KR20180085200A - Magnetic material apparatus for preventing decreasing emission efficiency of antenna in mobile phone - Google Patents

Abstract

Disclosed is a magnetic apparatus, preventing reduction in performance of an antenna caused due to a structural problem in a metal phone. The magnetic apparatus is used for a metal phone, in which an antenna is spaced from a metal frame and a touch window at predetermined intervals, and installed to cover the interval between the antenna and the metal frame. Moreover, in a frequency band of 700MHz-2690MHz, a real number unit has magnetic permeability more than 5 and magnetic loss tangent (μ″/μ′) equal to or less than 0.025.

Description

TECHNICAL FIELD [0001] The present invention relates to a magnetic material apparatus for preventing emission efficiency of an antenna in a mobile phone,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic body device for improving the radiation efficiency of an antenna of a mobile phone, and more particularly to a technique capable of preventing performance degradation of an antenna due to a structural problem in a metal phone.

1 is an exploded perspective view showing a structure of a general metal phone.

A touch window 110 and a metal frame 120 are one of the main causes for attenuating antenna performance in a metal-phone structure having a separation interval to form an antenna.

Reference numeral 150 denotes a battery cover, and reference numeral 140 denotes a circuit board.

The gap 130 between the antenna 130 and the metal frame 120 is about 0.5 mm to 1.0 mm and the antenna 130 and the touch window 110 are spaced apart by about 0.5 mm to 3 mm do.

In order to secure the antenna radiation performance, the antenna 130 needs to be sufficiently spaced from the metal frame 120 or the touch window 110, but is designed to be very close in consideration of design aspects.

Since the metal element such as indium is included in a fine line shape for the electrostatic operation of the touch window 110, the touch window 110 operates as a kind of metal plate with respect to the antenna 130. As described above, Since the touch window 110 is very close to the antenna 130 and has a length of about 1/4? In the 700 MHz band, a considerable portion of the radio wave energy radiated from the antenna 130 is re- absorbed toward the touch window 110 Or interference is caused, and the radiation performance is deteriorated.

Also, the metal frame 120, which is spaced apart from the antenna 130 by a very narrow gap 122, is also a factor that degrades the antenna performance for the same reason as the touch window 110.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a magnetic body device capable of minimizing deterioration of antenna radiation performance due to a touch window and a metal frame separated by an antenna and a narrow gap.

The object of the present invention is also achieved by providing an antenna for a metal phone spaced apart from a metal frame and a touch window by a predetermined distance so as to cover a gap between the antenna and the metal frame, Is not less than 5 and the magnetic loss tangent (μ "/ μ ') is 0.025 or less.

Preferably, the magnetic body device is further provided so as to cover a gap between the antenna and the touch window.

Preferably, the vertical cross section of the magnetic device may be L-shaped.

Preferably, the magnetic device is provided at both ends of the antenna, and the magnetic device provided closer to the feeding part of the antenna may be shorter than the length of the magnetic device provided at a farther side.

Preferably, the magnetic device device comprises a magnetic substance material layer and an insulating adhesive layer laminated on the magnetic substance material layer.

Preferably, the magnetic body device comprises: a magnetic material layer having a plurality of minute ventilation holes; And an insulating adhesive layer laminated on the magnetic material layer.

Preferably, the vent holes are smaller than the wavelength of the operating frequency, and the spacing between the vent holes is smaller than the wavelength.

Preferably, the vent hole may be filled with a magnetic material having a magnetic permeability different from that of the magnetic material layer of the magnetic material layer, or may be filled with a dielectric material having a dielectric constant or a metal component of high electrical conductivity, or may be filled with air.

According to the above configuration, by using a magnetic material having a low magnetic loss (Magnetic Loss Tangent) in the frequency region of 700 MHz or more, the gap between the antenna and the metal frame or the antenna and the touch window is cut off in the metal phone, The radiation efficiency of the antenna can be improved by minimizing the influence.

1 is an exploded perspective view showing a structure of a general metal phone.
2 is a partial perspective view showing a state in which the magnetic substance device of the present invention is applied.
FIG. 3 is a graph showing a result of simulating the return loss of an antenna to which the present invention is applied by using HFSS.
4 is a graph showing the radiation efficiency of the antenna.
5 is a graph showing antenna radiation efficiency according to the length of the magnetic device.
6 is a graph showing the antenna radiation efficiency according to the thickness of the magnetic device.
7 is a graph showing antenna radiation efficiency according to a magnetic loss tangent of a magnetic device.
Fig. 8 shows another example of the magnetic body device.
Fig. 9 shows another example of the magnetic body device.

