Internal antenna module

TECHNICAL FIELD

0001The present invention relates generally to an internal antenna module and, more particularly, to an internal antenna module installed in a terminal.

BACKGROUND ART

0002With the spread of mobile communication terminals, people can make phone calls and answer phone calls anytime and anywhere. Accordingly, there has been an innovative change in all aspects of real life. Furthermore, with an increase in the number of users who are always carrying a mobile communication terminal, various functions are added, which is helpful to real life. Among these various functions of the mobile communication terminal, parts related to multimedia are making rapid progress. Currently, mobile communication terminals which have added functions that are capable of generating and playing various multimedia files are being put on the market. That is, such a mobile communication terminal is no longer considered a device only for voice calls, but is considered an integrated handheld device having a variety of user convenience and entertainment functionality. A user can watch a movie, listen to music, and perform communication using one terminal, and can make a phone call when necessary. Accordingly, the time during which a user carries and uses the mobile communication terminal is gradually increasing.

0003Meanwhile, if a user wants to watch a movie or listen to music using a mobile communication terminal, the user has to download and watch the movie or listen to the music content one by one, which adds to the cost. In contrast, in the case of FM radio broadcasting, a user does not need to download individual pieces of new broadcasting content one by one in order to enjoy the content, and also may enjoy the content without any burden because additional costs are not incurred. For this reason, there is a need for a mobile communication terminal including an FM radio reception function.

0004However, an antenna for receiving FM radio must have a long radiation line because it must resonate at a low frequency band from about 87.5 to 108 MHz. Accordingly, the antenna inevitably has a large physical size. This makes it difficult to implement a small-sized internal antenna suitable for recent small-sized and slim mobile communication terminals (the physical size of the antenna increases in inverse proportion to the frequency (i.e., in proportion to the wavelength)).

0005In order to overcome the above problems, there is a case where the size of the antenna is reduced using a dielectric having a high dielectric constant However, when an internal antenna module for a low frequency band is implemented using the dielectric having a high dielectric constant, problems arise in that the manufacturing cost of the antenna increases and also the frequency bandwidth is narrowed in a low frequency band. Accordingly, an internal antenna module for a low frequency band having a desired radiation gain characteristic has not been implemented.

0006Furthermore, in order to overcome the above problems, there is a case where an earphone is used as an antenna for receiving FM radio based on the fact that most users listen to FM radio broadcasting using an earphone. In this case, if the earphone (i.e., a headset or an ear microphone) is removed, a fatal problem arises in that FM radio reception efficiency is very poor. For example, if an FM radio broadcast is output through a speaker contained in a terminal or if an external speaker is connected to an earphone jack (in this case, the connection part plays the role of an antenna for an FM receiver, but the length of the connection part is not suitable and the connection part may interfere with an amplification unit or the like), FM radio may not normally be heard because the FM reception performance is very low. Furthermore, the recent mobile communication terminal having a Bluetooth function is problematic in that it does not adopt a method using the line of a radio earphone as an antenna through the earphone jack because it receives a voice signal output from the terminal through the earphone. Furthermore, a mobile communication terminal that lacks the Bluetooth function is disadvantageous in that the earphone should be connected to the terminal in order to receive FM radio broadcasts.

0007For the above reason, there is a need for an internal antenna module for a low frequency band that is applied to a mobile communication terminal, that can achieve a small-sized and slim mobile communication terminal and that enables FM radio reception at high-level Received Signal Strength Indication (RSSI).

0008Furthermore, the recent use of Bluetooth devices is increasing. Accordingly, a separate Bluetooth antenna for receiving signals in the Bluetooth frequency band for communication with the Bluetooth device is mounted on a mobile communication terminal. In this case, it is difficult to achieve recent small-sized and slim mobile communication terminals, which is the recent trend, because both an internal antenna module for a low frequency band and a Bluetooth antenna module must be installed.

0009In light of the above problems, there is a need for an internal antenna module that is applied to a mobile communication terminal and that can receive signals in both the FM and Bluetooth frequency bands.

DISCLOSURE

Technical Problem

0010The present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an internal antenna module that is installed in a terminal and that can receive signals in both the FM and Bluetooth frequency bands so as to achieve a small-sized, slim terminal.

Technical Solution

0011In order to accomplish the above object, the present invention provides an internal antenna module, including a polyhedral chip antenna configured to have a first radiant pattern and a coupling pattern formed thereon; a flexible circuit board configured to have a first conductive pad connected to the first radiant pattern, a second conductive pad connected to the coupling pattern, and a second radiant pattern connected to the first radiant pattern; and a signal switching unit formed between the second conductive pad and a ground, and configured to prevent any one of a first frequency band signal and a second frequency band signal, received through the chip antenna and the flexible circuit board, from reaching the ground.

0012The second radiant pattern may be configured in a meander line form.

0013The signal switching unit may prevent the second frequency band signal from reaching the ground and send the second frequency band signal to a Bluetooth signal processing module.

0014The signal switching unit may be formed of an inductor that prevents a Bluetooth frequency band signal from reaching the ground.

0015The second frequency band signal may be a Bluetooth frequency band signal.

0016The first frequency band signal may be an FM frequency band signal.

0017The internal antenna module may further include a filter unit for removing a high frequency component from the first frequency band signal.

0018The internal antenna module further includes a Low Noise Amplifier (LNA) for amplifying a reception signal from which the high frequency component has been removed by the filter unit.

0019The internal antenna module may further include a matching capacitor formed between the second conductive pad and the second radiant pattern and configured to correct a difference in impedance between the second conductive pad and a circuit mounted on a substrate on which the flexible circuit board is mounted.

0020The internal antenna module may further include a matching inductor formed on the second conductive pad and configured to correct a difference in impedance between the second conductive pad and a circuit mounted on a substrate on which the flexible circuit board is mounted.

0021In order to accomplish the above object, the present invention provides an internal antenna module, including a polyhedral chip antenna configured to have a first radiant pattern and a coupling pattern formed therein; a flexible circuit board configured to have a first conductive pad connected to the first radiant pattern, a second conductive pad connected to the coupling pattern, and a second radiant pattern connected to the first radiant pattern; and a signal branch unit configured to branch a first frequency band signal and a second frequency band signal received through the chip antenna and the flexible circuit board.

0022The signal branch unit separates the first frequency band signal off into an FM signal processing module and the second frequency band signal off into a Bluetooth signal processing module.

0023The internal antenna module may further include an LNA for amplifying the first frequency band signal separated off by the signal branch unit

0024The first frequency band signal may be an FM frequency band, signal and the second frequency band signal may be a Bluetooth frequency band signal.

0025The signal branch unit is formed of a diplexer for separating an FM frequency band signal off into an FM signal processing module and a Bluetooth frequency band signal off into a Bluetooth signal processing module.

0026In order to accomplish the above object, the present invention provides an internal antenna module, including a polyhedral chip antenna configured to have a first radiant pattern and a coupling pattern formed therein; a flexible circuit board configured to have a first conductive pad connected to the first radiant pattern, a second conductive pad connected to the coupling pattern, and a second radiant pattern connected to the first radiant pattern; and a third radiant pattern formed adjacent to the second radiant pattern on the flexible circuit board.

0027The third radiant pattern may be electrically connected to a Bluetooth signal processing module.

0028The internal antenna module may further include a fourth radiant pattern formed adjacent to the third radiant pattern on the flexible circuit board, and the fourth radiant pattern may be electrically connected to a GPS signal processing module.

0029The third radiant pattern may be electrically connected to a GPS signal processing module.

0030The internal antenna module may further include a fourth radiant pattern formed adjacent to the third radiant pattern on the flexible circuit board, and the fourth radiant pattern may be electrically connected to a Bluetooth signal processing module.

0031In order to accomplish the above object, the present invention provides an internal antenna module, including a chip antenna of a polyhedral block on which a first radiant pattern and a coupling pattern are formed; and a flexible circuit board in which a first conductive pad connected to the first radiant pattern, a second conductive pad connected to the coupling pattern, and a second radiant pattern connected to the first radiant pattern are formed; wherein the first conductive pad is electrically connected to an FM signal processing module and a Bluetooth signal processing module, and sends reception signals, received through the chip antenna and the flexible circuit board, to the FM signal processing module and the Bluetooth signal processing module.

0032The internal antenna module may further include a filter unit for removing a high frequency component from the reception signal sent to the FM signal processing module.

0033The internal antenna module may further include an LNA for amplifying the reception signal from which the high frequency component has been removed by the filter unit

0034In order to accomplish the above object, the present invention provides an internal antenna module, including a polyhedral chip antenna on which a first radiant pattern and a coupling pattern are formed; and a flexible circuit board in which a first conductive pad connected to the first radiant pattern, a second conductive pad connected to a coupling pattern of the chip antenna, and a second radiant pattern adjacent to the second conductive pad are formed; wherein the flexible circuit board further comprises a switching element formed between the second radiant pattern and the first radiant pattern and prevents any one of a first frequency band signal and a second frequency band signal, received through the second radiant pattern, from reaching the first radiant pattern.

0035The switching element may block the second frequency band signal received through the second radiant pattern and sends the second frequency band signal to a Bluetooth signal processing module.

0036The second frequency band signal may be a Bluetooth frequency band signal.

0037The switching element may be formed of an inductor for preventing a Bluetooth frequency band signal from reaching the first radiant pattern.

Advantageous Effects

0038The internal antenna module according to the present invention does not require a separate Bluetooth antenna because it receives signals at FM and Bluetooth frequencies at the same time. Accordingly, it is possible to apply the internal antenna module to a mobile communication terminal and make the mobile communication terminal small and slim.

