WO2009035180A1

WO2009035180A1 - Strap-typed dmb antenna apparatus for mobile communication terminal

Info

Publication number: WO2009035180A1
Application number: PCT/KR2007/004547
Authority: WO
Inventors: Yong -Il Song
Original assignee: Digiwave Co., Ltd
Priority date: 2007-09-10
Filing date: 2007-09-19
Publication date: 2009-03-19
Also published as: KR100778002B1

Abstract

The present invention relates to a DMB antenna apparatus for a mobile communication terminal, and more particularly to a strap-typed DMB antenna apparatus for a mobile communication terminal capable of receiving DMB signals. The strap-typed DMB antenna apparatus in accordance with the present invention comprises a flexible circuit board folded in an extending direction thereof; an electrically conductive radiator for receiving DMB signals which is printed on one side of the flexible circuit board; and a sliding tab capable of sliding in the extending direction of the folded circuit board, uniting the folded circuit board, wherein a frequency band of the DMB signals received by the radiator is changed by sliding the sliding tab. Accordingly, in accordance with the present invention, there is provided an antenna with an extended electrical length so as to be suitable for a transmission or reception of low frequency signals while keeping the size of the antenna small. Alternatively, in accordance with the present invention, there is provided an antenna apparatus properly adjusting the resonant frequency and bandwidth thereof is provided so as to excellently receive the total DMB channel in a VHF band by extending the electrical length of the antenna even if a received bandwidth is narrow. Further, in accordance with the present invention, there is provided a strap-typed DMB antenna apparatus usually used for a hand strap in addition to a DMB receiving antenna for a mobile communication terminal and thereby the portability and convenience of the DMB antenna is improved.

Description

[DESCRIPTION] [Invention Title]

STRAP-TYPED DMB ANTENNA APPARATUS FOR MOBILE COMMUNICATION TERMINAL [Technical Field]

<i> The present invention relates to an antenna apparatus for a mobile communication terminal, and more particularly to a strap-typed DMB(Digital Multimedia Broadcasting) antenna apparatus for a mobile communication terminal capable of receiving DMB signals. [Background Art]

<2> In wireless communication system capable of transmitting or receiving information using electromagnetic waves, an antenna which induces electric currents from electromagnetic waves or induces electromagnetic waves from electric currents must be essentially incorporated as a endmost terminal element to an analog circuit for the wireless communication system. The structures of antennas are categorized to a dipole antenna, a monopole antenna, etc, and in a handheld wireless communication apparatus, a small- sized monopole antenna is more preferred. The monopole antenna is designed to have a 1/4 length of resonant wavelength (generally, a wavelength with respect to a center frequency in a target frequency band) due to the mirror effect of ground surface. Thus, the longer the wavelength of used signals used becomes (that is, the lower the frequency of the signals becomes), the longer the monopole antenna becomes.

<3> Meanwhile, a VHF band means a frequency band of 30 ~ 300 MHz, and has been generally used for FM radio broadcasting or TV broadcasting services. Recently, Terrestrial DMB(TDMB) services was designated to use a VHF band of 170 ~ 220 MHz, and as a result, terminals for receiving signals at a VHF band and antennas used therefor is being actively developed.

<4> Signals of the VHF band have a greatly lower frequency, that is, a greatly longer than those of a frequency band for cellular services of 900 MHz band or PCS(Personal Communications Service) of 2.4 GHz. If Signals at a frequency band with a center frequency of 200 MHz are received by an antenna, a resonant frequency of the antenna is also set to 200 MHz, and the electrical length of a monopole antenna becomes about 37.5 cm. However, considering the trend that the size of DMB mobile communication terminal (mobile phone, PDA or navigation, etc) becomes smaller, antennas with the length of more than 30 cm are not practical .

<5> Helical antennas have been suggested in order to reduce the external size of the monopole antennas by forming the monopole antennas in a helical shape. However, even if the helical antenna is used, some problems such as the increase in the diameter of the antenna due to the reduction in the size of the antenna, the increase in capacitance due to the reduction in the pitch of the helix, and etc limit the miniaturization of the antenna. Particularly, if capacitance increases, the radiation efficiency of the antenna is degraded. Thus, the miniaturization of the antenna becomes more difficult. Further, in fabrication, the helical antenna has low economical efficiency due to a high failure rate.

