KR101110568B1 - Mobile Communication Terminal - Google Patents

Abstract

The present invention relates to a mobile communication terminal for improving hearing aid compatibility (HAC) and electromagnetic wave absorption rate (SAR). To this end, the present invention is a mobile communication terminal with a built-in antenna for performing wireless communication in the first frequency band and the second frequency band lower than the first frequency band, is formed on the internal substrate of the mobile communication terminal, the ground terminal of the antenna It is formed to be spaced apart from the ground and connected to the ground and a predetermined distance, and is configured to include a stub coupled to the ground in the first frequency band. Therefore, the mobile communication terminal according to the present invention improves hearing aid compatibility (HAC) and electromagnetic wave absorption rate (SAR) by inducing only the peak of the antenna radiation beam to the lower end while maintaining the antenna radiation output power.

Electromagnetic Absorption Rate, Hearing Aid Compatibility, Couplings, Stubs

Description

Mobile communication terminal

One embodiment of the present invention relates to a mobile communication terminal for improving hearing aid compatibility (HAC) and electromagnetic wave absorption rate (SAR).

Antennas used in mobile communication services are the key components that determine the call quality by handling the beginning and the end of signal input and output.

Recently, the antenna is mounted at the lower end of the mobile communication terminal. In this case, surface current and electromagnetic waves generated from the antenna are concentrated toward the voice output unit of the upper end. Accordingly, when a hearing impaired person wearing a hearing aid makes a call using a mobile communication terminal, the hearing impaired person cannot properly hear the voice transmitted from the voice output part by the surface current and the electromagnetic waves concentrated toward the voice output part.

Accordingly, when the antenna is mounted at the bottom of the terminal as described above, a method for improving HAC Hearing Aids Compatibility (SAR) and Specific Absorption Rate (SAR) without degrading the performance of the terminal is needed. It became.

Embodiments of the present invention provide a way to improve the hearing aid compatibility (HAC Hearing Aids Compatibility) and Specific Absorption Rate (SAR) by adding a separate stub so as to be spaced apart from the antenna ground portion of the mobile communication terminal by a predetermined interval. To provide.

A mobile communication terminal according to an embodiment of the present invention is a mobile communication terminal having a built-in antenna for performing wireless communication in a first frequency band and a second frequency band lower than the first frequency band, the inside of the mobile communication terminal And a stub formed on a substrate, the ground part connected to the ground terminal of the antenna and spaced apart from the ground part by a predetermined distance, and coupled to the ground part in the first frequency band.

A mobile communication terminal according to another embodiment of the present invention is a mobile communication terminal having a built-in antenna for performing wireless communication in a first frequency band and a second frequency band lower than the first frequency band, the inside of the mobile communication terminal It is formed on the substrate, and includes a ground portion connected to the ground terminal of the antenna, an inductor connected to one end of the ground portion and a stub connected to the other end of the inductor.

Embodiments of the present invention by adding a separate stub so as to be spaced apart from the antenna ground portion of the mobile terminal by a predetermined interval, the change of the ground environment through the electromagnetic coupling (coupling inductive coupling) between the stub and the ground in a predetermined frequency band By inducing (ground expansion effect), it is possible to improve the hearing aid compatibility (HAC) and the electromagnetic absorption rate (SAR) by inducing only the peak of the antenna radiation beam to the bottom while maintaining the total radiated power (TRP).

In addition, by implementing such a stub, it is possible to easily implement a stub that had to be additionally implemented to improve the compatibility of hearing aids, it can also reduce the additional mold manufacturing cost.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. 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.

The technical spirit of the present invention is determined by the claims, and the following embodiments are merely means for efficiently explaining the technical spirit of the present invention to those skilled in the art.

1 is a view showing a schematic structure of a general mobile communication terminal prior to explaining the mobile communication terminal according to an embodiment of the present invention.

As shown, the mobile communication terminal 100 includes a substrate 102, a voice output unit 104 and an antenna unit 106.

