KR101625678B1

KR101625678B1 - Apparatus for matching antenna impedance

Info

Publication number: KR101625678B1
Application number: KR1020090126160A
Authority: KR
Inventors: 장기철; 이상훈; 최재연; 김율오; 박주봉
Original assignee: 엘지이노텍 주식회사
Priority date: 2009-12-17
Filing date: 2009-12-17
Publication date: 2016-05-31
Also published as: KR20110069429A

Abstract

The present invention relates to an impedance matching device for an antenna, and is equipped with an impedance change value detector in a main body of a mobile communication terminal, detects an impedance change value when a user touches the mobile communication terminal by hand and responds to each impedance change value The impedance adjustment value for adjusting the impedance is stored in advance in the memory as a lookup table. The baseband unit reads the impedance adjustment value corresponding to the impedance change value detected by the impedance change value detection unit from the memory, and according to the read impedance adjustment value, The impedance of the regulating portion is adjusted to match the impedance between the antenna and the front end portion.

Impedance, Matching, Matching, Proximity Sensor, Body, Lookup Table, Impedance Value

Description

[0001] Apparatus for matching antenna impedance [0002]

The present invention relates to an impedance matching device for an antenna.

Generally, a mobile communication terminal has an antenna, and transmits and receives a signal of a predetermined frequency through the antenna.

In order for the antenna to have optimum transmission / reception radiation performance, the impedance must be accurately matched.

Therefore, the mobile communication terminal is provided with an antenna circuit for matching the impedance of the antenna with an optimum state by using a capacitor and an inductor. The impedance matching of the antenna is typically an impedance match in a free space.

On the other hand, the mobile communication terminal is used in a state in which the user holds the main body with his / her hand and puts it close to the ear, or puts it in a bag or bag, and uses earphones or the like.

As the user grips the main body of the mobile communication terminal by hand, puts it in close contact with the ear, puts it in a pocket, bag, or the like, the impedance matching condition of the antenna is varied, thereby deteriorating the transmitting and receiving radiation performance of the antenna.

Therefore, a mobile communication terminal typically adopts an adaptive tuning antenna circuit. The adaptive tuning antenna circuit automatically adjusts the impedance matching of the antenna according to the changed impedance matching condition when the impedance matching condition of the antenna is changed, so that the antenna has optimal transmission / reception radiation performance.

In order for the adaptive tuning antenna circuit to maintain the transmission / reception radiation performance of the antenna at an optimal state, a change state of the impedance matching condition of the antenna must be detected.

To this end, the adaptive tuning antenna circuit includes a power detector on a path where an RF signal is received, detects power and reflected power of an RF signal to be transmitted and outputted, and adjusts the impedance of the antenna according to the detected transmission power and reflected power. .

However, the above-described adaptive tuning antenna circuit has an additional insertion loss because a power detector for detecting the transmission power and the intensity of the reflected power is inserted in the path through which the RF signal is transmitted.

Also, since the transmission power and the reflected power are detected and the impedance is matched, accurate impedance matching is possible for the transmission signal, but the impedance can not be accurately matched to the reception signal.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method and apparatus for detecting a change in impedance caused by hand noise in order to use a mobile communication terminal by a user and detecting an impedance match of an antenna that accurately matches the impedance of the antenna according to a change value of the detected impedance Device.

The present invention has been made in view of the above problems, and it is an object of the present invention to at least partially solve the problems in the conventional arts. There will be.

According to the impedance matching device of the antenna of the present invention, the impedance adjustment value for adjusting the impedance with respect to each of the impedance change values generated by the hand operation of the main body of the mobile communication terminal is experimentally obtained in advance, and the obtained impedance adjustment values are stored in the lookup table In the memory.

When the user holds the main body of the mobile communication terminal by hand to use the mobile communication terminal, the impedance change value detecting unit detects the impedance change value, and according to the detected impedance change value, the base band unit stores the impedance change value in the lookup table Reads the corresponding impedance adjustment value, and matches the impedance of the antenna according to the read impedance adjustment value.

Therefore, the impedance matching device of the present invention comprises: an impedance change value detector for detecting an impedance change value of the main body of the mobile communication terminal; and an impedance change value detector for detecting an impedance change value for each of the impedance change values detected by the impedance change value detector, A memory for storing an impedance change value corresponding to an impedance change value detected by the impedance change value detecting unit and a memory for storing an impedance change value corresponding to the impedance change value detected by the impedance change value detecting unit; And an impedance adjusting unit for matching the impedance between the electrodes.

