A MIMO filter antenna

Abstract

The present invention discloses a MIMO filtering antenna, comprising at least two filtering antenna units, wherein adjacent filtering antenna units are connected via a decoupling structure, wherein the filtering antenna unit comprises a dielectric substrate, wherein two opposite sides thereof are respectively connected to a first metal antenna component and a second metal antenna component, and a plurality of radiation zero points are formed via a specific structure of the antenna unit, and these radiation zero points can be regulated and distributed at the high-frequency and low-frequency edges of the antenna passband, thereby achieving a filtering effect with a high roll-off characteristic, and via the decoupling structure, a reverse electromagnetic field can be introduced to offset the coupling field, thereby reducing the port coupling degree and improving the antenna's directional pattern stability, and at the same time, the antenna unit also has the technical effects of compact structure and small size, so that the MIMO filtering antenna can play an important role in an integrated radio frequency front-end system.

Description

Technical Field

[0001] The invention belongs to the technical field of antennas and relates to a filtering antenna, in particular to a MIMO filtering antenna. Background Art

[0002] With the development of science and technology, various mobile communication devices have become indispensable scientific and technological products in daily life. Miniaturization, lightness, high integration and multi-function have gradually become important features of mobile devices. Antennas and filters are important passive components in the RF front-end circuits of electronic devices. Antennas usually include transmitting antennas and receiving antennas. The transmitting antenna is used to convert electrical signals into electromagnetic waves and send them to free space, and the receiving antenna is used to receive incident electromagnetic waves in free space. The filter can filter out unwanted signals.

[0003] In order to achieve the miniaturization and integration of electronic equipment, the industry has developed filtering antennas in recent years. Filtering antennas are a new type of antenna that integrates antenna and filter functions. They can filter signals while receiving and transmitting electromagnetic wave signals, significantly reducing the technical requirements of the antenna system for the RF front end. This type of antenna has broad application prospects in wireless communications, radar systems and other fields.

[0004] In addition, in today's wireless communication systems, there are higher requirements for communication speed and stability. Multiple-input multiple-output (MIMO) antenna technology can increase the channel capacity of the transceiver system exponentially without adding additional spectrum resources and antenna transmission power, greatly improving spectrum utilization. It has become one of the important technologies for wireless communication in recent years. MIMO antennas with filtering functions are expected to play an important role in the next generation of wireless communication systems. At present, the common filtering MIMO antenna has a large size and is difficult to meet the miniaturization requirements of electronic devices because it uses multiple antennas at both the transmitting and receiving ends. At the same time, there is still a lot of room for optimization and improvement in the conformal and frequency selection characteristics of the directional pattern.

[0005] In view of this, it is necessary to further improve the MIMO antenna with filtering function in the prior art. Summary of the invention

[0006] To this end, the technical problem to be solved by the present invention is that the traditional MIMO antenna with filtering function is large in size, has poor directional pattern conformality and frequency selection characteristics, and thus proposes a MIMO filtering antenna with small size, higher integration, stable directional pattern and good frequency selection characteristics.

[0007] In order to solve the above technical problems, the technical solution of the present invention is:

[0008] The present invention provides a MIMO filtering antenna, which includes at least two filtering antenna units, and adjacent filtering antenna units are connected via a decoupling structure;

[0009] The filtering antenna unit comprises a dielectric substrate, the dielectric substrate comprises a first plate surface and a second plate surface arranged opposite to each other, the first plate surface is connected with a first metal antenna component, the first metal antenna component comprises a first metal patch, the first metal patch has a U-shaped groove, and a second metal patch is arranged in the U-shaped groove at intervals;

[0010] The second board surface is connected to a second metal antenna assembly, the second metal antenna assembly includes a third metal patch, a fourth metal patch and a metal patch group sequentially arranged in a first direction of the second board surface, and the metal patch group includes a fifth patch and a sixth patch distributed in a second direction of the second board surface;

[0011] The first metal patch is connected to the fourth metal patch through a feeding mechanism, and the first metal patch is connected to the third metal patch, the fourth metal patch, the fifth metal patch, and the sixth metal patch through a metal connector, and the second metal patch is also connected to the fourth metal patch through a metal connector.

