WO2012060665A2

WO2012060665A2 - Impedance matching device and system for optimizing matching of radio frequency in matching impedance of antenna

Info

Publication number: WO2012060665A2
Application number: PCT/KR2011/008389
Authority: WO
Inventors: Dong Chan Park
Original assignee: Lg Innotek Co., Ltd.
Priority date: 2010-11-04
Filing date: 2011-11-04
Publication date: 2012-05-10
Also published as: KR101683909B1; WO2012060665A3; KR20120047615A

Abstract

Disclosed is a system for optimizing matching of a radio frequency in matching impedance of an antenna. The system includes an antenna impedance matching circuit outputting mutual impedance values between antenna impedances, an antenna impedance adjusting part electrically connected to the antenna impedance matching circuit to detect mutual impedance values between antenna impedances from the antenna impedance matching circuit, thereby adjusting voltage applied to the antenna impedances using at least one variable capacitor provided in the antenna impedance matching circuit suitably for mutual impedance values between the antenna impedances to be compensated, so that the antenna impedance are matched with each other, a first radio frequency matching optimizing part for antenna impedance matching electrically connected to the antenna impedance matching circuit to set at least one of adjusted variable capacitor value, which are output from the antenna impedance matching circuit, as a coordinate on a coordinate plane formed based on at least one capacitor value by using a lookup table when present antenna impedances are matched with each other through the antenna impedance adjusting part, and to store a radio frequency band point in one region range of a reference variable capacitor while performing an optimization operation by matching at least one adjusted variable capacitor value with the radio frequency band point in one region range of the reference variable capacitor, when the at least one adjusted variable capacitor value is determined as being in the one region range of the reference variable capacitor based on the comparison with region ranges of the reference variable capacitor which are previously stored and defined on a coordinate plane, so that an optimization operation is performed and a second radio frequency matching optimizing part for antenna impedance matching electrically connected to the antenna impedance matching circuit to set at least one adjusted variable capacitor value, which is output from the antenna impedance matching circuit, as a coordinate through a prediction algorithm when next antenna impedances are matched with each other through the antenna impedance adjusting part, and to match the coordinate of the at least one adjusted variable capacitor value to a radio frequency band point existing in the another region range of the reference variable capacitor, after searching for the coordinate of the at least one adjusted variable capacitor value from the radio frequency band point, which exists in the one region range of a first reference capacitor and is stored by the first radio frequency matching optimizing part for antenna impedance matching, when the at least one adjusted variable capacitor value is in another region range of the reference variable capacitor, so that the optimization operation is performed.

Description

IMPEDANCE MATCHING DEVICE AND SYSTEM FOR OPTIMIZING MATCHING OF RADIO FREQUENCY IN MATCHING IMPEDANCE OF ANTENNA

The embodiment relates to an impedance matching device for an antenna and a system for optimizing the matching of radio frequency in matching the impedance of the antenna. In more particular, the embodiment relates to a system for optimizing the matching of the radio frequency in matching the impedance of an antenna, capable of reducing impedance matching time by using the optimal points, which are obtained through a prediction algorithm, as starting points of the impedance matching.

In general, an antenna impedance matching scheme is to match impedances to each other so that specific frequency energy can be effectively transceived between wireless communication devices.

Recently, researches and studies have been continuously performed with respect to an advanced antenna impedance matching system capable of matching antenna impedances with each other within a short time by providing transceiver signals having radio frequency bands representing superior efficiency while rapidly scanning adjusted variable capacitor values output from an antenna impedance matching circuit, and continuously maintaining signal sensitivity of transceive signals by continuously preventing the distortion of the transceive signals from being degraded.

A system for optimizing the matching of radio frequency in matching the impedance of an antenna according to the embodiment can continuously maintain signal sensitivity of transceive signals by continuously preventing the distortion of the transceive signals from being degraded while performing impedance matching of antennas within a short time.