<6> As another prior art, there was known a method of extending the electrical length of an antenna by using a multi-staged rod antenna. If the multi-staged rod antenna is used, the length of the rod antenna can be greatly reduced when it is drawn. However, the multi-staged rod antenna is enlarged when the rod antenna is extended. For this reason, the rod antenna has problems in that it is vulnerable to external physical impacts and is easily broken by external forces. Furthermore, the multi-staged load antenna can be easily carried because the length thereof is shrunk when it is inserted. However, when the antenna is drawn, the length thereof is extended. Thus, there is no effect of the shrunken antenna size when the antenna is substantially used for the terminal.

<7> Moreover, there has been suggested many various ways for improving receive performance by extending the electrical length of an antenna while keeping the physical length of the antenna short. However, there are some problems in that antenna gain is reduced and a received frequency bandwidth becomes narrow. <8> If the received frequency bandwidth becomes narrow, the total frequency band of broadband services such as a high VHF band used for Terrestrial DMB services is difficult to receive. Accordingly, there happen some problems that only broadcasting signals of a particular channel out of many channels in DMB band is received, and that the other channels are difficult to receive. Actually, there happens a phenomenon that the receive performance of a frequency band of 181.280 ~ 184.736 MHz allocated to channel No. 8 is greatly degraded as compared to that of a frequency band of 205.280 ~ 208.736 MHz allocated to channel No. 12. [Disclosure] [Technical Problem]

<9> In order to solving the above-mentioned problems, one object of the present invention is to provide an antenna with an extended electrical length so as to be suitable for a transmission or reception of low frequency signals while keeping the size of the antenna small.

<io> Alternative object of the present invention is to provide an antenna properly adjusting the resonant frequency and bandwidth thereof so as to excellently receive the total DMB channel in a VHF band by extending the electrical length of the antenna even if a received bandwidth becomes narrow.

<ii> Another alternative object of the present invention is to provide a strap-typed DMB antenna usually used for a hand strap in addition to a DMB receiving antenna for a mobile communication terminal. [Technical Solution]

<12> To achieve the above-mentioned objects, according to an embodiment of the present invention, there is provided a strap-typed DMB antenna apparatus comprising a flexible circuit board folded in an extending direction thereof; an electrically conductive radiator for receiving DMB signals which is printed on one side of the flexible circuit board; and a sliding tab capable of sliding in the extending direction of the folded circuit board, uniting the folded circuit board, wherein a frequency band of the DMB signals received by the radiator is changed by sliding the sliding tab. <13> Preferably, the flexible circuit board is a flexible printed circuit board (FPCB).

<14> Preferably, the radiator is printed in a shape of meander.

<i5> Preferably, the flexible circuit board is covered with leather, plastic, natural fiber, or synthetic fiber.

<16> Preferably, the apparatus further comprises a body part to which at least one end of the flexible circuit board is fixed; and a connector for connecting one end of the radiator electrically to input and output terminals for a mobile communication terminal using the antenna apparatus, the connector being fixed to the body part.

<17> Preferably, the connector is one of a 24-pin connector for the mobile communication terminal, a 20-pin connector for the mobile communication terminal, or an earphone connector for a mobile communication terminal.

<18> Preferably, the apparatus further comprises a hinge part between the connector and the body part so that the connector can be rotated and bended.

<19> Preferably, the apparatus further comprises a cap removable from the body part whose internal hollow space can receive the connector.

<20> Preferably, the apparatus further comprises a connection string for appending the apparatus to the mobile communication terminal, the connection string being connected to the strap-typed DMB antenna apparatus, wherein the connection string passes through the cap and is connected to the mobile communication terminal.

<2i> Preferably, both ends of the flexible circuit board come in contact with each other, and the both ends of the circuit board is united and fixed by the body part .

<22> According to another embodiment of the present invention, there is provided a mobile communication terminal comprising a strap-typed DMB antenna for receiving DMB signals; a signal processing part for converting the DMB signals to baseband image signals; and a display part for displaying the image signals, the strap-typed DMB antenna apparatus comprising a flexible circuit board folded in an extending direction thereof; an electrically conductive radiator for receiving DMB signals which is printed on one side of the flexible circuit board; and a sliding tab capable of sliding in the extending direction of the folded circuit board, uniting the folded circuit board, wherein a frequency band of the DMB signals received by the radiator is changed by sliding the sliding tab.

