Two-port MIMO antenna based on broadband neutral line decoupling and preparation method thereof
By introducing rectangular parasitic strips and neutralizing line structures into MIMO antennas, the problem of electromagnetic coupling effect in miniaturized design is solved, and a high isolation and wide bandwidth MIMO antenna is realized to meet the needs of modern communication systems.
Patent Information
- Application Number
- CN202510541811.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-27
- Publication Date
- 2025-07-25
AI Technical Summary
In the miniaturized design, existing MIMO antennas have strong electromagnetic coupling effects between adjacent antennas, resulting in reduced port isolation, pattern distortion and radiation efficiency, which is difficult to meet the performance requirements of modern broadband communication systems.
A two-port MIMO antenna design based on broadband neutralization line decoupling is adopted. By introducing rectangular parasitic strips, metal short-circuit columns and neutralization lines of different structures on the L-shaped patch, multiple resonance points and decoupling paths are formed to improve isolation and bandwidth.
It realizes a high isolation and wide bandwidth MIMO antenna in a compact structure, which can cover the N77, N79 and 5.2GHz WLAN frequency bands of the fifth generation of mobile communications, meeting various performance indicators of the mobile communication system.
Smart Images
Figure CN120376937A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of antenna decoupling, and particularly to a two-port MIMO antenna based on broadband neutralization line decoupling and a preparation method thereof. Background Art
[0002] MIMO technology, whose full name is Multiple Input Multiple Output, is a technology widely used in the field of wireless communication. By using multiple antennas for signal transmission and reception, MIMO technology significantly improves the performance of communication systems. Currently, it has been widely applied in the communication field. Microstrip antennas play an important role in MIMO system design due to their advantages such as low profile, easy conformal shaping, and low cost. However, with the increasing trend of communication devices towards miniaturization, one of the challenges in MIMO system design is to achieve miniaturization. During the miniaturization design process of MIMO systems, the strong electromagnetic coupling effect between adjacent antennas becomes a key factor restricting system performance. This mutual coupling phenomenon not only reduces the port isolation but also causes pattern distortion and radiation efficiency degradation, thus seriously affecting the realization of channel capacity and spatial multiplexing gain.
[0003] In recent years, the research on microstrip antenna decoupling technology has mainly focused on several key directions: The Defected Ground Structure (DGS) forms a band-stop characteristic by etching a specific pattern on the ground, but its perturbation effect on the radiation pattern is relatively obvious; the Electromagnetic Band Gap (EBG) structure can effectively suppress the propagation of surface waves, but there are problems such as high design complexity and narrow working bandwidth; the decoupling network method realizes impedance compensation by constructing a matching network, but it is prone to introducing additional insertion loss. In contrast, the neutralization line technology shows unique advantages in near-field coupling cancellation due to its simple physical connection mechanism. However, the traditional neutralization line scheme can only maintain effective decoupling within a narrow band and is difficult to meet the requirements of modern broadband communication systems. Therefore, for this research field, how to enable a two-port MIMO antenna to have sufficient isolation and working bandwidth and meet the performance indicators of mobile communication systems has important research value. Summary of the Invention
[0004] The purpose of this application is to provide a two-port MIMO antenna based on broadband neutralization line decoupling and a preparation method thereof, which can enable the two-port MIMO antenna to have sufficient isolation and working bandwidth and fully meet the performance indicators of mobile communication systems.
[0005] To achieve the above purpose, this application provides the following solutions:
[0006] In a first aspect, the present application provides a two-port MIMO antenna based on broadband neutralization line decoupling, comprising: a two-port MIMO antenna body, a main dielectric substrate, and a metal bottom plate; the two-port MIMO antenna body is disposed on the upper surface of the main dielectric substrate, and the metal bottom plate is disposed on the lower surface of the main dielectric substrate; the two-port MIMO antenna body includes an L-shaped patch, two rectangular parasitic strips respectively corresponding to the two free ends of the L-shaped patch, a set of cross-shaped metal shorting posts disposed at the middle corner of the L-shaped patch, a circular neutralization line connected to the inner right-angle side of the L-shaped patch, and an L-shaped neutralization line connected to the outer right-angle side of the L-shaped patch; the L-shaped patch is fed and connected to the metal bottom plate through two feed ports penetrating the main dielectric substrate; the rectangular parasitic strips and the metal shorting posts are used to introduce a low-frequency resonance point and a high-frequency resonance point for the two-port MIMO antenna body respectively; the circular neutralization line and the L-shaped neutralization line are used to decouple the two-port MIMO antenna body in different frequency bands.