0039Furthermore, the internal antenna module according to the present invention can receive FM radio at a high RSSI level.

0040Furthermore, spatial utilization can be increased because the spatial burden is reduced when the internal antenna module according to the present invention is mounted on a main printed circuit board. Accordingly, the degree of freedom for a structure in which parts are installed within a terminal can be improved.

0041Furthermore, the internal antenna module according to the present invention has a simple construction because it does not require additional means, such as an earphone for receiving FM radio. Accordingly, in the case of a Bluetooth mobile communication terminal, constant reception quality can be maintained without any reduction in the FM radio broadcasting reception ratio although a radio earphone is used.

DESCRIPTION OF DRAWINGS

0042<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view illustrating a chip antenna applied to an internal antenna module according to an embodiment of the present invention;

0043<figref idref="DRAWINGS">FIG. 2</figref> is an exploded view illustrating the structure of the radiant and coupling patterns of the chip antenna shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0044<figref idref="DRAWINGS">FIGS. 3(</figref><i>a</i>) to <b>3</b>(<i>c</i>) are plan views illustrating the structure of a flexible circuit board connected to the chip antenna of <figref idref="DRAWINGS">FIG. 1</figref>;

0045<figref idref="DRAWINGS">FIG. 4</figref> is a plan view illustrating the state in which the chip antenna of <figref idref="DRAWINGS">FIG. 1</figref> is mounted on the flexible circuit board shown in <figref idref="DRAWINGS">FIGS. 3(</figref><i>a</i>) to <b>3</b>(<i>c</i>);

0046<figref idref="DRAWINGS">FIG. 5</figref> is a diagram illustrating an internal antenna module according to a first embodiment of the present invention;

0047<figref idref="DRAWINGS">FIGS. 6 and 7</figref> are diagrams illustrating a signal switching unit of <figref idref="DRAWINGS">FIG. 5</figref>;

0048<figref idref="DRAWINGS">FIGS. 8 to 10</figref> are diagrams illustrating the filter unit and Low Noise Amplifier (LNA) of <figref idref="DRAWINGS">FIG. 5</figref>;

0049<figref idref="DRAWINGS">FIG. 11</figref> is a graph showing the frequency bands of the internal antenna module according to the first embodiment of the present invention;

0050<figref idref="DRAWINGS">FIG. 12</figref> is a diagram illustrating an internal antenna module according to a second embodiment of the present invention;

0051<figref idref="DRAWINGS">FIG. 13</figref> is a diagram illustrating an internal antenna module according to a third embodiment of the present invention;

0052<figref idref="DRAWINGS">FIG. 14</figref> is a diagram illustrating an internal antenna module according to a fourth embodiment of the present invention;

0053<figref idref="DRAWINGS">FIGS. 15(</figref><i>a</i>) to <b>15</b>(<i>c</i>) are plan views illustrating the structure of a flexible circuit board electrically connected to the chip antenna of <figref idref="DRAWINGS">FIG. 1</figref>;

0054<figref idref="DRAWINGS">FIG. 16</figref> is a plan view illustrating the state in which the chip antenna of <figref idref="DRAWINGS">FIG. 1</figref> is mounted on the flexible circuit board shown in <figref idref="DRAWINGS">FIGS. 15(</figref><i>a</i>) to <b>15</b>(<i>c</i>);

0055<figref idref="DRAWINGS">FIGS. 17 and 18</figref> are diagrams illustrating a signal switching unit of <figref idref="DRAWINGS">FIG. 16</figref>;

0056<figref idref="DRAWINGS">FIGS. 19 to 21</figref> are diagrams illustrating a filter unit and an LNA of <figref idref="DRAWINGS">FIG. 16</figref>;

0057<figref idref="DRAWINGS">FIG. 22</figref> is a graph showing the frequency bands of the internal antenna module according to the fourth embodiment of the present invention;

0058<figref idref="DRAWINGS">FIGS. 23 and 24</figref> are diagrams illustrating an internal antenna module according to a fifth embodiment of the present invention;

0059<figref idref="DRAWINGS">FIGS. 25 and 26</figref> are diagrams illustrating an internal antenna module according to a modified example of the fifth embodiment of the present invention;

0060<figref idref="DRAWINGS">FIGS. 27 and 28</figref> are diagrams illustrating an internal antenna module according to a sixth embodiment of the present invention;

0061<figref idref="DRAWINGS">FIGS. 29 and 30</figref> are diagrams illustrating an internal antenna module according to a modified example of the sixth embodiment of the present invention;

0062<figref idref="DRAWINGS">FIGS. 31 and 32</figref> are diagrams illustrating an internal antenna module according to a seventh embodiment of the present invention; and

0063<figref idref="DRAWINGS">FIG. 33</figref> is a graph showing the frequency bands of the internal antenna module according to the seventh embodiment of the present invention.

BEST MODE

0064Some embodiments of the present invention will now be described in detail with reference to the accompanying drawings in order for a person having ordinary skill in the art to be able to easily implement the technical spirit of the present invention. It should be noted that in assigning reference numerals to respective elements in the drawings, the same reference numerals designate the same elements although the elements are shown in different drawings. Furthermore, in describing the present invention, detailed descriptions of the known functions and constructions will be omitted if they are deemed to make the gist of the present invention unnecessarily vague. The embodiments of the present invention are provided in order to fully describe the present invention to a person having ordinary skill in the art. Accordingly, the shapes, sizes, etc. of the elements in the drawings may be exaggerated for the sake of a clear description.

0065Hereinafter, a chip antenna and a flexible circuit board which are applied in common to the embodiments of the present invention will be described with reference to the accompanying drawings

0066<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view illustrating a chip antenna applied to an internal antenna module according to an embodiment of the present invention, and <figref idref="DRAWINGS">FIG. 2</figref> is an exploded view illustrating the structure of the radiant and coupling patterns of the chip antenna shown in <figref idref="DRAWINGS">FIG. 1</figref>.

0067The chip antenna <b>100</b> includes a polyhedral block <b>110</b> made of a magneto-dielectric, a first radiant pattern <b>120</b> configured in a winding form along the external faces of the polyhedral block <b>110</b>, and a coupling pattern <b>125</b> spaced apart from the first radiant pattern <b>120</b> at specific intervals.

0068The polyhedral block <b>110</b> may be made of a magneto-dielectric. The magneto-dielectric refers to a magnetic material, including iron oxide, chrome oxide, cobalt, ferrite, etc.

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0069Equation 1 is an equation indicating that the bandwidth BW of an antenna increases with an increase in the ratio of the magnetic permeability to the dielectric constant when the size of the antenna remains unchanged. Here, λ₀is the wavelength, μ_ris the magnetic permeability, ε_ris the dielectric constant, and t is the thickness of the antenna. In general, a dielectric with a high dielectric constant that is applied to an antenna has a magnetic permeability lower than the dielectric constant. However, if a magneto-dielectric having a magnetic permeability greater than the dielectric constant (the magneto-dielectric applied to an embodiment of the present invention has a magnetic permeability of about 18 and a dielectric constant of about 10) is used, a wider bandwidth can be implemented than with a dielectric having a high dielectric constant for the same antenna size according to Equation 1. Accordingly, if an antenna for a low frequency band is implemented using a dielectric block having a high dielectric constant in order to reduce the size of the antenna, the phenomenon of narrowing the bandwidth can be overcome using a magneto-dielectric having a low dielectric constant and magnetic permeability, thereby being capable of maintaining the bandwidth but reducing the size of the antenna. Meanwhile, the polyhedral block <b>110</b> applied to the present invention may be selected depending on a desired resonant frequency because it has the different magnetic permeability and dielectric constant. Furthermore, the size and shape of the polyhedral block <b>110</b> may vary depending on the desired frequency band.

0070The first radiant pattern and the coupling pattern formed on the polyhedral block will be described below with reference to <figref idref="DRAWINGS">FIG. 2</figref>. In order to further understanding of the present invention, conductor patterns formed on the polyhedral block <b>110</b> are called the first radiant pattern <b>120</b>, and conductor patterns formed on a flexible circuit board <b>200</b> according to an embodiment of the present invention to be described later are called second radiant patterns <b>230</b>.

0071The first radiant pattern <b>120</b> I₁to I_kformed on one side face <b>110</b><i>a </i>of the polyhedral block <b>110</b> are connected to the first radiant pattern <b>120</b> I₁to I_kformed on the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>, respectively. In <figref idref="DRAWINGS">FIG. 2</figref>, the first radiant pattern <b>120</b> I₁to I_kformed on the one side face <b>110</b><i>a </i>are illustrated as seeming to be different from the first radiant pattern <b>120</b> I₁to I_kformed on the bottom <b>110</b><i>b. </i>If <figref idref="DRAWINGS">FIG. 2</figref> is implemented in the state of <figref idref="DRAWINGS">FIG. 1</figref>, the first radiant pattern <b>120</b> starts from one side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b> and form a winding form along the external faces of the polyhedral block <b>110</b>, thereby forming radiation lines. The length and line width of the first radiant pattern <b>120</b> and the interval there between may vary depending on the desired resonant frequency.

0072The coupling pattern <b>125</b> is formed on the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>, and is spaced apart from the first radiant pattern <b>120</b> at specific intervals. The coupling pattern <b>125</b> couples the flow of current introduced into the first radiant pattern <b>120</b>, thereby increasing the bandwidth of the antenna. In an embodiment of the present invention, the one coupling pattern <b>125</b> is formed on the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b> so that the coupling pattern <b>125</b> resonates in an FM radio frequency band (87.5 to 108 MHz). <figref idref="DRAWINGS">FIG. 2</figref> shows only the one coupling pattern <b>125</b>, but is not limited thereto. The number of coupling patterns <b>125</b> generating coupling may vary depending on the desired frequency band and bandwidth. A desired resonant frequency and bandwidth may be controlled by increasing or decreasing the number of coupling patterns <b>125</b>.

