KR101303153B1 - Antenna apparatus and wireless communicaiton terminal having the same - Google Patents

Abstract

The present invention relates to an antenna device and a mobile communication terminal having the same, comprising: a conductive antenna pattern portion having a plurality of sections bent and extended to have a length corresponding to a radio frequency to transmit and receive; It is electrically connected to the sections, and configured to include a resistance reducing portion for reducing the radiation resistance of the antenna pattern portion, it is possible to obtain a radiation efficiency of the expected level while minimizing the size.

Description

ANTENNA APPARATUS AND WIRELESS COMMUNICAITON TERMINAL HAVING THE SAME}

1 is a perspective view for explaining an example of a general mobile communication terminal,

2A is a perspective view of a mobile communication terminal having a built-in antenna device,

FIG. 2B is an enlarged perspective view of main parts for explaining the built-in antenna device of FIG. 2A;

3 is a perspective view showing an antenna device according to an embodiment of the present invention of FIG.

4 is a perspective view for explaining an antenna device according to another embodiment of the present invention;

5 is a perspective view for explaining an antenna device according to another embodiment of the present invention;

6 is an experimental graph of return loss of the antenna device according to another embodiment of the present invention illustrated in FIG.

7 is an experimental graph of a radiation pattern of an antenna device according to another embodiment of the present invention illustrated in FIG.

8 is an exploded perspective view of a mobile communication terminal according to another aspect of the present invention.

<Description of the symbols for the main parts of the drawings>

100, 200, 300: antenna device 110, 210, 310: antenna pattern portion

113 ', 213, 313, and 313': resistance reduction part 400: main body part

500: folder portion

The present invention relates to a mobile communication terminal having an antenna device, and more particularly, to an antenna device for transmitting and receiving radio frequency and a mobile communication terminal having such an antenna device to enable wireless communication.

 In general, an antenna device is a conducting wire placed in the air to efficiently radiate radio waves into a space in order to achieve the purpose of communication in wireless communication, or to efficiently radiate electromotive force by radio waves. The antenna device converts an electrical signal represented by voltage / current and electromagnetic waves represented by an electric field / magnetic field. Accordingly, the change of the electromagnetic field outside the antenna and the electrical signal on the antenna lead interoperate with each other, whereby an electronic device electrically connected to the antenna device detects an electromagnetic wave signal floating in the air and performs communication. The reverse is also possible.

1 illustrates a bar terminal in which a main body 10 is formed of one body as an example of a general mobile communication terminal. The upper part of the main body 10 is provided with a window 11 for viewing the display module (not shown) for outputting visual information from the outside. In addition, auditory information by a speaker module (not shown) is output through the speaker hole 12.

Below the main body 10, a keypad 13 for inputting letters, numbers, and the like, and a microphone hole 14 communicating with a microphone (not shown) for inputting sound are arranged. In addition, the battery 15 is detachably coupled to the other surface of the main body 10 (opposite side of the surface on which the keypad 13 and the like are arranged), and supplies power to the display module and the like.

In order to achieve a wireless communication function which is a basic function of the terminal, the antenna device 16 is mounted in a form protruding from one side of the main body 10. The antenna device 16 is electrically connected to a control circuit inside the main body 10 to transmit and receive radio waves to achieve a wireless communication function.

However, the antenna device 16 protruding to the outside of the main body 10 as described above causes mechanical interference with the surrounding environment in the case of carrying or storing the terminal. Accordingly, an attempt has been made to embed the antenna device inside the main body 10.

2A is a perspective view of a mobile communication terminal having a built-in antenna device, and FIG. 2B is an enlarged perspective view of main parts for explaining the built-in antenna device of FIG. 2A.

Referring to FIG. 2A, there is disclosed a folder type mobile communication terminal in which a main body portion 20 and a folder portion 30 are rotatably coupled. Here, descriptions of the keypad 21, the microphone hole 23, the battery 25, the window 31, and the speaker hole 33 will be described with reference to the keypad 13, the microphone hole 14, the battery 15, and the window. (11) and speaker hole 12 will be replaced by the description.

The built-in antenna device 27 has a form embedded in one side of the main body 20. Therefore, unlike the external antenna device 16 (FIG. 1), it is not exposed to the outside. The specific form of the built-in antenna device 27 will be described with reference to FIG. 2B.

