KR101174587B1

KR101174587B1 - MIMO Antenna Using CSRR Structure

Info

Publication number: KR101174587B1
Application number: KR1020100122898A
Authority: KR
Inventors: 최재훈; 이영기; 권결; 하재근
Original assignee: 한양대학교 산학협력단
Priority date: 2010-12-03
Filing date: 2010-12-03
Publication date: 2012-08-16
Also published as: KR20120061555A

Abstract

Disclosed is a MIMO antenna using a CSRR structure. The disclosed antenna includes a dielectric structure; A first radiator and a second radiator formed on the dielectric structure and spaced apart from each other by a predetermined distance; An isolation structure formed between the first radiator and the second radiator and symmetrically formed above and below the dielectric structure; And ground planes formed on upper and lower portions of the dielectric structure, wherein the isolation structure has a CSRR structure having an outer gap and an inner gap. The disclosed antenna can secure isolation between antennas in a miniaturized structure, and has an advantage of controlling the resonance frequency and the isolated frequency.

Description

MIMO Antenna Using CSRR Structure

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 a technique for securing isolation between antennas is required.

The present invention proposes a MIMO antenna using a CSRR structure capable of securing isolation between antennas with a miniaturized structure.

In addition, the present invention proposes a MIMO antenna using a CSRR structure capable of adjusting a resonant frequency and an isolated frequency.

According to a preferred embodiment of the present invention to achieve the above object, a dielectric structure; A first radiator and a second radiator formed on the dielectric structure and spaced apart from each other by a predetermined distance; An isolation structure formed between the first radiator and the second radiator and symmetrically formed above and below the dielectric structure; And a ground plane formed on upper and lower portions of the dielectric structure, wherein the isolation structure is provided with a MIMO antenna using a CSRR structure having a CSRR structure having an outer gap and an inner gap.

The first radiator and the second radiator have a CSRR structure having an inner gap and an outer gap.

The isolation structure preferably has a structure in which two CSRR structures are arranged at predetermined intervals.

The ground plane is removed in a region below the dielectric structure corresponding to the region where the first radiator and the second radiator are formed.

The frequency band isolated by the outer gap and the inner gap adjustment of the isolation structure having the CSRR structure is adjusted.

The resonance frequency is adjusted by adjusting external gaps of the first radiator and the second radiator.

According to another aspect of the invention, the dielectric structure; A first radiator and a second radiator formed on the dielectric structure and spaced apart from each other by a predetermined distance; An isolation structure formed between the first radiator and the second radiator; And ground planes formed on upper and lower portions of the dielectric structure, wherein the first radiator and the second radiator have a CSRR structure having an outer gap and an inner gap, and the resonance frequency is varied by adjusting the outer gap. A MIMO antenna using a CSRR structure is provided.

According to the present invention, it is possible to secure the isolation between antennas with a miniaturized structure and to adjust the resonance frequency and the isolated frequency.

1 is a top plan view of a MIMO antenna using a CSRR structure according to an embodiment of the present invention.
2 is a bottom plan view of an MMO antenna using a CSRR structure according to an embodiment of the present invention.
3 is a view showing a detailed structure of a radiator having a CSRR structure applied to the present invention.
4 illustrates a structure of an isolation structure according to an embodiment of the present invention.
5 is a diagram illustrating the isolation characteristics according to the change of the outer gap G1 of the radiator in the antenna according to an embodiment of the present invention.
6 is a diagram illustrating a return loss according to a change in an inner gap G2 of a radiator in an antenna according to an embodiment of the present invention.
7 is a diagram illustrating isolation characteristics according to a change in an inner gap G2 of a radiator in an antenna according to an embodiment of the present invention.
8 is a diagram illustrating return loss according to a change in an inner gap G2 of a radiator in an antenna according to an embodiment of the present invention.
9 is a diagram illustrating isolation characteristics according to a change in an external gap G3 of an isolation structure in an antenna according to an embodiment of the present invention.
FIG. 10 is a diagram illustrating isolation characteristics according to a change of an internal gap G4 of an isolation structure in an antenna according to an embodiment of the present invention.
FIG. 11 illustrates isolation characteristics according to a gap G5 between CSRR structures in an antenna according to an embodiment of the present invention. FIG.

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 top plan view of a MIMO antenna using a CSRR structure according to an embodiment of the present invention, Figure 2 is a view showing a bottom plan view of an MMO antenna using a CSRR structure according to an embodiment of the present invention to be.