It is noted that the technical terms used in the present invention are used only to describe specific embodiments and are not intended to limit the present invention. In addition, the technical terms used in the present invention should be construed in a sense generally understood by a person having ordinary skill in the art to which the present invention belongs, unless otherwise defined in the present invention, Should not be construed as interpreted or interpreted in an excessively reduced sense. In addition, when a technical term used in the present invention is an erroneous technical term that does not accurately express the concept of the present invention, it should be understood that technical terms can be understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted according to a predefined or prior context, and should not be construed as being excessively reduced.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

2 is a partial perspective view showing a state in which the magnetic substance device of the present invention is applied.

The printed circuit board 140 is accommodated in the metal frame 120 and the metal frame 120 is electrically connected to the ground pattern of the printed circuit board 140 via the connection terminal 124 via the ground terminal 144 Lt; / RTI >

The antenna 130 is spaced apart from the metal frame 120 to form a gap 122 and a ground pattern or a ground pattern or a ground pattern of the printed circuit board 140 via the connection tab 132 and the contact terminal 142. [ And is electrically connected to the conductive pattern.

2, the gap 122 between the antenna 130 and the metal frame 120 is about 0.5 mm to 1.0 mm and the antenna 130 and the touch window 110 are about 0.5 mm to 3 mm Respectively.

As described above, since the metal frame 120 or the touch window 110 is disposed in close proximity to the antenna 130 and the physical length is about 1/4? In the 700 MHz band, A significant portion of the propagation energy is absorbed or interfered with toward the metal frame 120 or the touch window 110, and as a result, the performance of the antenna is deteriorated.

In order to minimize the influence of the metal frame 120 or the touch window 110, the low loss magnetic body devices 210 and 220 are disposed between the antenna 130 and the metal frame 120 and between the antenna 130 and the touch window 110 (Not shown).

The magnetic substance devices 210 and 220 may have a vertical section I shape or an L shape as in this embodiment but the shape of the magnetic substance devices 210 and 220 is not limited and the gap 122 between the antenna 130 and the metal frame 120, And / or intercepting the gap 123 between the antenna 130 and the touch window 110 is possible.

The magnetic substance devices 210 and 220 may have an insulating adhesive layer for fixing to the antenna 130 or the metal frame 120 and may be made of a flexible material so as to facilitate detachment and attachment, It may be made of a hard material having high hardness.

For example, the magnetic substance devices 210 and 220 may be formed in the form of a thin tape made of a magnetic material having an insulating adhesive layer and having a small magnetic loss in a high frequency region.

The magnetic body devices 210 and 220 have a magnetic permeability of 5 or more in the real part of the complex permeability and a magnetic material thickness of 0.5 mm or more and a magnetic body device 210 near the feed part of the antenna 130 have a length , And the far-side magnetic body device 220 has a length L2 of 20 mm or more.

Generally, the magnetic material is represented by the magnetic permeability in the form of μ = μ '- jμ ".

In order to minimize the deterioration of the antenna radiation efficiency due to the touch window 110 and the metal frame 120, the magnetic devices 210 and 220 have a high permeability in the real part of the frequency band of 700 MHz to 2690 MHz while a very low permeability of the imaginary part Magnetic material, for example, such that the real part of the complex permeability has a value of at least 5.

In addition, the magnetic loss tangent (μ "/ μ ') should be a magnetic substance having a value of 0.025 or less.

Conventional spinel ferrites are cubic crystals and have small magnetic anisotropy so that the natural resonance frequency does not exceed the Snoek's limit, which is inversely proportional to the initial permeability. If the frequency of use is close to the resonance frequency, the loss increases very much and the frequency of use is limited in most ㎓ bands.

However, in the case of hexagonal ferrite, the initial permeability decreases from several hundred MHz to several GHz and the loss ratio does not increase. Therefore, the ferrite applied to the magnetic devices 210 and 220 according to this embodiment has a hexagonal crystal structure Chungfelite can be applied.

FIG. 3 is a graph showing a result of simulating the return loss of an antenna to which the present invention is applied by using HFSS.

The complex permeability μ of the applied magnetic body is 20-j0.5. As the inductance of the antenna increases due to the magnetic permeability, it can be seen that the resonance frequency is shifted to the low side in the low band and the high band.

4 is a graph showing the radiation efficiency of the antenna.

To confirm the effect of the real part of the complex permeability, the magnetic loss was assumed to be zero. The thickness of the magnetic body is 1 mm, and L1 lengths are 32 mm and 12 mm, respectively. The width W of the magnetic body has 9.5 mm.

The simulation result using HFSS shows the radiation efficiency when the loss due to mismatching is not considered in order to exclude the influence on the resonance frequency shift.