According to the embodiment, there is provided an impedance matching device of an antenna, which includes an antenna impedance matching circuit outputting mutual impedance values between antenna impedances, an antenna impedance adjusting part detecting the mutual impedance values output from the antenna impedance matching circuit and performing a predetermined operation with respect to antenna impedance values to be compensated, thereby adjusting the antenna impedances of the antenna impedance matching circuit based on the antenna impedance values subject to the predetermined operation, a first radio frequency matching optimizing part for antenna impedance matching to perform an optimization operation by searching for a first coordinate of at least one variable capacitor value output from the impedance matching circuit, which has been adjusted, in region ranges of a reference variable capacitor and matching the first coordinate to a radio frequency band point in at least one region range of the reference variable capacitor, and a second radio frequency matching optimizing part for antenna impedance matching to perform an optimizing operation by searching for a second coordinate of the at least one variable capacitor value, which is output from the adjusted impedance matching circuit, in the region ranges of the reference variable capacitor and matching the second coordinate to a radio frequency band point in at least one region range of the reference variable capacitor through a prediction algorithm.

According to the embodiment, there is provided a system for optimizing matching of a radio frequency in matching impedance of an antenna, which includes an antenna impedance matching circuit outputting mutual impedance values between antenna impedances, an antenna impedance adjusting part detecting the mutual impedance values output from the antenna impedance matching circuit and performing a predetermined operation with respect to antenna impedance values to be compensated, thereby adjusting the antenna impedances of the antenna impedance matching circuit based on the antenna impedance values subject to the predetermined operation, a first radio frequency matching optimizing part for antenna impedance matching to perform an optimization operation by searching for a first coordinate of at least one variable capacitor value output from the impedance matching circuit, which has been adjusted, in region ranges of a reference variable capacitor and matching the first coordinate to a radio frequency band point in at least one region range of the reference variable capacitor, and a second radio frequency matching optimizing part for antenna impedance matching to perform an optimizing operation by searching for a second coordinate of the at least one variable capacitor value, which is output from the adjusted impedance matching circuit, in the region ranges of the reference variable capacitor and matching the second coordinate to a radio frequency band point in at least one region range of the reference variable capacitor through a prediction algorithm.

As described above, the system for optimizing the matching of radio frequency in matching the impedance of an antenna according to the embodiment can continuously maintain signal sensitivity of transceive signals by continuously preventing the distortion of the transceive signals from being degraded while performing impedance matching of antennas within a short time.

FIG. 1 is a block diagram showing a system for optimizing the matching of radio frequency in matching the impedance of the antenna based on a prediction algorithm according to one embodiment;

FIG. 2 shows a circuit diagram of an antenna impedance matching circuit of FIG. 1 and a detailed block diagram of an antenna impedance adjusting part;

FIG. 3A is a graph showing coordinates set using adjusted variable capacitor values when present antenna impedances are matched with each other through a lookup table of a first radio frequency matching optimizing part for antenna impedance matching shown in FIGS. 1 and 2;

FIG. 3B is a graph showing searched coordinates of adjusted variable capacitor values when present antenna impedances are matched with each other through a lookup table of a first radio frequency matching optimizing part for antenna impedance matching shown in FIGS. 1 and 2;

FIG. 4A is a graph showing a coordinate set for adjusted variable capacitor values when next antenna impedances are matched with each other through a prediction algorithm of a second radio frequency matching optimizing part for antenna impedance matching shown in FIGS. 1 and 2; and

FIG. 4B is a graph showing the searching state for the coordinate of the adjusted variable capacitor values when next antenna impedances are matched with each other through a prediction algorithm of a second radio frequency matching optimizing part for antenna impedance matching shown in FIGS. 1 and 2.

Hereinafter, exemplary embodiments will be described in detail with reference to accompanying drawings.

FIG. 1 is a block diagram showing a system for optimizing the matching of radio frequency in matching the impedance of the antenna based on a prediction algorithm according to one embodiment.

