KR101119607B1 - Intenal antenna and mobile communication teminal having the same - Google Patents

Abstract

Disclosed are a built-in antenna and a mobile communication terminal having the same. According to an embodiment of the present invention, a built-in antenna and a mobile communication terminal having the same include a feed line formed along one side edge of one side of a substrate, spaced apart from an end of the feed line, and having a first via hole formed therein. And a first short circuit line formed spaced apart from the feed line along the other edge of one surface of the substrate, and having a second via hole formed at one end thereof, and formed on the other surface of the substrate, one end of which is formed through the first via hole. The second short circuit is electrically connected to the branch and electrically connected to the first short circuit through the second via hole, thereby reducing the electrical interference between the antenna and the outer case formed of a metal material, thereby reducing antenna efficiency. Keep it.

Description

Built-in antenna and mobile communication terminal having same {INTENAL ANTENNA AND MOBILE COMMUNICATION TEMINAL HAVING THE SAME}

The present invention relates to a built-in antenna and a mobile communication terminal having the same, a technology capable of maintaining the efficiency of the antenna in the form of various terminals and metal environments.

Recently, with the development of mobile communication technology, WiFi (Wireless Fidelity) technology for supporting various wired / wireless integrated services has been applied to a variety of mobile PCs, PDAs, mobile phones, TVs, PMPs, cameras, video game consoles, and robot toys. WiFi technology is a protocol that eliminates the limitations of Internet use as a protocol that does not require extensive cabling and router re-routing caused by IT activities in the company such as moving, adding, or changing the daily routine. Is developing.

However, when the external case of the terminals to which the WiFi technology is applied is made of a metallic material, mutual interference occurs between the external case and the antenna configured inside the terminal, thereby causing a problem that the efficiency of the antenna is degraded.

Therefore, there is a need for a technology that can be easily applied to various terminal types and metal environments without reducing the efficiency of the antenna.

Embodiments of the present invention by forming a short circuit line on the surface of the feed line and the feed line on one side of the substrate, by coupling (coupling) the current flowing between the feed line and the short circuit line, to maintain the efficiency of the antenna in a metal environment do.

In order to achieve the above object, a built-in antenna and a mobile communication terminal having the same according to the present invention is a substrate, a feed line is formed along one edge on one side of the substrate, and the end of the feed line on one side of the substrate A first shorting line formed to be spaced apart from the grounding part, and a first shorting line formed to be spaced apart from the feed line along the other edge of one surface of the substrate, and a second via hole formed at one end of the substrate; It is formed on the other side, one end is electrically connected to the ground portion through the first via hole, and includes a second short circuit line electrically connected to the first short circuit line through the second via hole.

According to embodiments of the present invention, by forming a shorting line spaced apart from the feed line and the feed line on one surface of the substrate, by coupling the current flowing between the feed line and the short line (coupling), the electrical interference between the metal environment and the antenna By reducing the efficiency of the antenna can be maintained.

In addition, by forming a short-circuit pattern on the other surface of the substrate, it is possible to easily adjust the resonant frequency band of the antenna, it is possible to form a wider antenna frequency band width.

Hereinafter, specific embodiments of the antenna device of the present invention will be described with reference to FIGS. 1 to 9. However, this is only an example and the present invention is not limited thereto.

In describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intention or custom of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

In addition, the embodiment of the present invention to be carried out below is provided in the antenna configuration of the mobile communication terminal to effectively describe the technical components constituting the present invention, or a mobile communication that is usually provided in the technical field to which the present invention belongs The antenna configuration of the terminal is omitted as much as possible, and will be mainly described for the functional configuration that should be additionally provided for the present invention. If those skilled in the art to which the present invention pertains, it will be able to easily understand the function of the components that are used in the prior art among the components omitted, not shown below, and also the components omitted as described above And the relationship between the components added for the present invention will be clearly understood.

As a result, the technical spirit of the present invention is determined by the claims, and the following examples are one means for efficiently explaining the technical spirit of the present invention to those skilled in the art to which the present invention pertains. It is only.

1 is a perspective view illustrating a general mobile communication terminal having a built-in antenna.

Referring to FIG. 1, the built-in antenna 100 may be located at the top or bottom of the mobile communication terminal 10. Here, the exterior case 1 of the mobile communication terminal 10 may be formed of a metal material. In this case, due to the metal outer case 1, the mutual interference with the built-in antenna 100 is generated.