1 and 2, a MIMO antenna using a CSRR structure according to an embodiment of the present invention includes a first radiator 100, a second radiator 102, an isolation structure 104, 104-1, and a ground plane. 106 and 106-1 and the dielectric structure 110.

The first radiator 100 and the second radiator 102 are formed in the dielectric structure 110 and are spaced apart from each other by a predetermined distance. The first radiator 100 and the second radiator 102 may be spaced apart by, for example, a half wavelength distance corresponding to a use frequency.

The first radiator 100 and the second radiator 102 may have the same shape to transmit signals of the same frequency, but are not limited to the structure having the same shape.

The first radiator 100 and the second radiator 102 have a complementary split ring resonator (CSRR) structure. SRR is a key component for the design of effective media with negative magnetic permeability or properties of left-handed metamaterials. The SRR structure proposed by Pendry can have a microstrip square open loop structure as a lower wavelength resonator structure that can block signal transmission in the narrow band near their resonant frequency when the magnetic field has polarity along the circular axis.

3 is a view showing a detailed structure of a radiator having a CSRR structure applied to the present invention.

Referring to FIG. 3, the radiator according to an embodiment of the present invention may be implemented in the form of a micro strip line and includes an outer gap G1 and an inner gap G2.

The radiator having the CSRR structure applied to the present invention may adjust the resonant frequency by adjusting the outer gap G1 and the inner gap G2, and the feeding may be applied to the outer loop.

According to an embodiment of the present invention, when the antenna of the present invention is applied to the WiMAX band, the radiators 100 and 102 may have a size of 12 x 12 mm.

As shown in FIG. 1, the first radiator 100 and the second radiator 102 may be disposed on both sides of the upper portion of the dielectric structure 110, and the ground plane 106 may be formed in other regions of the dielectric structure 110. Is formed.

In addition, referring to FIG. 2, a lower ground plane 106-1 is formed below the dielectric structure, and a lower ground plane 106-1 is not formed in an area corresponding to the radiators 100 and 102. Made of dielectric material.

In this way, the ground planes 106 and 106-1 formed on the upper and lower portions of the dielectric structure serve to provide an electrical ground signal to the antenna. As shown in FIG. 1, the upper ground plane 106 is formed in an area in which the radiators 100 and 102 are not formed on the upper portion of the dielectric structure 110, and the lower ground plane 106-1 is formed in the dielectric structure ( The region corresponding to the radiator forming region in the upper portion of the lower portion of 110 is made of a dielectric material without a ground plane.

An isolation structure 104, 104-1 is formed between the first radiator 100 and the second radiator 102.

1 and 2, isolation structures 104 and 104-1 are formed on top and bottom of dielectric structure 110. Isolation structure 104 formed on top of dielectric structure and isolation structure formed on bottom. 104-1 has a symmetrical shape and functions to suppress interference generated between the first radiator 100 and the second radiator 102 and to maintain isolation between the two radiators 100 and 102.

As described above, mutual interference or mutual coupling may occur between adjacent radiators in the MIMO antenna, and the isolation structures 104 and 104-1 function to prevent such interference or coupling. .

4 is a diagram illustrating a structure of an isolation structure according to an embodiment of the present invention.

1, 2 and 4, the isolation structures 104 and 104-1 according to one embodiment of the present invention are formed by removing a part of the ground plane.

According to a more preferred embodiment of the present invention, it is preferable that the isolation structures 104 and 104-1 have a form in which two CSRR structures 400 and 402 are arranged with a predetermined gap G5.

Two CSRR structures 400, 402 arranged in series also have an outer gap G3 and an inner gap G4.

The isolation structures 104 and 104-1 of the present invention having the CSRR structure can be made smaller than the structures for improving general isolation. Structures for preventing interference and coupling between antennas in MIMO antennas generally have a length of 1/4 or 1/2 of the wavelength of use, but an isolation structure having the CSRR structure of the present invention is manufactured to less than 1/10 of the wavelength of use. It may have a length of about 9 mm x 18.4 mm when used in the WiMAX band.

Meanwhile, although the isolation structure includes two CSRR structures 400 and 402 in FIGS. 1, 2 and 4, it may be implemented by a single CSRR structure.

The dielectric structure 110 may be a rectangular substrate as shown in FIGS. 1 and 2 or may be an antenna carrier having another structure. The dielectric structure has a predetermined dielectric constant and acts as a medium of the RF signal.

