MIMO antenna

Abstract

A MIMO antenna, according to one embodiment of the present invention, comprises: a substrate; a radiation element having a predetermined shape and arranged on one surface of the substrate; a first feed line for providing a feed signal to the radiation element in a first direction; a second feed line for providing a feed signal to the radiation element in a second direction; and a third feed line for providing a feed signal to the radiation element in a third direction, wherein the first direction and the second direction are perpendicular to each other in the XY plane direction, the first direction and the third direction are perpendicular to each other in the XZ plane direction, and the second direction and the third direction are perpendicular to each other in the YZ plane direction.

Description

MIMO antenna

[0001] The present invention relates to a MIMO antenna. More specifically, it relates to a MIMO antenna capable of performing multiple antenna functions while minimizing the overall antenna system size.

[0002] The demand for high-quality multimedia services using wireless communication technology is driving the need for next-generation wireless transmission technologies capable of transmitting more data faster. One of the proposed solutions is the Multi-Input Multi-Output (MIMO) antenna, which is widely used and integrated into various wireless terminals utilizing the latest wireless communication technologies.

[0003] These MIMO antennas perform multiple input / output operations by arranging multiple radiating elements in a special structure, and can improve data transmission speeds in a specific frequency range. However, since each of the multiple radiating elements acts as an individual antenna, there is a problem in that the size of the entire antenna system inevitably increases.

[0004] Meanwhile, recent wireless terminals are trending toward smaller and slimmer devices, which in turn necessitates miniaturization of various components. Antennas are also subject to these constraints, especially MIMO antennas, which utilize the latest wireless communication technologies. Therefore, the development of MIMO antennas that can miniaturize the overall antenna system is urgent.

[0005] The technical problem to be solved by the present invention is to provide a MIMO antenna that can reduce the size of the entire antenna system by allowing one radiating element to perform the role of multiple antennas.

[0006] The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0007] According to an embodiment of the present invention for achieving the above technical task, a MIMO antenna includes a substrate, a radiating element having a predetermined shape disposed on one surface of the substrate, a first feed line providing a feeding signal in a first direction to the radiating element, a second feed line providing a feeding signal in a second direction to the radiating element, and a third feed line providing a feeding signal in a third direction to the radiating element, wherein the first direction and the second direction are mutually perpendicular to each other in an XY plane direction, the first direction and the third direction are mutually perpendicular to each other in an XZ plane direction, and the second direction and the third direction are mutually perpendicular to each other in a YZ plane direction.

[0008] According to one embodiment, the radiating element is a patch type radiating element, and the shape may be a square shape having a symmetrical structure.

[0009] According to one embodiment, the third power line can pass through the radiating element from the direction in which the substrate is arranged through a first hole of a predetermined size arranged at the center of the radiating element.

[0010] According to one embodiment, the device further includes a parasitic element arranged on one side of the radiating element at a predetermined distance from the radiating element, and the third power supply line can pass through the parasitic element by passing through a second hole of a predetermined size arranged in the center of the parasitic element from the direction in which the substrate is arranged.

[0011] According to one embodiment, the length of the third power line protruding from the direction in which the substrate is arranged through the radiating element toward one side of the radiating element may be λ / 4.

[0012] According to one embodiment, the third power supply line may be reduced in length by a predetermined length from the length that protrudes toward one side of the radiating element through the radiating element from the direction in which the substrate is arranged, and either a disc of a conductor material having a diameter of the predetermined length or a fourth power supply line having the predetermined length may be arranged at an end of the third power supply line so as to be horizontal to the radiating element.

