Miniaturized ultra-wideband MIMO antenna

Abstract

A miniaturized ultra-wideband MIMO antenna disclosed by the present application comprises a dielectric layer, a radiation layer and a defect ground layer, the dielectric layer comprises a first surface and a second surface opposite to the first surface, the radiation layer is arranged on the first surface, the radiation layer comprises two antenna radiators, the defect ground layer is arranged on the second surface, and the defect ground layer is arranged on the second surface. And two L-shaped gaps are formed in the defect stratum. Thus, the L-shaped gap is formed in the defect ground layer, the isolation degree and the bandwidth between the antenna units can be effectively improved, and the small-sized ultra-wideband MIMO antenna can guarantee high isolation degree while achieving small size.

Description

Technical Field

[0001] The present invention relates to an antenna, and particularly to a miniaturized ultra-wideband MIMO antenna. Background Art

[0002] Ultra-wideband communication systems have advantages such as high transmission rate, low cost, and low power consumption. However, as one of the key components of ultra-wideband communication systems, ultra-wideband antennas have the problem of multipath attenuation and are difficult to transmit over long distances. To solve the problem of multipath attenuation and further increase the signal transmission rate, ultra-wideband MIMO antennas have been proposed. MIMO technology integrates two or more antenna elements on a dielectric substrate. The combination of ultra-wideband technology and MIMO technology can achieve simultaneous parallel transmission of multiple path signals and effectively solve the multipath attenuation problem of ultra-wideband. However, for existing ultra-wideband MIMO antennas, in order to ensure a high isolation degree, the distance between antenna elements cannot be too small to prevent the mutual interference between antenna elements from increasing due to coupling. Therefore, ultra-wideband MIMO antennas are often difficult to be miniaturized, which greatly affects their use in modern miniaturized wireless communication systems.

[0003] Therefore, how to achieve a small size and at the same time ensure a high isolation degree for ultra-wideband MIMO antennas is a difficult problem that needs to be solved urgently at present. Summary of the Invention

[0004] Embodiments of the present invention aim to provide a miniaturized ultra-wideband MIMO antenna, which can solve the technical problem that it is difficult for existing ultra-wideband MIMO antennas to achieve both a small size and a high isolation degree.

[0005] Embodiments of the present invention solve their technical problems by adopting the following technical solutions:

[0006] A miniaturized ultra-wideband MIMO antenna disclosed in the present application includes:

[0007] A dielectric layer, the dielectric layer including a first surface and a second surface opposite to the first surface;

[0008] A radiation layer disposed on the first surface, the radiation layer including two antenna radiators; and

[0009] A defected ground plane disposed on the second surface, and two L-shaped slots are formed on the defected ground plane.

[0010] By forming L-shaped slots on the defected ground plane, the isolation degree and bandwidth between antenna elements can be effectively improved, so that the miniaturized ultra-wideband MIMO antenna of the present application can achieve a small size while ensuring a high isolation degree.

[0011] As a possible implementation of the miniaturized ultra-wideband MIMO antenna of the present application, the two L-shaped slots are symmetrically arranged with respect to the diagonal of the dielectric layer.

[0012] As a possible implementation of the miniaturized ultra-wideband MIMO antenna of the present application, each of the L-shaped slots is formed by enclosing a first side, a second side, a third side, a fourth side, a fifth side, and a sixth side. The first side is aligned with one edge of the dielectric layer, the sixth side is aligned with the other edge of the dielectric layer, the sixth side is perpendicular to the first side, the first side is parallel to the third side and the fifth side, and the sixth side is parallel to the second side and the fourth side.

[0013] As a possible implementation of the miniaturized ultra-wideband MIMO antenna of the present application, the length of the first side is 15 mm, the length of the fourth side is 10 mm, and the length of the sixth side is 2 mm.

[0014] As a possible implementation of the miniaturized ultra-wideband MIMO antenna of the present application, the two antenna radiators are symmetrically arranged with respect to the diagonal of the dielectric layer.

[0015] As a possible implementation of the miniaturized ultra-wideband MIMO antenna of the present application, each of the antenna radiators includes a radiation patch and a microstrip feeder, and two symmetrically arranged strip-shaped slots are formed in each of the radiation patches.

