KR101174591B1 - MIMO Antenna Using Common Ground - Google Patents

Abstract

A MIMO antenna using a common ground is disclosed. The disclosed antenna includes a substrate; A ground plane coupled to a portion of the substrate; A first radiator coupled to the substrate; A second radiator spaced apart from the first radiator and coupled to the substrate; And a common ground strip electrically coupling the first radiator, the second radiator, and the ground plane. The disclosed antenna can secure good isolation in a small space, and has an advantage of improving isolation between antennas by using a common ground.

Description

MIMO Antenna Using Common Ground

Embodiments of the present invention relate to antennas, and more particularly, to a MIMO antenna for performing multiple inputs and multiple outputs.

As the demand for multimedia services is rapidly increasing, mobile communication systems are required to transmit reliable high speed data. Increased capacity is essential to enable high-speed data transmission over wireless channels that use limited bandwidth and power. Recently, there is a growing interest in techniques for improving capacity.

In a wireless communication environment, reliability of a received signal is greatly degraded due to fading, shadowing effects, radio wave attenuation, noise, and interference. Therefore, in order to enable high-speed data communication, an alternative for overcoming or using the characteristics of the radio channel is required. The proposed technique is a MIMO antenna technology according to such a necessity.

MIMO antenna technology is a technique for transmitting data using multiple antennas to a transmitter or a receiver using a spatial multiplexing technique.

MIMO technology has the advantage of extending the range and speed of wireless communication by transmitting two or more data signals in the same wireless channel using multiple antennas.

However, in MIMO, since two or more antenna elements are arranged, interference between radiators may occur. Such interference may distort the radiation pattern or cause mutual coupling between the radiators, and thus technology for securing antenna isolation is required.In a small device such as a USB dongle, the isolation between MIMO antennas is more important. It is becoming.

The present invention proposes a MIMO antenna capable of ensuring good isolation in a small space.

In addition, the present invention proposes a MIMO antenna that can improve the isolation between antennas by using a common ground.

According to a preferred embodiment of the present invention to achieve the above object, a substrate; A ground plane coupled to a portion of the substrate; A first radiator coupled to the substrate; A second radiator spaced apart from the first radiator and coupled to the substrate; Provided is a MIMO antenna using a common ground comprising a common ground strip electrically coupling the first radiator, the second radiator and the ground plane.

The common ground strip may have a T-shape including a first branch coupled to the first radiator, a second branch coupled to the second radiator, and a third branch coupled to the ground plane.

The first radiator and the second radiator have a same structure and a beveling structure whose width gradually increases from a coupling point with a feed point.

The MIMO antenna further includes a first dielectric structure coupled to the substrate and to which at least a portion of the first radiator is coupled and a second dielectric structure coupled to the substrate and to which at least a portion of the second radiator is coupled can do.

According to another aspect of the invention, the first radiator electrically coupled to the feed point; A second radiator spaced apart from the first radiator by a predetermined distance and having the same structure; And a common ground member having three branches, a first branch coupled to the first radiator, a second branch coupled to the second radiator, and a third branch electrically coupled to ground. An antenna is provided.

At least a portion of the first radiator and the second radiator and the ground and the common ground member are preferably formed on the same plane.

The common ground member may have a T shape and may have a conductive strip structure.

The first radiator and the second radiator may include a beveling structure in which the width of the first radiator and the second radiator are gradually increased from the coupling site with the feed point.

According to the present invention, it is possible to ensure good isolation in a small space, and there is an advantage of improving isolation between antennas by using a common ground.

1 is a perspective view of a MIMO antenna according to an embodiment of the present invention.
FIG. 2 is a plan view of a substrate with a dielectric structure removed from the MIMO antenna shown in FIG. 1; FIG.
3 is a rear view of the MIMO antenna according to the embodiment of the present invention shown in FIG.
4 is a graph illustrating S21 parameters according to the length L of the beveling unit in the MIMO antenna according to the exemplary embodiment of the present invention.
FIG. 5 is a graph illustrating S21 parameters with or without a common ground strip in a MIMO antenna according to an embodiment of the present invention. FIG.
6 illustrates a radiation pattern of a MIMO antenna according to an embodiment of the present invention.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing a perspective view of a MIMO antenna according to an embodiment of the present invention, Figure 2 is a plan view showing a substrate with a dielectric structure removed from the MIMO antenna shown in Figure 1, Figure 3 is a view 1 illustrates a rear view of a MIMO antenna according to an embodiment of the present invention.

