Multiple-input multiple-output antenna

Abstract

The present invention relates to a multiple-input multiple-output antenna having a decoupling structure in a non-grounded region, the antenna comprising: a substrate comprising a grounded region and a non-grounded region; a first antenna and a second antenna formed to be spaced apart from each other in the non-ground region; and a pattern portion provided in a non-ground region between the first antenna and the second antenna and having a plurality of sensing patterns that cancel coupling between the first antenna and the second antenna. The pattern portion includes: a quadrilateral spiral first pattern disposed to be spaced apart from the first antenna by a predetermined distance; a ground pattern connecting an end portion of the first pattern to the ground region; a quadrilateral spiral second pattern disposed at a position symmetrical to the first pattern with respect to the ground pattern; and a quadrilateral spiral-shaped third pattern disposed between the ground pattern and the ground region, which, when there are two or more antennas using the same frequency band, can block mutual electromagnetic interference between the two antennas, and can improve isolation by preventing current from flowing into the other antennas via coupling.

Description

Technical Field

[0001] The present disclosure relates to a multiple-input multiple-output antenna, and more particularly, to a multiple-input multiple-output antenna having a decoupling structure in a non-grounded area. Background Art

[0002] As the demand for multimedia services grows, mobile communication systems need to reliably transmit high-speed data. In order to transmit data at high speeds through wireless channels using limited bandwidth and power, it is necessary to increase capacity. Recently, attention to technologies to increase capacity is growing.

[0003] In wireless communication environments, the reliability of received signals is greatly reduced due to fading, shadowing, radio attenuation, noise, interference, etc. Therefore, in order to achieve high-speed data communication, alternative solutions to overcome or utilize these wireless channel characteristics are needed, and in order to meet this demand, multiple-input multiple-output (MIMO) antenna technology has been proposed.

[0004] The MIMO antenna technology is a technology that transmits data using multiple antennas in a transmitter or a receiver and uses a spatial multiplexing technology.

[0005] MIMO antenna technology has the advantage of extending the range of wireless communication and greatly increasing its speed by transmitting two or more data signals over the same wireless channel using multiple antennas.

[0006] However, in MIMO antenna technology, since more than two antenna elements are provided, interference between radiators may occur. Such interference may distort the radiation pattern or cause mutual coupling between radiators, so a technology to ensure isolation between antennas is required. Summary of the invention

[0007] Technical issues

[0008] An object of the present disclosure is to provide a multiple-input multiple-output antenna capable of minimizing coupling between antennas without changing the shape of an existing antenna.

[0009] The technical problems of the present disclosure are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

[0010] Technical Solution

[0011] According to the present disclosure, the above-mentioned objects and other objects can be achieved by providing a multi-input multi-output antenna, which includes: a substrate, including a grounding area and a non-grounding area; a first antenna and a second antenna, which are formed to be spaced apart from each other in the non-grounding area; and a pattern portion, which is arranged in the non-grounding area between the first antenna and the second antenna and has a plurality of inductive patterns configured to offset the coupling between the first antenna and the second antenna, wherein the pattern portion includes: a first pattern, which is arranged to be spaced apart from the first antenna by a predetermined distance; a grounding pattern, which is configured to connect an end of the first pattern to the grounding area; a second pattern, which is arranged at a position symmetrical to the first pattern relative to the grounding pattern; and a third pattern, which is arranged between the grounding pattern and the grounding area.

[0012] In one embodiment of the MIMO antenna according to the present disclosure, the number of turns of the third pattern may be greater than the number of turns of the first pattern and the number of turns of the second pattern.

[0013] In one embodiment of the MIMO antenna according to the present disclosure, the substrate may include an upper substrate and a lower substrate configured to be stacked, and respective ends of the first to third patterns may be connected to the upper and lower substrates through via holes, respectively.

[0014] In one embodiment of the MIMO antenna according to the present disclosure, the first pattern and the second pattern may be arranged to have different distances from the ground area.

[0015] In one embodiment of the MIMO antenna according to the present disclosure, the first pattern and the second pattern may have symmetrical shapes with respect to each other.

[0016] In one embodiment of the MIMO antenna according to the present disclosure, the first pattern and the second pattern may transmit signals of the same frequency band.

