A double-sided MIMO antenna

Abstract

This invention provides a dual-sided MIMO antenna, characterized by comprising a substrate, a ground plane, an "F"-shaped first radiating component, a rectangular ring-shaped second radiating component, and a feed strip; the substrate is located above and connected to the ground plane; the first and second radiating components are located on opposite sides of the substrate; the feed strip is electrically connected to the second radiating component; the first radiating component is electrically connected to the ground plane; the rectangular second radiating component can form a resonant cavity in the middle, while the first radiating component includes multiple radiating branches; the first and second radiating components are coupled to each other to form a single-cavity multimode trace structure, which can easily achieve wide bandwidth through adjustment without the need for discrete matching elements.

Description

Technical Field

[0001] This invention relates to the field of wireless communication, and in particular to a broadband 5G antenna with antenna traces designed on both sides of a dielectric substrate. Background Technology

[0002] Coupling: When two or more radiating units are arranged in free space, a radiating unit is affected not only by the electromagnetic effect generated by its own current, but also by the electromagnetic effect generated by the current of other radiating units. Especially when the radiating units are close to each other, they will have complex interactions, which are called mutual coupling.

[0003] MIMO antenna: MIMO stands for Multiple-Input Multiple-Output. It is commonly used in IEEE 802.11n, but can also be used in other 802.11 technologies. MIMO technology can be broadly divided into two categories: transmit / receive diversity and spatial multiplexing. MIMO antennas are sometimes called spatial diversity because they use multiple spatial channels to transmit and receive data. MIMO technology can improve channel capacity.

[0004] With the rapid development of the wireless communication industry, especially the widespread adoption of 5G multi-band technology, supporting multiple 5G bands alone may require several antennas. This necessitates integrating more antennas into the limited internal space of mobile terminals. Therefore, terminal antenna manufacturers need to improve antenna structures to reduce their space occupancy. Currently, integrating multi-band antennas and reducing antenna size have become important research directions for terminal manufacturers. Existing solutions all use a dielectric substrate on the same side for antenna design. Due to size limitations, antenna bandwidth is restricted, making it difficult to achieve wide-bandwidth radiation. When antenna stubs are close together or need to couple to adjust the bandwidth, discrete matching elements are sometimes added between the antenna stubs. However, these discrete elements are easily affected by the ground plane, reducing their auxiliary effect.

[0005] In view of this, there is an urgent need to design a new type of broadband 5G antenna with double-sided traces on the dielectric substrate that does not require the addition of discrete components, in order to solve the current requirements for antenna size and bandwidth. Summary of the Invention

[0006] The purpose of this invention is to provide a dual-sided MIMO antenna that solves the problem that traditional MIMO antennas often cannot achieve good bandwidth and radiation efficiency at the same time.

[0007] To address the aforementioned problems, this invention provides a dual-sided MIMO antenna, comprising a substrate, a ground plane, an "F"-shaped first radiating component, a rectangular second radiating component, and a feed strip; the substrate is located above and connected to the ground plane; the first radiating component and the second radiating component are respectively located on opposite sides of the substrate; the feed strip is electrically connected to the second radiating component; the first radiating component is electrically connected to the ground plane; the second radiating component includes a cavity structure for adjusting the discrete characteristics of the antenna.

[0008] Optionally, in the aforementioned dual-sided MIMO antenna, the first radiating component further includes a first radiating stub, a second radiating stub, and a third radiating stub; the first radiating stub and the second radiating stub are both perpendicularly connected to the third radiating stub.

[0009] Optionally, in one of the dual-sided MIMO antennas, the length of the first radiating stub is longer than the length of the second radiating stub.

[0010] Optionally, in one type of dual-sided MIMO antenna, the second radiating component further includes a fourth radiating stub, a fifth radiating stub, a sixth radiating stub, and a seventh radiating stub; the fourth radiating stub, the fifth radiating stub, the sixth radiating stub, and the seventh radiating stub are sequentially and vertically connected to form a rectangular cavity structure; the fifth radiating stub is electrically connected to the feed strip.