0073<figref idref="DRAWINGS">FIGS. 3(</figref><i>a</i>) to <b>3</b>(<i>c</i>) are plan views illustrating the structure of the flexible circuit board <b>200</b> connected to the chip antenna <b>100</b> of <figref idref="DRAWINGS">FIG. 1</figref>, and <figref idref="DRAWINGS">FIG. 4</figref> is a plan view illustrating the state in which the chip antenna of <figref idref="DRAWINGS">FIG. 1</figref> is mounted on the flexible circuit board shown in <figref idref="DRAWINGS">FIGS. 3(</figref><i>a</i>) to <b>3</b>(<i>c</i>).

0074First, the structure of the flexible circuit board <b>200</b> applied to the present invention will now be described with reference to <figref idref="DRAWINGS">FIGS. 3(</figref><i>a</i>) to <b>3</b>(<i>c</i>).

0075The chip antenna <b>100</b> is mounted on any one face (e.g., the top surface of the flexible circuit board <b>200</b>) of the flexible circuit board <b>200</b>.

0076The flexible circuit board <b>200</b> includes a first conductive pad <b>210</b>, a second conductive pad <b>220</b>, and a second radiant pattern <b>230</b>.

0077The first conductive pad <b>210</b> is used as a feeding pad. The first conductive pad <b>210</b> is soldered and electrically connected to the first radiant pattern <b>120</b> I₁formed at the end of one side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>.

0078The second conductive pad <b>220</b> is used as a ground pad. The second conductive pad <b>220</b> is soldered and electrically connected to the coupling pattern <b>125</b> formed on the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>.

0079The second radiant pattern <b>230</b> is soldered and electrically connected to the first radiant pattern <b>120</b> I_k+1formed at the end of the other side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>. For this purpose, the second radiant pattern <b>230</b> includes a connection part connected to the first radiant pattern <b>120</b> I_k+1and a radiation part configured to extend from the connection part and formed outside an area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b>. Here, the connection part and the radiation part may be distinguished from each other on the basis of a bent part <b>235</b> shown in <figref idref="DRAWINGS">FIG. 3</figref>. That is, a part soldered to the first radiant pattern <b>120</b> I_k+1corresponds to the connection part, and a part configured to extend from the connection part and formed outside the area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b> corresponds to the radiation part, on the basis of the bent part <b>235</b> in the second radiant pattern <b>230</b>. This is applied to the drawings which will be described later.

0080When the second radiant pattern <b>230</b> is electrically connected to the first radiant pattern <b>120</b> I_k+1formed at the end of the other side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>, the first radiant pattern <b>120</b> and the second radiant pattern <b>230</b> formed on the flexible circuit board <b>200</b> form one radiation line (refer to <figref idref="DRAWINGS">FIG. 4</figref>).

First Embodiment

0081Hereinafter, an internal antenna module according to a first embodiment of the present invention will be described in detail with reference to the accompanying drawings. <figref idref="DRAWINGS">FIG. 5</figref> is a diagram illustrating the internal antenna module according to the first embodiment of the present invention. <figref idref="DRAWINGS">FIGS. 6 and 7</figref> are diagrams illustrating the signal switching unit of <figref idref="DRAWINGS">FIG. 5</figref>. <figref idref="DRAWINGS">FIGS. 8 to 10</figref> are diagrams illustrating the filter unit and Low Noise Amplifier (LNA) of <figref idref="DRAWINGS">FIG. 5</figref>. First, since the chip antenna and flexible circuit board of the internal antenna module according to the first embodiment of the present invention are the same as the chip antenna and the flexible circuit board described with reference to <figref idref="DRAWINGS">FIGS. 1 to 4</figref>, descriptions thereof will be omitted here and the same reference numerals are used. Furthermore, since an FM signal processing module and a Bluetooth signal processing module may be easily implemented by a person having ordinary skill in the art using the known art, detailed descriptions thereof will be omitted here.

0082As shown in <figref idref="DRAWINGS">FIG. 5</figref>, the internal antenna module includes the chip antenna <b>100</b>, the flexible circuit board <b>200</b>, a signal switching unit <b>300</b>, the filter unit <b>400</b>, and the LNA <b>500</b>.

0083One side of the signal switching unit <b>300</b> is connected to the second conductive pad <b>220</b>, and the other side thereof is connected to a ground GND. That is, one side of the signal switching unit <b>300</b> is soldered and electrically connected to the second conductive pad <b>220</b> of the flexible circuit board <b>200</b>, and the other side thereof is soldered and electrically connected to the ground GND. Here, the signal switching unit <b>300</b> is formed of an inductor that transmits a reception signal in an FM frequency band and blocks a reception signal in the Bluetooth frequency band. The purpose of this is to separate the reception signal in an FM frequency band and the reception signal in the Bluetooth frequency band using the characteristics of the inductor which has an impedance that increases when a passing frequency increases and thus operates as a Low Pass Filter (LPF) and has an impedance that falls when a passing frequency falls and thus operates as a High Pass Filter (HPF). Here, the inductor used as the signal switching unit <b>300</b> has about 22 nH that transmits the reception signal in an FM frequency band (about 87.5 to 108 MHz) and blocks the reception signal in the Bluetooth frequency band (about 2.45 GHz).

0084The signal switching unit <b>300</b> severs the connection with the ground GND depending on the frequency of a reception signal received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>. Here, the signal switching unit <b>300</b> maintains the connection with the ground GND when the frequency of the reception signal is a low frequency signal, and severs the connection with the ground GND in order to send the reception signal to a Bluetooth signal processing module <b>700</b> when the frequency of the reception signal is a high frequency signal. That is, when the reception signal in an FM frequency band (i.e., a low frequency) is received, the signal switching unit <b>300</b> plays the role of a line to maintain the connection with the ground GND. When the reception signal in the Bluetooth frequency band (i.e., at a high frequency) is received, the signal switching unit <b>300</b> severs the connection with the ground GND so that the reception signal is prevented from being sent to the ground GND.

0085The signal switching unit <b>300</b> formed of the inductor having 22 nH will now be described in more detail. When the reception signal in an FM frequency band (i.e., at a low frequency) is received through the chip antenna <b>100</b> and the flexible circuit board <b>200</b>, the inductor maintains the connection part and the ground GND in a connected state and thus plays the role of a line that transmits the reception signal to the ground GND. Accordingly, the second conductive pad <b>220</b> plays the role of ground, and the internal antenna module operates, as shown in <figref idref="DRAWINGS">FIG. 6(</figref><i>a</i>).

0086When the reception signal in the Bluetooth frequency band (i.e., at a high frequency) is received through the chip antenna <b>100</b> and the flexible circuit board <b>200</b>, the inductor is opened so that the reception signal is prevented from being sent to the ground GND. Accordingly, the internal antenna module operates as a circuit, not including the inductor and the ground GND, as shown in <figref idref="DRAWINGS">FIG. 6(</figref><i>b</i>), and thus operates as a monopole antenna. That is, as shown in <figref idref="DRAWINGS">FIG. 7</figref>, coupling is generated because the second conductive pad <b>220</b> is spaced apart from the radiation part of the second radiant pattern <b>230</b> at a specific interval. The radiation part plays the role of a λ/4 resonant line in the Bluetooth frequency band, and operates as a Bluetooth antenna.

0087Meanwhile, the reception signal in the Bluetooth frequency band blocked by the signal switching unit <b>300</b> is input to the Bluetooth signal processing module <b>700</b>.

0088The filter unit <b>400</b> is provided on the flexible circuit board <b>200</b>. One side of the filter unit <b>400</b> is electrically connected to the first radiant pattern <b>120</b> formed on the polyhedral block <b>110</b> via the first conductive pad <b>210</b>, and the other side of the filter unit <b>400</b> is electrically connected to the LNA <b>500</b>. The filter unit <b>400</b> removes a high frequency component from the reception signal received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>. In the case of Bluetooth, a transmission signal in the Bluetooth frequency band is periodically generated from a terminal and a Bluetooth device for communication between the terminal and the Bluetooth device. Accordingly, the reception signal in an FM frequency band may interfere with the transmission signal in the Bluetooth frequency band. The filter unit <b>400</b> removes a high frequency component in order to prevent signal interference from being generated in the reception signal due to the transmission signal in a Bluetooth frequency band.

0089The LNA <b>500</b> is provided on the flexible circuit board <b>200</b>, and is electrically connected to the filter unit <b>400</b>. The LNA <b>500</b> amplifies the reception signal from which the high frequency component has been removed by the filter unit <b>400</b> (i.e., the reception signal in an FM frequency band from which signal interference due to the transmission signal in the Bluetooth frequency band has been removed), thereby enabling FM radio to be received at a high RSSI level. The LNA <b>500</b> is designed by setting an operating point and a matching point so that the reception signal has a low Noise Factor (NF). The reception signal amplified by the LNA <b>500</b> is input to an FM signal processing module <b>600</b>.

0090Since the LNA <b>500</b> applied to the present invention is a technical element which may be easily implemented by a person having ordinary skill in the art using the known art, a detailed description thereof will be omitted here.