[0012] Preferably, the first metal patch includes a patch body, a first extension branch and a second extension branch connected at both ends of the patch body, and the U-shaped groove is formed between the first extension branch, the second extension branch and the patch body; the spacing between the second metal patch and the patch body is 0.01λ-0.1λ, the spacing between the second metal patch and the first extension branch is 0.001λ-0.1λ, and the spacing between the second metal patch and the second extension branch is 0.001λ-0.1λ, wherein λ is the wavelength at the antenna operating frequency.

[0013] Preferably, one end of the patch body is connected to the third metal patch through a first metal connector, and the first extension branch is connected to the third metal patch through a second metal connector. The patch body, the first metal connector, the third metal patch, the second metal connector, and the first extension branch form a closed loop structure.

[0014] Preferably, the circumference of the closed-loop structure is 0.3λ-1.5λ.

[0015] Preferably, one end of the patch body is connected to the fifth metal patch through a third metal connector, and the second extended branch is connected to the sixth metal patch through a fourth metal connector, and the patch body, the third metal connector, the fifth metal patch, the sixth metal patch, the fourth metal connector, and the second extended branch form an open-loop structure.

[0016] Preferably, the spacing between the fifth metal patch and the sixth metal patch is 0.01λ-0.1λ, the fifth metal patch and the sixth metal patch are both rectangular patches, and the length of the fifth metal patch and the sixth metal patch is 0.1λ-0.4λ and the width is 0.01λ-0.1λ.

[0017] Preferably, the second metal patch and the patch body are both rectangular structures, and the lengths of the second metal patch and the patch body are both 0.1λ-0.4λ, and the widths are both 0.01λ-0.1λ.

[0018] Preferably, the dielectric substrate is a rectangular plate, the first direction is the width direction of the dielectric substrate, the second direction is the length direction of the dielectric substrate, the length of the dielectric substrate is 0.25λ-0.75λ, the width is 0.05λ-0.4λ, and the thickness is 0.001λ-0.2λ, wherein λ is the wavelength at the operating frequency of the antenna.

[0019] Preferably, the fourth metal patch is a rectangular patch, the length of the fourth metal patch is 0.1λ-0.4λ, and the width is 0.01λ-0.2λ; the feeding mechanism is a coaxial feeding mechanism, the outer conductor of the coaxial feeding mechanism is connected to the fourth metal patch, and the inner conductor of the coaxial feeding mechanism is connected to the patch body.

[0020] Preferably, the MIMO filter antenna includes four filter antenna units, which are arranged sequentially and spaced apart along the length direction, and adjacent filter antenna units are connected through the decoupling structure, and the decoupling structure is a neutralization line. The spacing between adjacent filter antenna units is not less than 0.01λ, and the total length of the neutralization line is 0.1λ-0.4λ, wherein λ is the wavelength at the antenna operating frequency.

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

[0022] The MIMO filtering antenna provided by the present invention comprises at least two filtering antenna units, each filtering antenna unit comprises a dielectric substrate, the dielectric substrate comprises a first plate surface and a second plate surface arranged opposite to each other, the first plate surface is connected to a first metal antenna component, the first metal antenna component comprises a first metal patch, the first metal patch has a U-shaped groove, and a second metal patch is arranged at intervals in the U-shaped groove; the second plate surface is connected to a second metal antenna component, the second metal antenna component comprises a third metal patch, a fourth metal patch and a metal patch group arranged in sequence at intervals along a first direction of the second plate surface, the metal patch group comprises a fifth patch and a sixth patch distributed at intervals along a second direction of the second plate surface; the first metal patch is connected to the fourth metal patch through a feeding mechanism, and the first metal patch and the fourth metal patch, the first metal patch and the fifth metal patch, the first metal patch and the sixth metal patch, and the second metal patch and the fourth metal patch are all connected through metal connectors. Through the above structure, the first metal patch, the second metal patch, the fourth metal patch, the feeding mechanism and the metal connector form a first radiator, the first metal patch, the third metal patch and the metal connector form a second radiator, and the first metal patch, the fifth metal patch, the sixth metal patch and the metal connector form a third radiator. Through field coupling, radiation zero points can be generated at the first radiator, the second radiator and the third radiator. These radiation zero points can be controlled and distributed at the high-frequency and low-frequency edges of the antenna passband, thereby achieving a filtering effect with a high roll-off characteristic. Through the decoupling structure, a reverse electromagnetic field can be introduced to offset the coupling field, thereby reducing the port coupling degree and improving the antenna's directional pattern stability. At the same time, the antenna unit of the above structure also has the technical effects of compact structure and small size, so that the MIMO filtering antenna can play an important role in the integrated RF front-end system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0024] Figure 1 is a schematic diagram of an exploded view of a filter antenna unit in a MIMO filter antenna provided by an embodiment of the present invention;