[0011] Optionally, in one of the dual-sided MIMO antennas, the fourth radiating stub is longer than the sixth radiating stub.

[0012] Optionally, in one type of dual-sided MIMO antenna, the fifth radiating stub is longer than the seventh radiating stub.

[0013] Optionally, in one of the dual-sided MIMO antennas, a feed point is provided at the end of the feed strip away from the second radiating component; the feed point is fed by a 50Ω coaxial line.

[0014] Optionally, the dual-sided MIMO antenna further includes a matching unit, which is electrically connected between the feed strip and the second radiating component.

[0015] Optionally, in one type of dual-sided MIMO antenna, the matching unit is one or more of a capacitor, an inductor, and a resistor.

[0016] Optionally, the double-sided MIMO antenna further includes a first through-hole and a second through-hole, wherein the first radiating component and the second radiating component are electrically connected through the first through-hole and the second through-hole.

[0017] The beneficial effects of this invention are:

[0018] A broadband MIMO antenna is provided, comprising a substrate, a ground plane, an "F"-shaped first radiating component, a second radiating component with a rectangular ring structure, and a feed strip. The substrate is located above and connected to the ground plane. The first and second radiating components are located on opposite sides of the substrate. The feed strip is electrically connected to the second radiating component. The first radiating component is electrically connected to the ground plane. A resonant cavity can be formed in the middle of the rectangular second radiating component, while the first radiating component includes multiple radiating branches. The first and second radiating components are coupled to each other to form a single-cavity multimode trace structure. Broadband can be easily achieved by adjustment without the need for discrete matching elements. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a structural diagram of a double-sided MIMO antenna provided in this embodiment;

[0021] Figure 2 This is a structural diagram of the first radiating component of a double-sided MIMO antenna provided in this embodiment;

[0022] Figure 3 This is a structural diagram of the second radiating component of a double-sided MIMO antenna provided in this embodiment;

[0023] Figure 4 The S-parameter simulation diagram of a double-sided traced MIMO antenna provided in this embodiment;

[0024] Figure 5 This is a simulation comparison diagram of the real and imaginary parts of the input impedance of a dual-sided traced MIMO antenna provided in this embodiment.

[0025] Figure 6 This is a simulation diagram of the inter-antenna reflection coefficient and isolation of a dual-sided traced MIMO antenna provided in this embodiment;

[0026] Figure 7This is a simulation diagram of the efficiency of a double-sided traced MIMO antenna provided in this embodiment;

[0027] Figure 8 This is a simulation diagram of the surface current distribution of a dual-sided trace MIMO antenna provided in this embodiment;

[0028] Figure 9 This is a directional simulation diagram of a dual-sided MIMO antenna provided in this embodiment;

[0029] Figure 10 This is a simulation result diagram of another embodiment of the double-sided traced MIMO antenna of the present invention;

[0030] Figure 11 This is a simulation result of antenna radiation for another embodiment of the double-sided traced MIMO antenna of the present invention;

[0031] Figure 12 This is an antenna element gain diagram of another embodiment of the double-sided traced MIMO antenna of the present invention.

[0032] The labels in the accompanying drawings are explained as follows:

[0033] 1 – Substrate; 2 – Ground plane; 3 – First radiating component; 4 – Second radiating component; 5 – Feed strip; 11 – First through hole; 12 – Second through hole; 31 – First radiating branch; 32 – Second radiating branch; 33 – Third radiating branch; 41 – Fourth radiating branch; 42 – Fifth radiating branch; 43 – Sixth radiating branch; 44 – Seventh radiating branch; 51 – Feed point. Detailed Implementation