Accordingly, an embodiment of the present invention is to propose a method for maintaining the efficiency of the antenna even in a metal environment by reducing the influence of mutual interference between the metal case and the internal antenna.

2 is a plan view showing one surface (upper surface) of the built-in antenna according to an embodiment of the present invention, and FIG. 3 is a plan view showing the other surface (lower surface) of the built-in antenna according to the embodiment of the present invention.

2 and 3, the built-in antenna 200 includes a substrate 210, a feed line 220, a ground unit 230, a first short circuit 240, a second short circuit 250, and a first antenna 200. And a three short circuit track 260 and a tuning stub 270. The built-in antenna 200 may perform wireless communication in, for example, a wireless fidelity (WiFi) band of about 2.4 GHz. However, the built-in antenna 200 is not limited to the WiFi band and may be used in various frequency bands.

The substrate 210 may use a FR-4 double-sided dielectric substrate. However, the material, size, thickness, shape, etc. of the substrate 210 are not limited, and generally, a flat rectangular plate-shaped printed circuit board (PCB) substrate used in constructing an antenna may be used. For example, the substrate 210 may be variously changed according to the characteristics of the built-in antenna 200 and the usage environment of the mobile communication terminal 10 in the present invention.

The feed line 220 may be formed along one side edge of one surface (upper surface) of the substrate 210. In this case, the resonance frequency of the built-in antenna 200 may be adjusted by adjusting the length A and the width of the feed line 220.

The ground portion 230 may be formed to be spaced apart from the end of the feed line 220.

A first via hole 235 is formed in the ground portion 230, and the first via hole 235 is formed on the ground portion 230 and the other surface (lower surface) of the substrate 210 to be described later. It serves as a passage for electrically connecting the second short circuit line (250).

The first short circuit line 240 may be formed at the other side edge of one surface of the substrate 210 spaced apart from the feed line 220 at predetermined intervals. The reason why the first short circuit 240 is formed on one surface of the substrate 210 in the same manner as the power supply line 220 is because the first short circuit 240 flows between the first short circuit 240 and the power supply line 220. This is to couple the current.

In this case, mutual interference between the metal case 1 constituting the mobile communication terminal 10 and the built-in antenna 200 is reduced. This is due to the coupling of the current flowing between the feed line 220 and the first short circuit 240, the amount of current flowing in the feed line 220 and the first short circuit 240 is increased. This is because interference between the built-in antenna 200 and the metal case 10 is reduced. Therefore, even if the antenna is embedded in the terminal having a metal outer case it is possible to maintain the efficiency of the antenna.

At this time, by adjusting the separation distance between the feed line 220 and the first short circuit 240, it is possible to determine the degree of coupling of the current flowing between the feed line 220 and the first short circuit 240. .

Meanwhile, a second via hole 245 is formed at one end of the first short circuit line 240, and the second via hole 245 is electrically connected to the other surface of the substrate 210. For example, the second via hole 245 serves as a path for electrically connecting the first short circuit line 240 and the second short circuit line 250 formed on the other surface of the substrate 210.

In addition, at least one fine via hole 246 smaller than the diameter of the second via hole 245 is formed in the other end direction of the first short circuit line 240. The fine via hole 246 formed at the other end of the first short circuit line 240 facilitates the flow of current flowing through the first short circuit line 240. For example, the current flowing along the first short circuit line 240 is concentrated around the fine via hole 246. Accordingly, the amount of current flowing in the first short circuit line 240 is increased. Smooth flow of current flowing along the first short circuit line 240. In this case, the degree of coupling of the current flowing between the feed line 220 and the first short circuit line 240 may be improved.

The second short circuit line 250 is formed on the other surface (lower surface) of the substrate 210, and includes a first line 251 and a first line 251 formed along an edge of the substrate 210. The second line 253 is formed to extend vertically at the end. In addition, the first via hole 235 and the second via hole 245 are formed in the second short circuit line 250.

The first via hole 235 is formed at one end of the second line 253, and serves as a passage for electrically connecting the second short line 250 and the ground portion 230. The second via hole 245 is formed at one end of the first line 251. The second via hole 245 serves as a passage that electrically connects the first short circuit 240 and the second short circuit 250.

Meanwhile, a tuning stub 270 is formed at the second line 253 to be electrically connected to the third short line 260 which will be described below. A detailed description thereof will be described with reference to the third short line 260. It will be mentioned in the description.