[0025] Figure 2 It is a structural schematic diagram of a filter antenna unit in a MIMO filter antenna provided by an embodiment of the present invention;

[0026] Figure 3 is a schematic diagram of another angle structure of the filter antenna unit in the MIMO filter antenna provided by an embodiment of the present invention;

[0027] Figure 4is a side view of a filter antenna unit in a MIMO filter antenna provided by an embodiment of the present invention when there is no dielectric substrate;

[0028] Figure 5 It is a schematic structural diagram of a MIMO filter antenna provided by an embodiment of the present invention when the filter antenna unit has no dielectric substrate;

[0029] Figure 6 It is a structural schematic diagram from another angle when the filter antenna unit in the MIMO filter antenna provided by an embodiment of the present invention has no dielectric substrate;

[0030] Figure 7 is a schematic structural diagram of a MIMO filter antenna provided in Embodiment 2 of the present invention;

[0031] Figure 8 yes Figure 7 A magnified schematic diagram of part A;

[0032] Fig. 9 is the S of the filter antenna unit in the MIMO filter antenna provided in the embodiment of the present invention. 11

[0033] Performance curves and gain curve graphs;

[0034] Fig.10 is a radiation pattern of a filter antenna unit in a MIMO filter antenna provided in an embodiment of the present invention;

[0035] Fig.11 is an S parameter curve diagram of the MIMO filter antenna provided in Embodiment 2 of the present invention;

[0036] Fig.12 is a gain curve diagram of the MIMO filter antenna provided in Embodiment 2 of the present invention;

[0037] Fig.13 is the radiation pattern of the first antenna unit in the MIMO filter antenna provided in Embodiment 2 of the present invention;

[0038] Fig.14 is the radiation pattern of the second antenna unit in the MIMO filter antenna provided in Embodiment 2 of the present invention;

[0039] Fig.15 is the radiation pattern of the third antenna unit in the MIMO filter antenna provided in Embodiment 2 of the present invention;

[0040] Fig.16 This is the radiation pattern of the fourth antenna unit in the MIMO filter antenna provided in Embodiment 2 of the present invention.

[0041] The reference numerals in the figure are represented as follows: 1-dielectric substrate; 101-first board surface; 102-second board surface; 2-first metal patch; 201-patch body; 202-first extension branch; 203-second extension branch; 3-second metal patch; 4-third metal patch; 5-fourth metal patch; 6-fifth metal patch; 7-sixth metal patch; 8-feeding mechanism; 9-first metal connector; 10-second metal connector; 11-third metal connector; 12-fourth metal connector; 13-fifth metal connector; 14-sixth metal connector; 15-decoupling structure. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0043] In the description of the present invention, it should be understood that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the products of the present invention are conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. These are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] The terms “first”, “second”, etc. in the present invention are only used to distinguish between the two in the description and have no special meaning.

[0045] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting" and "installation" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] Example 1

[0047] This embodiment provides a MIMO filter antenna, which includes at least two filter antenna units. Adjacent filter antenna units are connected through a decoupling structure to form a multi-input multi-output antenna structure. Figure 1-Figure 6 The filtering antenna unit includes a dielectric substrate 1, wherein the dielectric substrate 1 has a first plate surface 101 and a second plate surface 102 arranged opposite to each other. Figure 1-Figure 3As shown, in this embodiment, the first board surface 101 is the upper surface of the dielectric substrate 1, then the second board surface 102 is the lower surface of the dielectric substrate 1. The first board surface 101 is connected with a first metal antenna assembly. The first metal antenna assembly includes a first metal patch 2. One side of the first metal patch 2 has a U-shaped groove, and a second metal patch 3 is arranged in the U-shaped groove. The second metal patch 3 is arranged at an interval from the first metal patch 2.

