KR20070059780A - Mobile terminal and method for matching antenna impedance thereof - Google Patents

Abstract

A portable terminal and an antenna impedance matching method thereof are provided to match impedance between a wireless communication unit and an antenna by the first impedance matching circuit in standby state, and to match the impedance between the wireless communication unit and the antenna by converting into the second impedance matching circuit when a call is made, thereby maintaining optimum radio sensitivity. A wireless communication unit(11) processes a data signal and a voice signal for call reception and origination. An antenna matching circuit unit(12) selectively matches impedance between the wireless communication unit(11) and an antenna(ANT) through different impedance matching circuits(12a,12b), depending on whether a call is made. A sensor unit(13) senses whether a portable terminal is open or closed, and senses whether the call is made. A controller(14) checks whether the call is made through the sensor unit(13), and outputs a switch control signal to the antenna matching circuit unit(12).

Description

Portable terminal and its impedance matching method {MOBILE TERMINAL AND METHOD FOR MATCHING ANTENNA IMPEDANCE THEREOF}

1 is an exemplary view showing the configuration of a portable terminal according to an embodiment of the present invention.

2 is a flow chart showing an antenna impedance matching method of a portable terminal according to an embodiment of the present invention.

*** Explanation of symbols for main parts of drawing ***

11: wireless communication unit 12: antenna matching circuit unit

12a and 12b: first and second antenna matching circuits: sensor unit

13a: Folder open / close sensor 13b: Light sensor

14: control unit ANT: antenna

SW: switch

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable terminal, and more particularly, to a portable terminal and an antenna impedance matching method thereof capable of varying impedance matching of an antenna according to received field strength.

In general, a matching circuit is the smallest transmission of power loss by equalizing the impedance of the input side at the output of one circuit and the input impedance of the other circuit when the two circuits are electrically coupled. It is a circuit to insert.

The matching circuit is provided as an antenna matching circuit between an antenna for receiving a radio signal in a portable terminal and an RF unit for processing a radio signal received through the antenna.

In particular, the antenna of the portable terminal uses a variety of antenna technology to improve the sound quality transmitted and received. Monopoles, dipoles, helical, whip antennas, etc. are used as such antennas. In addition, the antenna is classified into a directional antenna and an omnidirectional antenna as a classification based on a radiation pattern. The omni-directional antenna radiates equal radio waves in all directions. Therefore, the omnidirectional antenna has a characteristic of low radiated propagation intensity. The directional antenna has a characteristic of emitting a radio wave only in a predetermined direction, and thus has a characteristic of emitting a strong electric wave.

In the conventional portable terminal, the impedance when the folder or slide is opened and the impedance when the folder or slide is closed are changed. In addition, the impedance is changed even when holding a specific part by hand for use of the portable terminal or when the terminal is in close contact with the ear for a call. As a result, the voltage standing wave ratio of the antenna matching circuit is remarkably changed, and thus, there is a problem in that call quality deterioration and call drop phenomenon occur in the weak field region.

Accordingly, an object of the present invention is to provide a portable terminal and an antenna impedance matching method thereof in which the impedance matching of the antenna can be varied according to the received electric field strength.

It is also an object of the present invention to provide a portable terminal and an antenna matching method for improving call quality by varying impedance matching of an antenna to received field strength to increase reception sensitivity.

The present invention for achieving the above object, and a wireless communication unit for processing a voice signal and a data signal for call origination;

An antenna matching circuit unit for matching an impedance between the antenna and the wireless communication unit through a different impedance matching circuit depending on whether a call is in progress;

A sensor unit for detecting whether the portable terminal is opened or closed and detecting whether the portable terminal is in a call;

It is characterized in that the control unit for outputting the switch control signal to the antenna matching circuit unit side by checking whether or not the call through the sensor unit.

In addition, the present invention provides a method of a portable terminal for matching the impedance between the antenna and the wireless communication unit for processing a high frequency signal to achieve the above object,

Matching an impedance of a terminal in a standby state through a first antenna matching circuit in a normal standby state and determining whether a call is in progress;

Maintaining the first antenna matching circuit if it is not in a call as a result of the determination;

If it is determined that the call is in progress, the first antenna matching circuit may switch to the second antenna matching circuit, and a process of matching different impedances between the antenna and the wireless communication unit may be performed.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

It should be noted that in the following description, only parts necessary for understanding the operation and operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

In the following description specific details of the portable terminal of the present invention and its antenna impedance matching method are presented to provide a more general understanding of the present invention. It will be apparent to one of ordinary skill in the art that the present invention may be readily practiced without these specific details and also by their modifications.

On the other hand, in the embodiment of the present invention to switch the antenna impedance according to the standby state and the call state in order to be able to vary the antenna impedance according to the call state and the standby state not talking through the portable terminal It is proposed to improve the reception sensitivity. In this case, a sensor is provided to detect whether the portable terminal is in a call state.

Accordingly, in the embodiment of the present invention, the folder opening / closing sensor and the light sensor are used to determine whether the user is in a call, and based on the determination result, the voltage standing wave ratio (VSWR) increased when the user is talking on the phone with his ear more than usual. Or SWR).

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a configuration of a portable terminal according to an embodiment of the present invention.

Referring to FIG. 1, the wireless communication unit 11 processes a voice signal and a data signal for an incoming / outgoing call. The wireless communication unit 11 includes an RF transmitter for upconverting and amplifying a frequency of a transmitted signal, an RF receiver for low noise amplifying and downconverting a received signal, and encoding and modulating the transmitted signal. And a codec for demodulating and decoding the signal. The codec includes a data codec for processing packet data and an audio codec for processing an audio signal such as voice.