[0017] In one embodiment of the MIMO antenna according to the present disclosure, the first pattern and the second pattern may have the same shape.

[0018] Beneficial Effects

[0019] If there are two or more antennas using the same frequency band, the MIMO antenna according to the present disclosure can block electromagnetic interference between the two antennas and prevent current from flowing into another antenna due to coupling, thereby being able to improve isolation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a diagram showing a conventional multiple-input multiple-output antenna.

[0021] Figure 2is a diagram illustrating a multiple-input multiple-output antenna according to one embodiment of the present disclosure.

[0022] FIG. 3 shows a graph representing voltage standing wave ratio (VSWR) and insertion loss before the present disclosure is applied.

[0023] FIG. 4 shows a graph representing voltage standing wave ratio (VSWR) and insertion loss when the present disclosure is applied.

[0024] Figure 5a and Figure 5b are exemplary diagrams showing insulation improvements before and after application of the present disclosure. DETAILED DESCRIPTION

[0025] Regarding the embodiments of the present disclosure set forth herein, specific structural or functional descriptions are only exemplarily given to describe the embodiments of the present disclosure, and the embodiments of the present disclosure may be implemented in various forms and should not be construed as being limited to the embodiments set forth herein.

[0026] The present disclosure may be modified in various ways and in various forms, and specific embodiments will be shown in the accompanying drawings and described in detail herein. However, this is not intended to limit the present disclosure to a specific disclosed form, and it should be understood that this includes all modifications, equivalents or substitutes that fall within the spirit and technical scope of the present disclosure.

[0027] Terms such as "first", "second", etc. are used to describe various elements, and these elements should not be construed as being limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present disclosure, the first element described below may be referred to as the second element, and similarly, the second element described below may be referred to as the first element.

[0028] When an element or layer is referred to as being "connected to" or "coupled to" another element or layer, it may be directly connected or coupled to the other element or layer, or intervening elements or layers may be present. Conversely, when an element or layer is referred to as being "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers. Other expressions used to describe the relationship between elements should be interpreted in a similar manner, for example, "between" versus "directly between," "adjacent" versus "directly adjacent," etc.

[0029] The terms used herein are only for describing specific embodiments and are not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular form may also be intended to include the plural form. The terms "comprise", "including", "comprising", and "having" are inclusive, thus specifying the presence of the described features, integers, steps, operations, elements, parts, and / or combinations thereof, without excluding the possibility of the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or combinations thereof.

[0030] Unless otherwise defined, all terms (including technical or scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. Terms commonly used in dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted as having an ideal or overly formal meaning unless explicitly defined in the specification.

[0031] In addition, when the embodiment can be implemented differently, the function or operation specified in a specific frame may occur in an order different from the order specified in the flow chart. For example, according to the relevant function or operation, two consecutive frames can actually be executed substantially at the same time, or these frames can be executed oppositely.

[0032] Hereinafter, a multiple-input multiple-output antenna according to the present disclosure will be described with reference to the accompanying drawings.

[0033] Figure 1 is a diagram showing a conventional multiple-input multiple-output antenna. Because multiple antennas are used in a multiple-input multiple-output (MIMO) antenna, interference between antennas may occur. Therefore, the radiation pattern may be distorted, or mutual coupling may occur between the antennas. In addition, in order to implement a multiple-input multiple-output antenna in a limited space, more than two antenna elements must be arranged in a small space, making it difficult to improve isolation characteristics.

[0034] Figure 2 is a diagram showing a multiple-input multiple-output antenna according to an embodiment of the present disclosure. Figure 2 , a MIMO antenna 100 according to an embodiment of the present disclosure includes a substrate 10 , a plurality of antennas 20 , and a pattern part 30 .

[0035] The substrate 10 may be implemented as a single dielectric or multiple dielectrics having metal surfaces on its upper and lower surfaces. One surface of the substrate 10 may include a non-grounding area 12 and a grounding area 14. The grounding area 14 is formed on the substrate 10 with a specific area.

[0036] The plurality of antennas 20 may include more than two antennas. In one embodiment, the plurality of antennas 20 may include a first antenna 22 and a second antenna 24. The first antenna 22 and the second antenna 24 may refer to two antennas that are closest to each other.