[0048] The second board surface 102 is connected with a second metal antenna assembly. The second metal antenna assembly includes a third metal patch 4, a fourth metal patch 5, and a metal patch group that are sequentially arranged at intervals in the first direction along the second board surface 102. The metal patch group includes a fifth metal patch 6 and a sixth metal patch 7 that are distributed at intervals in the second direction along the second board surface 102. In this embodiment, as Figure 1 shown, the first direction is the x direction, the second direction is the y direction. At the same time, the dielectric substrate 1 also has a third direction, that is, the z direction.

[0049] To realize the feeding function of the filtering antenna unit, the first metal patch 2 and the fourth metal patch 5 are connected through a feeding mechanism 8. The first metal patch 2 and the third metal patch 4 are also connected through a metal connecting piece, and the first metal patch 2 is also connected with the fourth metal patch 5, the fifth metal patch 6, and the sixth metal patch 7 through metal connecting pieces. At the same time, the second metal patch 3 and the fourth metal patch 5 are also connected through a metal connecting piece.

[0050] The MIMO filtering antenna provided in this embodiment adopts the above filtering antenna unit structure. Among them, since the second metal patch 3 is accommodated in the U-shaped groove of the first metal patch 2, it is equivalent to forming a planar folding structure between the first metal patch 2 and the second metal patch 3, so that the antenna unit structure is more compact and the size is smaller. Along the z direction of the dielectric substrate 1, the first metal patch 2, the second metal patch 3, the fourth metal patch 5, the feeding mechanism 8, and the metal connecting piece form a horizontally placed "day" character structure (as Figure 4 shown), and this folding structure forms a first radiator; along the z direction of the dielectric substrate 1, the first metal patch 2, the third metal patch 4, and the metal connecting piece form a closed-loop structure (as Figure 5 shown), and this closed-loop structure forms a second radiator; since the fifth metal patch 6 and the sixth metal patch 7 are arranged at intervals, along the z direction of the dielectric substrate 1, the first metal patch 2, the fifth metal patch 6, the sixth metal patch 7, and the metal connecting piece form an open-loop structure (as Figure 6As shown in the figure, the switch structure forms a third radiator. After the RF energy is fed into the antenna unit, it is first fed into the first radiator, and then through direct coupling, part of the energy is fed into the second radiator and part of the energy is fed into the third radiator. The three radiators will generate electromagnetic radiation. Due to the superposition of electromagnetic fields, they will superimpose in phase and cancel each other out of phase in the far field. When the radiation field has the same phase and opposite phase, the three radiators will generate radiation zeros. These radiation zeros can be adjusted and distributed at the high-frequency and low-frequency edges of the antenna passband, thereby achieving a filtering effect with a high roll-off characteristic. Through the decoupling structure, a reverse electromagnetic field can be introduced to offset the coupling field, thereby reducing the port coupling degree and improving the antenna's directional pattern stability. At the same time, the antenna unit of the above structure also has the technical effects of compact structure and small size, so that the MIMO filter antenna can play an important role in the integrated RF front-end system.

[0051] In this embodiment, the dielectric substrate 1 is made of Rogers RO5880 material, and the dielectric substrate 1 is a rectangular plate structure, the length direction of which is the y direction (the second direction), the width direction is the x direction (the first direction), and the thickness direction is the z direction. As a convertible implementation, the dielectric substrate 1 can also be made of FR4 material, or, instead of a dielectric plate, an air medium can be used. In this embodiment, the metal connector is a plurality of metallized vias that penetrate the dielectric substrate 1.