When the real part of the complex permeability is 2 or less, the improvement of the antenna radiation efficiency is insignificant. As shown in FIG. 4, it can be seen that the radiation efficiency of the antenna increases in proportion to the real part of the magnetic permeability.

5 is a graph showing antenna radiation efficiency according to the length of the magnetic device.

Represents the antenna radiation efficiency according to the length of the magnetic body device when the real part of the complex permeability of the magnetic body devices 210 and 220 is 20, the thickness is 1 mm, the width is 9.5 mm and the magnetic loss is zero.

The magnetic body device 210 shows the antenna radiation efficiency when the length of the magnetic body device 220 is changed to a distance of 12 mm from the antenna feeding part. When the length is 22 mm or more, the antenna radiation efficiency is improved The improvement effect is insignificant at 17 mm or less.

6 is a graph showing the antenna radiation efficiency according to the thickness of the magnetic device.

The antenna radiation efficiency according to the thickness of the magnetic device 210 or 220 is shown when the complex magnetic permeability of the magnetic device 210 or 220 is 20, the length is 12 mm or 32 mm, the width is 9.5 mm, and the magnetic loss is 0 .

When the thickness of the magnetic body device is 0.5 mm or more, the antenna radiation efficiency is improved. However, when the thickness is 0.2 mm or less, the effect of improving the antenna radiation efficiency is insignificant.

7 is a graph showing antenna radiation efficiency according to a magnetic loss tangent of a magnetic device.

It is assumed that the real part of the complex permeability of the magnetic substance devices 210 and 220 is 20, the thickness of the magnetic substance device is 1 mm, the width is 9.5 mm, and the lengths are 12 mm and 32 mm, respectively.

As shown in FIG. 7, the radiation efficiency of the antenna is greater as the magnetic loss is smaller. On the other hand, when the magnetic loss is larger than 0.1, the antenna radiation efficiency is lowered.

Fig. 8 shows another example of the magnetic body device.

The magnetic body device is formed by laminating an insulating adhesive layer 231 on a uniform magnetic material layer 232.

Fig. 9 shows another example of the magnetic body device.

A plurality of fine air holes 243 are formed in the magnetic substance material layer 242 so that the air holes 243 are filled with the magnetic material 244 and the insulating adhesive layer 241 is formed on the magnetic substance material layer 242. In this embodiment, Are stacked.

The vent holes 243 are formed to have a size much smaller than the wavelength of the operating frequency and the spacing between the vent holes 243 is also very small compared to the wavelength.

The magnetic material 244 filling the vent hole 243 may be any magnetic material having a magnetic permeability different from that of the magnetic material constituting the magnetic material layer 242 and may be a dielectric material having an arbitrary dielectric constant or a metal material having a high electrical conductivity. It is possible. Further, it can be formed in an air-filled state without filling anything.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Accordingly, the scope of the present invention should not be construed as being limited to the embodiments described above, but should be construed in accordance with the following claims.

110: touch window (touch wondow)
120: metal frame
122, 123: clearance
124, 132: Connect tab
130: Antenna
140: printed circuit board
150: Battery cover
210, 220: Magnetic body device

Claims (8)

The antenna is applied to a metal frame which is spaced apart from the metal frame and the touch window at regular intervals,
A metal frame provided so as to cover a gap between the antenna and the metal frame,
Wherein the magnetic permeability in the real part of the frequency band of 700 MHz to 2690 MHz is 5 or more and the magnetic loss tangent (μ "/ μ ') is 0.025 or less. In claim 1,
Wherein the magnetic body device is further provided so as to cover a gap between the antenna and the touch window. In claim 2,
Wherein the vertical cross section of the magnetic body device is L-shaped. In claim 1,
Wherein the magnetic body device is provided at both ends of the antenna,
Wherein a magnetic body device provided on a side close to the feeding part of the antenna is smaller than a length of a magnetic body device provided on a far side. In claim 1,
Wherein the magnetic body device comprises a magnetic substance material layer and an insulating adhesive layer laminated on the magnetic substance material layer. In claim 1,
The magnetic body device comprising:
A magnetic material layer having a plurality of minute vent holes formed therein; And
And an insulating adhesive layer laminated on the magnetic substance material layer. In claim 6,
Wherein the air holes have a size smaller than the wavelength of the operating frequency and the intervals between the air holes are smaller than the wavelengths. In claim 6,
Characterized in that a magnetic material having a magnetic permeability different from that of the magnetic material of the magnetic material layer is filled in the vent hole or a dielectric material having a certain dielectric constant or a metal component having a high electrical conductivity is filled or air is filled. Magnetic layer.

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