[0037] In one embodiment, the first antenna 22 may be formed on one side of the non-ground area 12, and the second antenna 24 may be formed on the other side of the non-ground area 12. In addition, the first antenna 22 and the second antenna 24 may have the same structure to transmit signals of the same frequency band, and are arranged to be spaced apart from each other by a predetermined distance. The distance between the first antenna 22 and the second antenna 24 may be adjusted as needed. The first antenna 22 and the second antenna 24 may be modified according to the desired frequency band.

[0038] The pattern part 30 is disposed in the non-ground region 12 between the first antenna 22 and the second antenna 24 , and includes a plurality of induction patterns that cancel coupling between the first antenna 22 and the second antenna 24 .

[0039] The pattern portion 30 includes a quadrilateral spiral first pattern 31 disposed at a predetermined distance from the first antenna 22, a ground pattern 34 connecting an end of the first pattern 31 to a ground area, a quadrilateral spiral second pattern 32 disposed at a position symmetrical to the first pattern 31 relative to the ground pattern 34, and a quadrilateral spiral third pattern 33 disposed between the ground pattern 34 and the ground area 14.

[0040] If the first pattern 31, the second pattern 32 and the third pattern 33 are formed in a spiral shape, they are used in the form of a resonator to reduce coupling in a structure where adjacent antennas share a ground. Because the first pattern 31, the second pattern 32 and the third pattern 33 are all frequency-dependent, the length of each antenna depends on the frequency.

[0041] The first antenna 22 and the second antenna 24 have the same shape and transmit signals of the same frequency band. This is one embodiment, and the present disclosure is not limited thereto.

[0042] The first pattern 31 and the second pattern 32 have symmetrical shapes with respect to each other, and are disposed at different distances from the ground area 14. This is also an embodiment, and the present disclosure is not limited thereto.

[0043] Basically, the first pattern 31 and the second pattern 32 are the main elements for performing decoupling, and the third pattern 33 can be used to remove a small amount of coupling in a structure where adjacent antennas share a ground. That is, the coupling can be first offset by the first pattern 31 and the second pattern 32, and the remaining coupling component can be offset secondarily by the third pattern 33.

[0044] The number of turns of the third pattern 33 may be greater than the number of turns of the first pattern 31 and the number of turns of the second pattern 32. Since the number of turns depends on the resonant frequency, it is better if the number of turns of the patterns is the same, but since Bluetooth / WiFi has a frequency band of 2.424-2.484 GHz and the decoupling band area may be different in some cases, the number of turns of the first pattern 31 may be the same as the number of turns of the second pattern 32, and the same as or less than the number of turns of the third pattern 33. In the same way, the number of turns of the second pattern 32 may be the same as the number of turns of the first pattern 31, and the same as or less than the number of turns of the third pattern 33.

[0045] In addition, if the substrate and the conductive layer are formed as multiple layers, the pattern portion 30 may be provided on each layer. Here, each end of the pattern portion 30 may be connected by means of a through hole. If the distance between the first antenna 22 and the second antenna 24 is narrow, the distance may not be suitable for defining a sufficient area to form a number of turns according to the frequency. Therefore, a through hole may be formed through the stacked substrates so that the pattern portion 30 may be formed on at least one substrate and connected through the through hole.

[0046] The substrate includes an upper substrate and a lower substrate which are stacked, and respective ends of the first to third patterns are connected to the upper and lower substrates through through holes.

[0047] Figure 3a and Figure 3b FIG. 4 shows a graph showing a voltage standing wave ratio (VSWR) and an insertion loss before the present disclosure is applied, and FIG. 5 shows a graph showing a voltage standing wave ratio (VSWR) and an insertion loss when the present disclosure is applied.

[0048] The voltage standing wave ratio (VSWR) is the ratio of the maximum amplitude to the minimum amplitude of the voltage. Insertion loss refers to the signal power loss that occurs when a device is inserted into a transmission line or optical fiber in communication, and is usually expressed in decibels (dB). That is, it is called "insertion loss" because it is a loss calculated by measuring the signal strength when the signal reaches the destination after being input at the starting point. Here, the insertion loss is calculated using the formula IL = -10Log (Pout / Pin).

