KR102026796B1 - Mimo antenna apparatus with wideband isolation for smart glasses - Google Patents

Abstract

Provided is a MIMO antenna device having broadband isolation for smart glasses. According to one embodiment of the present invention, the MIMO antenna device having broadband isolation for smart glasses comprises: a T-shaped ground formed on a substrate; a plurality of feeding units each formed around a plurality of feeders configured on both sides of the lower end of the T-shaped ground; and a plurality of radiation units having a meander structure respectively configured on both sides of the plurality of feeders, wherein a first antenna may be formed on one side and a second antenna may be formed on the other side based on the T-shaped ground.

Description

MIMO ANTENNA APPARATUS WITH BROADBAND Isolation for Smart Glasses {MIMO ANTENNA APPARATUS WITH WIDEBAND ISOLATION FOR SMART GLASSES}

The following embodiments relate to a MIMO antenna device having broadband isolation for smart glasses, and more particularly, to a MIMO antenna device having broadband isolation for smart glasses by designing a MIMO antenna on a smart glasses leg to enable wireless communication. .

With the introduction of smart glasses, the antenna for wireless communication is being introduced to the glasses. However, due to the structural characteristics of the glasses, the antenna designable part is limited to the legs of the glasses, which are narrow and long. In such a limited structure, the performance of a multiple input multiple output (MIMO) antenna is degraded and it is difficult to secure isolation characteristics between antennas.

Conventional smart glasses are inconvenient because the wearable part is thick and large for the antenna installation or a separate antenna part is attached and the wearing comfort is not good.

Korean Patent Laid-Open Publication No. 10-2016-0071572 relates to such a spectacle-mounted transparent antenna module and a method for reducing SAR using the same, and describes a technique related to a device for selecting an attachment position of a transparent antenna using a transparent electrode on a spectacle lens. Doing.

Korean Patent Publication No. 10-2016-0071572

Embodiments describe a MIMO antenna device having broadband isolation for smart glasses, and more specifically, provides a technique for improving the isolation between antennas by designing a MIMO antenna on a leg portion of smart glasses.

Embodiments of the present invention provide broadband isolation for smart glasses capable of realizing broadband isolation characteristics by forming a slot in the ground to improve isolation, an important characteristic of the MIMO antenna, and placing a capacitor in the slot to control isolation resonance. To provide a MIMO antenna device having a.

MIMO antenna device having a broadband isolation for smart glasses according to an embodiment, the T-shaped ground formed on the substrate; A plurality of feeders each formed around a plurality of feeders configured on both sides of a lower end of the T-shaped ground; And a plurality of radiators having a meander structure each configured to both sides of the plurality of feeders, wherein one side of the first antenna is formed and the other side of the second antenna is formed based on the T-shaped ground. Can be.

A slot configured in the center portion of the ground; And a passive element configured in the slot.

The passive element is a capacitor configured at the inner center of the slot for broadband isolation characteristics, and may control isolation resonance using a value of the capacitor.

The ground may be bent in a '-' shape at both ends to implement the antenna in a miniaturized size.

The first antenna and the second antenna may form a symmetrical structure based on the T-shaped ground and may be inserted into a leg portion of the smart glasses.

According to embodiments, a MIMO antenna device having broadband isolation for smart glasses that improves isolation between antennas by designing a MIMO antenna on a leg portion of smart glasses may be provided.

In addition, according to embodiments, the broadband isolation for smart glasses can be realized by forming a slot in the ground and placing a capacitor in the slot to control the isolation resonance to improve the isolation, an important characteristic of the MIMO antenna. A MIMO antenna device can be provided.

1 is a diagram for describing smart glasses configured with a MIMO antenna device according to an exemplary embodiment.
FIG. 2 is a diagram illustrating a MIMO antenna device having broadband isolation for smart glasses according to one embodiment. FIG.
3 is an enlarged view illustrating a portion A of FIG. 2.
4 is a diagram illustrating isolation between antennas according to antennas.
5 is a diagram illustrating isolation between antennas according to slot lengths.
6 is a diagram illustrating isolation between antennas according to capacitor values located in slots.
7 is a diagram illustrating an example of an antenna model according to an embodiment.
8 is a diagram illustrating a radiation pattern of an antenna according to an exemplary embodiment.

Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings. However, the described embodiments may be modified in many different forms, and the scope of the present invention is not limited to the embodiments described below. In addition, various embodiments are provided to more fully describe the present invention to those skilled in the art. Shape and size of the elements in the drawings may be exaggerated for more clear description.

1 is a diagram for describing smart glasses configured with a MIMO antenna device according to an exemplary embodiment.

Referring to FIG. 1, a smart glasses configured with a MIMO antenna device according to an exemplary embodiment are illustrated, and a MIMO antenna is designed in a leg portion of the smart glasses g and a slot is implemented to improve isolation between antennas. You can. That is, the MIMO antenna device 100 having the broadband isolation for smart glasses may be implemented in the leg portion of the smart glasses g.

MIMO antenna device 100 having a broadband isolation for smart glasses according to one embodiment, in order to improve the antenna performance degradation and poor isolation characteristics, which is a conventional problem, and forms a slot in the ground (ground) of the antenna, By configuring a capacitor inside the slot to adjust the isolation resonance characteristics, the slot isolation characteristics can be realized through the slot.

Hereinafter, the MIMO antenna device 100 having the broadband isolation degree for the small smart glasses designed on the leg of the smart glasses g will be described in more detail.

FIG. 2 is a diagram illustrating a MIMO antenna device having broadband isolation for smart glasses according to one embodiment. FIG. 3 is an enlarged view of a portion A of FIG. 2.

2 and 3 illustrate a MIMO antenna device 100 having a broadband isolation for smart glasses according to an embodiment, and may include a substrate, a first antenna, and a second antenna. More specifically, the ground 110 may be configured on the substrate, and the first and second antennas having respective feeding structures may be configured.

= 4.4, tan

= 0.03)이 사용될 수 있으며, 기판의 크기는 10mmХ37mm로 이루어질 수 있다. 기판은 PCB뿐 아니라 연성인쇄회로기판(Flexible Print Circuit Board, FPCB)이 사용될 수 있다. The substrate is a body portion to which the components of the MIMO antenna device 100 having the broadband isolation for smart glasses are coupled, and may be formed of a printed circuit board (PCB) or the like. The substrate may be made of a dielectric material, and the dielectric constant of the substrate may be determined by required radiation characteristics. In one example, an FR4 substrate (

= 4.4, tan

= 0.03) may be used, and the size of the substrate may be 10 mm Х 37 mm. The substrate may be a flexible printed circuit board (FPCB) as well as a PCB.

The ground 110 may be formed in a predetermined region above the substrate. The ground 110 is made of a conductive metal material and may be electrically coupled to the feeding structure.

The ground 110 is formed in a T shape, which is when the ground 110 is viewed in a reverse direction, the ground 110 may check the T shape. The following description will be made based on a case in which the figure of FIG. 2 is viewed in a reverse direction in order to describe the shape of the ground 110 in a T shape. The upper both ends of the ground 110 made of a T shape can be configured to be folded for miniaturization so as to be electrically longer than the standard ground 110.

In addition, the slot 140 may be configured to overcome the weakness of the poor isolation between the two antennas in the center portion of the ground 110, and the capacitor 150 may be added to the slot 140.

It may be designed to create a dual resonance mode using the ground 110 between two power supplies to obtain isolation between the miniaturized first and second antennas.

The dual resonance principle using the ground 110 may use three ports, and the three-port system may assume each antenna as port 1 and port 2 and the ground 110 as port 3.

Hereinafter, the MIMO antenna device 100 having the broadband isolation for smart glasses according to an embodiment of the size of 10 mm to 37 mm will be described in more detail as an example.

The MIMO antenna device 100 having broadband isolation for smart glasses according to an embodiment includes a first antenna and a second antenna, which are two meander antennas having a shorting pin and a T-shaped ground 110. It consists of. At this time, the size of the MIMO antenna device is 10 mm x 37 mm.

The MIMO antenna device 100 having the broadband isolation for smart glasses according to an embodiment may include a ground 110, a plurality of feeders, and a plurality of radiators 120. According to an embodiment, the MIMO antenna device 100 having the broadband isolation for smart glasses may further include a slot 140 and a passive element 150.