The substrate 102 includes a circuit unit formed inside the mobile communication terminal 100 to control an operation of the mobile communication terminal 100, and the voice output unit 104 generally includes the mobile communication. It is formed on the upper end of the terminal 100, and outputs voice, sound, and the like.

In addition, the antenna unit 106 is generally formed at the lower end of the mobile communication terminal 100 to mediate signal input / output of a predetermined frequency band of the mobile communication terminal 100.

That is, through the antenna unit formed at the lower end of the mobile communication terminal, a multi-band, for example, a DCS (Digital Cellular System) of about 1.8 GHz, a Personal Communication System (PCS) of about 1.9 GHz, a WCDMA of about 2.1 GHz Such as the first frequency band of a high frequency band, terrestrial DMB of about 174 to 216 MHz, FM of about 80 to 110 MHz, AM of about 530 to 1610 KHz, and Group Special Mobile (GSM) of about 850 to 900 MHz. Wireless communication is performed in the second frequency band of the low frequency band.

As such, as the antenna unit is formed at the lower end to transmit and receive a multi-band signal, problems may arise that the surface current and the electromagnetic waves are concentrated toward the voice output unit described above in the background art. One embodiment of the following will be described in detail.

2 is a diagram illustrating a substrate 102 of a mobile communication terminal according to an embodiment of the present invention.

As shown, the substrate 102 includes a ground portion 202 and a stub 204. The substrate 102 may be, for example, a flat rectangular plate shape, but is not limited to the material, size, thickness and shape of the substrate 102 in the present invention, it is embedded in the mobile communication terminal 100 It may be variously changed according to the characteristics of the antenna and the environment of use.

The ground portion 202 may be formed on an upper surface or a lower surface of the substrate 102 and is connected to the ground terminal of the antenna.

The stub 204 is formed spaced apart from the ground portion 202 by a predetermined distance. That is, the stub 204 is configured to be spaced apart by a predetermined distance without being in direct contact with the ground portion 202. However, the stub 204 has an electromagnetic coupling (hereinafter, ““) at a specific frequency band. By changing the environment of the grounding portion 202 due to the grounding extension effect, thereby changing the pattern of the radiation beam emitted from the antenna portion 106.

A distance between the stub 204 and the ground part 202 is coupled to the ground part 202 in the first frequency band (ie, the high frequency band), and the second frequency band. (I.e., low frequency band) is set so as not to be coupled (i.e. open) with the ground portion 202. If the distance is too close, coupling may occur with the ground part 202 even in the second frequency band. If the distance is too long, the coupling with the ground part 202 may be lost in the first frequency band. Since it may not occur, the separation distance may be appropriately set in consideration of the first frequency, the band of the second frequency, the width or length of the stub 204, and the like.

Therefore, in one embodiment of the present invention, the distance between the stub 204 and the ground part 202 is not limited to a specific distance, and those skilled in the art can use the frequency or stub width used in the mobile communication terminal 100. It is obvious that various design changes can be made in consideration of the length and length.

Accordingly, the stub 204 is coupled to the ground portion 202 in the high frequency band of the mobile communication terminal 100 to change the environment of the ground portion 202 to move the peak of the antenna radiation beam. It can be guided to the lower end of the communication terminal 100. In addition, since the stub 204 is not coupled with the ground portion 202 in the low frequency band, the environment of the ground portion of the ground portion 202 does not change in the low frequency band.

Because, as the spacing between the ground and the stub at a predetermined interval, a substrate having a predetermined dielectric constant between the ground 202 and the stub 206 acts as a capacitor, the frequency band in the environment where the capacitor is formed The higher this value, the lower the impedance. Therefore, as the impedance decreases, coupling occurs between the ground portion 202 and the stub 206. That is, the coupling effect is generated in the high frequency band by forming the capacitor according to the separation distance. On the other hand, in the low frequency band, the impedance increases. Therefore, an open effect occurs in the low frequency band.