1 to 3, an MMO antenna according to an embodiment of the present invention may include a substrate 100, a ground plane 102, a first radiator 104, a second radiator 106, and a common ground strip 108. ), A first dielectric structure 110 and a second dielectric structure 112.

The substrate 100 functions as a body of the antenna and is made of a dielectric material. The substrate 100 is coupled to antenna elements such as ground plane 102 and radiators 104, 106. Although a substrate having a rectangular shape is shown in FIG. 1, the shape of the substrate is not limited thereto, and it will be apparent to those skilled in the art that various types of dielectric structures may be substituted for the substrate according to the accommodation space of the antenna.

A part of the upper portion of the substrate 100 has a ground plane 102 that is electrically grounded. The size of the ground plane is adaptively set according to the use frequency. For example, the ground plane may have a size of 63.5 mm x 25 mm when used in the frequency band of 3.5 to 3.7 GHz.

The first radiator 104 and the second radiator 106 may be installed at a predetermined distance and may be positioned at both sides of the substrate 100 as shown in FIG. 1. The first radiator 104 and the second radiator 106 have the same shape and are disposed with a symmetrical structure. The first radiator 104 and the second radiator 106 having the same shape emit signals of the same frequency. Portions of the first radiator 104 and the second radiator 106 are coupled to the first dielectric structure 110 and the second dielectric structure 112, respectively.

1 to 3, a radiator according to an embodiment of the present invention includes beveling portions 104a and 106a, flat plate portions 104b and 106b, and line portions 104c and 106c that are coupled onto a substrate. ) May be included.

Beveling portions 104a and 106a are formed on the substrate and one end is electrically coupled to the feed point. Beveling portions 104a and 106a have a structure that gradually widens from the end joined with the feed point. Referring to FIG. 2, the case in which the beveling unit 200 has an isosceles triangle shape is illustrated. However, if the beveling unit 200 has a structure in which the width thereof is gradually increased, the beveling unit 200 may be implemented in various structures without being limited to the shape shown in FIG. 2. For example, it may have a structure in which the width thereof increases while having the shape of a right triangle.

The beveling parts 104a and 106a are formed at the beginning of the radiator for smooth impedance matching of the antenna. The beveling units 104a and 106a prevent a sudden change in current at the coupling portion between the radiator and the feed point, and thus efficient impedance matching can be achieved. The beveling parts 104a and 106a may be omitted when a separate impedance matching structure is not required according to the frequency of use. However, when the antenna is arranged in a narrow space of a small device such as a USB dongle, the beveling parts 104a and 106a may be used. Ensures a smooth matching in a narrow space.

The degree of impedance matching may vary according to the length of the beveling unit 200, and as the length of the beveling unit becomes longer, better impedance matching may be secured.

4 is a graph illustrating S21 parameters according to the length L of the beveling unit in the MIMO antenna according to the exemplary embodiment of the present invention.

Referring to FIG. 4, when the beveling portion is not formed (L = 0), it can be seen that the impedance matching characteristic is very poor, and the impedance matching characteristic is improved as the length becomes longer. If the length is secured to some extent, the same matching characteristics may be obtained regardless of the length, and the resonance frequency may change according to the change in the length of the beveling unit.

Referring again to FIGS. 1 through 3, the plate portions 104b and 106b extend from the beveling portions 104a and 106a and are coupled to one of the sides of the dielectric structure in the form of a plate. Referring to FIG. 3, it can be seen that flat portions 104b and 106b are formed on one of four surfaces of the dielectric structures 110 and 112.