According to one embodiment of the present invention, the dielectric structure 110 may be a general-purpose glass epoxy substrate FR-4 having a dielectric constant ε r of 4.4, but is not limited thereto.

5 is a diagram illustrating isolation characteristics according to a change of an outer gap G1 of a radiator in an antenna according to an embodiment of the present invention, and FIG. 6 is an inner gap of the radiator in an antenna according to an embodiment of the present invention. The figure shows the reflection loss according to the change of (G2).

Referring to FIG. 6, it can be seen that the resonance frequency changes according to the change of the outer gap of the radiator. The antenna according to an embodiment of the present invention can change the resonant frequency by adjusting the external gap, which means that the resonant frequency can be changed without changing the overall size of the radiator. It can be seen that the resonance frequency moves to the low frequency band as the gap is reduced.

Meanwhile, referring to FIG. 5, when the outer gap of the radiator is reduced, the isolated frequency range may also be changed. Accordingly, the isolation characteristics may be adjusted by adjusting the size of the outer gap.

FIG. 7 is a diagram illustrating isolation characteristics according to change of an inner gap G2 of a radiator in an antenna according to an embodiment of the present invention, and FIG. 8 is an inner gap of the radiator in an antenna according to an embodiment of the present invention. It is a figure which shows the reflection loss by the change of (G2).

Referring to FIG. 8, it can be seen that the resonance frequency of the high frequency does not move according to the change of the internal gap, but the impedance bandwidth increases and the impedance matching is improved while the resonance frequency of the low frequency moves to a lower frequency band. On the other hand, referring to Figure 7, it can be seen that the isolation characteristics change with the change of the internal gap.

FIG. 9 is a diagram illustrating isolation characteristics according to a change of an external gap G3 of an isolation structure in an antenna according to an embodiment of the present invention, and FIG. 10 is an interior of an isolation structure in an antenna according to an embodiment of the present invention. FIG. 11 is a diagram illustrating isolation characteristics according to a change of a gap G4, and FIG. 11 is a diagram illustrating isolation characteristics according to a gap G5 between CSRR structures in an antenna according to an exemplary embodiment of the present invention.

Referring to FIG. 9, it can be seen that a frequency-domain change of the isolation characteristic is possible according to the change of the outer gap of the isolation structure, and it is possible to adjust the outer gap to maintain the isolation characteristic in a desired band. . 10 and 11, it is possible to improve the isolation characteristic in the center frequency band according to the change in the gap between the internal gap and the CSRR structure.

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

Dielectric structure
A first radiator and a second radiator which are formed on the dielectric structure and are spaced a predetermined distance apart from each other;
An isolation structure formed between the first radiator and the second radiator and symmetrically formed above and below the dielectric structure;
It includes a ground plane formed on the top and bottom of the dielectric structure,
The isolation structure is a MIMO antenna using a CSRR structure, characterized in that the two CSRR structure having an outer gap and the inner gap is arranged at a predetermined interval.

The method of claim 1,
And the first radiator and the second radiator have a CSRR structure having an inner gap and an outer gap.

delete

The method of claim 1,
And a ground plane is removed from a lower region of the dielectric structure corresponding to a region in which the first radiator and the second radiator are formed.

The method of claim 1,
MIMO antenna using a CSRR structure, characterized in that the frequency band isolated by the external gap and the internal gap control of the isolation structure having the CSRR structure is adjusted.

The method of claim 2,
MIMO antenna using a CSRR structure, characterized in that the resonant frequency is adjusted by the external gap control of the first radiator and the second radiator.

Dielectric structure
A first radiator and a second radiator which are formed on the dielectric structure and are spaced a predetermined distance apart from each other;
An isolation structure formed between the first radiator and the second radiator and symmetrically formed above and below the dielectric structure;
It includes a ground plane formed on the top and bottom of the dielectric structure,
The first radiator and the second radiator have a CSRR structure having an outer gap and an inner gap, and the resonance frequency is changed by adjusting the outer gap,
The isolation structure is a MIMO antenna using a CSRR structure, characterized in that the two CSRR structure having an outer gap and the inner gap is arranged at a predetermined interval.

delete

The method of claim 7, wherein
And a ground plane is removed from a lower region of the dielectric structure corresponding to a region in which the first radiator and the second radiator are formed.