As described above, the ground 110 may be formed in a T shape on the substrate.

The ground 110 may be configured to have a folded shape at both ends to implement an antenna having a miniaturized size. More specifically, the ground 110 may implement an antenna having a miniaturized size by bending both ends in a 'c' shape to be embedded in the leg portion of the smart glasses.

For example, the bent shape of the ends of one side (eg, left-side ground) and the other side (eg, right-side ground) of the ground 110 may be configured identically or similarly, and the ground 110 may be formed before bending. The width is 1.85mm and the width of the ground 110 after bending is 1.65mm and the gap between the two may be 0.5mm.

As shown in FIG. 3, the plurality of feeders may be formed around a plurality of feeders configured at both ends of the lower end of the T-shaped ground 110, respectively. More specifically, a plurality of power supplies may be configured on both sides of the lower end of the T-shaped ground 110, and short-circuit pins respectively connected to the plurality of radiating parts 120 may be configured.

The plurality of radiating parts 120 may be formed in a meander structure each configured on both sides of the plurality of feeding parts. Each of the plurality of feed units may be composed of a feed line having a width of 0.3 mm, a conductor line having a width of 1.1 mm, a gap line having a width of 0.9 mm, and 3.5 turns. The width and height of the shorting pin and the distance from the feed line may be set to 0.3 mm, 1.4 mm and 1.35 mm, respectively.

Accordingly, a first antenna may be formed at one side and a second antenna may be formed at the other side based on the T-shaped ground 110. Here, the first antenna and the second antenna may be a meander antenna and may be disposed symmetrically with each other. The first antenna and the second antenna form a symmetrical structure based on the T-shaped ground 110 and may be inserted into the leg portion of the smart glasses.

The slot 140 may be configured at the center portion of the ground 110, and the passive element 150 may be configured at the slot 140. Here, the passive element 150 is a capacitor 150 configured at the inner center of the slot 140 for the broadband isolation characteristic, and may control the isolation resonance using the value of the capacitor 150.

For example, the width of the ground 110 between the plurality of power supplies may be 5 mm, the width of the inserted slot 140 is 2.2 mm and the length may be 8.3 mm. A capacitor 150 is configured in the slot 140, and at this time, a capacitor 150 having a size of 1.0 pF may be configured at a central position of the slot 140.

According to embodiments, the slot 140 is formed in the ground 110 to improve the isolation characteristic, which is an important characteristic of the MIMO antenna, and the capacitor 150 is positioned in the slot 140 to control the isolation resonance. Can be implemented.

4 is a diagram illustrating isolation between antennas according to antennas.

Referring to FIG. 4, a diagram illustrating isolation between antennas varying according to antennas, (a) shows an antenna case 1 using a common ground, and (b) shows an antenna case using a T-shaped ground. 2), (c) shows a MIMO antenna device (case 3) having a broadband isolation for smart glasses according to an embodiment, the slot and the capacitor is added to the T-shaped ground.

And (d) is a simulation result showing the isolation between the antennas that change depending on the antenna of (a), (b) and (c). As shown in the simulation result, in case of the MIMO antenna device case 3 having the broadband isolation for smart glasses according to an embodiment, double resonance occurs.

To create a double resonance in the T-shaped ground, a ground is inserted between the two power supplies and a capacitor is inserted in the center of the slot. By inducing a resonance similar to the LC resonance through the loop current and the capacitor around the formed slot, a second resonance can occur in ground mode.

5 is a diagram illustrating isolation between antennas according to slot lengths.

Referring to FIG. 5, it can be seen that the isolation between antennas is changed according to the change in the length of the slot configured at the ground center position of the MIMO antenna device having the broadband isolation for smart glasses according to an embodiment.

When the slot length is 7.7 mm, ground mode resonance occurs at 2.4 GHz and 2.6 GHz, and when the slot length is 8.2 mm, resonance occurs at 2.43 GHz and 2.51 GHz. And when the length of the slot is 8.7mm, it can be seen that the two resonances are coupled and the characteristics deteriorate.