[0007] Optionally, the L-shaped patch is obtained by partially overlapping two rectangular patches with the same size.
[0008] Optionally, the long side of the rectangular parasitic strip is the same as the side length of the overlapping area of the two rectangular patches, and the long side of the rectangular parasitic strip coincides with the side of the main dielectric substrate; the two rectangular parasitic strips are respectively corresponding to the free sides of the two rectangular patches; the free side of the rectangular patch is the side of the rectangular patch far from the overlapping area.
[0009] Optionally, several metal shorting posts are arranged in a cross shape within the overlapping area of the two rectangular patches.
[0010] Optionally, the two feed ports penetrating the main dielectric substrate are disposed outside the overlapping area of the two rectangular patches.
[0011] Optionally, the circular neutralization line is connected to the two sides of the inner right angle of the L-shaped patch through two neutralization line branches respectively, and the circular neutralization line is used to provide two decoupling paths with the same length to decouple the low-frequency band and the high-frequency band of the two-port MIMO antenna body.
[0012] Optionally, the L-shaped neutralization line is connected to the two sides of the outer right angle of the L-shaped patch through two neutralization line branches respectively, and the L-shaped neutralization line is used to provide a decoupling path to decouple the middle frequency band of the two-port MIMO antenna body.
[0013] Optionally, the main dielectric substrate is made of FR4 material, with a relative dielectric constant of 4.4 and a loss tangent of 0.02; the two-port MIMO antenna body and the metal bottom plate are both made of metal and are respectively disposed on the upper surface and the lower surface of the main dielectric substrate.
[0014] Optionally, when a plurality of two-port MIMO antenna bodies are arranged equidistantly on the main dielectric substrate, a large-scale MIMO antenna array is formed.
[0015] In a second aspect, the present application provides a preparation method for a two-port MIMO antenna based on broadband neutralization line decoupling, including the following steps:
[0016] An L-shaped patch and a metal bottom plate are respectively arranged on the upper surface and the lower surface of the main dielectric substrate; the L-shaped patch is fed and connected to the metal bottom plate through two feeding ports penetrating the main dielectric substrate.
[0017] Two rectangular parasitic strips are arranged on the upper surface of the main dielectric substrate at positions corresponding to the two free ends of the L-shaped patch to introduce a low-frequency resonance point for the two-port MIMO antenna body.
[0018] A group of cross-shaped metal shorting posts are arranged at the middle corner of the L-shaped patch to introduce a high-frequency resonance point for the two-port MIMO antenna body.
[0019] A circular neutralization line and an L-shaped neutralization line are respectively arranged on the inner right-angle side and the outer right-angle side of the L-shaped patch to decouple the two-port MIMO antenna body in different frequency bands.
[0020] According to the specific embodiments provided by the present application, the following technical effects are disclosed:
[0021] The present application provides a two-port MIMO antenna based on broadband neutralization line decoupling and a preparation method thereof. In the two-port MIMO antenna, the two-port MIMO antenna body is arranged on the upper surface of the main dielectric substrate, and a metal bottom plate is arranged on the lower surface of the main dielectric substrate; the two-port MIMO antenna body is an L-shaped patch, and the L-shaped patch is fed and connected to the metal bottom plate through two feeding ports penetrating the main dielectric substrate. Two rectangular parasitic strips are correspondingly arranged at the two free ends of the L-shaped patch, and a group of cross-shaped metal shorting posts are arranged at the corner of the middle part of the L-shaped patch. The two are respectively used to introduce a low-frequency resonance point and a high-frequency resonance point for the two-port MIMO antenna body. Since two new resonance points are introduced on the basis of the original resonance points, the two-port MIMO antenna can cover the N77, N79, and 5.2 GHz WLAN frequency bands divided in the fifth-generation mobile communication; in addition, an annular neutralization line is connected to the inner right-angle side of the L-shaped patch, and an L-shaped neutralization line is connected to the outer right-angle side of the L-shaped patch. The two are respectively used to decouple the two-port MIMO antenna body in different frequency bands, which can effectively improve the isolation inside the two-port MIMO antenna, and all its indicators meet the requirements of the MIMO antenna. The two-port MIMO antenna based on broadband neutralization line decoupling has the characteristics of compact structure, easy manufacturing, high isolation, and wide bandwidth, and can well meet the current design requirements for mobile terminal systems. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] 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 required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0023] Figure 1 FIG. is a schematic structural diagram of a two-port MIMO antenna based on broadband neutralization line decoupling provided by an embodiment of the present application.