0091Meanwhile, if the filter unit <b>400</b> and the LNA <b>500</b> are included in the flexible circuit board <b>200</b>, they may be included in separate areas on the same plane as the chip antenna <b>100</b> as shown in <figref idref="DRAWINGS">FIGS. 8 and 9</figref>, or may be included on the other face (i.e., an area ‘A’ of <figref idref="DRAWINGS">FIG. 10</figref>) opposite to one face on the flexible circuit board <b>200</b> on which the chip antenna <b>100</b> is mounted, as shown in <figref idref="DRAWINGS">FIG. 10</figref>. The filter unit <b>400</b> and the LNA <b>500</b> may be included on different faces. In this case, spatial utilization can be increased because the spatial requirements can be reduced when the internal antenna module according to the present invention is subsequently mounted on a main printed circuit board (not shown). Accordingly, the degree of freedom for a structure in which parts are installed within a terminal can be improved.

0092<figref idref="DRAWINGS">FIG. 11</figref> is a graph showing the frequency bands of the internal antenna module according to the first embodiment of the present invention.

0093<figref idref="DRAWINGS">FIG. 11</figref> is a graph showing the frequencies of reception signals received via the first conductive pad <b>210</b> and the second conductive pad <b>220</b> and the signal interference between the reception signals, when the internal antenna module according to the first embodiment of the present invention is used. In this graph, “A” indicates the frequency of the reception signal received via the first conductive pad <b>210</b>, and “B” is the frequency of the reception signal received via the second conductive pad <b>220</b>. Furthermore, “C” is the amount of the reception signal that is received via the second conductive pad <b>220</b> and then goes over to the first conductive pad <b>210</b> (i.e., the amount of signal interference).

0094The frequency of the reception signal (i.e., “A” in <figref idref="DRAWINGS">FIG. 11</figref>) received via the first conductive pad <b>210</b> shows that it has a resonant frequency band of about 87.5 MHz to 108 MHz. That is, the radiation part formed on the flexible circuit board <b>200</b> and the first radiant pattern <b>120</b> formed on the chip antenna <b>100</b> form one radiation line, so that the reception signal in a low frequency band (i.e., an FM frequency band from 87.5 MHz to 108 MHz) is received.

0095Furthermore, the frequency of the reception signal (i.e., “B” in <figref idref="DRAWINGS">FIG. 11</figref>) received via the second conductive pad <b>220</b> shows that it has a resonant frequency band of about 2.4 GHz. That is, the second conductive pad <b>220</b> is spaced apart from the radiation part, so that coupling is generated. The radiation part plays the role of a λ/4 resonant line in the Bluetooth frequency band. Accordingly, the internal antenna module operates as a monopole antenna using coupling, and thus receives a reception signal having the frequencies of a Bluetooth frequency band.

0096Here, from the amount of signal interference (i.e., “C” in <figref idref="DRAWINGS">FIG. 11</figref>), it can be seen that signal interference of the reception signal received via the second conductive pad <b>220</b> with the reception signal received via the first conductive pad <b>210</b> is weak

Second Embodiment

0097Hereinafter, an internal antenna module according to a second embodiment of the present invention will be described in detail with reference to the accompanying drawing. <figref idref="DRAWINGS">FIG. 12</figref> is a diagram illustrating the internal antenna module according to the second embodiment of the present invention.

0098First, since the chip antenna and flexible circuit board of the internal antenna module according to the second embodiment of the present invention are the same as the chip antenna and the flexible circuit board described with reference to <figref idref="DRAWINGS">FIGS. 1 to 4</figref>, descriptions thereof will be omitted here and the same reference numerals are used. Furthermore, since an FM signal processing module and a Bluetooth signal processing module may be easily implemented by a person having ordinary skill in the art using the known art, detailed descriptions thereof will be omitted here.

0099As shown in <figref idref="DRAWINGS">FIG. 12</figref>, the internal antenna module includes a chip antenna <b>100</b>, a flexible circuit board <b>200</b>, a signal branch unit <b>800</b>, and an LNA <b>500</b>.

0100One side of the signal branch unit <b>800</b> is electrically connected to the first conductive pad <b>210</b> of the flexible circuit board <b>200</b>, and the other side thereof is electrically connected to the LNA <b>500</b> and a Bluetooth signal processing module <b>700</b>. Here, the signal branch unit <b>800</b> is formed of a diplexer for branching a reception signal, received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>, based on the frequencies of the reception signal. The diplexer includes an LPF and an HPF, and separates reception signals of a low frequency and a high frequency off into different paths based on the frequencies of the reception signals.

0101The signal branch unit <b>800</b> branches a reception signal, received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>, based on the frequencies of the reception signal. That is, the signal branch unit <b>800</b> branches a reception signal to an FM signal processing module <b>600</b> via the LNA <b>500</b> or to the Bluetooth signal processing module <b>700</b> based on the frequencies of the reception signal. Here, the signal branch unit <b>800</b> branches the reception signal in an FM frequency band (i.e., a low frequency), received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>, to the FM signal processing module <b>600</b>, and branches the reception signal in the Bluetooth frequency band (i.e., at a high frequency), received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>, to the Bluetooth signal processing module <b>700</b>.

0102The LNA <b>500</b> is provided on the flexible circuit board <b>200</b>, and is electrically connected to the signal branch unit <b>800</b>. The LNA <b>500</b> amplifies the reception signal of a low frequency (i.e., the reception signal in an FM frequency band) branched by the signal branch unit <b>800</b>, thereby enabling FM radio to be received at a high RSSI level. The LNA <b>500</b> is designed by setting an operating point and a matching point so that the reception signal has a low NF. The reception signal amplified by the LNA <b>500</b> is input to the FM signal processing module <b>600</b>.

0103Since the LNA <b>500</b> applied to the present invention is a technical element that may be implemented by a person having ordinary skill in the art using the known art, a detailed description thereof will be omitted here.

Third Embodiment

0104Hereinafter, an internal antenna module according to a third embodiment of the present invention will be described in detail with reference to the accompanying drawing. <figref idref="DRAWINGS">FIG. 13</figref> is a diagram illustrating the internal antenna module according to the third embodiment of the present invention. First, since the chip antenna and flexible circuit board of the internal antenna module according to the third embodiment of the present invention are the same as the chip antenna and the flexible circuit board described with reference to <figref idref="DRAWINGS">FIGS. 1 to 4</figref>, descriptions thereof will be omitted here and the same reference numerals are used. Furthermore, an FM signal processing module and a Bluetooth signal processing module are technical elements that may be easily implemented by a person having ordinary skill in the art using the known art, and a detailed description thereof will be omitted here.

0105As shown in <figref idref="DRAWINGS">FIG. 13</figref>, the internal antenna module includes a chip antenna <b>100</b>, a flexible circuit board <b>200</b>, a filter unit <b>400</b>, and an LNA <b>500</b>.

0106The first conductive pad <b>210</b> of the flexible circuit board <b>200</b> is electrically connected to the filter unit <b>400</b> and a Bluetooth signal processing module <b>700</b>. Here, a reception signal received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b> is input to the filter unit <b>400</b> and the Bluetooth signal processing module <b>700</b> at the same time.

0107The filter unit <b>400</b> is provided on the flexible circuit board <b>200</b>. One side of the filter unit <b>400</b> is electrically connected to the first radiant pattern <b>120</b> formed on the polyhedral block <b>110</b> via the first conductive pad <b>210</b>, and the other side thereof is electrically connected to the LNA <b>500</b>. The filter unit <b>400</b> blocks a reception signal which belongs to reception signals received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b> and corresponds to a Bluetooth frequency band, transmits a reception signal which belongs to reception signals and corresponds to an FM frequency band, and inputs the reception signal corresponding to an FM frequency band to the LNA <b>500</b>.

0108The filter unit <b>400</b> removes a high frequency component in order to prevent signal interference generated in a reception signal due to a transmission signal in the Bluetooth frequency band. Since this is the same as the filter unit <b>400</b> of the first embodiment, a detailed description thereof will be omitted here.

0109The LNA <b>500</b> is provided on the flexible circuit board <b>200</b>, and is electrically connected to the filter unit <b>400</b>. The LNA <b>500</b> amplifies a reception signal from which the high frequency component has been removed by the filter unit <b>400</b> (i.e., a reception signal in an FM frequency band from which signal interference due to a transmission signal in the Bluetooth frequency band and a reception signal in the Bluetooth frequency band have been removed), thereby enabling FM radio to be received at a high RSSI level. The LNA <b>500</b> is designed by setting an operating point and a matching point so that the reception signal has a low NF. The reception signal amplified by the LNA <b>500</b> is input to the FM signal processing module <b>600</b>.

0110Since the LNA <b>500</b> applied to the present invention is a technical element that may be implemented by a person having ordinary skill in the art using the known art, a detailed description thereof will be omitted here.

Fourth Embodiment

0111Hereinafter, an internal antenna module according to a fourth embodiment of the present invention will be described in detail with reference to the accompanying drawings. <figref idref="DRAWINGS">FIG. 14</figref> is a diagram illustrating the internal antenna module according to the fourth embodiment of the present invention. <figref idref="DRAWINGS">FIGS. 15(</figref><i>a</i>) to <b>15</b>(<i>c</i>) are plan views illustrating the structure of a flexible circuit board electrically connected to the chip antenna of <figref idref="DRAWINGS">FIG. 1</figref>. <figref idref="DRAWINGS">FIG. 16</figref> is a plan view illustrating the state in which the chip antenna of <figref idref="DRAWINGS">FIG. 1</figref> is mounted on the flexible circuit board shown in <figref idref="DRAWINGS">FIGS. 15(</figref><i>a</i>) to <b>15</b>(<i>c</i>). <figref idref="DRAWINGS">FIGS. 17 and 18</figref> are diagrams illustrating a signal switching unit of <figref idref="DRAWINGS">FIG. 16</figref>. <figref idref="DRAWINGS">FIGS. 19 to 21</figref> are diagrams illustrating a filter unit and an LNA of <figref idref="DRAWINGS">FIG. 16</figref>. First, since the chip antenna of the internal antenna module according to the fourth embodiment of the present invention is the same as the chip antenna described with reference to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, a description thereof will be omitted here and the same reference numerals will be assigned. Furthermore, since an FM signal processing module and a Bluetooth signal processing module are technical elements that may be easily implemented by a person having ordinary skill in the art using the known art, detailed descriptions thereof will be omitted here.