FIG. 2 shows a circuit diagram of an antenna impedance matching circuit of FIG. 1 and a detailed block diagram of an antenna impedance adjusting part.

FIG. 3A is a graph showing coordinates set using adjusted variable capacitor values when present antenna impedances are matched with each other through a lookup table of a first radio frequency matching optimizing part for antenna impedance matching shown in FIGS. 1 and 2.

FIG. 3B is a graph showing searched coordinates of adjusted variable capacitor values when present antenna impedances are matched with each other through a lookup table of a first radio frequency matching optimizing part for antenna impedance matching shown in FIGS. 1 and 2.

Referring to FIGS. 1 and 2, a system 100 for optimizing the matching of radio frequency through a greedy algorithm in matching the impedance of the antenna according to the embodiment includes an antenna impedance matching circuit 102, an antenna impedance adjusting part 104, a first radio frequency matching optimizing part 106 for antenna impedance matching, and a second radio frequency matching optimizing part 108 for antenna impedance matching.

The antenna impedance matching circuit 102 outputs mutual impedance values between present antenna impedances.

The antenna impedance adjusting part 104 is electrically connected to the antenna impedance matching circuit 102. The antenna impedance adjusting part 104 detects mutual impedance values between antenna impedances Z1 and ZANT from the antenna impedance matching circuit 102, thereby adjusting the voltages applied to the antenna impedances Z1 and ZANT through at least one of variable capacitors VC1 and VC2 provided in the antenna impedance matching circuit 102, suitably for mutual impedance values between the antenna impedances Z1 and ZANT to be compensated , so that the antenna impedances Z1 and ZANT are matched with each other.

In this case, antenna impedance adjusting part 104 may include an MCU (Micro Controller Unit).

In detail, the antenna impedance adjusting part 104 includes an antenna impedance detector 104a, an antenna impedance controller 104b, a digital-analogue converter 104c, and an antenna impedance adjusting unit 104d.

The antenna impedance detector 104a is electrically connected to the antenna impedance matching circuit 102 to detect the mutual impedance values between the antenna impedances Z1 and ZANT from the antenna impedance matching circuit 102.

The antenna impedance controller 104b is electrically connected to the antenna impedance detector 104a to compare present impedance values between the antenna impedances Z1 and ZANT with reference impedance values between the antenna impedances Z1 and ZANT, which are previously stored, and to perform a predetermined operation with respect to mutual impedance values between the antenna impedances Z1 and ZANT to be compensated.

The digital-analogue converter 104c is electrically connected to the antenna impedance controller 104b to convert digital signals, which correspond to the mutual impedance values between the antenna impedances Z1 and ZANT to be compensated, which are obtained from the antenna impedance controller 104b, into analogue signals.

The antenna impedance adjusting unit 104d is electrically connected to the digital-analogue converter 104c to receive the analog signals, which correspond to the mutual impedance values between the antenna impedances Z1 and ZANT to be compensated and are obtained through the D/A conversion of the digital-analogue converter 104c, thereby adjusting the voltages applied to the antenna impedances Z1 and ZANT by using at least one of the variable capacitors VC1 and VC2 provided in the antenna impedance matching circuit 102 suitably for the mutual impedance values between the antenna impedances Z1 and ZANT to be compensated , so that the antenna impedances Z1 and ZANT are matched with each other.

In this case, at least one of the variable capacitors VC1 and VC2 may include the first and second variable capacitors VC1 and VC2 electrically connected to each other in parallel between the antenna impedances Z1 and ZANT.