The length A of the stub 204 is preferably set to a length corresponding to 1/4 λ of the first frequency, but is not limited thereto, and may change an environment of a ground part, and may radiate an antenna radiation beam pattern. The length of the stub 204 can be freely adjusted to induce a change of. At this time, the reason that the length (A) of the stub 204 corresponds to the first frequency is because the stub 204 is coupled to the ground portion 202 in the first frequency band, the ground portion 202 Because it changes the environment.

In addition, the stub 204 may be formed along the lower surface 202b of the substrate 102 in the lower direction of the substrate 102. For example, the stub 204 is formed while the portion formed in the direction parallel to the side surface 202a of the substrate 102 and the portion formed in the direction parallel to the lower surface 202b of the substrate 102 are formed vertically. Can be. However, the shape of the stub 204 is not limited in the present invention, and any shape may be adopted as long as the shape of the ground 202 may be changed through the stub 204.

As such, according to the embodiment of the present invention, by forming a stub spaced a predetermined distance apart from the ground portion, a coupling is formed between the ground portion and the stub in the high frequency band of the mobile communication terminal 100, the radiation beam radiated from the antenna Useful for changing patterns.

On the other hand, to change the antenna radiation beam in the low frequency band will be described in the following embodiment.

3 is a diagram illustrating a mobile communication terminal according to another embodiment of the present invention.

The mobile communication terminal 300 performs a wireless communication in a first frequency band and a second frequency band lower than the first frequency band like the mobile communication terminal 100 shown in FIGS. 1 and 2. The ground part 302 formed inside the mobile communication terminal 300, the inductor 306 having one end connected to the ground part 302, and the stub 304 connected with the other end of the inductor 306. It includes.

Since the internal structure of the mobile communication terminal 300 is the same as that of the mobile communication terminal 100 described above with reference to FIGS. 1 and 2, the following description will focus on differences.

3, the ground portion 302 and the stub 304 are not spaced apart from each other, as in the embodiment of FIG. 2, but the ground portion 302 and the stub 304 are connected to the inductor. 306 is different from the embodiment shown in FIG. 2 in that it is electrically connected to each other.

That is, in the embodiment of FIG. 3, the stub 304 is coupled to the ground unit 302 in the low frequency band of the mobile communication terminal 300 so as to change the environment of the ground unit 302. Change the peak of an antenna (not shown) radiation beam of the mobile communication terminal 300 to the lower end of the mobile communication terminal 300, and is not coupled to the ground portion 302 in the high frequency band, so that the high frequency band In this case, the environment of the ground portion 302 is not changed.

In the embodiment of FIG. 2, the capacitor is formed according to the separation distance between the ground portion and the stub. However, in the embodiment of FIG. 3, the impedance is reduced in the low frequency band by the inductor 306, thereby coupling. This is because the effect occurs, and in the high frequency band, the open effect occurs due to the increase of the impedance.

The value of the inductor 306 is that the stub 304 is coupled with the ground portion 302 in the second frequency band (low frequency band), and in the first frequency band (high frequency band) the ground portion ( 302 may be set not to be coupled. Preferably, the value of the inductor 306 may be set in a range of about 30 nH (nano Henry). However, in another embodiment of the present invention is not limited to the value of the inductor 306, those skilled in the art can be changed in various designs in consideration of the frequency radiated from the mobile communication terminal 300 and the width or length of the stub, etc. Is obvious.

The length A of the stub 304 is preferably set to a length corresponding to 1/4 λ of the second frequency, but is not limited thereto, and may change an environment of a ground part, and an antenna radiation beam pattern The length of the stub 304 can be freely adjusted to induce a change of. In this case, the reason why the length A of the stub 304 corresponds to the second frequency is that the stub 304 is coupled to the ground portion 202 in the second frequency band to change the ground portion environment. Because.