[0013] According to another embodiment of the present invention for solving the above technical problem, a MIMO antenna comprises a substrate, N (N is a natural number greater than or equal to 2) radiating elements having a predetermined shape arranged on one surface of the substrate, N 1-1' feed lines providing a feed signal in a first direction to each of the N radiating elements, a 1' feed line connected to the end of the N 1-1' feed lines and providing a feed signal, N 2-1' feed lines providing a feed signal in a second direction to each of the N radiating elements, a 2' feed line connected to the end of the N 2-1' feed lines and providing a feed signal, N 3-1' feed lines providing a feed signal in a third direction to each of the N radiating elements, and a 3' feed line connected to the end of the N 3-1' feed lines and providing a feed signal, wherein the first direction and the second direction are perpendicular to each other in the XY plane direction, The first and third directions are mutually perpendicular to the XZ plane direction, and the second and third directions are mutually perpendicular to the YZ plane direction.

[0014] According to the present invention, it is possible to provide a power supply signal in the first direction, the second direction, and the third direction to one radiating element so that it can operate as three different antennas, thereby having the effect of dramatically reducing the size of the entire antenna system compared to implementing an antenna system including three radiating elements.

[0015] In addition, when the third direction is the Z-axis direction, the same performance can be secured by reducing the length of the third transmission line and placing a disk with the same diameter or a fourth transmission line with the same length at the end of the third transmission line so that it is horizontal to the radiating element, which has the effect of reducing the height of the entire antenna system.

[0016] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0017] FIG. 1 is a diagram illustrating the configuration of a MIMO antenna according to a first embodiment of the present invention.

[0018] Figure 2 is an enlarged drawing of only the radiating element, the first feed line, the second feed line, and the third feed line illustrated in Figure 1.

[0019] Figures 3 and 4 are performance evaluation simulation data of a MIMO antenna according to the first embodiment of the present invention.

[0020] FIG. 5 is an enlarged drawing of a MIMO antenna according to a second embodiment of the present invention, in which only the radiating element, the first feed line, the second feed line, and the third feed line are extracted as in FIG. 2.

[0021] Figures 6 and 7 are performance evaluation simulation data of a MIMO antenna according to the second embodiment of the present invention.

[0022] FIG. 8 is an enlarged drawing of a MIMO antenna according to a third embodiment of the present invention, in which only the radiating element, the first feed line, the second feed line, and the third feed line are extracted as in FIG. 2.

[0023] FIG. 9 is an enlarged drawing of a MIMO antenna according to a fourth embodiment of the present invention, in which only the radiating element, the first feed line, the second feed line, and the third feed line are extracted as in FIG. 2.

[0024] FIG. 10 is an enlarged drawing of a MIMO antenna according to a fifth embodiment of the present invention, in which not only the radiating element, the first feed line, the second feed line, and the third feed line as in FIG. 2, but also the first' feed line, the second' feed line, and the third' feed line are extracted and shown.

[0025] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described in detail below together with the attached drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

[0026] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise. The terminology used herein is for the purpose of describing embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms, unless specifically stated otherwise.

[0027] As used herein, the terms “comprises” and / or “comprising” do not exclude the presence or addition of one or more other components, steps, operations and / or elements.

[0028] FIG. 1 is a drawing illustrating the configuration of a MIMO antenna (100) according to a first embodiment of the present invention.

[0029] The MIMO antenna (100) according to the first embodiment of the present invention may include a substrate (10), a radiating element (20), a first feed line (30), a second feed line (40), and a third feed line (50), and of course, may further include other conventional configurations required to achieve the purpose of the present invention.

[0030] The substrate (10) can use a general antenna substrate. For example, a well-known universal substrate (10) such as a PCB (Printed Circuit Board) or an F-PCB (Flexible Printed Circuit Board) can be used. Since the area of ​​the substrate is closely related to the size of the entire antenna, there is no need to use an excessively wide substrate to miniaturize the antenna. A substrate having an area sufficient to place the radiating element (20), the first feed line (30), the second feed line (40), and the third feed line (50) on one surface is sufficient.