0112As shown in <figref idref="DRAWINGS">FIG. 14</figref>, the internal antenna module includes a chip antenna <b>100</b>, a flexible circuit board <b>200</b>, a signal switching unit <b>300</b>, a filter unit <b>400</b>, and an LNA <b>500</b>.

0113The chip antenna <b>100</b> is mounted on any one face (e.g., a top surface of the flexible circuit board <b>200</b>) of the flexible circuit board <b>200</b>.

0114The flexible circuit board <b>200</b> includes a first conductive pad <b>210</b>, a second conductive pad <b>220</b>, a second radiant pattern <b>230</b>, a matching capacitor <b>240</b>, and a matching inductor <b>250</b>, as shown in <figref idref="DRAWINGS">FIG. 15</figref>.

0115The first conductive pad <b>210</b> is used as a feeding pad, and is soldered and electrically connected to the first radiant pattern <b>120</b> I₁formed at the end of one side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>.

0116The second conductive pad <b>220</b> is used as a ground pad. The second conductive pad <b>220</b> is soldered and electrically connected to the coupling pattern <b>125</b> formed on the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>.

0117The second radiant pattern <b>230</b> is formed in a specific meander line form (e.g., a “<img file="US2012280867A1_D0002.tif" />” form), and is soldered and electrically connected to the first radiant pattern <b>120</b> I_k+1formed at the end of the other side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>. For this purpose, the second radiant pattern <b>230</b> includes a connection part connected to the first radiant pattern <b>120</b> I_k+1and a radiation part configured to extend from the connection part and formed outside an area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b>. Here, the radiation part of the second radiant pattern <b>230</b> is formed in a meander line form, and the radiation part and the connection part may be distinguished from each other based on a bent part <b>235</b>. That is, a part that is soldered to the first radiant pattern <b>120</b> I_k+1based on the bent part <b>235</b> of the second radiant pattern <b>230</b> corresponds to the connection part, and a part that extends from the connection part and is formed outside the area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b> corresponds to the radiation part in a meander line form. This will be applies to the following drawings in the same manner. Since the second radiant pattern <b>230</b> is formed in a meander line form as described above, the area of the flexible circuit board <b>200</b> can be reduced, and a mobile communication terminal to which the internal antenna module of the present invention is applied can be reduced in size and can be made slim.

0118When the second radiant pattern <b>230</b> is electrically connected to the first radiant pattern <b>120</b> I_k+1formed at the end of the other side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>, the first radiant pattern <b>120</b> and the second radiant pattern <b>230</b> formed on the flexible circuit board <b>200</b> form one radiation line (refer to <figref idref="DRAWINGS">FIG. 16</figref>).

0119The matching capacitor <b>240</b> is formed between the second conductive pad <b>220</b> and the second radiant pattern <b>230</b>, and corrects a difference in impedance between the second conductive pad <b>220</b> and a circuit mounted on a substrate on which the flexible circuit board <b>200</b> is mounted. That is, the matching capacitor <b>240</b> optimizes the antenna characteristics in the Bluetooth frequency band by matching impedance between the internal antenna module and a mobile communication terminal on which the internal antenna module is mounted. Here, a capacitor having a different value according to the state of a mobile communication terminal on which the internal antenna module is mounted is used as the matching capacitor <b>240</b>. In addition, the matching capacitor <b>240</b> may optimize both the antenna characteristics in the Bluetooth frequency band and the antenna characteristics in an FM frequency band.

0120The matching inductor <b>250</b> is formed on the second conductive pad <b>220</b>, and corrects a difference in impedance between the second conductive pad <b>220</b> and the circuit mounted on the substrate on which the flexible circuit board <b>200</b> is mounted. That is, the matching inductor <b>250</b> optimizes the antenna characteristics in the Bluetooth frequency band by matching impedance between the internal antenna module and a mobile communication terminal on which the internal antenna module is mounted. Here, a capacitor having a different value according to the state of a mobile communication terminal on which the internal antenna module is mounted is used as the matching inductor <b>250</b>. In addition, the matching inductor <b>250</b> may optimize both the antenna characteristics in the Bluetooth frequency band and the antenna characteristics in an FM frequency band.

0121One side of the signal switching unit <b>300</b> is connected to the second conductive pad <b>220</b>, and the other side thereof is connected to a ground GND. That is, one side of the signal switching unit <b>300</b> is soldered and electrically connected to the second conductive pad <b>220</b> of the flexible circuit board <b>200</b>, and the other side thereof is soldered and electrically connected to the ground GND. Here, the signal switching unit <b>300</b> is formed of an inductor for transmitting a reception signal in an FM frequency band, but blocks a reception signal in the Bluetooth frequency band. The purpose of this is to separate the reception signal in an FM frequency band and the reception signal in the Bluetooth frequency band using the characteristics of the inductor which has an impedance that increases when a passing frequency increases and thus operates as an LPF and has an impedance that falls when a passing frequency falls and thus operates as an HPF. Here, the inductor used as the signal switching unit <b>300</b> has about 22 nH that transmits the reception signal in an FM frequency band (about 87.5 to 108 MHz) and blocks the reception signal in the Bluetooth frequency band (about 2.45 GHz).

0122The signal switching unit <b>300</b> may sever the connection with the ground GND depending on the frequency of a reception signal received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>. Here, the signal switching unit <b>300</b> maintains the connection with the ground GND when the frequency of the reception signal is a low frequency signal and severs the connection with the ground GND in order to send the reception signal to a Bluetooth signal processing module <b>700</b> when the frequency of the reception signal is a high frequency signal. That is, when the reception signal in an FM frequency band (i.e., a low frequency) is received, the signal switching unit <b>300</b> plays the role of a line to maintain the connection with the ground GND. When the reception signal in the Bluetooth frequency band (i.e., at a high frequency) is received, the signal switching unit <b>300</b> severs the connection with the ground GND in order to prevent the reception signal from being sent to the ground GND.

0123The signal switching unit <b>300</b> formed of the inductor having 22 nH will now be described in more detail. When the reception signal in an FM frequency band (i.e., at a low frequency) is received through the chip antenna <b>100</b> and the flexible circuit board <b>200</b>, the inductor maintains the connection part and the ground GND in a connected state and thus plays the role of a line that transmits the reception signal to the ground GND. Accordingly, the second conductive pad <b>220</b> plays the role of a ground, and the internal antenna module operates, as shown in <figref idref="DRAWINGS">FIG. 17(</figref><i>a</i>).

0124When the reception signal in the Bluetooth frequency band (i.e., at a high frequency) is received through the chip antenna <b>100</b> and the flexible circuit board <b>200</b>, the inductor is opened so that the reception signal is prevented from being sent to the ground GND. Accordingly, the internal antenna module operates as a circuit, not including the inductor and the ground GND, as shown in <figref idref="DRAWINGS">FIG. 17(</figref><i>b</i>), and thus operates as a monopole antenna. That is, as shown in <figref idref="DRAWINGS">FIG. 18</figref>, coupling is generated because the second conductive pad <b>220</b> is spaced apart from the radiation part of the second radiant pattern <b>230</b> by a specific interval. The radiation part plays the role of a λ/4 resonant line in the Bluetooth frequency band and thus operates as a Bluetooth antenna.

0125Meanwhile, the reception signal in the Bluetooth frequency band blocked by the signal switching unit <b>300</b> is input to the Bluetooth signal processing module <b>700</b>.

0126The filter unit <b>400</b> is provided on the flexible circuit board <b>200</b>. One side of the filter unit <b>400</b> is electrically connected to the first radiant pattern <b>120</b> formed on the polyhedral block <b>110</b> via the first conductive pad <b>210</b>, and the other side of the filter unit <b>400</b> is electrically connected to the LNA <b>500</b>. The filter unit <b>400</b> removes a high frequency component from the reception signal received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>. In the case of Bluetooth, a terminal and a Bluetooth device periodically generate a transmission signal in the Bluetooth frequency band for the purpose of communication between the terminal and the Bluetooth device. Accordingly, the reception signal in an FM frequency band may interfere with the transmission signal in the Bluetooth frequency band. The filter unit <b>400</b> removes a high frequency component in order to prevent signal interference from being generated in the reception signal due to the transmission signal in the Bluetooth frequency band.

0127The LNA <b>500</b> is provided on the flexible circuit board <b>200</b>, and is electrically connected to the filter unit <b>400</b>. The LNA <b>500</b> amplifies the reception signal from which the high frequency component has been removed by the filter unit <b>400</b> (i.e., the reception signal in an FM frequency band from which signal interference due to the transmission signal in the Bluetooth frequency band has been removed), thereby enabling FM radio to be received at a high RSSI level. The LNA <b>500</b> is designed by setting an operating point and a matching point so that the reception signal has a low NF. The reception signal amplified by the LNA <b>500</b> is input to the FM signal processing module <b>600</b>.

0128Since the LNA <b>500</b> applied to the present invention is a technical element that may be implemented by a person having ordinary skill in the art using the known art, a detailed description thereof will be omitted here.