[Advantageous Effects] <24> There is provided an antenna with an extended electrical length suitable for a transmission or reception of low frequency signals while keeping the size of the antenna small. <25> Alternatively, in accordance with the present invention, an antenna properly adjusting the resonant frequency and bandwidth thereof is provided so as to excellently receive the total DMB channel in a VHF band by extending the electrical length of the antenna even if a receiving bandwidth is narrow. <26> Further, in accordance with the present invention, a strap-typed DMB antenna usually used for a hand strap in addition to a DMB receiving antenna for a mobile communication terminal is provided. [Description of Drawings] <27> FIG. 1 is an illustration of a strap-typed DMB antenna in accordance with an embodiment of the present invention. <28> Fig. 2 is an illustration of an exemplary pattern of an electrically conductive radiator included in a strap-typed DMB antenna in accordance with an embodiment of the present invention. <29> Fig. 3 and Fig. 4 are an illustration of various shapes of connectors included in a strap-typed DMB antenna in accordance with an embodiment of the present invention. <30> Fig. 5 is an illustration of a mobile communication terminal including a strap-typed DMB antenna in accordance with an embodiment of the present invent ion . <3i> Fig. 6 is a schematic illustration of showing a relative position of a sliding tab of a strap-typed DMB antenna as the sliding tab slides along the strap in accordance with an embodiment of the present invention. <32> Fig. 7 to 10 illustrates a graph showing a voltage standing wave ratio of a strap-typed antenna apparatus measured as the sliding tab of the antenna apparatus slides in accordance with an embodiment of the present invention.

[Mode for Invention] <33> The embodiments are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, the term "electromagnetic coupling" is used to mean that two components are disposed with dielectric interposed therebetween or not so that current is mutually induced between the two components even if current path is not formed between the two components and the two components are electrically separated. The term "electromagnetic connection" is used to mean that two components are combined so that charge can move between the two components if the two components are electromagnet ical Iy combined, or if current path is not formed between the two components.

<34> FIG. 1 is an illustration of a strap-typed DMB antenna in accordance with an embodiment of the present invention.

<35> Referring to Fig. 1, a strap-typed DMB antenna apparatus 100 comprises a flexible circuit board 101 which is folded in an extending direction thereof, an electrically conductive radiator 102 printed on one side of the flexible circuit board 101, and a sliding tab 103 which is able to slide uniting the folded flexible circuit 101.

<36> Further, the strap-typed DMB antenna apparatus 100 further comprises a body part 104 to which at least one end of the flexible circuit board 101 is fixed and a connector 105 which connects one end of the electrically conductive radiator 102 electrically to a mobile communication terminal using the antenna apparatus 100.

<37> The flexible circuit board 101 is formed of a dielectric material so as to support the radiator 102, and as shown in Fig. 1, must have flexibility so that the flexible circuit board 101 may not be broken even if bent or folded. Preferably, the flexible circuit board 101 can be formed of a flexible printed circuit board (FPCB). Further, the flexible circuit board 101 can reduce effective wavelength in the radiator 102. Generally, as the effective

wavelength of electromagnetic waves in dielectric means λ , wherein λis a wavelength of electromagnetic wave and ε is a relative permittivity of the dielectric material, the effective wavelength can be reduced by using a relative permittivity which is more than one.

<38> The radiator 102 is printed on one side of the flexible circuit board 101, and is electrically connected through the connector 105 to a mobile communication terminal using the strap-typed DMB antenna apparatus 100 in accordance with the present invention. An embodiment of a printed pattern is shown in Fig. 2.

<39> Fig. 2 is an illustration of an exemplary pattern of an electrically conductive radiator included in a strap-typed DMB antenna in accordance with an embodiment of the present invention.

<40> Referring to Fig.2, the radiator 102 includes a connection part 201 and a line pattern 202. The connection part 201 is electrically connected to the connector 105. As shown in Fig. 2, the line pattern 202 can be formed in a shape of meander formed of various bent lines, and thereby a physical length of an antenna can be reduced. As above mentioned, typically, the antenna length must be about 37.5 cm so as to receive a VHF band. However, if the line pattern as shown in Fig. 2 is used, the length of the radiator 102 can be reduced up to about 16 cm - 20 cm.

<4i> Further, by folding in half the flexible circuit board 101 on which this radiator 102 is printed, the physical length of the antenna can be reduced up to about 8 cm - 10 cm. In other words, as the radiator 102 is configured to be in a shape of meander, the strap-typed DMB antenna in accordance with an embodiment of the present invention can reduce the physical length of the antenna. Further, as the flexible circuit board 101 with the radiator 102 printed thereon is folded in half and used, the effect that the physical length of the antenna can be once more reduced can be achieved.