The third short circuit 260 is formed at one edge of the other surface of the substrate 210 to be spaced apart from the second short circuit 250. The fine via hole 246 is formed in the third short circuit 260 to smoothly flow current flowing along the third short circuit 260.

In addition, the third short circuit 260 is formed slightly spaced apart from the second short circuit 250, the tuning stub 270 between the second short circuit 250 and the third short circuit 260. ) Is formed to electrically connect the second short circuit 250 and the third short circuit 260.

For example, the tuning stub 270 is formed at the other ends of the second line 253 and the third short line 260 of the second short line 250, and thus the second short line 250. And the third short circuit line 260 are electrically connected to each other.

However, the embodiment of the present invention is not limited to the position where the tuning stub 270 is formed, and is formed between the second short circuit 250 and the third short circuit 260, and these are electrically connected. If it is formed in a position that can be connected to.

Meanwhile, the resonance frequency and the Q value of the built-in antenna 200 may be tuned by adjusting the position and width C of the tuning stub 270. For example, if the operating frequency of the mobile communication terminal 10 is 2.44 GHz, and the resonant frequency of the built-in antenna 100 is 2.42 GHz, by adjusting the position and width (C) of the tuning stub 270, The frequency may be tuned such that the resonant frequency of the built-in antenna 100 is 2.44 GHz, which is a frequency used by the mobile communication terminal 10. This makes it possible to finely control the flow of the current flowing through the tuning stub 270 to the ground of the substrate 210, thereby fine tuning the resonance frequency of the mobile communication terminal 10. In addition, the Q value can also be finely tuned.

As described above, according to the embodiment of the present invention, the feed line and the short-circuit line are formed on one surface of the substrate to be spaced apart from each other, and the current flowing therebetween is coupled, thereby reducing the electrical interference between the external case and the antenna formed of the metal material. The efficiency of the antenna can be maintained.

In addition, by forming a short circuit pattern such as a second short circuit and a third short circuit on the other surface of the substrate, the resonance frequency band of the antenna can be easily adjusted, and the antenna frequency band width can be made wider. That is, by forming the short-circuit pattern on the other surface of the substrate, it is possible to form a wider antenna frequency bandwidth than when the other surface of the substrate is formed of the ground plane.

Further, by forming the tuning stub 270, and adjusting its position and width, it is possible to finely adjust the resonant frequency and Q value of the built-in antenna 200.

4 is a diagram illustrating a current distribution flowing in a mobile communication terminal equipped with a built-in antenna according to an embodiment of the present invention.

As shown in FIG. 4, the built-in antenna 200 may be formed at the top or bottom of the mobile communication terminal 10. In an embodiment of the present invention, the built-in antenna may be connected to the mobile communication terminal 10. Formed on top of the).

Here, in the current distribution diagram illustrated in FIG. 4, the amount of current flowing through the built-in antenna 200 means that the current flowing in the red region is greater than the yellow colored region.

As shown, it can be seen that most of the current in the built-in antenna 200 flows along the feed line 220 and the first short circuit line (240). This is because a coupling is generated between the feed line 220 and the first short circuit 240 to increase the current flowing through the feed line 220 and the first short circuit 240. Through this, by reducing the electrical interference between the antenna and the outer case formed of a metal material, it is possible to form an antenna that can be adapted in a metal environment.

5 is a graph showing a voltage standing wave ratio (VSWR) of the built-in antenna 200 according to an exemplary embodiment of the present invention. Here, the standing wave ratio represents the ratio of the magnitude of the forward frequency signal exiting from the built-in antenna 200 and the magnitude of the reverse frequency signal reflected back to the embedded antenna 200.

In general, the standing wave ratio indicates an optimal condition, which means when there is no reverse frequency signal coming into the antenna, and in general, when the standing wave ratio does not exceed 2 and is about 1.5, the state of the antenna is good. have.

Referring to the standing wave ratio graph of the built-in antenna shown in FIG. 5, the X-axis (horizontal axis) represents a frequency band (about 2 GHz to 3 GHz) and the Y-axis (vertical axis) represents the reflectance value of the built-in antenna. will be. Here, IFBW (Intermediate Frequency Band Width) was 70 KHz.

In addition, according to an embodiment of the present invention, the built-in antenna may be configured according to the length of the feed line 220 constituting the built-in antenna 200 and the length of the first, second, and third short circuit lines 240, 250, and 260. The frequency band at which 200 operates may vary, where the built-in antenna 200 is configured to operate in a WiFi band of about 2.4 GHz frequency band.