Referring to FIG. 2B, the built-in antenna device 27 has a form in which a conductive antenna pattern 27-2 is formed on a carrier 27-1, which is a dielectric. The length of the antenna pattern 27-2 is determined according to the length of the wavelength of the frequency band to be transmitted and received. Furthermore, in order to minimize the overall size of the built-in antenna device 27 while securing the length as described above, the antenna pattern 27-2 is bent and extended at least once.

Therefore, in this figure, the antenna pattern 27-2 is divided into four sections (parts through which currents indicated by I1 to I4 respectively) are divided by bent portions. At this time, the currents flowing in the opposite directions to the adjacent sections with each other, in particular the currents I2 and I4, are canceled by a coupling phenomenon. This consequently increases the radiation resistance of the built-in antenna device 27, causing a problem of lowering the radiation efficiency.

To compensate for this degradation, that is, the size of the built-in antenna device 27 itself must be increased in order to secure the interference avoidance gap between adjacent sections. Furthermore, the antenna pattern 27-2 should be kept at a predetermined distance from the ground portion (not shown) to which the antenna pattern 27-2 is electrically connected to prevent the radiation efficiency from decreasing.

Accordingly, a conventional antenna device such as the antenna device 27 (FIG. 2B) required an installation volume of 2.5 cc (cm 3) to ensure a certain level of operation in the Digital Core Networks (DCN) frequency band. In addition, the antenna device had to stand at least 7 mm high from the ground grounded. As a result, the minimum radiation efficiency of the antenna device was only 30%.

As a result, in order to reduce the size of the built-in antenna device 27 and to realize overall slimming of the terminal, there is a problem in that the wireless communication performance must be reduced.

In order to solve the above problems, an object of the present invention is to be able to improve the desired communication performance while reducing the size of the antenna device.

In addition, an object of the present invention is to improve the slimming and wireless communication performance of a mobile communication terminal having an antenna device.

In order to achieve the above object, the antenna device according to an aspect of the present invention comprises a conductive antenna pattern portion having a plurality of sections that are bent and extended to have a length corresponding to the radio frequency to transmit and receive; And a resistance reduction part electrically connected to the sections to reduce radiation resistance of the antenna pattern part.

According to another aspect of the present invention, a mobile communication terminal includes: a main body on which at least one electronic component is mounted; A printed circuit board mounted to the main body to electrically control the electronic component; A conductive antenna pattern portion electrically connected to the printed circuit board and having a plurality of sections extending and bent to have a length corresponding to a radio frequency to transmit and receive; And a resistance reduction part electrically connected to the sections to reduce radiation resistance of the antenna pattern part.

In addition, in the present specification, not only a terminal manufactured based on a wireless communication function, but also a PDA (Personal Digital Assistants) in which a wireless communication function is added to a basic function (a function not directly related to wireless communication) by a separate antenna device and a communication module. ) Is also included in the mobile communication terminal.

Hereinafter, an antenna device and a mobile communication terminal having the same according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a perspective view illustrating an antenna device 100 according to an embodiment of the present invention.

Referring to FIG. 3, the antenna device 100 includes a conductive antenna pattern unit 110 having a length determined according to a radio frequency to transmit and receive. The length of the antenna pattern unit 110 depends on the structure of the antenna device, but typically has a length of about 1/2 or 1/4 of the wavelength of the radio frequency to be transmitted and received. In addition, the power feeding part 120 and the ground part 130 may be formed separately in the antenna pattern part 110. They supply current to the antenna pattern portion 110 or ground the antenna pattern portion 110.

The antenna pattern part 110 may be bent and extended without extending in one straight line. This is to minimize the area occupied by the antenna pattern unit 110. In addition, the antenna pattern unit 110 may be divided into a plurality of sections 111 to 115 by bending as described above. The antenna pattern unit 110 is an open-loop method, and the first section 111 and the fifth section 115 are not connected to each other.

A current supplied through the power supply unit 120 flows in each of the plurality of sections 111 through 115, and a flow direction of the current may be indicated by arrows I1 through I5, respectively. In addition, the resonance length is a length obtained by adding the entire lengths of the plurality of sections 111 to 115.