<42> As typically, the length of about 8 cm - 10 cm is similar to that of a strap of a typical mobile communication terminal widely used, it is not inconvenient at all to carry a DMB receiving apparatus such as a mobile communication terminal, with the antenna of the length suspended to the DMB receiving apparatus. Therefore, because the strap-typed DMB antenna apparatus 100 in accordance with an embodiment of the present invention is suspended to a handheld DMB terminal such as a mobile communication terminal, the antenna apparatus can allow users to watch DMB by connecting the connector to a handheld DMB terminal, while the antenna may allow users to use it as a hand strap. As a result, the strap-typed DMB antenna apparatus 100 serve users much more convenience.

<43> Turning back to Fig.l, the sliding tab 103 unites the folded flexible circuit board 101. In this specification, to Folding the flexible circuit board 101 means to bend the flexible circuit board 101 using the flexibility thereof. By uniting the bent flexible circuit board 101 with the sliding tab 103, one part of the flexible circuit board 101 get overlapped. Thus, the circuit board 101 has a folded form.

<44> The sliding tab 103 is not immovably fixed to the flexible circuit board 101 but slidably mounted to the flexible circuit board 101 between the body part 104 and a folded part of the flexible circuit board 101. At the body part (104), the body part 103 can prevent the sliding tab 103 from coming out of the circuit board 101, and at the folded part of the flexible circuit board 101, the part thicken by folding the flexible circuit board 101 can prevent the sliding tab from coming out of the flexible circuit board 101. By adjusting appropriately the size of an opening formed at the central part of the sliding tab 103 so as to unite the folded flexible circuit board 101, the sliding can be allowed to slide only if a moderate force is exerted on the sliding tab 103. The method for sliding the sliding tab 103 and the effect thereof will be described later referring to Fig.5.

<45> At least one end of the flexible circuit board 101 is adhered and fixed to one end of the body part 104. Preferably, both ends of the flexible circuit board 101 come in contact with each other, the both ends is united and fixed by the body part. Further, the connector 105 which is electrically connected to an input/output terminal of a mobile communication terminal is combined to the other end of the body part 104. The connector 105 is electrically connected to one end of the radiator 102 printed on the flexible circuit board 101 inside the body part 104.

<46> The connector 105 is electrically connected to the input/output terminal of a mobile communication terminal using a strap-typed DMB antenna in accordance with an embodiment of the present invention so as to transmit DMB signals received through the radiator 102 to the mobile communication terminal .

<47> The standard of input/output terminals in Korean mobile communication terminal is established by Telecommunications Technology Association. One object of this standard is to maximize the usability of mobile terminal by facilitating a battery charging in a digital mobile communication terminal and a linkage with other peripheral devices outside, and the standard recommends the connection standards of input/output terminals in the mobile communication terminal.

<48> Similarly, the standards of the input/output terminals of the mobile communication terminal have been established for each country or each region of the same mobile communication services, but, the international standard thereof has no been established as yet. Therefore, the connector 105 may be defined by these various standards or may be adaptable for any of input/output terminals that would be defined later. For example, the connector 105 may be a 24-pin connector or 20-pin connector for a mobile communication terminal, or a earphone connector for a mobile communication terminal and so on. These various types of connectors 105 are shown in Fig. 3 and 4.

<49> Fig. 3(a) illustrates a part of a strap-typed DMB antenna apparatus including a 24-pin connector 301 for a mobile communication terminal, Fig. 3(b) illustrates a part of a strap-typed DMB antenna apparatus including a 20-pin connector 302 for a mobile communication terminal, and Fig. 3(c) illustrates a part of a strap-typed DMB antenna apparatus including an earphone connector 303 for a mobile communication terminal. Fig. 4 illustrates that a hinge part 106 is included between the connector and body part of Fig. 3. There is obvious to those skilled in the art that the types of connectors shown in Fig. 3 and 4 are suggested by way of example only and the connector 105 accordance with the present invention is not limited to these types.

<50> Returning to Fig. 1, as the rotation of the strap-typed DMB antenna apparatus may be requested for the improvement of the portability and receive performance of a mobile communication terminal when the antenna apparatus is connected to the mobile communication terminal, the hinge part 106 may be included between the connector 105 and the body part 104 so that the antenna can be rotated and bended. Thus, as the antenna apparatus can be rotated and bended by using the hinge part 106 when a receive status of DMB signals is poor, it is possible to improve the receive performance without further adjusting a position of the antenna apparatus.