The first radio frequency matching optimizing part 106 for antenna impedance matching is electrically connected to the antenna impedance matching circuit 102 to set at least one of adjusted variable capacitor value VC1 and VC2, which are output from the antenna impedance matching circuit 102, as a coordinate P1 on a coordinate plane formed based on at least one capacitor value by using a lookup table shown in FIG. 3A when present antenna impedances are matched with each other through the antenna impedance adjusting part 104. Although impedance matching is performed on a 2-D plane formed based on two variable capacitor values according to the present disclosure, the embodiment is not limited thereto in the number of variable capacitors and the dimension of the coordinate plane.

Thereafter, as shown in FIG. 3B, when at least one of the adjusted variable capacitor values VC1 and VC2 is in a region range R3 of region ranges R1, R2, and R3 of a reference variable capacitor based on the comparison with the region ranges R1, R2, and R3 of the reference variable capacitor defined by coordinates previously stored in the lookup table, the first radio frequency matching optimizing part 106 for antenna impedance matching performs optimization by matching the at least one of the adjusted variable capacitor values VC1 and VC2 to a radio frequency band point in the region range R3 of the reference variable capacitor and storing the radio frequency band point in the region range R3 of the reference variable capacitor.

In this case, the region ranges R1, R2, and R3 of the reference variable capacitor may be set in predetermined size on the coordinate plane without overlapping with each other. For example, the region ranges R1, R2, and R3 of the reference variable capacitor may be set in predetermined size from the middle region of the coordinate plane to the end region thereof without overlapping with each other.

In other words, as shown in FIG. 3B, the first radio frequency matching optimizing part 106 for antenna impedance matching may sequentially search the region ranges R1, R2, and R3 of the reference variable capacitor whether the at least one of the adjusted variable capacitor value VC1 and VC2 is in the region range R3 of the reference variable capacitor.

Next, when the coordinate P1 of the at least one of the adjusted variable capacitor value VC1 and VC2 exists out of the coordinate range of the region range R3 of the reference variable capacitor, the first radio frequency matching optimizing part 106 for antenna impedance matching may skip the search operation in the region range R2 without the coordinate P1 among the region ranges R1, R, and R3 of the reference variable capacitor.

Next, after searching for the coordinate P1 of the at least one of the adjusted variable capacitor values VC1 and VC2 in the region range R3 of the reference variable capacitor, the first radio frequency matching optimizing part 106 for antenna impedance matching performs optimization by matching the coordinate P1 of the at least one of the adjusted variable capacitor values VC1 and VC2, which exist in the searched region range R3 of the reference variable capacitor, to the radio frequency band point in the searched region range R3 of the reference variable capacitor. According to the disclosure, the coordinate P1 may be a first coordinate.

The second radio frequency matching optimizing part 108 for antenna impedance matching is electrically connected to the antenna impedance matching circuit 102 to set at least one of the adjusted variable capacitor values VC1 and VC2, which are output from the antenna impedance matching circuit 102, to a coordinate P2 through a prediction algorithm as shown in FIG. 4A when next antenna impedances are matched with each other through the antenna impedance adjusting part 104. According to the disclosure, the coordinate P2 may be a second coordinate.

Thereafter, as shown in FIG. 4B, when the at least one of the adjusted variable capacitor values VC1 and VC2 exists in a region range R4 of the reference variable capacitor selected from among region ranges R1, R2, R3, R4 of the reference variable capacitor, the second radio frequency matching optimizing part 108 for antenna impedance matching performs optimization by matching the coordinate P2 of the at least one of the adjusted variable capacitor values VC1 and VC2 to a radio frequency band point in the region range R4 of the reference variable capacitor after performing a search operation from the radio frequency band point in the region range R3 of the first reference variable capacitor, which is stored by the first radio frequency matching optimizing part 106 for antenna impedance matching.

In this case, the region ranges R1, R2, R3, and R4 of the reference variable capacitor may be classified in predetermined size on the coordinate plane without overlapping with each other.

In other words, as shown in FIG. 4B, the second radio frequency matching optimizing part 108 for antenna impedance matching can sequentially search the region ranges R1, R2, R3, and R4 of the reference variable capacitor whether the at least one of the adjusted variable capacitor value VC1 and VC2 is in the region range R4 of the reference variable capacitor among the region ranges R1, R2, R3, and R4 of the reference variable capacitor.