[0024] Figure 2 FIG. is a schematic cross-sectional view of a two-port MIMO antenna based on broadband neutralization line decoupling provided by an embodiment of the present application in the thickness direction.
[0025] Figure 3 FIG. is a curve diagram of the S parameter of a two-port MIMO antenna based on broadband neutralization line decoupling provided by an embodiment of the present application changing with frequency.
[0026] Figure 4 FIG. is a flowchart of a preparation method of a two-port MIMO antenna based on broadband neutralization line decoupling provided by an embodiment of the present application.
[0027] Reference numerals: 1: main dielectric substrate; 2: metal bottom plate; 3: two-port MIMO antenna body; 4: L-shaped patch; 5: rectangular parasitic strip; 6: group of metal shorting posts; 7: circular neutralization line; 8: L-shaped neutralization line; 9: feed port one; 10: feed port two. Detailed implementation manners
[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.
[0029] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners.
[0030] A two-port MIMO antenna based on broadband neutralization line decoupling provided by an embodiment of the present application, in an exemplary embodiment, as Figure 1 shown, includes: a main dielectric substrate 1, a metal bottom plate 2, and a two-port MIMO antenna body 3; the two-port MIMO antenna body 3 is disposed on the upper surface of the main dielectric substrate 1, and the metal bottom plate 2 is disposed on the lower surface of the main dielectric substrate 1; the two-port MIMO antenna body 3 includes an L-shaped patch 4, two rectangular parasitic strips 5 respectively corresponding to the two free ends of the L-shaped patch, a group of cross-shaped metal shorting posts 6 disposed at the middle corner of the L-shaped patch, a circular neutralization line 7 connected to the inner right-angle side of the L-shaped patch, and an L-shaped neutralization line 8 connected to the outer right-angle side of the L-shaped patch; the L-shaped patch 4 is fed and connected to the metal bottom plate 2 through two feed ports penetrating the main dielectric substrate, as Figure 1 shown, the two feed ports one 9 and feed port two 10 penetrating the main dielectric substrate are disposed outside the overlapping area of the two rectangular patches; the two rectangular parasitic strips 5 and a group of metal shorting posts 6 are used to introduce a low-frequency resonance point and a high-frequency resonance point for the two-port MIMO antenna body 3 respectively; the circular neutralization line 7 and the L-shaped neutralization line 8 are used to decouple the two-port MIMO antenna body in different frequency bands.
[0031] In a specific embodiment, the L-shaped patch is obtained by partially overlapping two rectangular patches with the same size, so that the layout of the two-port MIMO antenna body 3 is very compact, and the size of the two-port MIMO antenna body 3 can be effectively reduced.
[0032] As an exemplary option, the long side of the rectangular parasitic strip 5 has the same length as the side length of the overlapping region of the two rectangular patches, and the long side of the rectangular parasitic strip 5 coincides with the side of the main dielectric substrate 1; the two rectangular parasitic strips 5 are respectively arranged corresponding to the free edges of the two rectangular patches; the free edge of the rectangular patch is the edge of the rectangular patch far from the overlapping region.
[0033] As Figure 1 shown, a plurality of metal shorting posts are arranged in a cross shape within the overlapping region of the two rectangular patches to short the L-shaped patch 4 to the metal bottom plate 2.
[0034] The circular neutralization line 7 is connected to the two sides of the inner right angle of the L-shaped patch 4 through two neutralization line stubs respectively. The circular neutralization line 7 is used to provide two decoupling paths with the same length to decouple the low-frequency band and the high-frequency band of the two-port MIMO antenna body 3.
[0035] The L-shaped neutralization line 8 is connected to the two sides of the outer right angle of the L-shaped patch 4 through two neutralization line stubs respectively. The L-shaped neutralization line 8 is used to provide a decoupling path to decouple the middle frequency band of the two-port MIMO antenna body 3.
[0036] In this embodiment, the main dielectric substrate 1 is made of FR4 material with a relative dielectric constant of 4.4 and a loss tangent of 0.02; the two-port MIMO antenna body 3 and the metal bottom plate 2 are both metals and are respectively arranged on the upper surface and the lower surface of the main dielectric substrate 1.