[0049] like Figure 3a As shown, when the VSWR of the first antenna is 1.85 and the VSWR of the second antenna is 1.74 in the frequency band of 2.45 GHz and thus satisfies the VSWR standard of 3.0 or less, the insertion loss occurring in the antenna before applying the present disclosure is -18.41 dB in the frequency band of 2.45 GHz, as shown in FIG. Figure 4a shown.

[0050] At the same time, if Figure 3bAs shown, when the VSWR of the first antenna is 2.13 in the frequency band of 2.45 GHz and the VSWR of the second antenna is 2.00 and thus satisfies the VSWR standard of 3.0 or less, the insertion loss occurring in the MIMO antenna according to the present disclosure is -26.39 dB in the frequency band of 2.45 GHz, as shown in FIG. Figure 4b shown.

[0051] That is, it can be confirmed that the current flowing from the first antenna to the second antenna is significantly reduced.

[0052] Figure 5a and Figure 5b are exemplary diagrams showing insulation improvements before and after application of the present disclosure.

[0053] Figure 5a is an example diagram showing current flow in an antenna before the present disclosure is applied. If the pattern portion for decoupling is not applied, it can be confirmed that the current generated from the first antenna 22 (as shown by the thick dotted line) moves toward the second antenna 24 through the ground region as shown in region "A".

[0054] Figure 5b is an example diagram showing the insulation improvement of the MIMO antenna according to the present disclosure, and is Figure 5a Unlike the example of , it can be confirmed that the current generated from the first antenna 22 (as shown by the thick dotted line) is guided to the first pattern 31 of the pattern portion and does not affect the second antenna 24, as shown in the area "B".

[0055] As is apparent from the above description, as in the present disclosure, an induction pattern that cancels out coupling between two adjacent antennas is provided in a non-grounded region between adjacent antennas, thereby being able to reduce a current introduced by coupling.

[0056] Although the present disclosure has been described with reference to exemplary embodiments thereof, it will be appreciated by those skilled in the art that various modifications and changes may be made to the present disclosure within the scope and spirit of the present disclosure as described in the appended claims.

[0057] Industrial Applicability

[0058] The MIMO antenna according to the present disclosure may be used in various communication devices.

Claims

1. A multiple-input multiple-output antenna, comprising: A substrate including a grounded area and a non-grounded area; a first antenna and a second antenna formed to be spaced apart from each other in the non-ground region; as well as a pattern portion disposed in the non-grounded region between the first antenna and the second antenna and having a plurality of induction patterns configured to cancel coupling between the first antenna and the second antenna, Wherein, the pattern part comprises: a first pattern, arranged to be spaced apart from the first antenna by a predetermined distance; a ground pattern configured to connect an end of the first pattern to the ground region; a second pattern disposed at a position symmetrical to the first pattern with respect to the ground pattern; and The third pattern is arranged between the ground pattern and the ground area.

2. The MIMO antenna according to claim 1, wherein: The first pattern to the third pattern are formed in a quadrilateral spiral shape.

3. The MIMO antenna according to claim 1, wherein: The number of turns of the first pattern is the same as the number of turns of the second pattern, and is the same as or smaller than the number of turns of the third pattern.

4. The MIMO antenna according to claim 1, wherein: The number of turns of the second pattern is the same as the number of turns of the first pattern, and is the same as or smaller than the number of turns of the third pattern.

5. The MIMO antenna according to claim 1, wherein: The substrates are formed in multiple layers, and the pattern part is formed on at least one substrate.

6. The MIMO antenna according to claim 5, wherein: The substrate includes an upper substrate and a lower substrate which are stacked, and respective ends of the first to third patterns are connected to the upper substrate and the lower substrate through through holes, respectively.

7. The MIMO antenna according to claim 1, wherein: The first pattern and the second pattern are disposed at different distances from the ground area.

8. The MIMO antenna according to claim 1, wherein: The first pattern and the second pattern transmit signals of the same frequency band.

9. The MIMO antenna according to claim 8, wherein: The first pattern and the second pattern have the same shape.

10. The MIMO antenna according to claim 1, wherein: When the first antenna and the second antenna satisfy a voltage standing ratio standard of 3.0 or less in a frequency band of 2.45 GHz, the insertion loss is greater than -30 dB and less than -20 dB.

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