<5i> Further, the strap-typed antenna apparatus 100 further comprises a cap 107 removable from the body part 104. One side of the cap 107 is open, and the other side of the cap 107 has a small hole which a connection string 108 can pass through. As the inside of the cap 107 is hollow, it receives the connector 105 when the cap 107 is combined to the body part 104. The case that the cap 107 is combined to the body part 104 is shown in Fig. 5.

<52> Fig.5 is an illustration of a mobile communication terminal including a strap-typed DMB antenna in accordance with an embodiment of the present invention.

<53> Referring to Fig. 5, a DMB mobile communication terminal 400 comprises a strap-typed DMB antenna apparatus 100 for receiving DMB signals, a signal processing part 401 for converting the DMB signals to baseband image signals, and a display part 402 for displaying the image signals.

<54> The strap-typed DMB antenna apparatus 100 comprises a flexible circuit board 101 which is folded in an extending direction thereof, an electrically conductive radiator 102 printed in a shape of meander on one side of the flexible circuit board 101, and a sliding tab 103 which is able to slide uniting the folded flexible circuit 101.

<55> The signal processing part 401 comprises a series of circuits for converting received DMB signals of a VHF band to image signals of a baseband, and as the specific constitution thereof is widely known in the art, the present specification does not describe it specifically. Further, the display part 402 displays images using image signals generated by the signal processing part 401, and as the specific constitution thereof is also widely known in the art, the present specification does not describe it specifically.

<56> Referring to Fig. 5, the strap-typed DMB antenna apparatus 100 is fixed to a DMB mobile communication terminal through a connection string 108 adhered to the cap 107. Therefore, it is possible to carry the strap-typed DMB antenna apparatus 100 on hand as an accessory such as a hand strap of a mobile communication terminal when DMB is not viewed, and only if DMB is viewed, it is possible to use the strap-typed DMB antenna apparatus 100 by combining the strap-typed DMB antenna apparatus electrically to the signal processing part 401 of a DMB receiving apparatus.

<57> Accordingly, it is possible to reduce a size and a unit cost of production of a DMB mobile communication terminal by not including an antenna for receiving DMB inside the DMB mobile communication terminal. Further, it is possible to carry a DMB receiving apparatus on hand with ease by using the strap-typed DMB antenna apparatus 100 as a hand strap. Furthermore, the strap-typed DMB antenna apparatus 100 can improve aesthetic impression on a DMB receiving apparatus as an accessory.

<58> If the strap-typed DMB antenna apparatus 100 is used as a hand strap, the external surface of the circuit board 101 may be covered with leather, plastic or a natural /synthetic fiber so as to improve a feeling of grip when the strap-typed DMB antenna apparatus 100 being gripped. Thus, this covering may allow the radiator 102 printed on the circuit board 101 to be protected.

<59> Further, as the cap 107 is fixed to a DMB receiving apparatus through the connection string 108, there is no concern about missing the cap. Furthermore, by employing the connection string 108 for connecting the cap 107 with the body part 104, it is possible to noticeably reduce the concern about losing the DMB receiving apparatus 100. The connection string 108 may have elasticity. Thus, by fixing the cap 107 to the mobile communication terminal and connecting the cap 107 with the body part 104, it is possible to carry the antenna apparatus 100 on hand all the time, and to reduce the concern about losing the antenna apparatus 100.

<60> Now referring to Fig. 6 to 10, the function of selecting a reception band of a strap-typed DMB antenna in accordance with the present invention wi 11 be described.

<6i> Fig.6 is a schematic illustration of showing a relative position of a sliding tab of a strap-typed DMB antenna as the sliding tab slides.

<62> As above-mentioned, the sliding tab 103 can slide uniting the folded circuit board 101. The range where the sliding tab can slides is between the body part 104 and the end part at which the circuit 101 is folded. If the position where the sliding tab 103 can not slide any more due to the body part 104 is set to ¹O' and the position where the sliding tab can not slide any longer because the thickness increased by folding the circuit board 101 is more than that of the opening of the sliding tab 103 is set to 'I¹, Fig. 6(a) illustrates that the sliding tab 103 is positioned at '0' Fig. 6(b) illustrates that the sliding tab 103 is positioned at '1/3', Fig. 6(c) illustrates that the sliding tab 103 is positioned at '2/3', Fig. 6(d) illustrates that the sliding tab 103 is positioned at '1'.

<63> Fig. 7 to 10 illustrates a graph showing a voltage standing wave ratio of an antenna apparatus measured when the sliding tab 103 is positioned at the position of ¹O¹, '1/3', '2/3' and ¹I', respectively.