The antenna pattern portion 110 is formed with a resistance reducing portion 113 ′ for reducing radiation resistance. Specifically, the resistance reducing unit 113 ′ is a connecting section connecting the sections 112 and 114 adjacent to the third section 113, which is one of the plurality of sections 111 to 115.

The connecting section 113 ′ above is arranged parallel to and spaced apart from the third section 113. Accordingly, the current I3 ′ flowing along the connection section 113 ′ flows in parallel with the current I 3 flowing along the third section 113.

As such, as the connection section 113 ′ is formed as the resistance reduction portion, current passing through the second section 112 can flow through two paths by the third section 113 or the connection section 113 ′. Will be. Therefore, in the portion where the third section 113 and the connecting section 113 'parallel to it are formed, the electric current can emit electromagnetic waves while the resistance flows in a smaller state. As a result, the radiation efficiency of the antenna pattern portion 110 is improved.

In other words, the current I3 flowing in the third section 113 and the current I5 flowing in the fifth section 115 flow in opposite directions, so that even if the overall electric field strength is canceled by the coupling, the current ( The current I3 'by the current I3' of the connection section 113 'flowing in the same direction as the direction I3) has a polarization characteristic of the current in that direction as a whole. Thus, effective radiation of electromagnetic waves in the connecting section 113 ′ or in the third section 113 is possible.

Furthermore, as the section in which the connection section 113 'is formed in the vicinity, the third section 113 is connected to the ground portion 130 and radiates as far as the section farthest from the ground (not shown) formed on a circuit board (not shown). The efficiency is effectively selected.

4 is a perspective view illustrating an antenna device 200 according to another embodiment of the present invention.

Referring to FIG. 4, the antenna device 200 also has an antenna pattern part 210, a power feeding part 220, and a ground part 230, like the antenna device 100 described above. In addition, the antenna pattern part 210 has first to fifth sections 211 to 215, and the currents I1 ′ to I5 ′ flowing through the sections 211 to 215 are indicated by arrows indicating the flow direction thereof. do.

However, in the antenna pattern part 210, the third section 113 has a wider width than the other sections 111, 112, 114, and 115 in order to function as a resistance reducing part. The current I3 flowing through the resistance reducing unit or the third section 113 is subjected to a smaller resistance than the currents I1, I2, I4 and I5 flowing through the other sections 111, 112, 114 and 115. Accordingly, as the flow of current is improved to have a stronger polarization characteristic, the radiation efficiency of the antenna pattern portion 210 is improved.

Further, the selection of the third section as the extension section 213 is made for the same reason as the connection section 113 ′ is formed in the vicinity of the third section 113 in the above description with reference to FIG. 3.

5 is a perspective view for explaining the antenna device 300 according to another embodiment of the present invention.

Referring to FIG. 5, the antenna device 300 includes an antenna pattern part 310, a power feeding part 320, a grounding part 330, and a carrier 340.

The antenna pattern portion 310 in this embodiment has a form in which the antenna pattern portions 110 and 210 in the above two embodiments are combined. In other words, in addition to the plurality of sections 311 to 315 constituting the antenna pattern portion 310, the connecting section 313 ′ is further disposed to connect the sections 312 and 314. Further, the third section 313 is formed of an expanded section having an expanded width compared to the other sections 311 and the like.

According to this configuration, the current I3 flowing through the third section 313, which is the extended section, and the current I3 'flowing through the connecting section 313' are subjected to less resistance, and thus have a strong polarization characteristic. The radiation efficiency of the antenna pattern portion 310 is increased.

Further, a bending line 313-1 is formed in the expansion section 313. The bending line 313-1 is a portion indicated such that the expanded section 313 is bent based on the press working or the like. As the bending line 313-1 is thus formed, when the antenna pattern portion 310 is mounted to the carrier 340, the extension section 313 is mounted over two adjacent surfaces of the carrier 340. can do. In other words, the bending line 313-1 serves as a reference for bending the expansion section 313. As such, since the expansion section 313 is easily bent and adhered to the adjacent face of the carrier 340, the wide width of the expansion section 313 has the advantage that no additional placement space is required.