0129Meanwhile, if the filter unit <b>400</b> and the LNA <b>500</b> are included in the flexible circuit board <b>200</b>, they may be included in separate areas on the same plane as the chip antenna <b>100</b>, as shown in <figref idref="DRAWINGS">FIGS. 19 and 20</figref>, or may be included on the other face (i.e., an area ‘A’ in <figref idref="DRAWINGS">FIG. 21</figref>) opposite to the one face on the flexible circuit board <b>200</b> on which the chip antenna <b>100</b> is mounted as shown in <figref idref="DRAWINGS">FIG. 21</figref>. The filter unit <b>400</b> and the LNA <b>500</b> may be included on different faces. In this case, when the internal antenna module according to the present invention is subsequently mounted on a main printed circuit board (not shown), a spatial burden can be reduced and space utilization can be increased. Accordingly, the degree of freedom of a structure in which a part is installed within a terminal can be improved.

0130<figref idref="DRAWINGS">FIG. 22</figref> is a graph showing the frequency bands of the internal antenna module according to the fourth embodiment of the present invention. <figref idref="DRAWINGS">FIG. 22</figref> is a graph showing the frequencies of reception signals received via the first conductive pad <b>210</b> and the second conductive pad <b>220</b> and signal interference of the reception signals when the internal antenna module according to the fourth embodiment of the present invention is used.

0131“A” as shown in <figref idref="DRAWINGS">FIG. 22(</figref><i>a</i>) is the frequency of a reception signal received via the first conductive pad <b>210</b> (i.e., a reception signal received when both the first radiant pattern <b>120</b> and the second radiant pattern <b>230</b> operate as one antenna (i.e., a reception signal at an FM frequency)). “B” is the degree of isolation between a reception signal received via the second conductive pad <b>220</b> (i.e., a reception signal received from the second radiant pattern <b>230</b> (i.e., a reception signal of a Bluetooth frequency)) and a reception signal received via the first conductive pad <b>210</b>.

0132The frequency of the reception signal (i.e., “A” in <figref idref="DRAWINGS">FIG. 22(</figref><i>a</i>)) received via the first conductive pad <b>210</b> shows that it has a resonant frequency band of about 87.5 MHz to 108 MHz. That is, the radiation part formed on the flexible circuit board <b>200</b> and the first radiant pattern <b>120</b> formed on the chip antenna <b>100</b> form one radiation line, thus receiving the reception signal in a low frequency band (i.e., an FM frequency band (87.5 MHz to 108 MHz)).

0133Here, the degree of isolation (i.e., “B” in <figref idref="DRAWINGS">FIG. 22(</figref><i>a</i>)) of the reception signal received through the first conductive pad <b>210</b> is about 17 dB. It can be seen that the degree of interference of the reception signal received via the second radiant pattern <b>230</b>, affecting the reception signal received via the first conductive pad <b>210</b>, is weak

0134“C” as shown in <figref idref="DRAWINGS">FIG. 22(</figref><i>b</i>) is the frequency of a reception signal received via the second conductive pad <b>220</b> (i.e., a reception signal received from the second radiant pattern <b>230</b> (i.e., a reception signal of a Bluetooth frequency)). “D” is the degree of isolation between a reception signal received via the second conductive pad <b>220</b> (i.e., a reception signal of a Bluetooth frequency) and a reception signal via the first conductive pad <b>210</b> (i.e., a reception signal received when both the first radiant pattern <b>120</b> and the second radiant pattern <b>230</b> operate as one antenna (i.e., a reception signal of an FM frequency)).

0135The frequency of the reception signal (i.e., “B” in <figref idref="DRAWINGS">FIG. 22</figref>) received via the second conductive pad <b>220</b> shows that a resonant frequency band is about 2.4 GHz. That is, coupling is generated because the second conductive pad <b>220</b> is adjacent to the radiation part in a meander line form. The radiation part in a meander line form plays the role of a λ/4 resonant line in the Bluetooth frequency band. Accordingly, the internal antenna module operates as a monopole antenna using coupling, thus receiving a reception signal having a frequency in the Bluetooth frequency band.

0136Here, the degree of isolation (i.e., “D” in <figref idref="DRAWINGS">FIG. 22(</figref><i>b</i>)) of the reception signal received via the second conductive pad <b>220</b> is about 32.6 dB. It can be seen that the degree of interference of the reception signal received via the first conductive pad <b>210</b>, affecting the reception signal received via the second conductive pad <b>220</b>, is weak

Fifth Embodiment

0137Hereinafter, an internal antenna module according to a fifth embodiment of the present invention will be described in more detail with reference to the accompanying drawings <figref idref="DRAWINGS">FIGS. 23 and 24</figref> are diagrams illustrating the internal antenna module according to the fifth embodiment of the present invention. First, since the chip antenna of the internal antenna module according to the fifth embodiment of the present invention is the same as the chip antenna described with reference to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, descriptions thereof will be omitted here and the same reference numerals will be assigned. Furthermore, since an FM signal processing module <b>600</b> and a Bluetooth signal processing module <b>700</b> are technical elements that may be easily implemented by a person having ordinary skill in the art using the known art, a detailed description thereof will be omitted here.

0138As shown in <figref idref="DRAWINGS">FIG. 23</figref>, the internal antenna module includes a chip antenna <b>100</b>, and a flexible circuit board <b>200</b>.

0139The chip antenna <b>100</b> is mounted on any one face (e.g., a top surface of the flexible circuit board <b>200</b>) of the flexible circuit board <b>200</b>.

0140The flexible circuit board <b>200</b> includes a first conductive pad <b>210</b>, a second conductive pad <b>220</b>, and a second radiant pattern <b>230</b>, and a third radiant pattern <b>260</b>.

0141The first conductive pad <b>210</b> is used as a feeding pad, and is soldered and electrically connected to the first radiant pattern <b>120</b> I₁formed at the end of one side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>. Here, one side of the first conductive pad <b>210</b> is electrically connected to an FM signal processing module <b>600</b>, and sends an signal in the FM frequency band, received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>, to the FM signal processing module <b>600</b>.

0142The second conductive pad <b>220</b> is used as a ground pad. The second conductive pad <b>220</b> is soldered and electrically connected to the coupling pattern <b>125</b> formed on the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>. Here, one side of the second conductive pad <b>220</b> is electrically connected to a ground GND.

0143The second radiant pattern <b>230</b> is formed in a specific meander line form (e.g., a “<img file="US2012280867A1_D0003.tif" />” form), and is soldered and electrically connected to the first radiant pattern <b>120</b> I_k+1formed at the end of the other side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>. For this purpose, the second radiant pattern <b>230</b> includes a connection part connected to the first radiant pattern <b>120</b> I_k+1and a radiation part configured to extend from the connection part and formed outside an area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b>. Here, the radiation part of the second radiant pattern <b>230</b> is formed in a meander line form, and the radiation part and the connection part may be distinguished from each other based on the bent part <b>235</b>. That is, a part soldered to the first radiant pattern <b>120</b> I_k+1based on the bent part <b>235</b> of the second radiant pattern <b>230</b> corresponds to the connection part, and a part configured to extend from the connection part and formed outside the area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b> corresponds to the radiation part in a meander line form. This will be applied to the following drawings in the same manner.

0144When the second radiant pattern <b>230</b> is electrically connected to the first radiant pattern <b>120</b> I_k+1formed at the end of the other side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>, the first radiant pattern <b>120</b> and the second radiant pattern <b>230</b> formed on the flexible circuit board <b>200</b> form one radiation line.

0145The third radiant pattern <b>260</b> is spaced apart from the second radiant pattern <b>230</b> by a specific interval. The third radiant pattern <b>260</b> is formed in parallel to the second radiant pattern <b>230</b> and formed in a specific meander line form (e.g., a form in which “<img file="US2012280867A1_D0004.tif" />” and “<img file="US2012280867A1_D0005.tif" />” are combined). The third radiant pattern <b>260</b> is formed outside the area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b>. One side of the third radiant pattern <b>260</b> is electrically connected to a Bluetooth signal processing module <b>700</b>. The third radiant pattern <b>260</b> operates as a Bluetooth antenna that receives a signal in the Bluetooth frequency band and sends the signal to the Bluetooth signal processing module <b>700</b>.

0146As shown in <figref idref="DRAWINGS">FIG. 24</figref>, the internal antenna module may further include a filter unit <b>400</b> and an LNA <b>500</b>.

0147The filter unit <b>400</b> is provided on the flexible circuit board <b>200</b>. One side of the filter unit <b>400</b> is electrically connected to the first radiant pattern <b>120</b> formed on the polyhedral block <b>110</b> via the first conductive pad <b>210</b>, and the other side thereof is electrically connected to the LNA <b>500</b>. The filter unit <b>400</b> removes a high frequency component from a reception signal received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>. In the case of Bluetooth, a terminal and a Bluetooth device periodically generate a transmission signal in the Bluetooth frequency band for the purpose of communication between the terminal and the Bluetooth device. Accordingly, the reception signal in the FM frequency band may interfere with the transmission signal in the Bluetooth frequency band. The filter unit <b>400</b> removes the high frequency component in order to prevent signal interference from being generated in the reception signal due to the transmission signal in the Bluetooth frequency band.

0148The LNA <b>500</b> is provided on the flexible circuit board <b>200</b>, and is electrically connected to the filter unit <b>400</b>. The LNA <b>500</b> amplifies the reception signal from which the high frequency component has been removed by the filter unit <b>400</b> (i.e., the reception signal in an FM frequency band from which signal interference due to the transmission signal in the Bluetooth frequency band has been removed), thereby enabling FM radio to be received at a high RSSI level. The LNA <b>500</b> is designed by setting an operating point and a matching point so that the reception signal has a low Noise Factor (NF). The reception signal amplified by the LNA <b>500</b> is input into the FM signal processing module <b>600</b>.

0149Since the LNA <b>500</b> applied to the present invention is a technical element that may be implemented by a person having ordinary skill in the art using the known art a detailed description thereof will be omitted here.