The impedance change value detection unit includes a sensor installed in the main body and detecting a change in impedance, and a determination unit determining an impedance change value based on an output signal of the sensor.

The sensor is a proximity sensor, and the determination unit determines an impedance change value from an output signal of the proximity sensor.

Further, the sensor is a proximity sensor array, and the determination unit determines a position where the user holds the main body of the mobile communication terminal with an output signal of the proximity sensor, and determines an impedance change value according to the determined position.

The front end module converts the RF signal received by the front end module into a baseband signal and outputs the baseband signal to the baseband unit, converts the baseband signal provided by the baseband unit into an RF signal, And a transmission / reception unit for outputting to the front end module.

The impedance adjusting unit includes a first variable capacitor and a first inductor connected in parallel between the antenna and the ground, a second variable capacitor and a second inductor connected in series between the antenna and a transmission / reception terminal of the front end module, And a third variable capacitor and a third inductor connected between the transmission / reception terminal of the front end module and the ground.

The first to third variable capacitors use a variable capacitance diode.

According to the impedance matching device of the antenna of the present invention, the impedance adjustment value according to the noise of the main body of the mobile communication terminal is pre-stored in the memory as a look-up table, without providing a separate power detection part in the path where the RF signal is transmitted and received Leave.

When the user holds the main body of the mobile communication terminal, the impedance change value detector detects the impedance change value of the main body of the mobile communication terminal, reads the impedance adjustment value corresponding to the detected impedance change value from the memory, .

Therefore, the insertion loss is not generated due to the power detection unit because no separate power detection unit is used, and the impedance of the antenna can be matched to the RF signal to be received, as well as the RF signal to be transmitted, in an optimal state.

The following detailed description is merely an example, and is merely an example of the present invention. Further, the principles and concepts of the present invention are provided for the purpose of being most useful and readily explaining.

Accordingly, it is not intended to provide a more detailed structure than is necessary for a basic understanding of the present invention, but it should be understood by those skilled in the art that various forms that can be practiced in the present invention are illustrated in the drawings.

1 is a view showing an example of a proximity sensor array installed in a mobile communication terminal according to an impedance matching device of the present invention. Here, reference numeral 100 denotes a main body of the mobile communication terminal. For example, the main body 100 is a main body of the folding mobile communication terminal.

A sensor 110 is provided on the back surface of the main body 100 to detect a change in impedance that is generated when a user touches the main body 100 by hand according to the impedance matching device of the present invention.

The sensor 110 may use, for example, a proximity sensor or a proximity sensor array.

2 is a block diagram showing the configuration of a preferred embodiment of the impedance matching device of the present invention. Here, reference numeral 200 denotes an impedance change value detecting portion. The impedance change value detector 200 includes the sensor 100 and a determination unit 202 for determining an impedance change value based on an output signal of the sensor 100.

Reference numeral 210 denotes an antenna, and reference numeral 220 denotes an impedance control unit. The impedance adjuster 220 varies the impedance according to the control signal.

Reference numeral 230 denotes a front end module. The front end module 230 processes signals transmitted and received through the impedance adjuster 220 and the antenna 210. [

Reference numeral 240 denotes a transmitting / receiving unit. The transceiver 240 converts a transmission signal into a radio frequency (RF) signal, outputs the signal to the front-end module 230, and converts the RF signal received by the front-end module 230 into a baseband signal.

Reference numeral 250 denotes a memory. The memory 250 stores an impedance adjustment value for adjusting the impedance of the impedance adjuster 220 for each of the impedance change values determined by the impedance change value detector 200 as a lookup table.

Reference numeral 260 denotes a baseband unit. The baseband unit 260 reads the impedance adjustment value corresponding to the impedance change value detected by the impedance change value detection unit 200 from the memory 250 and outputs the impedance adjustment value corresponding to the impedance change unit 220 And adjusts the impedance of the antenna 210 to match the impedance of the antenna 210. The baseband unit 260 processes the baseband signal converted by the transmission / reception unit 240 and outputs a baseband signal to be transmitted to the transmission / reception unit 240.