When the coordinate P2 of the at least one of the adjusted variable capacitor values VC1 and VC2 exists out of the coordinate range of the region range R4 of the reference variable capacitor, the second radio frequency matching optimizing part 108 for antenna impedance matching may skip the region ranges R1 and R2 of the reference variable capacitor without the coordinate P2 among the region ranges R1, R2, R3, and R4 of the reference variable capacitor.

The second radio frequency matching optimizing part 108 for antenna impedance matching can perform optimization by matching the coordinate P2 of the at least one of the adjusted variable capacitor values VC1 and VC2 to the radio frequency band point in the region range R4 of the reference variable capacitor, after performing a search operation from the radio frequency band point in the region range R3 of the first reference variable capacitor stored through the first radio frequency matching optimizing part 106 for antenna impedance matching.

As described above, the system 100 for optimizing the matching of radio frequency in matching the impedance of the antenna according to one embodiment includes the antenna impedance matching circuit 102, the antenna impedance adjusting part 104, the first radio frequency matching optimizing part 106 for antenna impedance matching, and the second radio frequency matching optimizing part 108 for antenna impedance matching.

Therefore, the system 100 for optimizing the matching of radio frequency in matching the impedance of the antenna according to one embodiment can rapidly scan the adjusted variable capacitor values VC1 and VC2, which are adjusted through the antenna impedance adjusting part 104 and output from the antenna impedance matching circuit 102, while supplying transceive signals having radio frequency bands representing superior efficiency.

Meanwhile, the disclosure is applicable to the impedance matching device equipped with the system for optimizing the matching of radio frequency, and applicable to an antenna subject to the impedance matching through the impedance matching device.

Therefore, the system 100 for optimizing the matching of radio frequency in matching the impedance of an antenna according to the embodiment can continuously maintain signal sensitivity of transceive signals by continuously preventing the distortion of the transceive signals from being degraded while performing impedance matching of antennas within a short time.

Although the exemplary embodiments of the present invention have been described, it is understood that the present invention should not be limited to these exemplary embodiments but various changes and modifications can be made by one ordinary skilled in the art within the spirit and scope of the present invention as hereinafter claimed.

Claims

An impedance matching device of an antenna, comprising:

an antenna impedance matching circuit outputting mutual impedance values between antenna impedances;

an antenna impedance adjusting part detecting the mutual impedance values output from the antenna impedance matching circuit and performing a predetermined operation with respect to antenna impedance values to be compensated, thereby adjusting the antenna impedances of the antenna impedance matching circuit based on the antenna impedance values subject to the predetermined operation;

a first radio frequency matching optimizing part for antenna impedance matching to perform an optimization operation by searching for a first coordinate of at least one variable capacitor value output from the impedance matching circuit, which has been adjusted, in region ranges of a reference variable capacitor and matching the first coordinate to a radio frequency band point in at least one region range of the reference variable capacitor; and