[0037] The antenna structure designed in this embodiment can be expanded. When a plurality of two-port MIMO antenna bodies 3 are arranged on the main dielectric substrate 1 at equal intervals, a large-scale MIMO antenna array is formed.
[0038] In a specific embodiment, the size of the metal bottom plate 2 is 46 mm × 46 mm, and the size of the main dielectric substrate 1 covered above it is 46 mm × 46 mm × 3 mm, with a relative dielectric constant of 4.4 and a loss tangent of 0.02. The L-shaped patch 4 of the two-port MIMO antenna body 3 is obtained by overlapping two rectangular patches with the same size, and the size of the rectangular patch is 34 mm × 19.5 mm. The sizes of the two rectangular parasitic strips 5 are 19.5 mm × 2 mm, and the distance between them and the L-shaped patch 4 is 0.5 mm. The radius of this group of metal shorting posts 6 arranged in a cross shape is 0.3 mm. Among them, the distance between the 5 metal shorting posts placed along the y-axis and the long side of the L-shaped patch 4 is 8.8 mm, and the distance between any two metal shorting posts is 2.8 mm. The inner radius of the circular neutralization line 7 is 7.7 mm, and the outer radius is 7.9 mm. The line widths of the circular neutralization line 7 and the L-shaped neutralization line 8 are both 0.2 mm.
[0039] As Figure 2As shown, when looking in the x-axis direction, i.e., the thickness direction, the two thicker cylinders passing through the main dielectric substrate 1 are the first feed port 9 and the second feed port 10; the thinner cylinder between them is the metal shorting post.
[0040] In terms of the feeding method, the coaxial feeding method is used to directly feed the L-shaped patch 4 and couple-feed the two rectangular parasitic strips 5. To meet the requirements of a full-screen mobile phone, the proposed two-port MIMO antenna body 3 has no slit on the metal bottom plate 2 and has a complete metal bottom plate 2. When the two rectangular parasitic strips 5 and a group of metal shorting posts 6 are not placed, the L-shaped patch 4 has only one resonant frequency point with a relatively narrow bandwidth and can only cover part of the N77 band. After arranging two rectangular parasitic strips 5 parallel to the free edge of the L-shaped patch 4, the L-shaped patch 4 adds a low-frequency resonant point; after loading a group of metal shorting posts 6 on the L-shaped patch 4, the L-shaped patch 4 also adds a high-frequency resonant point. At this time, the L-shaped patch 4 has a total of three resonant points, and the bandwidth is effectively broadened.
[0041] To decouple the two-port MIMO antenna, first, a circular neutralization line 7 is loaded at the two sides of the inner right-angle side of the L-shaped patch 4 to introduce two coupling paths with the same length for decoupling the low-frequency and high-frequency bands; moreover, after adding the circular neutralization line 7, the L-shaped patch 4 adds a mid-frequency resonant point, and the high-frequency resonant point shifts downward. Then, an L-shaped neutralization line 8 is loaded at the two long sides of the L-shaped patch 4 to decouple the mid-frequency band. It should be noted that after adding the two neutralization lines for decoupling, the bandwidth becomes slightly narrower, but it can still cover part of the N77 band, the complete N79 band, and the 5G WLAN band in 5G mobile communication.
[0042] Simulate the two-port MIMO antenna based on broadband neutralization line decoupling provided in this embodiment. In the Figure 3 two-dimensional coordinate system, the abscissa represents the signal frequency range, and the ordinate shows the magnitude characteristics of the S-parameters. Among them, the Sii parameter specifically refers to the reflection coefficient of the i-th feed port, and its value intuitively reflects the impedance matching quality of this feed port; the Sij parameter is defined as the energy ratio of the signal transmitted from the j-th feed port to the i-th feed port when the i-th feed port is in an impedance matching state. In engineering practice, the Sij parameter is called the antenna system isolation index, and this parameter quantitatively characterizes the performance interference intensity caused by the electromagnetic coupling effect between each radiation unit when multiple antennas work together. In this embodiment, the first feed port is the first feed port 9, and the second feed port is the second feed port 10.