The antenna matching circuit unit 12 matches impedance between the antenna ANT and the wireless communication unit 11 to reduce reflection due to the difference in impedance between two different connection terminals. Here, the antenna matching circuit unit 12 includes first and second antenna matching circuits 12a and 12b and a switch SW. The antenna matching circuit unit 12 switches to the first antenna matching circuit 12a in a standby state when not in a call. The impedance of the antenna ANT and the wireless communication unit 11 is matched through the first antenna matching circuit 12a. However, when in a call, the second antenna matching circuit 12b is switched to match the impedance of the antenna ANT and the wireless communication unit 11 through the second antenna matching circuit 12b.

The sensor unit 13 detects whether the portable terminal is opened or closed and detects whether a call is in progress. Here, the sensor unit 13 is provided with a folder opening and closing sensor (13a) and the light sensor (13b), it is possible to detect whether or not a call. In the present invention, the light sensor 13b is positioned (ear-piece part) at a part where the user must closely contact the ear of the human body so that the user can talk. At this time, the light is not detected by the light sensor 13b when the call is in progress, and the light is detected by the light sensor 13b when the call is not in use.

The controller 14 performs a function of controlling the overall operation of the portable terminal. In addition, the control unit 14 checks whether the call is in progress through the sensor unit 13 according to the embodiment of the present invention and outputs a switch control signal to the antenna matching circuit unit 12 side. Thus, the switch SW is switched to the first antenna matching circuit 12a or the second antenna matching circuit 12b to control the overall operation of improving the reception sensitivity.

Referring to FIG. 1, the operation of the portable terminal for matching the antenna impedance according to whether the user is busy or not, the controller 14 switches the switch SW when the result detected by the sensor unit 13 is in the standby state. The switch control signal is output to be switched to the first antenna matching circuit 12a. Then, the first antenna matching circuit 12a operates to match an impedance between the antenna ANT and the wireless communication unit 11. However, the controller 14 outputs a switch control signal to switch to the second antenna matching circuit 12b when the result detected by the sensor unit 13 is in a call.

Then, the impedance between the antenna ANT and the wireless communication unit 11 is matched by the first and second antenna matching circuits 12a and 12b to reduce reflection due to the difference in impedance between the antenna and the wireless communication unit. And can improve reception sensitivity

2 is a flowchart illustrating an antenna impedance matching method of a portable terminal according to an exemplary embodiment of the present invention. Herein, the portable terminal will be described as a folder type terminal as an example.

Referring to FIG. 2, in step 201, the controller 14 matches the impedance of the terminal in the standby state through the first antenna matching circuit 12a.

In step 203, the controller 14 detects whether a folder is opened. At this time, if the folder is not opened, the first antenna matching circuit 12a is maintained as it is.

However, if the folder is opened as a result of the detection, in step 205, the controller 14 detects whether a call is in progress.

In step 207, the controller 14 switches from the first antenna matching circuit 12a to the second antenna matching circuit 12b when the detection result is the call.

In operation 209, the controller 14 controls to match different impedances between the antenna ANT and the wireless communication unit 11 through the second antenna matching circuit 12b.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described in detail above, the present invention matches the impedance of the antenna and the wireless communication unit with the first impedance matching circuit in the normal standby state, and switches to the second impedance matching circuit when making a call in close contact with the earpiece of the terminal. By matching the impedance of the antenna and the wireless communication unit, it is possible to maintain the optimal wireless sensitivity, improve the call quality, and improve the call quality by overcoming the cold drop phenomenon in the weak field area.

Claims (8)

A wireless communication unit which processes a voice signal and a data signal for a call origination call; An antenna matching circuit unit for matching an impedance between the antenna and the wireless communication unit through a different impedance matching circuit depending on whether a call is in progress; A sensor unit for detecting whether the portable terminal is opened or closed and detecting whether the portable terminal is in a call; And a controller for checking whether the call is in progress through the sensor unit and outputting a switch control signal to the antenna matching circuit unit. According to claim 1, The antenna matching circuit part includes first and second antenna matching circuits and a switch. In the standby state not in a call, switching to the first antenna matching circuit matches the impedance of the antenna and the wireless communication unit through the first antenna matching circuit, and in the case of a call, switches to the second antenna matching circuit and the second antenna A portable terminal, characterized in that for matching the impedance of the antenna and the wireless communication unit through a matching circuit. According to claim 1, The sensor unit is provided with a folder opening and closing sensor and a light sensor, A portable terminal, characterized in that for detecting the opening and closing of the folder, it is possible to detect whether or not a call. The method of claim 3, wherein The light sensor is a portable terminal, characterized in that the user is located in the part of the human body to be in close contact with the terminal in order to detect whether the user is busy. The method of claim 3, wherein The light sensor is a portable terminal, characterized in that the light is not detected when the call is busy, the light is detected when the call is not busy. In the method of the portable terminal for matching the impedance between the antenna and the radio communication unit for processing a high frequency signal, Matching an impedance of a terminal in a standby state through a first antenna matching circuit in a normal standby state and determining whether a call is in progress; Maintaining the first antenna matching circuit if it is not in a call as a result of the determination; And if the call is busy, switching from the first antenna matching circuit to the second antenna matching circuit to match different impedances between the antenna and the wireless communication unit. The method of claim 6, wherein the determining of the call is in progress. And detecting whether a call is in progress by a light sensor located at an opening / closing sensor and an ear-piece portion of the terminal. The antenna impedance matching method of claim 7, wherein the light is not detected by the light sensor when the call is in progress, and the light is detected when the call is not in use.

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