[0034] The following detailed description, in conjunction with the accompanying drawings, tables, and specific embodiments, provides a further detailed account of a dual-sided wiring MIMO antenna and terminal proposed in this invention. It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects in order to describe embodiments of the invention, and are not intended to describe a specific order or sequence. It should be understood that such uses of these terms are interchangeable where appropriate. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0036] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] Currently, to support more 5G frequency bands, such as N77 and N78, terminal 5G antennas are designed with MIMO antennas to increase bandwidth. Traditional MIMO antennas require numerous antenna stubs to achieve multiple inputs and multiple outputs, inevitably encroaching on more antenna space. Furthermore, due to antenna size limitations, undesigned coupling can occur between antenna stubs, affecting antenna efficiency. Additionally, terminal millimeter-wave antennas also suffer from these issues. For example, the N257 and N258 bands in terminal millimeter-wave antennas also exhibit narrow bandwidth and low radiation efficiency. In such cases, the antenna needs further design of discrete components to counteract the effects of this coupling and assist in antenna coupling. However, MIMO antennas often require a large ground plane area. The influence of this ground plane affects the efficiency of discrete components, increasing the difficulty from the initial design stage.

[0038] Currently, the conventional solution for MIMO antenna design involves creating multiple intersecting perpendicular antenna stubs, among which are parallel stubs. Discrete components, typically capacitors of a certain capacitance, are added between these parallel stubs to assist in the antenna stub's radiation. In addition, a matching unit, usually a capacitor and inductor circuit, is connected in series between the feed point and the antenna stub to eliminate the influence of the ground plane on the discrete components. This MIMO antenna design is quite complex and often fails to achieve the desired effect.

[0039] This invention provides a broadband MIMO antenna comprising a substrate, a ground plane, an "F"-shaped first radiating component, a second radiating component with a rectangular ring structure, and a feed strip; the substrate is located above and connected to the ground plane; the first radiating component and the second radiating component are respectively located on opposite sides of the substrate; the feed strip is electrically connected to the second radiating component; the first radiating component is electrically connected to the ground plane; the second radiating component, with its rectangular main body, can form a resonant cavity in the middle, while the first radiating component includes multiple radiating branches; the first and second radiating components are coupled to each other to form a single-cavity multimode trace structure, which can easily achieve broadband performance through adjustment without the need for discrete matching elements.

[0040] Please see Figure 1 , Figure 1 This is a structural diagram of a dual-sided MIMO antenna provided in this embodiment. The invention provides a dual-sided MIMO antenna, including a substrate 1, a ground plane 2, an "F"-shaped first radiating component 3, a second radiating component 4, and a feed strip 5; the substrate 1 is located above and connected to the ground plane 2; the first radiating component 3 and the second radiating component 4 are respectively located on two sides of the substrate 1; the feed strip 5 is electrically connected to the second radiating component 4; the first radiating component 3 is electrically connected to the ground plane 2.

[0041] Please continue reading. Figure 2 , Figure 2 This is a structural diagram of a first radiating component of a dual-sided MIMO antenna provided in this embodiment. The main body of the first radiating component 3 is "F" shaped, including a first radiating branch 31, a second radiating branch 32, and a third radiating branch 33. The first radiating branch 31 and the second radiating branch 32 are both perpendicularly connected to the third radiating branch 33, wherein the length of the first radiating branch 31 is longer than the length of the second radiating branch 32.

[0042] Please continue reading. Figure 3 , Figure 3 This is a structural diagram of the second radiating component of a dual-sided MIMO antenna provided in this embodiment. The second radiating component 4 has a rectangular ring structure, including the fourth radiating segment 41, the fifth radiating segment 42, the sixth radiating segment 43, and the seventh radiating segment 44. The fourth radiating segment 41, the fifth radiating segment 42, the sixth radiating segment 43, and the seventh radiating segment 44 are connected vertically in sequence to form a rectangular cavity structure. The fourth radiating segment 41 is longer than the sixth radiating segment 43, the fifth radiating segment 42 is longer than the seventh radiating segment 44, and the fifth radiating segment 42 is electrically connected to the feed strip 5.