[0031] Meanwhile, the type, area, and shape of the substrate (10) may vary depending on the specifications of the wireless terminal on which the MIMO antenna (100) according to the first embodiment of the present invention is mounted, and a substrate (10) that meets the specifications required by the wireless terminal manufacturer may be selected. Accordingly, the shape of the substrate illustrated in FIG. 1 is only one embodiment, and it goes without saying that substrates (10) of various shapes may be used as needed.

[0032] The radiating element (20) is placed on one surface of the substrate (10) and has a predetermined shape.

[0033] Here, one side of the substrate (10) may be either the upper or lower surface of the substrate (10), and although FIG. 1 illustrates that the radiating element (20) is arranged on the upper surface of the substrate (10), this is only one embodiment and is not necessarily limited thereto.

[0034] Meanwhile, the radiating element (20) may be a patch-type radiating element, and the shape may be a shape having a symmetrical structure, for example, a square shape that is symmetrical when viewed in the XY plane direction, such as a circle, a square, or a regular octagon. Although Fig. 1 illustrates the radiating element (20) as being formed in a square shape, this is also only one embodiment and is not necessarily limited thereto.

[0035] The first feed line (30) provides a feed signal in a first direction to the radiating element (20), the second feed line (40) provides a feed signal in a second direction to the radiating element (20), and the third feed line (50) provides a feed signal in a third direction to the radiating element (20).

[0036] Since the first power supply line (30), the second power supply line (40), and the third power supply line (50) must all provide a power supply signal to the radiating element (20), they can be made of a conductive material, and the difference between them is that the directions in which the power supply signal is provided to the radiating element (20) are the first direction, the second direction, and the third direction.

[0037] More specifically, the first direction and the second direction are perpendicular to each other in the XY plane direction, the first direction and the third direction are perpendicular to each other in the XZ plane direction, and the second direction and the third direction can be perpendicular to each other in the YZ plane direction. In simple terms, as illustrated by example in FIG. 1, the first direction in which the first feed line (30) provides a feed signal to the radiating element (20) is the X-axis direction, the second direction in which the second feed line (40) provides a feed signal to the radiating element (20) is the Y-axis direction, and the third direction in which the third feed line (50) provides a feed signal to the radiating element (20) is the Z-axis direction, such that the two directions are perpendicular to each other in different plane directions based on one direction.

[0038] Meanwhile, since the third power supply line (50) must provide a power supply signal to the radiating element (20) in the Z-axis direction when the first direction is the X-axis direction and the second direction is the Y-axis direction, it can pass through the radiating element (20) from the direction in which the substrate (10) is arranged through a first hole (Hole, H) of a predetermined size arranged at the center of the radiating element (20), and in this case, the power supply signal can be provided to the radiating element (20) through a coupling method rather than direct contact.

[0039] FIG. 2 is an enlarged drawing of only the radiating element (20), the first power supply line (30), the second power supply line (40), and the third power supply line (50) illustrated in FIG. 1, and it can be confirmed that the third power supply line (50) passes through the radiating element (20) without making contact with the inside of the first hole (H) arranged in the center of the radiating element (20).

[0040] Meanwhile, the length of the third feed line (50) protruding from the direction in which the substrate (10) is arranged and penetrating the radiating element (20) toward one side of the radiating element (20) may be λ / 4. In this case, the radiating element (20) may operate as a monopole antenna due to the third feed line (50). Since the case of a general antenna system is implemented with a gap of λ / 2 based on the patch-type radiating element (20) and the air layer, the radiating element (20) may be arranged with room to spare within the case when it operates as a monopole antenna due to the third feed line (50).

[0041] In this way, when power supply signals are provided in three directions, the first direction, the second direction, and the third direction, for one radiating element (20), the power supply signal provided in the first direction can function as one antenna, the power supply signal provided in the second direction can function as another antenna, and the power supply signal provided in the third direction can function as another antenna, for a total of three antennas. This can be viewed as a true Multi Input Multi Output.