[0052] To realize the folding structure, in this embodiment, the first metal patch 2 includes: a patch body 201, a first extension branch 202 and a second extension branch 203 connected to both ends of the patch body 201, such as Figure 1-Figure 2 As shown, the patch body 201 is a rectangular structure, the first extension branch 202 and the second extension branch 203 are respectively integrally formed at both ends of the patch body 201 in the width direction, and extend along the length direction of the patch body 201, so that a U-shaped groove structure with one end open is formed between the patch body 201, the first extension branch 202, and the second extension branch 203, and the second metal patch 3 is accommodated in the U-shaped groove at intervals. The spacing between the second metal patch 3 and the patch body 201 is 0.01λ-0.1λ, preferably 0.05λ in this embodiment, the spacing between the second metal patch 3 and the first extension branch 202 is 0.001λ-0.1λ, preferably 0.01λ in this embodiment, the spacing between the second metal patch 3 and the second extension branch 203 is 0.001λ-0.1λ, preferably 0.01λ in this embodiment, and the spacing between the second metal patch 3 and the second extension branch 203 is 0.001λ-0.1λ, preferably 0.01λ in this embodiment, and in this embodiment, λ is the wavelength at the working frequency of the antenna.

[0053] In this embodiment, the length of the patch body 201 is 0.1λ - 0.4λ, preferably 0.2λ in this embodiment; the width is 0.025λ - 0.25λ, preferably 0.15λ in this embodiment. The second metal patch 3 is a rectangular patch, with a length of 0.1λ - 0.4λ, preferably 0.2λ in this embodiment; the width is 0.04λ - 0.2λ, preferably 0.1λ in this embodiment. The total length of the outer periphery of the horizontally placed "day"-shaped folding mechanism is about 1λ, and this dimension is related to the radiation null at low frequency (about 2.2 GHz).

[0054] Please refer to Figure 1 、 Figure 5 , one end of the patch body 201 away from the second metal patch 3 is connected to one end of the third metal patch 4 through the first metal connector 9, and the end of the first extension branch 202 is connected to the other end of the third metal patch 4 through the second metal connector 10. Thus, the patch body 201, the first metal connector 9, the third metal patch 4, the second metal connector 10, and the first extension branch 202 enclose the above-mentioned closed-loop structure. The perimeter of the closed-loop structure is 0.3λ - 1.5λ, preferably 1λ in this embodiment. The total length of the closed-loop structure is related to the radiation null at the highest frequency (about 2.9 GHz).

[0055] Furthermore, one end of the patch body 201 away from the second metal patch 3 is also connected to the fifth metal patch 6 through the third metal connector 11, and the third metal connector 11 and the first metal connector 9 are respectively connected to both ends of the patch body 201 in the width direction; the second extension branch 203 is connected to the sixth metal patch 7 through the fourth metal connector 12. In this way, the patch body 201, the third metal connector 11, the fifth metal patch 6, the sixth metal patch 7, the fourth metal connector 12, and the second extension branch 203 form an open-loop structure. The opening of the open-loop structure is the interval between the fifth metal patch 6 and the sixth metal patch 7. Among them, the opening size is 0.01λ - 0.1λ, that is, the distance between the fifth metal patch 6 and the sixth metal patch 7 is 0.01λ - 0.1λ, preferably 0.05λ in this embodiment. Both the fifth metal patch 6 and the sixth metal patch 7 are rectangular patches, with a length of 0.1λ - 0.4λ and a width of 0.01λ - 0.1λ. In this embodiment, the length is preferably 0.2λ and the width is preferably 0.05λ. The total length of the open-loop structure is about 1λ, and this dimension is related to the radiation null at the sub-high frequency (about 2.7 GHz). When the total lengths of the above-mentioned closed-loop structure, open-loop structure, and folding structure increase, the radiation null moves towards the low frequency, and when it decreases, it moves towards the high frequency.

[0056] The end of the patch body 201 away from the second metal patch 3 is also connected to the fourth metal patch 5 through a plurality of fifth metal connectors 13. In this embodiment, there are eight fifth metal connectors 13, and the eight fifth metal connectors 13 are sequentially spaced along the width direction of the patch body 201. The end of the second metal patch 3 away from the patch body 201 is connected to the fourth metal patch 5 through a plurality of sixth metal connectors 14. In this embodiment, there are also eight sixth metal connectors 14, and the eight sixth metal connectors 14 are sequentially spaced along the width direction of the second metal connector 10. In this embodiment, the first metal connector 9 to the sixth metal connector 14 are all metalized vias, and the aperture and hole spacing of the metalized vias are not greater than 0.1λ.