For the antenna device 300, the results of experiments to confirm the improvement of the frequency transmission and reception characteristics of the digital core network (DCN) band (frequency band: 824 ~ 894 MHz, bandwidth: 70 MHz) is shown in Figs. When introduced with reference to:

First, the length of the third section 313 is set to 41 mm, the length of the second section 312 is set to 7 mm, and the distance between the antenna pattern portion 310 and the ground is set to 5 mm. The volume occupied by the antenna pattern part 310 is 1.5 cc. Furthermore, the distance between the expansion section third section 313 and the connection section 313 'is about 1 mm.

FIG. 6 is a graph illustrating results of experiments on return loss of the antenna device 300.

Referring to FIG. 6, the S-parameter or return loss graph S1 of the antenna device 300 has a minimum value at about 0.97 GHz. Furthermore, the bandwidth is 71 MHz at VSWR (Voltage Standing Wave Ratio) 2.5, that is, at a return loss of about -7 dB. This bandwidth (71 MHz) satisfies the bandwidth of the DCN band (70 MHz).

In the DCN band, however, the frequency band is 824 to 894 MHz, but the resonance frequency range of the reflection loss graph S1 is not in the range. This is in consideration of the influence of the dielectric constant of the case or carrier of the terminal when the antenna device 300 is employed in the terminal.

Therefore, when the antenna device 300 is employed in the actual terminal, a new reflection loss graph S2 obtained by shifting the reflection loss graph S1 to the left (achieved by the tuning process) according to the shift of the resonance frequency is obtained. See also.

According to the new return loss graph (S2), the antenna device 300 mounted on the terminal has a bandwidth of 71 MHz based on VSWR 2.5 and can also transmit and receive frequencies in the 824 to 894 MHz band. In other words, it is possible to transmit and receive the frequency of the DCN band. Still, when the conventional antenna device 27 (FIG. 2B) has a volume of 2.5 cc, it only has a volume of 1.5 cc.

The following table shows the gain and emission efficiency in the above DCN band.

Frequency (MHz) 824 849 869 894 Gain average (dB) -2.13 -0.95 -2.08 -3.44 Emission Efficiency (%) 61.20 80.44 61.96 45.27

Here, the gain is expressed as a gain average value which is an average for each emission angle. In addition, as the antenna device 300 is employed in the terminal, the radiation efficiency in the DCN band is at least 45% (when the frequency is about 894 MHz). Considering that the minimum value of the radiation efficiency of the conventional antenna device 27 is 30%, it can be seen that the antenna device 300 according to the embodiment of the present invention improves the radiation efficiency by 50% or more.

Furthermore, referring to FIG. 7, which is an experimental result graph illustrating a radiation pattern of the antenna device 300, it can be seen that the antenna device 300 has radiation characteristics in all directions. Therefore, it can be said that the antenna device 300 has no directivity. In addition, the maximum value of gain is about 1.3 dB.

Next, a mobile communication terminal according to an embodiment of the present invention will be described with reference to FIG.

8 is an exploded perspective view of a mobile communication terminal according to another aspect of the present invention.

Referring to FIG. 8, there is illustrated a foldable terminal in which a main body is rotatably coupled to a main body 400 and a folder 500 by a hinge 450. The folder unit 500 includes electronic components such as a display module (not shown) for outputting visual information and a speaker module (not shown) for outputting auditory information.

The main body 400 has a form in which the upper cover 410 and the lower cover 420 are coupled to each other, and a user's push on the surface side of the upper cover 410 facing the folder part 500 such as a keypad (not shown). An input unit for inputting numbers, characters, and the like by an operation is provided.

Further, various components for electrically controlling electronic components such as a display module are mounted on the printed circuit board 430 embedded in the main body 400.

In addition, the embedded antenna device 300 is coupled to one side of the printed circuit board. In this case, the power supply unit 320 is connected to a power supply unit 431 electrically connected to a communication module (not shown) mounted on the printed circuit board 430, and the ground unit 330 is connected to the printed circuit board 430. It is connected to the ground 433 formed. Accordingly, the third or extended section 313 and the connecting section 313 ′ are disposed at the furthest position from the ground 433.