[0043] Specifically, when a signal is injected from a certain feed port of the antenna, by monitoring the signal intensity received by other feed ports, the electromagnetic isolation performance between different antenna units inside the antenna array can be accurately evaluated. From Figure 3From the S-parameters, it can be obtained that the -6 dB bandwidth of the proposed two-port MIMO antenna based on broadband neutralization line decoupling is 3.79 GHz - 5.34 GHz, and the isolation between MIMO antenna elements within the operating frequency band is higher than 11 dB. Therefore, the two-port MIMO antenna body 3 proposed in this embodiment can cover the N77, N79, and 5.2 GHz WLAN frequency bands divided in the fifth-generation mobile communication, and can simultaneously achieve narrow-spacing decoupling and miniaturization. It can cover the N77, N79, and 5.2 GHz WLAN frequency bands divided in the fifth-generation mobile communication, and all its indicators meet the requirements of MIMO antennas; the present invention has the characteristics of compact structure, easy manufacturing, high isolation, and wide bandwidth, and can well meet the current design requirements for mobile terminal systems.
[0044] Based on the same inventive concept, an embodiment of the present application also provides a method for manufacturing a two-port MIMO antenna based on broadband neutralization line decoupling as involved in the above embodiment. The implementation solution provided by this manufacturing method to solve the problem is similar to the implementation solution recorded in the above hardware structure. In an exemplary embodiment, as Figure 4 shown, a method for manufacturing a two-port MIMO antenna based on broadband neutralization line decoupling is provided, including the following steps:
[0045] A1. Set an L-shaped patch and a metal bottom plate on the upper surface and the lower surface of the main dielectric substrate respectively; the L-shaped patch is fed and connected to the metal bottom plate through two feeding ports penetrating the main dielectric substrate.
[0046] A2. Set two rectangular parasitic strips at positions corresponding to the two free ends of the L-shaped patch on the upper surface of the main dielectric substrate to introduce a low-frequency resonance point for the two-port MIMO antenna body.
[0047] A3. Set a group of cross-shaped metal shorting posts at the middle corner of the L-shaped patch to introduce a high-frequency resonance point for the two-port MIMO antenna body.
[0048] A4. Set a circular neutralization line and an L-shaped neutralization line on the inner right-angle side and the outer right-angle side of the L-shaped patch respectively to decouple the two-port MIMO antenna body in different frequency bands.
[0049] During the manufacturing process of the two-port MIMO antenna based on broadband neutralization line decoupling, for the selection of the feeding method, in this embodiment, the coaxial feeding method is used to directly feed the L-shaped patch 4 and couple-feed the two rectangular parasitic strips 5.
[0050] In order to achieve broadband, the antenna needs to have multiple resonant frequencies, that is, the antenna has multiple working modes; at the same time, in order to meet the needs of full-screen mobile phones, the two-port MIMO antenna proposed in this embodiment has no seams on the metal base plate and has a complete metal base plate. When two rectangular parasitic strips and a group of metal short-circuit posts are not placed, the L-shaped patch has only one resonant frequency, the bandwidth is relatively narrow, and it can only cover part of the N77 frequency band. After arranging two rectangular parasitic strips in parallel along the free edge of the L-shaped patch, the L-shaped patch adds a low-frequency resonance point; after loading a group of metal short-circuit posts on the L-shaped patch, the L-shaped patch also adds a high-frequency resonance point. At this time, the L-shaped patch 4 has a total of three resonance points, and the bandwidth is effectively widened.
[0051] In order to decouple the two-port MIMO antenna, the neutralization line technology with a simpler physical connection mechanism was selected. First, a circular neutralization line is loaded at the two sides of the inner right angle of the L-shaped patch, and two coupling paths of the same length are introduced to decouple the low-frequency band and the high-frequency band; and after adding the circular neutralization line, the L-shaped patch adds a mid-frequency resonance point, and the high-frequency resonance point shifts to a lower level. Then, an L-shaped neutralization line is loaded at the two sides of the outer right angle of the L-shaped patch to decouple the mid-frequency band. It is worth noting that after adding two neutralization lines for decoupling, the bandwidth becomes narrower, but it can still cover part of the N77 band, the complete N79 and the 5.2GHz WLAN band in 5G mobile communications.
[0052] In summary, the above-mentioned two-port MIMO antenna prepared in this embodiment uses a coaxial feeding method, loads two rectangular parasitic strips and a group of metal short-circuit columns to expand the bandwidth, and the two neutralization lines with different structures have a multi-band decoupling effect, which can effectively improve the isolation inside the two-port MIMO antenna. Finally, the designed two-port MIMO antenna can cover the N77, N79 and 5.2GHz WLAN bands divided in the fifth generation of mobile communications, and its various indicators meet the requirements of MIMO antennas, with the characteristics of compact structure, easy manufacturing, high isolation and wide bandwidth, which can well meet the current design requirements for mobile terminal systems.