a second radio frequency matching optimizing part for antenna impedance matching to perform an optimizing operation by searching for a second coordinate of the at least one variable capacitor value, which is output from the adjusted impedance matching circuit, in the region ranges of the reference variable capacitor and matching the second coordinate to a radio frequency band point in at least one region range of the reference variable capacitor through a prediction algorithm.
The impedance matching device of claim 1, wherein the first radio frequency matching optimizing part for antenna impedance matching sets the first coordinate on a coordinate plane , which is formed based on the at least one variable capacitor value, by using a lookup table.
The impedance matching device of claim 1, wherein, when performing sequentially a searching operation for the region ranges of the reference variable capacitor to determine if at least one adjusted capacitor value exists in one of the region ranges of the reference variable capacitor, the first radio frequency matching optimizing part for antenna impedance matching skips the searching operation with respect to the region ranges of the reference variable capacitor without a coordinate of the at least one adjusted variable capacitor value if the coordinate of the at least one adjusted variable capacitor value exists out of the one region range of the reference variable capacitor, and matches the coordinate of the at least one adjusted variable capacitor value existing in the one region range of the reference capacitor to a radio frequency band point existing in the one region range of the reference variable capacitor after searching for the coordinate of the at least one adjusted variable capacitor value existing in the one region range of the reference capacitor, so that the optimization operation is performed.
The impedance matching device of claim 1, wherein, when performing sequentially a searching operation for the region ranges of the reference variable capacitor to determine if at least one adjusted capacitor value exists in another of the region ranges of the reference variable capacitor, the second radio frequency matching optimizing part for antenna impedance matching skips the searching operation with respect to the region ranges of the reference variable capacitor without a coordinate of the at least one adjusted variable capacitor value if the coordinate of the at least one adjusted variable capacitor value exists out of the another region range of the reference variable capacitor, and matches the coordinate of the at least one adjusted variable capacitor value to a radio frequency band point existing in the another region range of the reference variable capacitor, after searching for the coordinate of the at least one adjusted variable capacitor value from the radio frequency band point, which exists in the one region range of a first reference capacitor and is stored by the first radio frequency matching optimizing part for antenna impedance matching , so that the optimization operation is performed.
The impedance matching device of claim 1, wherein the region ranges of the reference variable capacitor are defined with a predetermined size on a coordinate plane in such a manner that the region ranges are not overlapped with each other.
The impedance matching device of claim 1, wherein the region ranges of the reference variable capacitor are defined with a predetermined size from a middle region of a coordinate plane to an end region of the coordinate plane in such a manner that the region ranges are not overlapped with each other.
The impedance matching device of claim 1, wherein the antenna impedance adjusting part comprises:

an antenna impedance detector electrically connected to the antenna impedance matching circuit to detect the mutual impedance values between the antenna impedances from the antenna impedance matching circuit;

an antenna impedance controller electrically connected to the antenna impedance detector to compare the mutual impedance values between the antenna impedances detected from the antenna impedance matching circuit with reference mutual impedance values between the antenna impedances, which are previously stored, and to perform the predetermined operation with respect to the mutual impedance values between the antenna impedances to be compensated;

a digital-analogue converter electrically connected to the antenna impedance controller to convert a digital signal, which corresponds to the mutual impedance values between the antenna impedances to be compensated, which are obtained from the antenna impedance controller, into an analogue signal; and

an antenna impedance adjusting unit electrically connected to the digital-analogue converter to receive the analog signal, which correspond to the mutual impedance values between the antenna impedances to be compensated and are obtained through digital/analog conversion of the digital-analogue converter, thereby adjusting voltage applied to the antenna impedances by using at least one variable capacitor provided in the antenna impedance matching circuit, suitably for the mutual impedance values between the antenna impedances to be compensated, so that the antenna impedances are matched with each other.
A system for optimizing matching of a radio frequency in matching impedance of an antenna, the system comprising:

an antenna impedance matching circuit outputting mutual impedance values between antenna impedances;

an antenna impedance adjusting part detecting the mutual impedance values output from the antenna impedance matching circuit and performing a predetermined operation with respect to antenna impedance values to be compensated, thereby adjusting the antenna impedances of the antenna impedance matching circuit based on the antenna impedance values subject to the predetermined operation;

a first radio frequency matching optimizing part for antenna impedance matching to perform an optimization operation by searching for a first coordinate of at least one variable capacitor value output from the impedance matching circuit, which has been adjusted, in region ranges of a reference variable capacitor and matching the first coordinate to a radio frequency band point in at least one region range of the reference variable capacitor; and