MODIFIED EXAMPLE OF FIFTH EMBODIMENT

0150Hereinafter, an internal antenna module according to the modified example of the fifth embodiment of the present invention will be described in detail with reference to the accompanying drawings. <figref idref="DRAWINGS">FIGS. 25 and 26</figref> are diagrams illustrating the internal antenna module according to the modified example of the fifth embodiment of the present invention. First, since the chip antenna of the internal antenna module according to the modified example of the fifth embodiment of the present invention is the same as the chip antenna described with reference to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, a description thereof will be omitted here and the same reference numerals will be assigned. Furthermore, since an FM signal processing module <b>600</b>, a Bluetooth signal processing module <b>700</b>, and a GPS signal processing module <b>900</b> are technical elements that may be easily implemented by a person having ordinary skill in the art using the known art, detailed descriptions thereof will be omitted here.

0151As shown in <figref idref="DRAWINGS">FIG. 25</figref>, the internal antenna module includes a chip antenna <b>100</b> and a flexible circuit board <b>200</b>. As shown in <figref idref="DRAWINGS">FIG. 26</figref>, the internal antenna module may further include a filter unit <b>400</b> and an LNA <b>500</b>. Here, since the filter unit <b>400</b> and the LNA <b>500</b> are the same as those of the fifth embodiment, detailed descriptions thereof will be omitted here.

0152The chip antenna <b>100</b> is mounted on any one face (e.g., a top surface of the flexible circuit board <b>200</b>) of the flexible circuit board <b>200</b>.

0153The flexible circuit board <b>200</b> includes a first conductive pad <b>210</b>, a second conductive pad <b>220</b>, a second radiant pattern <b>230</b>, a third radiant pattern <b>260</b>, and a fourth radiant pattern <b>270</b>. Since the first conductive pad <b>210</b>, the second conductive pad <b>220</b>, the second radiant pattern <b>230</b>, and the third radiant pattern <b>260</b> are the same as those of the fifth embodiment, detailed descriptions thereof will be omitted here.

0154The fourth radiant pattern <b>270</b> is spaced apart from the third radiant pattern <b>260</b> by a specific interval. The fourth radiant pattern <b>270</b> is formed in parallel to the third radiant pattern <b>260</b> and formed in a specific meander line form (e.g., a “<img file="US2012280867A1_D0006.tif" />” form). Here, the fourth radiant pattern <b>270</b> is formed outside the area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b>. One side of the fourth radiant pattern <b>270</b> is electrically connected to the GPS signal processing module <b>900</b>. The fourth radiant pattern <b>270</b> operates as a GPS antenna that receives a signal of a GPS frequency band and sends the signal to the GPS signal processing module <b>900</b>.

0155The internal antenna module according to the modified example of the fifth embodiment of the present invention receives signals in the FM frequency, the Bluetooth frequency, and the GPS frequency, and therefore it does not require additional Bluetooth and GPS antennas. Accordingly, it is possible to apply the internal antenna module of the present embodiment to a mobile communication terminal, thereby reducing the size and width of the mobile communication terminal.

Sixth Embodiment

0156Hereinafter, an internal antenna module according to a sixth embodiment of the present invention will be described in detail with reference to the accompanying drawings. <figref idref="DRAWINGS">FIGS. 27 and 28</figref> are diagrams illustrating the internal antenna module according to the sixth embodiment of the present invention. First, since the chip antenna of the internal antenna module according to the sixth embodiment of the present invention is the same as the chip antenna described with reference to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, a description thereof will be omitted here and the same reference numeral will be assigned. Furthermore, since an FM signal processing module <b>600</b> and a GPS signal processing module <b>700</b> are technical elements that may be easily implemented by a person having ordinary skill in the art using the known art, a detailed description thereof will be omitted here.

0157As shown in <figref idref="DRAWINGS">FIG. 27</figref>, the internal antenna module includes a chip antenna <b>100</b> and a flexible circuit board <b>200</b>.

0158The chip antenna <b>100</b> is mounted on any one face (e.g., a top surface of the flexible circuit board <b>200</b>) of the flexible circuit board <b>200</b>.

0159The flexible circuit board <b>200</b> includes a first conductive pad <b>210</b>, a second conductive pad <b>220</b>, and a second radiant pattern <b>230</b>, and a third radiant pattern <b>260</b>.

0160The first conductive pad <b>210</b> is used as a feeding pad, and is soldered and electrically connected to the first radiant pattern <b>120</b> I₁formed at the end of one side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>. Here, one side of the first conductive pad <b>210</b> is electrically connected to an FM signal processing module <b>600</b>, and sends an FM frequency band signal, received via the chip antenna <b>100</b> and the flexible circuit board <b>200</b>, to the FM signal processing module <b>600</b>.

0161The second conductive pad <b>220</b> is used as a ground pad. The second conductive pad <b>220</b> is soldered and electrically connected to the coupling pattern <b>125</b> formed on the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>. Here, one side of the second conductive pad <b>220</b> is electrically connected to a ground GND.

0162The second radiant pattern <b>230</b> is formed in a specific meander line form (e.g., a “<img file="US2012280867A1_D0007.tif" />” form), and is soldered and electrically connected to the first radiant pattern <b>120</b> I_k+1formed at the end of the other side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>. For this purpose, the second radiant pattern <b>230</b> includes a connection part connected to the first radiant pattern <b>120</b> I_k+1and a radiation part configured to extend from the connection part and formed outside an area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b>. Here, the radiation part of the second radiant pattern <b>230</b> is formed in a meander line form, and the radiation part and the connection part may be distinguished from each other based on the bent part <b>235</b>. That is, a part soldered to the first radiant pattern <b>120</b> I_k+1based on the bent part <b>235</b> of the second radiant pattern <b>230</b> corresponds to the connection part, and a part extended from the connection part and formed outside the area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b> corresponds to the radiation part in a meander line form. The same principle applies to the following drawings.

0163When the second radiant pattern <b>230</b> is electrically connected to the first radiant pattern <b>120</b> I_k+1formed at the end of the other side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b>, the first radiant pattern <b>120</b> and the second radiant pattern <b>230</b> formed on the flexible circuit board <b>200</b> form one radiation line.

0164The third radiant pattern <b>260</b> is spaced apart from the second radiant pattern <b>230</b> by a specific interval. The third radiant pattern <b>260</b> is formed in parallel to the second radiant pattern <b>230</b>, and is formed in a specific meander line form (e.g., a “<img file="US2012280867A1_D0008.tif" />” form). The third radiant pattern <b>260</b> is formed outside the area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b>. One side of the third radiant pattern <b>260</b> is electrically connected to a GPS signal processing module <b>900</b>. The third radiant pattern <b>260</b> operates as a GPS antenna for receiving a signal of a GPS frequency band and sending the signal to the GPS signal processing module <b>900</b>.

0165As shown in <figref idref="DRAWINGS">FIG. 28</figref>, the internal antenna module may further include a filter unit <b>400</b> and an LNA <b>500</b>. Here, the filter unit <b>400</b> and the LNA <b>500</b> are the same as those of the fifth embodiment, and a detailed description thereof will be omitted here.

MODIFIED EXAMPLE OF THE SIXTH EMBODIMENT

0166Hereinafter, an internal antenna module according to a modified example of the sixth embodiment of the present invention will be described in detail with reference to the accompanying drawings. <figref idref="DRAWINGS">FIGS. 29 and 30</figref> are diagrams illustrating the internal antenna module according to the modified example of the sixth embodiment of the present invention. First, since the chip antenna of the internal antenna module according to the modification of the sixth embodiment of the present invention is the same as the chip antenna described with reference to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, a description thereof will be omitted here and the same reference numerals will be assigned. Furthermore, since an FM signal processing module <b>600</b>, a Bluetooth signal processing module <b>700</b>, and a GPS signal processing module <b>900</b> are technical elements that may be easily implemented by a person having ordinary skill in the art using the known art, detailed descriptions thereof will be omitted here.

0167As shown in <figref idref="DRAWINGS">FIG. 29</figref>, the internal antenna module includes a chip antenna <b>100</b> and a flexible circuit board <b>200</b>. As shown in <figref idref="DRAWINGS">FIG. 30</figref>, the internal antenna module may further include a filter unit <b>400</b> and an LNA <b>500</b>. Here, since the filter unit <b>400</b> and the LNA <b>500</b> are the same as those of the sixth embodiment, detailed descriptions thereof will be omitted here.

0168The chip antenna <b>100</b> is mounted on any one face (e.g., a top surface of the flexible circuit board <b>200</b>) of the flexible circuit board <b>200</b>.

0169The flexible circuit board <b>200</b> includes a first conductive pad <b>210</b>, a second conductive pad <b>220</b>, a second radiant pattern <b>230</b>, a third radiant pattern <b>260</b>, and a fourth radiant pattern <b>270</b>. Here, since the first conductive pad <b>210</b>, the second conductive pad <b>220</b>, the second radiant pattern <b>230</b>, and the third radiant pattern <b>260</b> are the same as those of the sixth embodiment, detailed descriptions thereof will be omitted here.

0170The fourth radiant pattern <b>270</b> is spaced apart from the third radiant pattern <b>260</b> by a specific interval. The fourth radiant pattern <b>270</b> is formed in parallel to the third radiant pattern <b>260</b>, and is formed in a specific meander line form (e.g., a form in which “<img file="US2012280867A1_D0009.tif" />” and “<img file="US2012280867A1_D0010.tif" />” are combined). The fourth radiant pattern <b>270</b> is formed outside an area on which the polyhedral block <b>110</b> is mounted on the flexible circuit board <b>200</b>. One side of the fourth radiant pattern <b>270</b> is electrically connected to the Bluetooth signal processing module <b>700</b>. The fourth radiant pattern <b>270</b> operates as a Bluetooth antenna that receives a signal in the Bluetooth frequency band and sends the signal to the Bluetooth signal processing module <b>700</b>.