Therefore, another embodiment of the present invention is useful when trying to change only the antenna radiation beam pattern in the low frequency band of the mobile communication terminal 300.

On the other hand, the value of the inductor 306 may be set such that the stub 304 is coupled with the ground portion 302 in both the first frequency band and the second frequency band. That is, if the value of the inductor 306 is appropriately changed in consideration of frequency, stub width, length, or the like, the stub 304 may be coupled with the ground unit 304 without opening in the first frequency band. have. Therefore, in this case, unlike the above two embodiments, since the environment of the grounding part occurs in both the first frequency band and the second frequency band, antenna patterns of all bands of the dual band mobile communication terminal can be changed. In this case, the value of the inductor 306 may be preferably set in the range of about 10 nH (nano Henry).

As described above, the antenna radiation beam pattern is changed according to the ground extension extension effect due to the coupling effect in the high frequency or low frequency band by forming the stub and the inductor. Shall be.

FIG. 4 is a distribution chart measuring electromagnetic waves emitted from a mobile communication terminal to which a HAC scan region is designated and an HAC scan region in order to measure an electromagnetic distribution of a general mobile communication terminal without a stub. 5 is a distribution chart of measuring electromagnetic waves radiated from a mobile communication terminal to which a HAC scan region is designated and an HAC scan region in order to measure an electromagnetic distribution of a mobile communication terminal having a stub according to an embodiment of the present invention.

First, as shown in (a) of FIG. 4, the voice output unit of the mobile communication terminal is scanned to measure the electromagnetic distribution of the mobile communication terminal. That is, as shown, a predetermined range within the voice output unit is designated as the HAC scan area, and the electromagnetic waves distributed in the HAC scan area were measured.

Then, as shown in (b) of Figure 4, it can be seen that the electromagnetic wave distribution in the HAC scan region is shown. Here, it means that more electromagnetic waves are emitted in the order of navy blue, purple, orange, and yellow. That is, it can be seen that the portion where the voice output unit is located in the HAC scan area is output in a bright color, and the most electromagnetic waves are emitted. It can be seen that the decrease.

As described above, the mobile communication terminal used generally concentrates when the hearing impaired person wearing a hearing aid makes a call using the mobile communication terminal as the surface current and the electromagnetic wave generated from the antenna are concentrated toward the voice output unit of the upper end. Due to the surface current and electromagnetic waves, a problem occurs that the hearing impaired person cannot properly hear the voice transmitted from the voice output unit. Therefore, when measuring the electromagnetic wave distribution of the mobile communication terminal according to an embodiment of the present invention to improve such a problem as follows.

As shown in (a) of FIG. 5, the voice output unit of the mobile communication terminal is scanned to measure the electromagnetic wave distribution of the mobile communication terminal according to the exemplary embodiment of the present invention. In this case, as shown in (a) of FIG. 4, a predetermined range within the voice output unit is designated as the HAC scan area, and electromagnetic waves distributed in the HAC scan area are measured.

Then, as shown in (b) of FIG. 5, as in FIG. 4 (b), the most electromagnetic waves are emitted in the portion where the voice output unit is located in the HAC scan area, and the farther away from the voice output unit It can be seen that the electromagnetic wave is reduced. However, unlike the electromagnetic emission diagram shown in (b) of FIG. 4, it can be seen that in the electromagnetic emission diagram shown in (b) of FIG. 5, the yellow region output near the voice output unit is significantly reduced.

This is because the stub is formed inside the mobile communication terminal, thereby changing the beam pattern emitted from the antenna. That is, in the general mobile communication terminal which does not form a stub, the electromagnetic wave is mainly concentrated in the voice output unit, which is the upper side of the terminal, but as in the embodiment of the present invention, the electromagnetic wave radiated from the upper and This is because it is dispersed and released downward.

To examine this in detail, as shown in Table 1, before and after forming the stub, the radiated output power (TRP; Total Radiated Power (TRP)) of the mobile communication terminal is as follows.