The mobile communication terminal configured as described above transmits and receives a radio frequency through the built-in antenna device 300 during wireless communication. In this case, as the resistance reduction parts 313 and 313 ′ are formed in the antenna pattern part 310 of the embedded antenna device 300, the radiation efficiency of the antenna device 300 is improved.

In spite of such an improvement in efficiency, the overall size of the built-in antenna device 300 is reduced compared to the prior art, thereby making it possible to slim the terminal.

In other words, the wireless communication performance may be degraded according to the miniaturization of the antenna device for the slimming of the terminal, but the resistance reduction parts 313 and 313 'may not only cause such a problem but also may improve the communication performance. .

 In the above description, the antenna device according to the present invention and a mobile communication terminal having the same have been described with reference to the accompanying drawings, but the present invention is not limited to the embodiments and drawings disclosed herein, Various modifications can be made by those skilled in the art within the scope.

For example, in the description with reference to FIG. 8, the antenna device 300 is taken as an example, but other antenna devices 100 and 200 may be mounted on the printed circuit board 430. In this case, a carrier (not shown) may be separately provided to support the antenna devices 100 and 200 with respect to the printed circuit board 430.

In addition, in the present specification, the mobile communication terminal has been described as an example of a mobile communication terminal as an example. However, the present invention provides a flip type, a slide type, a swing type, etc. Applicability to any form will be understood by those skilled in the art.

In addition, although the experimental result in the DCN band has been described as an example, it will be apparent to those skilled in the art that the antenna device according to the present invention may be used for other frequency bands (PCS band, etc.).

As described above, the antenna device according to the present invention has a resistance reduction portion in the antenna pattern portion, thereby densely arranging sections of the antenna pattern portion, thereby enabling radiation efficiency to be higher than before.

In addition, as the mobile communication terminal according to the present invention includes the antenna device as described above, the wireless communication performance is improved while reducing the overall size of the terminal.

Claims (16)

A conductive antenna pattern portion having a plurality of sections bent and extended to have a length corresponding to a radio frequency to transmit and receive; And A resistance reduction part electrically connected to the sections to reduce radiation resistance of the antenna pattern part; The resistance reduction unit, Any one of said sections, an extension section disposed at a position farthest from said ground to have a polarization characteristic at a position farthest from a ground for discharging current of said antenna pattern portion, said extension section having an expanded width relative to other sections; And And a connection section arranged in parallel with said extension section and connecting adjacent sections with said extension section to form a current in the same direction as said extension section to limit field strength cancellation by coupling. delete delete The method of claim 1, And said connecting section is arranged spaced apart from said one section. delete The method of claim 1, And a bending line formed along a length direction of the extension section and serving as a reference line for bending the extension section. The method of claim 1, A feeding part electrically connected to the antenna pattern part to supply a current to the antenna pattern part; And a ground part electrically connected to the antenna pattern part to discharge the current to the ground. The method of claim 1, The antenna device is formed of a dielectric, characterized in that further comprising a carrier on which the antenna pattern portion is mounted. A body on which at least one electronic component is mounted; A printed circuit board mounted to the main body to electrically control the electronic component; A conductive antenna pattern portion electrically connected to the printed circuit board and having a plurality of sections extending and bent to have a length corresponding to a radio frequency to transmit and receive; And A resistance reduction part electrically connected to the sections to reduce radiation resistance of the antenna pattern part; The resistance reduction unit, Any one of said sections, an extension section disposed at a position farthest from said ground to have a polarization characteristic at a position farthest from a ground for discharging current of said antenna pattern portion, said extension section having an expanded width relative to other sections; And And a connection section arranged in parallel with said expansion section and connecting adjacent sections with said expansion section to form a current in the same direction as said expansion section to limit field strength cancellation by coupling. delete delete 10. The method of claim 9, And the connection section is arranged spaced apart from any one of the sections. delete 10. The method of claim 9, And a bending line formed along a length direction of the extension section and serving as a reference line for bending the extension section. 10. The method of claim 9, And a ground electrically connected to the antenna pattern part in the printed circuit board. 10. The method of claim 9, And a carrier disposed between the antenna pattern part and the printed circuit board, the carrier being a dielectric that couples the antenna pattern part to the printed circuit board.

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