[0042] Figures 3 and 4 are performance evaluation simulation data of a MIMO antenna (100) according to the first embodiment of the present invention.

[0043] Referring to FIG. 3, it can be confirmed that the MIMO antenna (100) according to the first embodiment of the present invention exhibits a directivity in which electromagnetic waves are radiated in a third direction when a feed signal is provided in the first or second direction, and exhibits a directivity in which electromagnetic waves are radiated in the first or second direction when a feed signal is provided in the third direction.

[0044] FIG. 4 shows the frequency characteristics of a MIMO antenna (100) according to the first embodiment of the present invention. It can be confirmed that the antenna when a feed signal is provided in a third direction starting at about 0 dB, the antenna when a feed signal is provided in a first direction starting at about -5 dB, and the antenna when a feed signal is provided in a second direction (two graphs are overlapped) all operate as effective antennas by implementing resonant frequencies within the same range.

[0045] This time, a MIMO antenna (100) according to the second embodiment of the present invention will be described.

[0046] FIG. 5 is an enlarged drawing of a MIMO antenna (100) according to a second embodiment of the present invention, in which only the radiating element (20), the first feed line (30), the second feed line (40), and the third feed line (50) are extracted as in FIG. 2.

[0047] The MIMO antenna (100) according to the second embodiment of the present invention has the same basic description as the MIMO antenna (100) according to the first embodiment of the present invention, and only the configurations that are different will be described below.

[0048] A MIMO antenna (100) according to a second embodiment of the present invention may further include a parasitic element (25) that is positioned on one side of the radiating element (20) at a predetermined distance from the radiating element (20), and includes a second hole (H2) in the center.

[0049] Here, the basic description of the parasitic element (25) is also the same as that of the radiating element (20), and in FIG. 5, the shape of the parasitic element (25) is a square, the same as that of the radiating element (20), and its size is shown larger, but this is only one embodiment, and it is obvious that the parasitic element (25) may have a different shape and may be smaller or even the same size as the radiating element (20).

[0050] Meanwhile, the distance at which the radiating element (20) and the parasitic element (25) are spaced in the third direction cannot be uniformly determined, and can be said to be a distance that can be changed by fine tuning according to the resonance frequency to be implemented.

[0051] Figures 6 and 7 are performance evaluation simulation data of a MIMO antenna (100) according to the second embodiment of the present invention.

[0052] Referring to FIG. 6, it can be confirmed that the MIMO antenna (100) according to the second embodiment of the present invention, like the MIMO antenna (100) according to the first embodiment of the present invention, exhibits directivity in which electromagnetic waves are radiated in the third direction when a feed signal is provided in the first or second direction, and exhibits directivity in which electromagnetic waves are radiated in the first or second direction when a feed signal is provided in the third direction.

[0053] FIG. 7 shows the frequency characteristics of a MIMO antenna (100) according to the second embodiment of the present invention. It can be confirmed that the antenna when a feed signal is provided in the third direction starting at about -1 dB, the antenna when a feed signal is provided in the first direction starting at -4.5 dB, and the antenna when a feed signal is provided in the second direction (two graphs are overlapped) all operate as effective antennas by implementing resonant frequencies within the same range.

[0054] In addition, the difference between the MIMO antenna (100) according to the second embodiment of the present invention and the MIMO antenna (100) according to the first embodiment of the present invention is that the MIMO antenna (100) according to the first embodiment of the present invention can obtain a wider bandwidth effect than the parasitic element (25) by including it further. This can also be confirmed with reference to FIG. 7.

[0055] This time, the MIMO antenna (100) according to the third and fourth embodiments of the present invention will be described.

[0056] FIG. 8 is an enlarged view of a MIMO antenna (100) according to a third embodiment of the present invention, in which only the radiating element (20), the first feed line (30), the second feed line (40), and the third feed line (50) are extracted and illustrated as in FIG. 2, and FIG. 9 is an enlarged view of a MIMO antenna (100) according to a fourth embodiment of the present invention, in which only the radiating element (20), the first feed line (30), the second feed line (40), and the third feed line (50) are extracted and illustrated as in FIG. 2.