[0053] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0054] In this article, specific examples are used to illustrate the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.
Claims
1. A two-port MIMO antenna based on broadband neutralization line decoupling, characterized in that Comprising: A two-port MIMO antenna body, a main dielectric substrate, and a metal bottom plate; the two-port MIMO antenna body is disposed on the upper surface of the main dielectric substrate, and the metal bottom plate is disposed on the lower surface of the main dielectric substrate; the two-port MIMO antenna body includes an L-shaped patch, two rectangular parasitic strips respectively corresponding to two free ends of the L-shaped patch, a group of cross-shaped metal shorting posts disposed at the middle corner of the L-shaped patch, a circular neutralization line connected to the inner right-angle side of the L-shaped patch, and an L-shaped neutralization line connected to the outer right-angle side of the L-shaped patch; the L-shaped patch is fed and connected to the metal bottom plate through two feed ports penetrating the main dielectric substrate; the rectangular parasitic strips and the metal shorting posts are used to introduce a low-frequency resonance point and a high-frequency resonance point for the two-port MIMO antenna body respectively; the circular neutralization line and the L-shaped neutralization line are used to decouple the two-port MIMO antenna body in different frequency bands.
2. The two-port MIMO antenna based on broadband neutralization line decoupling according to claim 1, characterized in that, The L-shaped patch is obtained by partially overlapping two rectangular patches with the same size.
3. The two-port MIMO antenna based on broadband neutralization line decoupling according to claim 2, wherein The long side of the rectangular parasitic strip is the same as the side length of the overlapping area of the two rectangular patches, and the long side of the rectangular parasitic strip coincides with the side of the main dielectric substrate; the two rectangular parasitic strips are respectively corresponding to the free sides of the two rectangular patches; the free side of the rectangular patch is the side of the rectangular patch far from the overlapping area.
4. The two-port MIMO antenna based on broadband neutralization line decoupling according to claim 2, wherein A plurality of the metal shorting posts are arranged in a cross shape within the overlapping area of the two rectangular patches.
5. The two-port MIMO antenna based on broadband neutralization line decoupling according to claim 4, wherein, Two feed ports penetrating the main dielectric substrate are disposed outside the overlapping area of the two rectangular patches.
6. The two-port MIMO antenna based on broadband neutralization line decoupling according to claim 2, wherein The circular neutralization line is connected to the two sides of the inner right angle of the L-shaped patch through two neutralization line branches respectively, and the circular neutralization line is used to provide two decoupling paths with the same length to decouple the low-frequency band and the high-frequency band of the two-port MIMO antenna body.
7. The two-port MIMO antenna based on broadband neutralization line decoupling according to claim 2, wherein The L-shaped neutralization line is connected to the two sides of the outer right angle of the L-shaped patch through two neutralization line branches respectively, and the L-shaped neutralization line is used to provide a decoupling path to decouple the middle frequency band of the two-port MIMO antenna body.
8. The two-port MIMO antenna based on broadband neutralization line decoupling according to claim 1, wherein, The main dielectric substrate uses FR4 material, with a relative dielectric constant of 4.4 and a loss tangent of 0.02; the two-port MIMO antenna body and the metal bottom plate are both metals, and are respectively disposed on the upper surface and the lower surface of the main dielectric substrate.
9. The two-port MIMO antenna based on broadband neutralization line decoupling according to claim 1, wherein When a plurality of the two-port MIMO antenna bodies are arranged on the main dielectric substrate at equal intervals, a large-scale MIMO antenna array is formed.
10. A preparation method for a two-port MIMO antenna based on broadband neutralization line decoupling, characterized in that Comprising: An L-shaped patch and a metal bottom plate are respectively disposed on the upper surface and the lower surface of the main dielectric substrate; The L-shaped patch is fed and connected to the metal bottom plate through two feed ports penetrating the main dielectric substrate; Two rectangular parasitic strips are disposed on the upper surface of the main dielectric substrate at positions corresponding to the two free ends of the L-shaped patch to introduce a low-frequency resonance point for the two-port MIMO antenna body; A group of cross-shaped metal shorting posts are disposed at the middle corner of the L-shaped patch to introduce a high-frequency resonance point for the two-port MIMO antenna body; A circular neutralization line and an L-shaped neutralization line are respectively arranged on the inner right-angle side and the outer right-angle side of the L-shaped patch to decouple different frequency bands of the two-port MIMO antenna body.