenna module 3 is improved, but the isolation between the two feeding ports 5 is still lower than 10 dB.

[0049] A5, for any rectangular patch, a capacitor 9 is arranged in the rectangular slot 8 of the rectangular patch, and a metal shorting post 10 is arranged in the square ring-shaped slot 7 of the rectangular patch. After slitting in the middle of the rectangular patch and adding the capacitor, the isolation of the port antenna module 3 is greatly improved, so that the isolation between the two feeding ports 5 is higher than 20 dB.

[0050] In the above decoupling design process of the MIMO patch antenna, in order to meet the demand of the full-screen mobile phone, the MIMO patch antenna with extremely narrow spacing proposed in the present application does not slit on the metal ground 2, and has the characteristic of zero net space. In order to reduce the size of the port antenna module 3 in the mobile phone, the two feeding ports 5 directly feed in the rectangular patch to radiate, and through the combined arrangement of the metal probe 6 and the metal shorting post 10, the space utilization rate of the internal antenna deployment of the mobile terminal device is effectively improved.

[0051] The port antenna module 3 in the embodiment uses a coaxial feeding mode for direct feeding. After the metal probe 6 is added to the port antenna module 3, the working frequency band can be improved, and the N79 frequency band divided in the fifth generation mobile communication can be completely covered. After the metal shorting column 10 and the slotted embedded capacitor 9 are added along the two right angles and the middle of the rectangular patch, the isolation is effectively improved. The MIMO patch antenna with an extremely narrow spacing designed in the application has the characteristics of extremely narrow spacing, low profile and wide working bandwidth, and can well meet the current design requirements for mobile terminals.

[0052] To prove the performance of the MIMO patch antenna with an extremely narrow spacing designed in the application, the curves of the scattering parameters of the MIMO patch antenna designed in the application varying with frequency, the curves of the envelope correlation coefficients varying with frequency and the curves of the efficiency varying with frequency are given, as shown in Figure 6 to Figure 7

[0053] From the scattering parameters S11 and S12 parameters in Figure 6 It can be concluded that in the proposed MIMO patch antenna, the -10dB working bandwidth of the port antenna module 3 is 4.40GHz-5.00GHz, and the isolation between the two feeding ports 5 in the port antenna module 3 is higher than 20dB. Therefore, the port antenna module 3 proposed in the application can cover the N79 frequency band divided in the fifth generation mobile communication, and can simultaneously realize wide bandwidth and high isolation.

[0054] From Figure 7 It can be concluded that in the MIMO patch antenna proposed in the application, the envelope correlation coefficients between the two feeding ports 5 are all less than 0.01 in the 4.40GHz-5.00GHz frequency band; the requirement of less than 0.5 for mobile terminal equipment is met. As can be seen from Figure 8 It can be seen that in the 4.40GHz-5.00GHz frequency band, the efficiency of the port antenna module 3 is higher than 87.5%, meeting the requirement that the efficiency of the mobile terminal antenna is greater than 40%, and the radiation performance of the antenna is good.

[0055] In summary, the MIMO patch antenna proposed in the application has the characteristics of extremely narrow spacing, low profile, wide working bandwidth, zero net space, etc. On the basis of ensuring the ultra-thin and full-screen of the mobile terminal equipment, the N79 frequency band divided in the fifth generation mobile communication can be effectively covered, and various performance requirements such as high isolation and low envelope correlation coefficient of the MIMO antenna system are met, which can be used in 5G and 6G mobile terminal MIMO communication applications such as 5G and 6G smart phones.

[0056] The technical features of the above embodiments can be combined in any way. To make the description concise, not all possible combinations of the technical features in the above embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the description. ​

[0057] The principles and implementations of the present application are described in detail with specific examples in this paper, and the above examples are only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation and application range will be changed. In summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A MIMO patch antenna, characterized in that, include: Port antenna module, main dielectric substrate, and metal ground; The port antenna module is disposed on the upper surface of the main dielectric substrate, and the metal ground is disposed on the lower surface of the main dielectric substrate. The port antenna module includes a first radiating element and a second radiating element arranged in parallel. The first radiating element and the second radiating element have identical structures and are symmetrical to each other. Each of the first radiating element and the second radiating element includes a rectangular patch. The short sides of the two rectangular patches are parallel and the distance between them is less than a preset distance threshold. For any rectangular patch, a feed port is provided on the rectangular patch. A set of metal probes is also arranged in the middle of the rectangular patch. The metal probes penetrate the rectangular patch and are located inside the main dielectric substrate. The metal probes are used to extend the antenna frequency band so that the frequency band of the port antenna module can cover the N79 frequency band. For any rectangular patch, a square annular slot and a rectangular slot are formed inside the rectangular patch near the center of the wide side of another rectangular patch; a capacitor is provided in the rectangular slot, one short side of the rectangular slot coincides with one side of the square annular slot, and the other short side of the rectangular slot is away from the other rectangular patch; for any rectangular patch, a metal shorting post is provided at the two right angles adjacent to the other rectangular patch and in the square annular slot to improve the isolation between the feed ports of the two rectangular patches; the metal shorting post passes through the rectangular patch and the main dielectric substrate and is connected to the metal ground.

2. The MIMO patch antenna according to claim 1, characterized in that, The number of metal shorting posts set at the two right angles adjacent to one rectangular patch can be multiple, in order to further improve the isolation between the power supply ports of the two rectangular patches.

3. The MIMO patch antenna according to claim 1, characterized in that, The capacitance of the capacitor is 3pF, and the preset spacing threshold is 0.2mm.

4. The MIMO patch antenna according to claim 1, characterized in that, The metal short-circuit posts located at the two right angles of the rectangular patch have different radii than the metal short-circuit posts located in the square annular gap.

5. The MIMO patch antenna according to claim 1, characterized in that, The rectangular patch has a length of 30mm and a width of 19.4mm; the outer side of the square annular slit has a length of 1mm and the inner side of the square annular slit has a length of 0.6mm; the rectangular slit has a length of 1mm and a width of 0.6mm.

6. The MIMO patch antenna according to claim 1, characterized in that, In a group of metal probes arranged in the middle of the rectangular patch, the spacing between the metal probes is not all the same.

7. The MIMO patch antenna according to claim 6, characterized in that, The number of metal probes is 4, and the distances between each metal probe are 6mm, 4mm and 6mm, respectively. The radius of each metal probe is 0.35mm.

8. The MIMO patch antenna according to claim 1, characterized in that, The main dielectric substrate is made of Rogers RT / duroid 5880 material with a relative permittivity of 2.2 and a loss tangent of 0.009; the metal ground and the port antenna module are made of metal.

9. The MIMO patch antenna according to claim 1, characterized in that, The number of port antenna modules can be multiple, forming a large-scale MIMO patch antenna array, and the edge of each port antenna module does not exceed the edge of the main dielectric substrate.

10. A decoupling design method for a MIMO patch antenna as described in any one of claims 1-9, characterized in that, include: A coaxial feeding method is adopted, with feeding ports set on two rectangular patches respectively, to directly feed the port antenna module; For any rectangular patch, a set of metal probes is arranged in the middle of the rectangular patch so that the frequency band of the port antenna module can cover the N79 frequency band. For any rectangular patch, a square annular slit and a rectangular slit are made inside the rectangular patch near the center of the wide side of another rectangular patch. For any rectangular patch, a metal short-circuit post is placed at each of the two right angles adjacent to another rectangular patch; For any rectangular patch, a capacitor is placed in the rectangular gap of the rectangular patch, and a metal short-circuit post is placed in the square annular gap of the rectangular patch.

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