For example, the length A of the feed line 220 formed on one surface of the substrate 210 is about 23.5 mm, the length of the ground portion 230 is about 2 mm, the feed line 220, The separation distance between the feed line 220 and the first short circuit line 240 and the length including the first short circuit line 240 were formed to be about 4 mm.

In addition, the length B of the third short line 260 formed on the other surface of the substrate 210 is about 15.6 mm, and the length of the first line 251 constituting the second short line 250. Is about 2 mm, the length of the second short circuit 250, the third short circuit 260 and the tuning stub 270 is formed to about 4 mm.

As shown in FIG. 5, the reflectance of the band of about 2.4 to 2.483 GHz, which is a frequency band of the built-in antenna 200, has a reflectivity of 1.38 at about 2.4 GHz, 1.27 at about 2.45 GHz, and about 2.48 GHz. It can be seen that a reflectance of 1.35 is shown. In other words, the standing wave ratio of the built-in antenna 200 satisfies all of the range of about 1.5: 1 in the 2.4 to 2.48 GHz WiFi band, the state of the built-in antenna 200 formed according to an embodiment of the present invention It can be seen that it is good.

6 to 9 are graphs showing the radiation pattern of the antenna radiator according to the embodiment of the present invention.

First, FIGS. 6 to 8 are graphs of radiation patterns emitted from the internal antennas measured on the X-Y-axis, the Y-Z-axis, and the X-Z-axis, respectively.

Here, 0 ° to 360 ° illustrated in FIGS. 6 to 8 are angles at which the built-in antenna is rotated, and a numerical value described therein in a circle representing 0 ° to 360 ° indicates a value representing the gain of the built-in antenna 200. to be.

At this time, since the antenna to be measured to measure the radiation pattern can be formed in the same antenna configuration as the configuration of the antenna formed to measure the standing wave ratio shown in FIG. 5, description of the antenna configuration will be omitted. do.

As shown in FIG. 6 to FIG. 8, it can be seen that the maximum gain of the built-in antenna measured in the X-Y, Y-Z and X-Z axes is represented by -1.21 dB to -1.36 dB. have.

Next, referring to FIG. 9, a radiation distribution diagram illustrating a radiation pattern emitted by the embedded antenna in 3D is illustrated. As shown in FIG. 9, it can be seen that the radiation pattern of the built-in antenna is radiated in all directions in the X, Y, and Z axes.

Accordingly, the maximum gain of the built-in antenna formed according to an embodiment of the present invention is measured as -1.21 dB to -1.36 dB, and the radiation beam emitted from the built-in antenna 200 is radiated in all directions without distortion. It can be seen that it can be used as a WiFi antenna.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. I will understand.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

1 is a perspective view showing a general mobile communication terminal having a built-in antenna.

Figure 2 is a plan view showing one side of the built-in antenna according to an embodiment of the present invention.

Figure 3 is a plan view showing the other side of the built-in antenna according to an embodiment of the present invention.

4 is a current distribution diagram of a built-in antenna according to an embodiment of the present invention.

5 is a standing wave ratio graph of a built-in antenna according to an embodiment of the present invention.

6 to 9 is a radiation pattern graph of the built-in antenna according to an embodiment of the present invention.

Claims (6)

Board; A feed line formed along one side edge of one surface of the substrate; A ground part formed on one surface of the substrate and spaced apart from an end of the feed line, and having a first via hole formed therein; A first short circuit line spaced apart from the feed line along the other edge on the substrate opposite to one side on one surface of the substrate, and having a second via hole formed at one end thereof; And A second short circuit line formed along an edge on the other surface of the substrate, one end of which is electrically connected to the ground portion through the first via hole, and the other end of which is electrically connected to the first short circuit line through the second via hole; Including, a built-in antenna. The method of claim 1, The second short circuit line, A first line having one end connected to the second via hole and formed along an edge of the substrate; And A second line extending perpendicular to the first line at the other end of the first line, An end of the second line is connected to the first via hole, the built-in antenna. The method of claim 1, The built-in antenna, And a third short circuit line formed on the other surface of the substrate to be spaced apart from the second short circuit line. The method of claim 3, The built-in antenna, And a tuning stub formed to connect the second short circuit and the third short circuit. The method of claim 3, The built-in antenna, And at least one fine via hole formed through the substrate in the first and third short lines. The mobile communication terminal provided with the built-in antenna of any one of Claims 1-5.

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