0171The internal antenna module according to the modified example of the sixth embodiment of the present invention receives signals at FM, Bluetooth and GPS frequencies, and therefore it does not require an additional Bluetooth antenna and an additional GPS antenna. Accordingly, it is possible to apply the internal antenna module of the present embodiment to a mobile communication terminal, thereby reducing the size and width of the mobile communication terminal.

Seventh Embodiment

0172Hereinafter, an internal antenna module according to a seventh embodiment of the present invention will be described in detail with reference to the accompanying drawings. <figref idref="DRAWINGS">FIGS. 31 and 32</figref> are diagrams illustrating the internal antenna module according to the seventh embodiment of the present invention. First, since the chip antenna of the internal antenna module according to the seventh embodiment of the present invention is the same as the chip antenna described with reference to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, a description thereof will be omitted here and the same reference numerals will be assigned. Furthermore, since an FM signal processing module <b>600</b> and a Bluetooth signal processing module <b>700</b> are technical elements that may be easily implemented by a person having ordinary skill in the art using the known art, detailed descriptions thereof will be omitted here.

0173As shown in <figref idref="DRAWINGS">FIG. 31</figref>, the internal antenna module includes a chip antenna <b>100</b> and a flexible circuit board <b>200</b>. As shown in <figref idref="DRAWINGS">FIG. 32</figref>, the internal antenna module may further include a filter unit <b>400</b> and an LNA <b>500</b>. Here, since the filter unit <b>400</b> and the LNA <b>500</b> are the same as those of the sixth embodiment, detailed descriptions thereof will be omitted here.

0174The chip antenna <b>100</b> is mounted on any one face (e.g., a top surface of the flexible circuit board <b>200</b>) of the flexible circuit board <b>200</b>.

0175The flexible circuit board <b>200</b> includes a first conductive pad <b>210</b>, a second conductive pad <b>220</b>, a connection pad <b>225</b>, a second radiant pattern <b>230</b>, and a switching element <b>280</b>. Here, since the first conductive pad <b>210</b> and the second conductive pad <b>220</b> are the same as those of the fourth embodiment, detailed descriptions thereof will be omitted here.

0176The connection pad <b>225</b> is soldered and electrically connected to the first radiant pattern <b>120</b> I_k+1formed on the bottom of the polyhedral block Here, the connection pad <b>225</b> is electrically connected to the second radiant pattern <b>230</b> via the switching element <b>280</b>.

0177The second radiant pattern <b>230</b> is formed in a specific meander line form (e.g., a form in which “<img file="US2012280867A1_D0011.tif" />” and a bent “1” are combined). One side of the second radiant pattern <b>230</b> is electrically connected to the Bluetooth signal processing module <b>700</b>. Here, the second radiant pattern <b>230</b> is connected to the connection pad <b>225</b>, connected to the first radiant pattern <b>120</b> I_k+1, via the switching element <b>280</b>. When the second radiant pattern <b>230</b> is electrically connected to the first radiant pattern <b>120</b> I_k+1formed at the end of the other side of the bottom <b>110</b><i>b </i>of the polyhedral block <b>110</b> via the switching element <b>280</b>, the first radiant pattern <b>120</b> and the second radiant pattern <b>230</b> formed on the flexible circuit board <b>200</b> form one radiation line.

0178The switching element <b>280</b> is formed on the flexible circuit board <b>200</b>. One side of the switching element <b>280</b> is connected to the connection pad <b>225</b>, and the other side thereof is connected to the second radiant pattern <b>230</b>. That is, one side of the switching element <b>280</b> is soldered and electrically connected to the connection pad <b>225</b>, and the other side thereof is soldered and electrically connected to the second conductive pad <b>220</b>. The switching element <b>280</b> is formed of an inductor that transmits a reception signal in an FM frequency band and blocks a reception signal of a Bluetooth band. The purpose of this is to separate the reception signal in an FM frequency band and the reception signal in the Bluetooth band using the characteristics of the inductor which has an impedance that increases when a passing frequency increases and thus operates as an LPF and has an impedance that falls when a passing frequency falls and thus operates as an HPF. The inductor used as the switching element <b>280</b> has about 22 nH that transmits a reception signal in an FM frequency band (about 87.5 to 108 MHz) and blocks a reception signal of a Bluetooth band (about 2.45 GHz).

0179The switching element <b>280</b> severs the connection with the connection pad <b>225</b> depending on the frequency of a reception signal received via the second radiant pattern <b>230</b>.

0180Here, the switching element <b>280</b> maintains the connection with the connection pad <b>225</b> when the frequency of the reception signal is a low frequency and severs the connection with the connection pad <b>225</b> when the frequency of the reception signal is a high frequency so that the second radiant pattern <b>230</b> operates as a monopole antenna. That is, when a reception signal in the FM frequency band (i.e., at a low frequency) is received, the switching element <b>280</b> maintains the connection with the connection pad <b>225</b> so that the first radiant pattern and the second radiant pattern <b>230</b> play the role of one radiation line. When a reception signal in the Bluetooth frequency band (i.e., at a high frequency) is received, the switching element <b>280</b> severs the connection with the connection pad <b>225</b> so that the second radiant pattern <b>230</b> plays the role of a monopole antenna for receiving the Bluetooth frequency band signal.

0181The switching element <b>280</b> formed of the inductor having 22 nH will now be described in more detail. When a reception signal in the FM frequency band (i.e., a low frequency) is received via the second radiant pattern <b>230</b>, the inductor maintains the connection pad <b>225</b> and the second radiant pattern <b>230</b> in a connected state and thus plays the role of a line that transmits the reception signal to the first radiant pattern. When a reception signal in the Bluetooth frequency band (i.e., at a high frequency) is received via the second radiant pattern <b>230</b>, the inductor is opened, so that the reception signal is prevented from reaching the first radiant pattern via the connection pad <b>225</b>. Accordingly, the second radiant pattern <b>230</b> operates as a Bluetooth antenna.

0182Meanwhile, the reception signal in the Bluetooth frequency band blocked by the switching element <b>280</b> is input to the Bluetooth signal processing module <b>700</b>.

0183<figref idref="DRAWINGS">FIG. 33</figref> is a graph showing the frequency bands of the internal antenna module according to the seventh embodiment of the present invention. <figref idref="DRAWINGS">FIG. 33</figref> is a graph showing the frequencies of reception signals received via the first conductive pad <b>210</b> and the second conductive pad <b>220</b> and the signal interference of the reception signals when the internal antenna module according to the seventh embodiment of the present invention is used.

0184“E” as shown in <figref idref="DRAWINGS">FIG. 33(</figref><i>a</i>) is the frequency of the reception signal received through the first conductive pad <b>210</b>, and “F′ is the degree of isolation of the reception signal received through the first conductive pad <b>210</b> and the reception signal received through the second conductive pad <b>220</b>.

0185The frequency of the reception signal (i.e., “E” in <figref idref="DRAWINGS">FIG. 29(</figref><i>a</i>)) received through the first conductive pad <b>210</b> shows that the resonant frequency band is about 87.5 MHz to 108 MHz. That is, the second radiant pattern <b>230</b> formed on the flexible circuit board <b>200</b> and the first radiant pattern <b>120</b> formed on the chip antenna <b>100</b> form one radiation line via the connection pad <b>225</b> and thus receive the reception signal in the low frequency band (i.e., the FM frequency band (87.5 MHz to 108 MHz)).

0186Here, the degree of isolation of the reception signal (i.e., “F′ in <figref idref="DRAWINGS">FIG. 29(</figref><i>a</i>)) received through the first conductive pad <b>210</b> is about 23.3 dB. It can be seen that the degree of interference of the reception signal received through the second conductive pad <b>220</b>, affecting the reception signal received through the first conductive pad <b>210</b>, is weak

0187In <figref idref="DRAWINGS">FIG. 33(</figref><i>b</i>), “G” is the frequency of the reception signal received through the second conductive pad <b>220</b>, and “H” is the degree of isolation of the reception signal received through the second conductive pad <b>220</b> and the reception signal received through the first conductive pad <b>210</b>.

0188The frequency of the reception signal (i.e., “G” in <figref idref="DRAWINGS">FIG. 29(</figref><i>b</i>)) received through the second conductive pad <b>220</b> shows that a resonant frequency band is about 2.4 GHz. That is, the second conductive pad <b>220</b> plays the role of a λ/4 resonant line in the Bluetooth frequency band, and receives a reception signal having the frequency in the Bluetooth frequency band.

0189Here, the degree of isolation of the reception signal (i.e., “H” in <figref idref="DRAWINGS">FIG. 29(</figref><i>b</i>)) received through the second conductive pad <b>220</b> is about 21.3 dB. It can be seen that the degree of interference of the reception signal received through the first conductive pad <b>210</b>, affecting the reception signal received through the second conductive pad <b>220</b>, is weak.

0190Although in the embodiments of the present invention, the filter unit <b>400</b> and the LNA <b>500</b> are illustrated as being mounted on the flexible circuit board <b>200</b>, the present invention is not limited thereto. For example, the filter unit <b>400</b> and the LNA <b>500</b> may be integrated with the FM signal processing module, and may process relevant functions.

0191Although the preferred embodiments of the present invention have been described, it will be appreciated by those skilled in the art will appreciate that various variations and modifications are possible without departing from the scope of the invention as disclosed in the accompanying claims.