[0016] As a possible implementation of the miniaturized ultra-wideband MIMO antenna of the present application, the distance between the two radiation patches is 4 mm.

[0017] As a possible implementation of the miniaturized ultra-wideband MIMO antenna of the present application, the length of the strip-shaped slot is 3 mm, and the width of the strip-shaped slot is 0.6 mm.

[0018] As a possible implementation of the miniaturized ultra-wideband MIMO antenna of the present application, the radiation patch includes a first metal side and a second metal side. The first metal side is close to the strip-shaped slot and parallel to the length direction of the strip-shaped slot. The distance between the first metal side and the boundary of the dielectric layer is 4.9 mm. The second metal side is far from the microstrip feeder and perpendicular to the extension direction of the microstrip feeder. The distance between the second metal side and the boundary of the dielectric layer is 17 mm. The distance between the microstrip feeder and the strip-shaped slot is 2.6 mm. The length of the first metal side is 7 mm, the length of the second metal side is 8.1 mm, the length of the microstrip feeder is 8 mm, the width of the microstrip feeder is 1.53 mm, the length of the dielectric layer is 32 mm, the width of the dielectric layer is 32 mm, and the dielectric constant of the dielectric layer is 4.4. Description of the Drawings

[0019] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, unless otherwise stated. The drawings in the figures do not constitute a scale limitation.

[0020] Figure 1 Side view of the miniaturized ultra-wideband MIMO antenna disclosed in the embodiment of the present invention;

[0021] Figure 2 Front view of the miniaturized ultra-wideband MIMO antenna disclosed in the embodiment of the present invention;

[0022] Figure 3 Rear view of the miniaturized ultra-wideband MIMO antenna disclosed in the embodiment of the present invention;

[0023] Figure 4 Another front view of the miniaturized ultra-wideband MIMO antenna disclosed in the embodiment of the present invention;

[0024] Figure 5 Another rear view of the miniaturized ultra-wideband MIMO antenna disclosed in the embodiment of the present invention;

[0025] Figure 6 Miniaturized ultra-wideband MIMO antenna according to the embodiment of the present invention with different L S2 Variation curve graph;

[0026] Figure 7 Miniaturized ultra-wideband MIMO antenna according to the embodiment of the present invention with different L S3 Variation curve graph;

[0027] Figure 8 Miniaturized ultra-wideband MIMO antenna according to the embodiment of the present invention with different W S2 Variation curve graph;

[0028] Figure 9 Simulation result curve graph of the reflection coefficient and transmission coefficient of the miniaturized ultra-wideband MIMO antenna disclosed in the embodiment of the present invention.

[0029] Reference numerals in the drawings and corresponding meanings:

[0030] Miniaturized ultra-wideband MIMO antenna 10;

[0031] Dielectric layer 11, first surface 11a, second surface 11b;

[0032] Radiation layer 12, antenna radiator 121, radiation patch 121a, microstrip feeder 121b, strip slot 121c, first metal edge 121d, second metal edge 121e, third metal edge 121f, fourth metal edge 121g;

[0033] Defective ground layer 13, L-shaped slot 131, first side 131a, second side 131b, third side 131c, fourth side 131d, fifth side 131e, sixth side 131f. Specific implementation manner

[0034] For ease of understanding of the present invention, the present invention will be described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is expressed as "fixed to" another element, it can be directly on the other element, or there can be one or more intermediate elements therebetween. When an element is expressed as "connected to" another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween. The terms "upper", "lower", "inner", "outer", "vertical", "horizontal", etc. used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0035] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not used to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0036] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] A miniaturized ultra-wideband MIMO antenna 10 disclosed in the present application, as Figures 1 - 3 shown, includes a dielectric layer 11, a radiation layer 12 and a defective ground layer 13. The dielectric layer 11 includes a first surface 11a and a second surface 11b opposite to the first surface 11a. The radiation layer 12 is disposed on the first surface 11a. The radiation layer 12 includes two antenna radiators 121. The defective ground layer 13 is disposed on the second surface 11b, and two L-shaped slots 131 are formed on the defective ground layer 13.