6 is a diagram illustrating isolation between antennas according to capacitor values located in slots.

Referring to FIG. 6, the isolation is changed according to the change in the value of the capacitor located in the slot. The simulation is based on the case where the value of the capacitor is 0.8 pF, 1.0 pF, and 1.2 pF, respectively. It can be seen that an optimal combination of capacitor and slot size is required.

The proposed antenna is designed on a 0.2 mm thick FR-4 (flame retardant type 4) substrate and is targeted for 2.4GHz Wi-Fi applications.

7 is a diagram illustrating an example of an antenna model according to an embodiment.

Referring to FIG. 7, a photograph of an actually manufactured antenna of a MIMO antenna device having broadband isolation for smart glasses according to an embodiment is illustrated. The fabricated antenna is 10mm x 37mm.

8 is a diagram illustrating a radiation pattern of an antenna according to an exemplary embodiment.

Referring to FIG. 8, the S-parameters of the MIMO antennas are shown in the simulation and the measurement. The simulated results are indicated by dotted lines and the measured results are indicated by solid lines. The reflection coefficient is less than -5.1 dB and the isolation distance between two antennas (first antenna and second antenna) is in the range of -15 dB to -32 dB in the operating band. You can see that the measurements are consistent with the simulation.

As described above, the embodiments may improve the isolation between antennas by designing a MIMO antenna and implementing a slot in the smart glasses leg portion. In particular, a slot is formed in the ground of the antenna to improve antenna performance and low isolation characteristics, which are problems of the prior art, and a capacitor can be used inside the slot to adjust the characteristics of isolation resonance. Broadband isolation can also be achieved using slots and capacitors located within the slots. Accordingly, a high performance MIMO antenna can be implemented in smart glasses.

The MIMO antenna device having the broadband isolation for smart glasses according to the embodiments is applicable to smart glasses that require MIMO technology, which has recently been introduced. That is, the MIMO antenna can be designed in the leg portion of the smart glasses that require the wireless communication function and can be applied to the wireless communication.

When a component is referred to as "connected" or "connected" to another component, the component may be directly connected to or connected to the other component, but another component may be present in the middle. It should be understood that. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In addition, terms such as “… unit”, “… module” described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software.

In addition, the components of the embodiments described with reference to the drawings are not limited to the corresponding embodiments, and may be implemented to be included in other embodiments within the scope of the technical spirit of the present invention. Even if the description is omitted, it is obvious that a plurality of embodiments may be reimplemented into one integrated embodiment.

In addition, in the description with reference to the accompanying drawings, the same components regardless of reference numerals will be given the same or related reference numerals and redundant description thereof will be omitted. In the following description of the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Although the embodiments have been described by the limited embodiments and the drawings as described above, various modifications and variations are possible to those skilled in the art from the above description. For example, the described techniques may be performed in a different order than the described method, and / or components of the described systems, structures, devices, circuits, etc. may be combined or combined in a different form than the described method, or other components. Or even if replaced or substituted by equivalents, an appropriate result can be achieved.

Therefore, other implementations, other embodiments, and equivalents to the claims are within the scope of the claims that follow.

Claims (5)

T-shaped ground formed on the substrate to be inserted or attached to the leg portion of the smart glasses;
A plurality of feeders each formed around a plurality of feeders configured on both sides of a lower end of the center portion of the T-shaped ground;
A plurality of radiators having a meander structure each formed at both sides of the plurality of feeders;
A slot configured inside the center portion of the T-shaped ground; And
Passive element configured in the slot to control isolation resonance
Including,
The T-shaped ground is
Both ends of the upper part are bent in a 'c' shape along the outer line of the substrate to realize the antenna with a miniaturized size, and one side is a meander antenna based on the T-shaped ground. Is formed and the other side is formed a second antenna which is a meander antenna disposed symmetrically with the first antenna
Characterized in that, MIMO antenna device having a broadband isolation for smart glasses. delete The method of claim 1,
The passive element,
A capacitor configured in the inner center of the slot for broadband isolation characteristics, and controlling the isolation resonance using the value of the capacitor
Characterized in that, MIMO antenna device having a broadband isolation for smart glasses. delete delete

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