The line portions 104c and 106c extend from the flat plate portions 104b and 106b and are coupled to the sides of the dielectric structures 110 and 112 in a line shape. The overall length of the plate portions 104b and 106b and the line portions 104c and 106c depends on the frequency band used, and as the frequency of the low frequency is used, the lengths of the plate portions 104b and 106b and the line portions 104c and 106c are used. Becomes longer.

1 to 3 show an embodiment in which a part of the radiator is coupled to the side of the dielectric structure to form an efficient use of space. The radiator is coupled to a dielectric structure having a predetermined height to enable three-dimensional arrangement of the radiator. If the spatial constraints are not large, the radiator may be implemented in one dimension on the substrate.

A common ground strip 108 is coupled to the first radiator 104 and the second radiator 106 spaced apart. In a common ground strip 108 having three branches, the first branch 108a is coupled to the first radiator 104, the second branch 108b is coupled to the second radiator 106, and the third branch ( 108c is coupled to the ground plane 102. 1 to 3, the common ground strip 108 preferably has a T shape, but is not limited thereto.

The first radiator 104 and the second radiator 106 are electrically coupled to the ground plane by a common ground strip 108 and each of the first radiator 104 and the second radiator 106 is coupled to a feed point and ground. It operates as a PIFA antenna.

The common ground strip 108 acts as an isolation structure to prevent mutual interference of the first radiator 104 and the second radiator 106. In common connection between the first radiator 104 and the second radiator 106 and the ground in the MIMO antenna, the current generated by the radiator in each radiator is prevented from moving to another radiator to ensure isolation between radiators.

FIG. 5 is a graph illustrating S21 parameters according to the presence or absence of a common ground strip in a MIMO antenna according to an embodiment of the present invention.

Referring to FIG. 5, it can be seen that the isolation characteristics are improved when the common ground strip exists compared to the case where there is no common ground strip. Such a common ground strip may have a simple structure and an isolation structure may be implemented.

6 is a diagram illustrating a radiation pattern of a MIMO antenna according to an embodiment of the present invention.

Referring to FIG. 6, it can be seen that the MIMO antenna according to the embodiment of the present invention exhibits good omnidirectional patterns in all of the XY plane, the YZ plane, and the XZ plane, and thus may be suitably used as an antenna for a terminal.

In the present invention as described above has been described by the specific embodiments, such as specific components and limited embodiments and drawings, but this is provided to help a more general understanding of the present invention, the present invention is not limited to the above embodiments. For those skilled in the art, various modifications and variations are possible from these descriptions. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (8)

Board;
A ground plane coupled to a portion of the substrate;
A first radiator coupled to the substrate;
A second radiator spaced apart from the first radiator and coupled to the substrate;
A common ground strip electrically coupling the first radiator, the second radiator, and the ground plane,
And the first radiator and the second radiator have the same structure and a beveling structure whose width gradually increases from a coupling point with a feed point. The method of claim 1,
The common ground strip may have a T-shape including a first branch coupled to the first radiator, a second branch coupled to the second radiator, and a third branch coupled to the ground plane. MIMO antenna used. delete The method of claim 1,
And a first dielectric structure coupled to the substrate and to which at least a portion of the first radiator is coupled and a second dielectric structure coupled to the substrate and to at least a portion of the second radiator coupled thereto. MIMO antenna using common ground. A first radiator electrically coupled with a feed point;
A second radiator spaced apart from the first radiator by a predetermined distance and having the same structure; And
A common ground member having three branches, a first branch coupled to the first radiator, a second branch coupled to the second radiator, and a third branch electrically coupled to ground;
The first radiator and the second radiator are MIMO antenna using a common ground, characterized in that it comprises a beveling structure whose width gradually widens from the joining point with the feed point. The method of claim 5,
At least a portion of the first radiator and the second radiator and the ground and the common ground member are formed on the same plane MIMO antenna using a common ground. The method of claim 6,
The common ground member has a T-shape, MIMO antenna using a common ground, characterized in that the conductive strip structure. delete

Images