[0038] The miniaturized ultra-wideband MIMO antenna 10 of the present application can effectively improve the isolation and bandwidth between antenna elements by providing an L-shaped slot 131 on the defective ground plane 13, enabling the miniaturized ultra-wideband MIMO antenna 10 of the present application to achieve a small size while ensuring high isolation.

[0039] In this embodiment, each antenna radiator 121 includes a radiation patch 121a and a microstrip feeder 121b electrically connected to the radiation patch 121a. Each radiation patch 121a is provided with two symmetrically arranged strip-shaped slots 121c. The strip-shaped slot 121c is a rectangular slot, and the strip-shaped slot 121c extends from the edge of the radiation patch 121a towards the middle.

[0040] In this way, the bandwidth can be increased. The symmetrically arranged strip-shaped slots 121c can achieve a wider operating frequency band in a smaller antenna element, thereby improving the performance of the miniaturized ultra-wideband MIMO antenna 10.

[0041] In this embodiment, the radiation layer 12 is a metal layer. The radiation patch 121a is substantially rectangular. Each radiation patch 121a includes a first metal side 121d, a second metal side 121e, a third metal side 121f, and a fourth metal side 121g. The first metal side 121d is parallel to the third metal side 121f. The second metal side 121e is parallel to the fourth metal side 121g. The second metal side 121e is perpendicular to the first metal side 121d. One strip-shaped slot 121c extends from the second metal side 121e towards the fourth metal side 121g, and the other strip-shaped slot 121c extends from the fourth metal side 121g towards the second metal side 121e. The first metal side 121d is close to the strip-shaped slot 121c and parallel to the length direction of the strip-shaped slot 121c. The second metal side 121e is far from the microstrip feeder 121b and perpendicular to the extension direction of the microstrip feeder 121b. One end of the microstrip feeder 121b is connected to the fourth metal side 121g of the radiation patch 121a, and the other end of the microstrip feeder 121b is aligned with the edge of the dielectric layer 11. In this way, the structure is simple and the layout is compact.

[0042] In this embodiment, the distance between adjacent two antenna elements is small, the structure is compact, and the miniaturization of the ultra-wideband MIMO antenna can be achieved.

[0043] Further, please refer to Figure 4 , the dielectric layer 11 is square, the number of antenna radiators 121 is two, and the two antenna radiators 121 are symmetrically arranged with respect to the diagonal AA' of the dielectric layer 11. Among them, the extension direction of the microstrip feeder 121b of one antenna radiator 121 is perpendicular to the extension direction of the microstrip feeder 121b of the other antenna radiator 121. The distance D between the two radiation patches 121a Ris 4 mm, and this spacing D R refers to the distance between the second metal side 121e of one radiation patch 121a and the third metal side 121f of another radiation patch 121a.

[0044] In this way, the two antenna radiators 121 are of a symmetric structure, which helps to achieve good antenna performance and has a compact structure.

[0045] In this embodiment, the defective ground plane 13 is composed of a metal ground plane with a pair of L-shaped slots 131. The two L-shaped slots 131 are symmetrically arranged with respect to the diagonal AA' of the dielectric layer 11, and each L-shaped slot 131 is composed of two vertically placed and connected rectangular slots.

[0046] In this way, by opening two symmetrically arranged L-shaped slots 131 on the defective ground plane 13, it is more beneficial to increase the bandwidth and optimize the matching, increase the isolation between the two antenna elements, improve the radiation performance, and can convert the directional antenna into an omnidirectional antenna.

[0047] In this embodiment, as Figure 5 shown, each L-shaped slot 131 is jointly enclosed by a first side 131a, a second side 131b, a third side 131c, a fourth side 131d, a fifth side 131e, and a sixth side 131f. The first side 131a is aligned with one edge of the dielectric layer 11, the sixth side 131f is aligned with the other edge of the dielectric layer 11, the sixth side 131f is perpendicular to the first side 131a, the first side 131a is parallel to the third side 131c and the fifth side 131e, and the sixth side 131f is parallel to the second side 131b and the fourth side 131d. One L-shaped slot 131 is located in the upper left corner of the dielectric layer 11, and the other L-shaped slot 131 is located in the lower right corner of the dielectric layer 11. In this way, it is more beneficial to increase the bandwidth, increase the isolation between the two antenna elements, and improve the radiation performance.