[0043] In this embodiment, the substrate 1 is an FR4 dielectric board with a dielectric constant of 4.3, a thickness of 0.8 mm, and a width of 8 ± 0.8 mm. The first radiating branch 31 has a length of 15.2 ± 1.5 mm and a width of 1.4 ± 0.14 mm; the second radiating branch 32 has a length of 9.4 ± 0.94 mm and a width of 1.4 ± 0.14 mm; the third radiating branch 33 has a length of 6.6 ± 0.66 mm and a width of 1.4 ± 0.14 mm; the fourth radiating branch 41 has a length of 5.8 ± 0.58 mm and a width of 1.4 ± 0.14 mm; the fifth radiating branch 42 has a length of 6.6 ± 0.66 mm and a width of 1.4 ± 0.14 mm; the sixth radiating branch has a length of 4 ± 0.4 mm and a width of 1.4 ± 0.14 mm; and the seventh radiating branch has a length of 4.8 ± 0.48 mm and a width of 1.4 ± 0.14 mm. As can be seen, the antenna provided by this invention occupies less space overall, allowing for easier placement of more other devices in the terminal. Please refer to [link / reference]. Figure 5 , Figure 5 This is a simulation comparison of the real and imaginary parts of the input impedance of a dual-sided trace MIMO antenna provided in this embodiment. As can be seen from the figure, there are two parts in the imaginary part that cross the zero point in the 3-6 GHz band. The frequency points corresponding to these two curved parts are the resonant frequencies of the antenna in the 3-6 GHz range. By introducing dual-frequency resonance, the broadband characteristics of the antenna are achieved without increasing the extra size of the antenna.

[0044] The first radiating component 3 and the second radiating component 4 have overlapping portions, and the substrate 1 is also provided with a first through hole 11 and a second through hole 12. The first radiating component 3 and the second radiating component 4 are electrically connected through the first through hole 11 and the second through hole 12. At this time, when the feeding strip 5 feeds power, a coupling effect will occur between the first radiating component 3 and the second radiating component 4, and the second radiating component 4 will form a current cavity structure. Please refer to [link / reference]. Figure 8 , Figure 8 The simulation diagrams of surface current distribution at 3.6GHz, 4.47GHz and 5GHz for a dual-sided MIMO antenna provided in this embodiment are shown. As can be seen from the diagrams, the first radiating component 3 and the second radiating component 4 on both sides of the substrate 1 achieve good current distribution and the resulting surface current distribution is relatively uniform. Therefore, through the above antenna routing method, a wide-band current distribution and radiation are achieved, thereby achieving a good resonant bandwidth.

[0045] Furthermore, both the first radiating component 3 and the second radiating component 4 include vertically connected radiating branches. The first radiating branch 31 and the second radiating branch 32 are both vertically connected to the third radiating branch 33. The fourth radiating branch 41, the fifth radiating branch 42, the sixth radiating branch 43, and the seventh radiating branch 44 are sequentially vertically connected to form a rectangular cavity structure. This design allows the antenna to achieve better omnidirectional radiation characteristics. Please refer to [link / reference]. Figure 9 , Figure 9 The simulation diagrams of the directional characteristics of a dual-sided MIMO antenna provided in this embodiment at frequencies of 3.6 GHz, 4.47 GHz, and 5 GHz show that the simulation results of the antenna at the three frequencies all exhibit good omnidirectionality. This is an excellent radiation pattern shape for the terminal antenna, which helps to receive signals from various directions caused by multipath reflections.

[0046] Please see Figure 4 and Figure 7 , Figure 4 This is a simulation diagram of the S-parameters of a dual-sided traced MIMO antenna provided in this embodiment. Figure 7 This is an efficiency simulation diagram of a dual-sided traced MIMO antenna provided in this embodiment, combined with... Figure 4 and Figure 7 As can be seen from the figure, the antenna achieves excellent radiation within a bandwidth of approximately 1.5 GHz (3.4-5.1 GHz) without requiring an additional feed circuit. Furthermore, the antenna's overall efficiency in the 3.6-5 GHz band exceeds 40%, achieving a very high overall terminal antenna efficiency. This also demonstrates that, through the aforementioned special double-sided structure design, coupling and forming a resonant cavity, no discrete components are needed between the antenna branches of the first radiating component 3, nor is a matching unit required between the feed strip 5 and the second radiating component 4. The antenna as a whole can achieve very good radiation efficiency.