[0057] The MIMO antenna (100) according to the third and fourth embodiments of the present invention has the same basic description as the MIMO antenna (100) according to the first embodiment of the present invention, and only the configurations that are different will be described below.

[0058] In the description of the third feed line (50) above, it was said that the length of the third feed line (50) protruding from the direction in which the substrate (10) is arranged and penetrating the radiating element (20) toward one side of the radiating element (20) is λ / 4. To achieve this, the entire antenna system must secure at least λ / 4 in the third direction, and if the third direction is the Z-axis direction, the height of the entire antenna system will increase. The MIMO antenna (100) according to the third and fourth embodiments of the present invention is an embodiment for solving this problem.

[0059] More specifically, the third embodiment illustrated in FIG. 8 is one in which the length of the third feed line (50) is reduced by a predetermined length from the length that the third feed line (50) protrudes toward one side of the radiating element (20) by penetrating the radiating element (20) from the direction in which the substrate (10) is arranged, and a disc (60) made of a conductor material having a diameter equal to the reduced predetermined length is arranged at the end of the third feed line (50), and the fourth embodiment illustrated in FIG. 9 corresponds to one in which the fourth feed line (70) having the reduced predetermined length is arranged at the end of the third feed line (50).

[0060] In this case, since both the diameter of the disk (60) and the length of the fourth feed line (70) are shorter than the horizontal or vertical length of the radiating element (20), the height of the entire antenna system can be reduced without affecting performance.

[0061] However, it is not possible to unconditionally accept a predetermined length for reducing the third feed line (50), and it should be kept in mind that the effective height position is fixed, and in case of low frequency, the case of the antenna system may be implemented closer in a state where the λ / 2 gap is not secured based on the patch type radiating element (20) and the air layer, and in such a case, the MIMO antenna (100) according to the third and fourth embodiments of the present invention, which reduces the length of the third feed line (50), may be actively utilized.

[0062] Finally, a MIMO antenna (100) according to the fifth embodiment of the present invention will be described.

[0063] The MIMO antenna (100) according to the fifth embodiment of the present invention also has the same basic description as the MIMO antenna (100) according to the first embodiment of the present invention, but the difference is that there are multiple radiating elements (20), and accordingly, there are also multiple first feed lines (30), second feed lines (40), and third feed lines (50) that provide feed signals to each radiating element (20). In the MIMO antenna (100) according to the fifth embodiment of the present invention, N radiating elements' (20'), N 1-1' feed lines (30-1'), N 2-1' feed lines (40-1'), and N 3-1' feed lines (50-1') are named, and a configuration that is connected to the ends of the N 1-1' feed lines (30-1') to provide a feed signal is named as a 1' feed line (30'), a configuration that is connected to the ends of the N 2-1' feed lines (40-1') to provide a feed signal is named as a 2' feed line (40'), and a configuration that is connected to the ends of the N 3-1' feed lines (50-1') to provide a feed signal is named as a 3' feed line (50').

[0064] FIG. 10 is an enlarged drawing of only N radiating elements' (20'), N 1-1' feed lines (30-1'), N 2-1' feed lines (40-1'), N 3-1' feed lines (50-1'), 1' feed line (30'), 2' feed line (40'), and 3' feed line (50') extracted from FIG. 2 in a MIMO antenna (100) according to the fifth embodiment of the present invention.