3 is a circuit diagram showing a configuration of a preferred embodiment of the impedance adjusting unit 220 in the impedance matching apparatus of the present invention. 3, a first variable capacitor VC1 and a first inductor L1 are connected in parallel between the antenna 210 and the ground, and the antenna 210, the first variable capacitor VC1, The connection point of the first inductor L1 is connected to the input / output terminal of the front end module 230 through the second variable capacitor VC2 and the second inductor L2, and the third variable The capacitor VC3 and the third inductor L3 are connected in parallel.

In the impedance matching device of the present invention configured as described above, when a user desires to make a telephone call using the mobile communication terminal, the user usually grasps the main body 100 by hand.

In the present invention, a sensor 110 is installed on the back surface of the main body 100. Therefore, the sensor 110 detects a change in the impedance that varies as the user hands the main body 100, and the determination unit 202 determines the impedance change value according to the output signal of the sensor 110.

For example, the sensor 110 detects whether or not the user holds the main body 100 by using the proximity sensor, and the determination unit 202 determines the impedance change value that varies according to the output signal of the proximity sensor .

Also, the sensor 110 detects the position where the user holds the main body 100 using the proximity sensor array, and the determination unit 202 determines that the user holds the main body 100 according to the output signal of the proximity sensor array. And determine an impedance change value according to the determined position.

The impedance change value determined by the determination unit 202 is output to the baseband unit 260.

The baseband unit 260 determines an impedance change value that varies according to the user's hand touch of the main body 100 with the output signal of the determination unit 202 and controls the impedance control unit 220 ) From the look-up table stored in the memory 250. The impedance adjustment value for adjusting the impedance of the antenna

When the impedance adjustment value is read, the baseband unit 260 adjusts the values of the plurality of variable capacitors VC1, VC2, and VC3 provided in the impedance controller 220 according to the read impedance value, Matching the impedance between the front end module 210 and the front end module 230.

For example, the first to third capacitors VC1, VC2, and VC3 use a variable capacitance diode. The base band unit 260 varies the impedance to the applied voltage of the variable capacitance diode, Can be matched.

The transceiver 240 converts the transmission signal output from the baseband unit 260 into an RF signal in the state where the impedances are matched and converts the RF signal to the front end module 230 and the impedance adjusting unit 220 To the antenna 210 and transmitted.

The RF signal received through the antenna 210 is input to and received by the front end module 230 through the impedance control unit 220. The RF signal received by the front end module 230 is transmitted to the transmission / Converted into a baseband signal, and then input to a baseband unit 260 (260).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, I will understand.

Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by equivalents to the appended claims, as well as the appended claims.

1 is a view illustrating an example of a proximity sensor array installed in a mobile communication terminal according to an impedance matching device of the present invention;

Fig. 2 is a block diagram showing a configuration of a preferred embodiment of the impedance matching device of the present invention, and Fig.

3 is a circuit diagram showing a configuration of an embodiment of the impedance adjusting unit in the impedance matching apparatus of the present invention.

Claims

A proximity sensor array installed on a back surface of the main body of the mobile communication terminal for detecting a position of a user;

A determination unit for determining an impedance change value with respect to a position to be picked up based on a detection value of the proximity sensor array;

A memory in which an impedance adjustment value for each of the impedance change values determined by the determination unit is stored in advance in a lookup table;

A base band unit for reading an impedance adjustment value corresponding to an impedance change value of the determination unit from the memory; And

And an impedance adjusting unit for matching an impedance between the antenna and the front end module according to an impedance adjustment value read from the memory,

Wherein the impedance adjuster comprises:

A first variable capacitor and a first inductor connected in parallel between the antenna and the ground; A second variable capacitor and a second inductor connected in series between the antenna and a transmission / reception terminal of the front end module; And a third variable capacitor and a third inductor connected between a transmission / reception terminal of the front end module and a ground.

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[2] The apparatus of claim 1, further comprising: a front end module;

And a transmitting and receiving unit for converting the RF signal received by the front end module into a baseband signal and outputting the baseband signal to the baseband unit and converting the baseband signal provided by the baseband unit into an RF signal and outputting the RF signal to the front end module An impedance matching device for an antenna.

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The plasma display apparatus of claim 5, wherein the first to third variable capacitors comprise:

An impedance matching device for an antenna that is a variable capacitance diode.