[0047] In some other embodiments, two identical MIMO antennas described above can also be used to implement a multi-MIMO antenna system. Please refer to [link to relevant documentation]. Figure 6 , Figure 6 This embodiment presents a simulation diagram of the inter-antenna reflection coefficient and isolation of a dual-sided traced MIMO antenna. In this embodiment, two MIMO antennas are used to form a terminal 2-MIMO antenna system, with a distance of 24mm between the ends of the two MIMO antennas. The simulation shows that the in-band isolation reaches over 15dB, indicating good resonance. Furthermore, other numbers of MIMO antennas can be used to form a terminal multi-MIMO antenna system, but the distance between the antennas must be carefully considered during design to ensure the isolation between the MIMO antenna systems. Please refer to [link to relevant documentation]. Figure 10-12 , Figure 10-12 In another embodiment of the present invention, the frequency band is N257 millimeter wave. Simulation results show that the double-sided wiring MIMO antenna scheme of the present invention broadens the radiation bandwidth of the millimeter wave antenna, not only improving radiation efficiency but also effectively enhancing directional radiation characteristics, with a gain exceeding 16 dBi. Of course, through numerous experiments, similar effects can be achieved with millimeter waves in other frequency bands.

[0048] In summary, this invention provides a dual-sided MIMO antenna, characterized by comprising a substrate, a ground plane, an "F"-shaped first radiating component, a rectangular ring-shaped second radiating component, and a feed strip; the substrate is located above and connected to the ground plane; the first and second radiating components are located on opposite sides of the substrate; the feed strip is electrically connected to the second radiating component; the first radiating component is electrically connected to the ground plane; the rectangular second radiating component can form a resonant cavity in the middle, while the first radiating component includes multiple radiating branches; the first and second radiating components are coupled to each other to form a single-cavity multimode trace structure, which can easily achieve wide bandwidth through adjustment without the need for discrete matching elements.

[0049] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A double-sided MIMO antenna, characterized in that, It includes a substrate, a ground plane, a first radiating component, a second radiating component, and a power supply strip; the substrate is located above the ground plane and connected to the ground plane; the first radiating component and the second radiating component are respectively located on two sides of the substrate; The feed strip is electrically connected to the second radiating component; the first radiating component is electrically connected to the ground plane; the second radiating component includes a cavity structure for adjusting the discrete characteristics of the antenna; the first radiating component is "F" shaped and further includes a first radiating stub, a second radiating stub, and a third radiating stub; the first radiating stub and the second radiating stub are both perpendicularly connected to the third radiating stub; the second radiating component further includes a fourth radiating stub, a fifth radiating stub, a sixth radiating stub, and a seventh radiating stub; The fourth, fifth, sixth, and seventh radial branches are connected vertically in sequence to form a rectangular cavity structure. The fifth radiating branch is electrically connected to the feed strip.

2. The double-sided MIMO antenna according to claim 1, characterized in that, The length of the first radiating branch is longer than the length of the second radiating branch.

3. A double-sided MIMO antenna according to claim 1, characterized in that, The fourth radiating branch is longer than the sixth radiating branch.

4. A double-sided MIMO antenna according to claim 1, characterized in that, The fifth radiating branch is longer than the seventh radiating branch.

5. A double-sided MIMO antenna according to claim 1, characterized in that, The end of the feed strip away from the second radiating component is also provided with a feed point; the feed point is fed by a 50Ω coaxial line.

6. A double-sided MIMO antenna according to claim 1, characterized in that, It also includes a matching unit, which is electrically connected between the feed strip and the second radiating component.

7. A double-sided MIMO antenna according to claim 6, characterized in that, The matching unit is one or more of capacitors, inductors, and resistors.

8. A double-sided MIMO antenna according to claim 1, characterized in that, It also includes a first through hole and a second through hole, through which the first radiation component and the second radiation component are electrically connected.

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