[0048] Further, please refer to Figure 5 and Figure 6 , the length L of the first side 131a of the L-shaped slot 131 S2 is 11 mm - 15 mm. As the parameter L S2 increases, the reflection coefficient S of the miniaturized ultra-wideband MIMO antenna 10 of the present application 11 decreases within the passband, and the bandwidth becomes wider; its isolation increases.

[0049] Please refer to Figure 7 , the length L of the fourth side 131d of the L-shaped slot 131 S3 is 9 mm - 11 mm. As the parameter L S3 increases, the reflection coefficient S of the miniaturized ultra-wideband MIMO antenna 10 of the present application 11It becomes smaller in the passband, the bandwidth becomes narrower; its isolation becomes smaller.

[0050] Please refer to Figure 8 , the length W of the sixth side 131f of the L-shaped slot 131 S2 is 2mm - 6mm. As the parameter W S2 increases, the reflection coefficient S of the miniaturized ultra-wideband MIMO antenna 10 of the present application 11 becomes smaller in the passband, the bandwidth becomes wider; its isolation becomes larger.

[0051] Thus, by studying the influence of the key parameters L S2 , L S3 , W S2 of the L-shaped slot 131 on the performance of the filtering antenna, the miniaturized ultra-wideband MIMO antenna 10 of the present application optimizes the key parameters L S2 , L S3 , W S2 to obtain better antenna performance.

[0052] Preferably, the size of the miniaturized ultra-wideband MIMO antenna 10 of the present application is 32mm * 32mmm, the dielectric constant of the dielectric layer 11 is 4.4, the dielectric loss is 0.02, the dielectric layer 11 is a circuit board with a thickness of 0.8mm, the length L G of the dielectric layer 11 is 32mm, the width W G of the dielectric layer 11 is 32mm, both the radiation layer 12 and the defect ground layer 13 are copper-plated, and the thicknesses are both 0.035mm; the distance D 1 between the first metal side 121d of the radiation patch 121a and the boundary of the dielectric layer 11 is 4.9mm, the distance D 2 between the second metal side 121e of the radiation patch 121a and the boundary of the dielectric layer 11 is 17mm, the distance D 3 between the microstrip feeder 121b and the strip slot 121c is 2.6mm, the length L S1 of the strip slot 121c of the radiation patch 121a is 3mm, the width W S1 of the strip slot 121c of the radiation patch 121a is 0.6mm, the length L R of the first metal side 121d of the radiation patch 121a is 7mm, the length W R of the second metal side 121e of the radiation patch 121a is 8.1mm, the microstrip feeder 121b is a 50-ohm feeder, the length L F of the microstrip feeder 121b is 8mm, the width W F of the microstrip feeder 121b is 1.53mm; the length L S2is 15 mm, and the length L of the fourth side 131d of the L-shaped slot 131 S3 is 10 mm, and the length W of the sixth side 131f of the L-shaped slot 131 S2 is 2 mm. The length of the fifth side 131e of the L-shaped slot 131 is the same as the length L of the microstrip feeder 121b F and the length of the third side 131c of the L-shaped slot 131 is the same as the length L of the first metal side 121d of the radiation patch 121a R The same.

[0053] Thus, the reflection coefficient S of the miniaturized ultra-wideband MIMO antenna 10 of the present application 11 and the isolation simulation results are as Figure 9 shown. It can be seen from Figure 9 that for the miniaturized ultra-wideband MIMO antenna 10, the bandwidth range where the reflection coefficient S is less than -10 dB is from 3.22 to 10.04 GHz, the center frequency is 6.63 GHz, the absolute bandwidth is 6.82 GHz, and the relative bandwidth is 102.3%, showing the characteristics of ultra-wideband. Moreover, within the bandwidth range, its isolation is greater than 16.8 dB. The miniaturized ultra-wideband MIMO antenna 10 of the present application is an omnidirectional antenna and has a high gain. 11 Of course, the parameters of the miniaturized ultra-wideband MIMO antenna 10 of the present application are not limited to the above embodiments and can be optimized and adjusted according to the desired antenna performance. For example, when the parameters of the dielectric layer 11 change, the parameters of the radiation patch 121a, the microstrip feeder 121b, and the L-shaped slot 131 can be adjusted accordingly through the analysis of the simulation results of the reflection coefficient and isolation of the miniaturized ultra-wideband MIMO antenna 10 to obtain optimized matching parameters.