[0065] Referring to FIG. 10, when N is 4, four radiating elements' (20') are arranged, and it can be confirmed that the 1-1' feed line (30-1') provides a feed signal in the first direction, the 2-1' feed line (40-1') provides a feed signal in the second direction, and the 3-1' feed line (50-1') provides a feed signal in the third direction to each radiating element' (20'), and it can be confirmed that one 1' feed line (30') is connected to the end of N 1-1' feed lines (30-1'), one 2' feed line (40') is connected to the end of N 2-1' feed lines (40-1'), and one 3' feed line (50') is connected to the end of N 3-1' feed lines (50-1'). In this case, each of the four radiating elements' (20') can operate as three antennas, and the entire antenna system can operate as 12 antennas even though it actually contains only four radiating elements' (20').

[0066] The MIMO antenna (100) according to the first to fifth embodiments of the present invention has been described so far. According to the present invention, since it can operate as three different antennas by providing feed signals in the first direction, the second direction, and the third direction for one radiating element (20), the size of the entire antenna system can be dramatically reduced compared to implementing an antenna system including three radiating elements (20). In addition, when the third direction is the Z-axis direction, the length of the third transmission line (50) can be reduced, and a disk (60) having the same diameter or a fourth transmission line (60) having the same length can be placed at the end of the third transmission line (50) so as to be horizontal to the radiating element (20), thereby securing the same performance, and even the height of the entire antenna system can be reduced.

[0067] Although embodiments of the present invention have been described with reference to the attached drawings, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical concept or essential features thereof. Therefore, the embodiments described above should be understood to be illustrative in all respects and not restrictive.

Claims

1. Substrate; A radiating element of a predetermined shape arranged on one side of the above substrate; A first feed line providing a feed signal in a first direction to the above radiating element; a second feed line providing a feed signal in a second direction to the radiating element; and A third feed line providing a feed signal from a third direction to the above radiating element; In a MIMO antenna including: The above first and second directions are, are perpendicular to each other in the XY plane direction, The above first and third directions are, are perpendicular to each other in the XZ plane direction, The above second and third directions Perpendicular to each other in the YZ plane direction, MIMO antenna.

2. In paragraph 1, The above radiating element is a patch type radiating element. The above shape is a square shape with a symmetrical structure. MIMO antenna.

3. In paragraph 1, The above third power line is, A first hole of a predetermined size arranged in the center of the above radiating element passes through the radiating element from the direction in which the substrate is arranged. MIMO antenna.

4. In paragraph 3, A parasitic element arranged on one side of the above radiating element at a predetermined distance from the above radiating element; Including more, The above third power line is, A second hole of a predetermined size arranged in the center of the parasitic element passes through the parasitic element from the direction in which the substrate is arranged. MIMO antenna.

5. In paragraph 3, The length of the third power line protruding from the direction in which the substrate is arranged through the radiating element toward one side of the radiating element is λ / 4. MIMO antenna.

6. In paragraph 3, The length of the third power line is reduced by a predetermined length from the length that the third power line protrudes toward one side of the radiating element by penetrating the radiating element from the direction in which the substrate is arranged. A conductor material disk having a diameter of the above-mentioned predetermined length and one of the fourth power supply lines having the above-mentioned predetermined length are arranged horizontally with the radiating element at the end of the third power supply line. MIMO antenna.

7. Substrate´; N (N is a natural number greater than or equal to 2) radiating elements of a predetermined shape arranged on one side of the above substrate; N first-1'th feed lines providing a feed signal in a first direction to each of the N radiating elements'; A 1' feed line connected to the terminal of the N 1-1' feed lines and providing a feed signal; N second-1' feed lines providing a feed signal in a second direction to each of the N radiating elements'; A 2' feed line connected to the terminal of the N 2-1' feed lines and providing a feed signal; N third-1' feed lines providing a feed signal in a third direction to each of the N radiating elements'; and A 3' feed line connected to the terminal of the N 3-1' feed lines and providing a feed signal; In a MIMO antenna including: The above first and second directions are, They are perpendicular to each other in the XY plane. The above first and third directions are, are perpendicular to each other in the XZ plane direction, The above second and third directions Perpendicular to each other in the YZ plane direction, MIMO antenna.

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