[0057] The fourth metal patch 5 is a rectangular patch with a length of 0.1λ-0.4λ, preferably 0.3λ in this embodiment, and a width of 0.01λ-0.2λ, preferably 0.15λ in this embodiment. The length of the dielectric substrate 1 is 0.25λ-0.75λ, preferably 0.5λ in this embodiment, a width of 0.05λ-0.4λ, preferably 0.3λ in this embodiment, and a thickness of 0.001λ-0.2λ, preferably 0.02λ in this embodiment.

[0058] In this embodiment, the feeding mechanism 8 is a coaxial feeding mechanism, whose outer conductor is welded to the fourth metal patch 5, and whose inner conductor passes through the dielectric substrate 1 and is connected to the patch body 201. As a convertible implementation, the feeding mechanism 8 can also be a microstrip feeder.

[0059] Example 2

[0060] This embodiment provides a MIMO filter antenna, such as Figure 7 As shown, it includes four filtering antenna units provided in Example 1, and the four filtering antenna units are sequentially arranged in the form of 1 row and 4 columns along the y direction. Two adjacent filtering antenna units are connected by a decoupling structure 15. In this embodiment, the decoupling structure 15 adopts a neutral line with a bent structure, such as Figure 8 As shown, the shape of the neutralization line is in the shape of a "mountain", and the line in the center of the "mountain" neutralization line is shorter than the lines on both sides, and the two ends of the neutralization line are each connected to a filter antenna unit. The spacing between two adjacent filter antenna units is not less than 0.01λ, the line width of the neutralization line is 0.00001λ-0.01λ, preferably 0.001λ in this implementation, and the total length of the neutralization line is 0.1λ-0.4λ, preferably 0.3λ in this embodiment. Among them, λ is the wavelength at the antenna operating frequency. In this embodiment, preferably, the spacing between two adjacent filter antenna units is 0.01λ-3λ.

[0061] Of course, as a convertible implementation, the MIMO filter antenna may also adopt a filter antenna unit array structure with other numbers and arrangements.

[0062] Experimental example

[0063] 1. Test the S of the filtering antenna unit provided in Example 1 11 Performance curve and gain performance curve, test results are as follows Fig. 9 shown.

[0064] It can be seen from the figure that the antenna's |S 11 |The parameters are better than -10dB in the range of 2.33 to 2.62 GHz, and the gain of the antenna is better than 1.0 dBi in the passband. A radiation null is found at 2.23 GHz, 2.73 GHz and 2.87 GHz, and the radiation gain is less than -20 dBi. The radiation gain curve of the antenna unit has extremely steep roll-offs in the 2.23-2.33 GHz and 2.63-2.73 GHz bands, respectively, making the antenna have a high frequency selectivity.

[0065] 2. Test the radiation pattern of the filtering antenna unit provided in Example 1 at a frequency of 2.45 GHz. The test results are as follows: Fig.10 shown.

[0066] It can be seen from the figure that the filtering antenna unit has an omnidirectional radiation pattern within the operating frequency band.

[0067] 3. Test the S parameter curve and gain curve of the MIMO filter antenna provided in Example 2. The test results are as follows: Figure 11-Figure 12 shown.

[0068] from Fig.11 It can be seen that the -10dB overlap bandwidth of each filter antenna unit in the MIMO filter antenna arranged in a 1*4 array provided in Example 2 is 2.37 - 2.70 GHz, and the coupling degree between ports is lower than -21dB.

[0069] from Fig.12 It can be seen that in the MIMO filter antenna provided in Example 2, the out-of-band suppression ratio of each filter antenna unit is higher than 14 dB, as shown by the curves in the figure: antenna 1, antenna 2, antenna 3, antenna 4.

[0070] 4. Test the radiation pattern of each antenna unit in the MIMO filter antenna provided in Example 2. The test results are as follows: Figure 13-Figure 16 shown.

[0071] It can be seen from the figure that each filtering antenna unit has omnidirectional radiation characteristics.