a second radio frequency matching optimizing part for antenna impedance matching to perform an optimizing operation by searching for a second coordinate of the at least one variable capacitor value, which is output from the adjusted impedance matching circuit, in the region ranges of the reference variable capacitor and matching the second coordinate to a radio frequency band point in at least one region range of the reference variable capacitor through a prediction algorithm.
The system of claim 8, wherein the first radio frequency matching optimizing part for antenna impedance matching sets the first coordinate on a coordinate plane, which is formed based on the at least one variable capacitor value, by using a lookup table.
The system of claim 8, wherein, when performing sequentially a searching operation for the region ranges of the reference variable capacitor to determine if at least one adjusted capacitor value exists in one of the region ranges of the reference variable capacitor, the first radio frequency matching optimizing part for antenna impedance matching skips the searching operation with respect to the region ranges of the reference variable capacitor without a coordinate of the at least one adjusted variable capacitor value if the coordinate of the at least one adjusted variable capacitor value exists out of the one region range of the reference variable capacitor, and matches the coordinate of the at least one adjusted variable capacitor value existing in the one region range of the reference capacitor to a radio frequency band point existing in the one region range of the reference variable capacitor after searching for the coordinate of the at least one adjusted variable capacitor value existing in the one region range of the reference capacitor, so that the optimization operation is performed.
The system of claim 8, wherein, when performing sequentially a searching operation for the region ranges of the reference variable capacitor to determine if at least one adjusted capacitor value exists in another of the region ranges of the reference variable capacitor, the second radio frequency matching optimizing part for antenna impedance matching skips the searching operation with respect to the region ranges of the reference variable capacitor without a coordinate of the at least one adjusted variable capacitor value if the coordinate of the at least one adjusted variable capacitor value exists out of the another region range of the reference variable capacitor, and matches the coordinate of the at least one adjusted variable capacitor value to a radio frequency band point existing in the another region range of the reference variable capacitor, after searching for the coordinate of the at least one adjusted variable capacitor value from the radio frequency band point, which exists in the one region range of a first reference capacitor and is stored by the first radio frequency matching optimizing part for antenna impedance matching , so that the optimization operation is performed.
The system of one of claims 8 to 11, wherein the region ranges of the reference variable capacitor are defined with a predetermined size on a coordinate plane in such a manner that the region ranges are not overlapped with each other.
The system of one of claims 8 to 12, wherein the region ranges of the reference variable capacitor are defined with a predetermined size from a middle region of the coordinate plane to an end region of the coordinate plane in such a manner that the region ranges are not overlapped with each other.
The system of claim 8, wherein the antenna impedance adjusting part comprises:

an antenna impedance detector electrically connected to the antenna impedance matching circuit to detect the mutual impedance values between the antenna impedances from the antenna impedance matching circuit;

an antenna impedance controller electrically connected to the antenna impedance detector to compare the mutual impedance values between the antenna impedances detected from the antenna impedance matching circuit with reference mutual impedance values between the antenna impedances, which are previously stored, and to perform the predetermined operation with respect to the mutual impedance values between the antenna impedances to be compensated;

a digital-analogue converter electrically connected to the antenna impedance controller to convert a digital signal, which corresponds to the mutual impedance values between the antenna impedances to be compensated, which are obtained from the antenna impedance controller, into an analogue signal; and

an antenna impedance adjusting unit electrically connected to the digital-analogue converter to receive the analog signal, which correspond to the mutual impedance values between the antenna impedances to be compensated and are obtained through digital/analog conversion of the digital-analogue converter, thereby adjusting voltage applied to the antenna impedances by using at least one variable capacitor provided in the antenna impedance matching circuit, suitably for the mutual impedance values between the antenna impedances to be compensated, so that the antenna impedances are matched with each other.
The system of claim 8, wherein the antenna impedance adjusting part includes an MCU (Micro Controller Unit).
The system of claim 8, wherein the at least one variable capacitor includes first and second variable capacitors electrically connected to each other in parallel between the antenna impedances.