Referring to Table 1, the TRP measurement value is shown by rotating the mobile communication terminal from 0 ° to 180 ° based on the long side of the mobile communication terminal, where the TRP measurement unit is fixed. The TRP of the mobile communication terminal moving by angles is measured.

First, looking at the left side of Table 1, the numerical value of the TRP of a typical terminal is shown. In the left table of Table 1, TRP was 23.92, 26.26, and 27.05dB in the low temperature ranges of Theta 30 ° and Phi 30 ° to 90 °. The low altitude region is an area near the voice output unit of the mobile communication terminal. In addition, the maximum value of TRP was 32.63 dB in the Theta 150˚ altitude region. The altitude region is a lower region of the mobile communication terminal.

Next, looking at the right table of Table 1, the numerical value of the TRP of the mobile communication terminal with the stub is shown according to an embodiment of the present invention. In the right table of Table 1, TRP was 23.06, 25.15, and 25.91 dB in the low temperature ranges of Theta 30˚ and Phi 30˚ ~ 90˚. In addition, the maximum value of TRP was 33 dB in the Theta 150˚ altitude region.

That is, when comparing the left table and the right table of Table 1, it can be seen that in each of the low region, the TRP decreases by about 1 dB from about 26.26 dB to 25.15 dB, whereby the HAC value of the HAC scan region is about. From 37.4dBV / m to 36.7dBV / m, the HAC is improved by 0.7dBV / m. In addition, the maximum value of the TRP was changed from 32.63 dB to 33 dB in each of the altitude regions, which is about 0.37 dB, indicating that the value of the TRP is almost the same without significant change.

As such, by adding a separate stub to the mobile communication terminal according to an embodiment of the present invention, the electromagnetic waves emitted when using the mobile communication terminal are distributed to the upper and lower portions of the mobile communication terminal, not just the upper portion of the voice output unit. Can be. Accordingly, it is possible to improve HAC and SAR without changing the TRP of the mobile communication terminal.

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 determined by the scope of the appended claims, as well as the appended claims.

1 is a bottom view of a mobile terminal generally used.

2 is a bottom view illustrating a substrate of a mobile communication terminal according to an embodiment of the present invention.

3 is a bottom view illustrating a substrate of a mobile communication terminal according to another embodiment of the present invention.

4 is a HAC scan area and electromagnetic wave distribution diagram of a mobile communication terminal generally used.

5 is a HAC scan area and electromagnetic wave distribution diagram of a mobile communication terminal according to an embodiment of the present invention.

Claims (7)

A mobile communication terminal having an antenna for performing wireless communication in a first frequency band and a second frequency band lower than the first frequency band, A ground part formed on an internal substrate of the mobile communication terminal and connected to a ground terminal of the antenna; And A stub formed to be spaced apart from the ground part by a predetermined distance and coupled to the ground part in the first frequency band; Mobile communication terminal comprising a. The method of claim 1, The stub is spaced apart from the ground part by a predetermined distance so as not to be coupled with the ground part in the second frequency band. The method according to claim 1 or 2, The stub is formed with a length corresponding to 1/4 λ of the first frequency. A mobile communication terminal having an antenna for performing wireless communication in a first frequency band and a second frequency band lower than the first frequency band, A ground part formed on an internal substrate of the mobile communication terminal and connected to a ground terminal of the antenna; An inductor having one end connected to the ground portion; And A stub connected to the other end of the inductor; Mobile communication terminal comprising a. 5. The method of claim 4, The value of the inductor is set so that the stub is coupled with the ground portion in the second frequency band and not coupled with the ground portion in the first frequency band. 5. The method of claim 4, The value of the inductor is set so that the stub is coupled with the ground portion in the first frequency band and the second frequency band. The method according to any one of claims 4 to 6, The stub is formed with a length corresponding to 1/4 λ of the second frequency.

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