[0072] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A MIMO filter antenna, characterized in that: The invention comprises at least two filtering antenna units, wherein adjacent filtering antenna units are connected by a decoupling structure, wherein the decoupling structure is a neutralization line, wherein the spacing between adjacent filtering antenna units is not less than 0.01λ, and the total length of the neutralization line is 0.1λ-0.4λ, wherein λ is the wavelength at the antenna operating frequency; The filtering antenna unit comprises a dielectric substrate, the dielectric substrate comprises a first plate surface and a second plate surface arranged opposite to each other, the first plate surface is connected with a first metal antenna component, the first metal antenna component comprises a first metal patch, the first metal patch has a U-shaped groove, and a second metal patch is arranged in the U-shaped groove at intervals; The second board surface is connected to a second metal antenna assembly, the second metal antenna assembly includes a third metal patch, a fourth metal patch and a metal patch group sequentially arranged in a first direction of the second board surface, and the metal patch group includes a fifth patch and a sixth patch distributed in a second direction of the second board surface; The first metal patch is connected to the fourth metal patch through a feeding mechanism, and the first metal patch is connected to the third metal patch, the fourth metal patch, the fifth metal patch, and the sixth metal patch through a metal connector, and the second metal patch is also connected to the fourth metal patch through a metal connector.

2. The MIMO filter antenna according to claim 1, characterized in that: The first metal patch includes a patch body, a first extension branch and a second extension branch connected to both ends of the patch body, and the U-shaped groove is formed between the first extension branch, the second extension branch and the patch body; The spacing between the second metal patch and the patch body is 0.01λ-0.1λ, the spacing between the second metal patch and the first extended branch is 0.001λ-0.1λ, and the spacing between the second metal patch and the second extended branch is 0.001λ-0.1λ, wherein λ is the wavelength at the antenna operating frequency.

3. The MIMO filter antenna according to claim 2, characterized in that: One end of the patch body is connected to the third metal patch through a first metal connector, and the first extension branch is connected to the third metal patch through a second metal connector. The patch body, the first metal connector, the third metal patch, the second metal connector, and the first extension branch form a closed loop structure.

4. The MIMO filter antenna according to claim 3, characterized in that: The circumference of the closed-loop structure is 0.3λ-1.5λ.

5. The MIMO filter antenna according to claim 2, characterized in that: One end of the patch body is connected to the fifth metal patch through a third metal connector, and the second extended branch is connected to the sixth metal patch through a fourth metal connector. The patch body, the third metal connector, the fifth metal patch, the sixth metal patch, the fourth metal connector, and the second extended branch form an open-loop structure.

6. The MIMO filter antenna according to claim 5, characterized in that: The distance between the fifth metal patch and the sixth metal patch is 0.01λ-0.1λ, the fifth metal patch and the sixth metal patch are both rectangular patches, the length of the fifth metal patch and the sixth metal patch is 0.1λ-0.4λ, and the width is 0.01λ-0.1λ.

7. The MIMO filter antenna according to claim 2, characterized in that: The second metal patch and the patch body are both rectangular structures. The lengths of the second metal patch and the patch body are both 0.1λ-0.4λ, and the widths are both 0.01λ-0.1λ.

8. The MIMO filter antenna according to claim 1, characterized in that: The dielectric substrate is a rectangular plate, the first direction is the width direction of the dielectric substrate, the second direction is the length direction of the dielectric substrate, the length of the dielectric substrate is 0.25λ-0.75λ, the width is 0.05λ-0.4λ, and the thickness is 0.001λ-0.2λ, wherein λ is the wavelength at the operating frequency of the antenna.

9. The MIMO filter antenna according to claim 2, characterized in that: The fourth metal patch is a rectangular patch, the length of the fourth metal patch is 0.1λ-0.4λ, and the width is 0.01λ-0.2λ; the feeding mechanism is a coaxial feeding mechanism, the outer conductor of the coaxial feeding mechanism is connected to the fourth metal patch, and the inner conductor of the coaxial feeding mechanism is connected to the patch body.

10. The MIMO filter antenna according to any one of claims 1 to 9, characterized in that: The MIMO filter antenna comprises four filter antenna units, which are arranged in sequence and spaced apart along the length direction, and adjacent filter antenna units are connected via the decoupling structure.

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