[0054] In summary, the working center frequency of the miniaturized ultra-wideband MIMO antenna 10 of the present application is mainly determined by the length L of the first metal side 121d of the radiation patch 121a

[0055] and the length W of the second metal side 121e. Its bandwidth and in-band matching are mainly determined by the parameters of the strip slot 121c on the radiation patch 121a and the parameters of the L-shaped slot 131 on the defect ground plane 13. Its radiation performance is mainly determined by the parameters of the L-shaped slot 131 on the defect ground plane 13. Its isolation is mainly determined by the positions of the two radiation patches 121a and the parameters of the L-shaped slot 131 on the defect ground plane 13. R and the length W of the second metal side 121e R of the radiation patch 121a.

[0056] The miniaturized ultra-wideband MIMO antenna 10 of the present application has an L-shaped slot 131 formed in the defective ground plane 13, which can effectively improve the isolation between antenna elements, so that the distance between two adjacent radiation patches 121a can be relatively small. That is, two adjacent antenna elements do not need to be arranged with a large distance to ensure high isolation. Therefore, the miniaturized ultra-wideband MIMO antenna 10 of the present application is not only small in size but also high in isolation.

[0057] In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In the present specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0058] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A miniaturized ultra-wideband MIMO antenna, characterized in that: include: a dielectric layer, the dielectric layer comprising a first surface and a second surface opposite to the first surface; A radiation layer disposed on the first surface, the radiation layer comprising two antenna radiators; and A defective stratum is arranged on the second surface, and two L-shaped gaps are formed on the defective stratum.

2. The miniaturized ultra-wideband MIMO antenna according to claim 1, characterized in that: The two L-shaped gaps are symmetrically arranged about a diagonal line of the dielectric layer.

3. The miniaturized ultra-wideband MIMO antenna according to claim 2, characterized in that: Each of the L-shaped gaps is enclosed by a first side, a second side, a third side, a fourth side, a fifth side and a sixth side, wherein the first side is aligned with an edge of the dielectric layer, the sixth side is aligned with another edge of the dielectric layer, the sixth side is arranged perpendicular to the first side, the first side is arranged parallel to the third side and the fifth side, and the sixth side is arranged parallel to the second side and the fourth side.

4. The miniaturized ultra-wideband MIMO antenna according to claim 3, characterized in that: The length of the first side is 15 mm, the length of the fourth side is 10 mm, and the length of the sixth side is 2 mm.

5. The miniaturized ultra-wideband MIMO antenna according to any one of claims 1 to 4, characterized in that: The two antenna radiators are symmetrically arranged about a diagonal line of the dielectric layer.

6. The miniaturized ultra-wideband MIMO antenna according to claim 5, characterized in that: Each of the antenna radiators includes a radiation patch and a microstrip feed line, and each of the radiation patches is provided with two symmetrically arranged strip-shaped gaps.

7. The miniaturized ultra-wideband MIMO antenna according to claim 6, characterized in that: The distance between the two radiation patches is 4 mm.

8. The miniaturized ultra-wideband MIMO antenna according to claim 7, characterized in that: The length of the strip-shaped gap is 3 mm, and the width of the strip-shaped gap is 0.6 mm.

9. The miniaturized ultra-wideband MIMO antenna according to claim 8, characterized in that: The radiation patch includes a first metal edge and a second metal edge, the first metal edge is close to the strip gap and parallel to the length direction of the strip gap, the distance between the first metal edge and the boundary of the dielectric layer is 4.9 mm, the second metal edge is far away from the microstrip feeder and is perpendicular to the extension direction of the microstrip feeder, the distance between the second metal edge and the boundary of the dielectric layer is 17 mm, the distance between the microstrip feeder and the strip gap is 2.6 mm, the length of the first metal edge is 7 mm, the length of the second metal edge is 8.1 mm, the length of the microstrip feeder is 8 mm, the width of the microstrip feeder is 1.53 mm, the length of the dielectric layer is 32 mm, the width of the dielectric layer is 32 mm, and the dielectric constant of the dielectric layer is 4.4.

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