<64> A "Voltage standing wave ratio (VSWR)" means the ratio of the amplitude at a maximum of a standing wave which is generated by the reflection of high frequency signals inputted to an antenna apparatus to the amplitude thereof at a minimum. As the VSWR approaches more approximately to '1', it means that the strap-typed antenna has a better impedance matching with respect to the corresponding frequency. Therefore, referring to Fig. 7 to 10, a bandwidth and a center frequency of the antenna apparatus 100 can be inferred.

<65> Fig. 7 illustrates a graph showing a VSWR of the strap-typed DMB antenna apparatus 100 measured in the case of Fig. 6(a). It can be understood that as the VSWR approaches to '1' when a frequency of inputted signals is about 180 MHz, the strap-typed antenna apparatus 100 is impedance- matched at a center frequency of about 180 MHz.

<66> Fig. 8 illustrates a graph showing a VSWR of a strap-typed DMB antenna apparatus 100 measured in the case of Fig. 6(b). It can be understood that as the VSWR approaches to '1' when a frequency of inputted signals is about 184 MHz, the strap-typed antenna apparatus 100 is impedance-matched at a center frequency of about 184 MHz.

<67> Fig. 9 illustrates a graph showing a VSWR of a strap-typed DMB antenna apparatus 100 measured in the case of Fig. 6(c). It can be understood that as the VSWR approaches to '1' when a frequency of inputted signals is about 190 MHz, the strap-typed antenna apparatus 100 is impedance-matched at a center frequency of about 190 MHz.

<68> Fig. 10 illustrates a graph showing a VSWR of a strap-typed DMB antenna apparatus 100 measured in the case of Fig. 6(d). It can be understood that as the VWSR approaches to '1' when a frequency of inputted signals is about 196 MHz, the strap-typed antenna apparatus 100 is impedance-matched at a center frequency of about 196 MHz.

<69> Accordingly, it can be understood that because a frequency for impedance-matching of the antenna apparatus 100 is changed by moving the sliding tab 103 as shown in Fig. 6, a received frequency band is changed. This principle that a received frequency band is changed by moving the sliding tab 103 is not clearly discovered but already proved experimentally. This could be inferred from the assumption that a electrical length of a radiator is changed by the electromagnetic coupling of the sliding tab 103 with the folded radiator 102 or the assumption that the sliding tab 103 functions as a kind of capacitor and influences the radiator.

<70> Thus, the strap-typed DMB antenna apparatus 100 in accordance with an embodiment of the present invention allows the position of the sliding tab 103 to be changed by sliding the sliding tab 103 so that the received frequency band may be changed. Accordingly, the strap-typed DMB antenna apparatus 100 can excellently receive the whole frequency bands for providing DMB services.

<7i> Although the present invention has been described in connection with the specific embodiments, the present invention is not limited to the embodiments and should be interpreted to have the widest range based on the basic spirit disclosed in the specification. Further, even though the inventions which can be anticipated by those skilled in the art or which fall within the equivalent scope of the present invention are not described specifically, it is evident that they also within the scope of the present invent ion.

Claims

[CLAIMS] [Claim 1]

<73> A strap-typed DMB antenna apparatus comprising: <74> a flexible circuit board folded in an extending direction thereof; <75> an electrically conductive radiator for receiving DMB signals which is printed on one side of the flexible circuit board; and <76> a sliding tab capable of sliding in the extending direction of the folded circuit board, uniting the folded circuit board,

<77> wherein a frequency band of the DMB signals received by the radiator is changed by sliding the sliding tab.

[Claim 2]

<78> The apparatus according to claim 1, wherein the flexible circuit board is a flexible printed circuit board (FPCB).

[Claim 3]

<79> The apparatus according to claim 1, wherein the radiator is printed in a shape of meander.

[Claim 4]

<80> The apparatus according to claim 1, wherein the flexible circuit board is covered with leather, plastic, natural fiber or synthetic fiber.

[Claim 5]

<8i> The apparatus according to claim 1, further comprising: <82> a body part to which at least one end of the flexible circuit board is f ixed; and

<83> a connector for connecting one end of the radiator electrically to input and output terminals for a mobile communication terminal using the antenna apparatus, the connector being fixed to the body part.

[Claim 6]

<84> The apparatus according to claim 5, wherein the connector is one of a 24-pin connector for the mobile communication terminal, a 20-pin connector for the mobile communication terminal, or an earphone connector for a mobile communication terminal.

[Claim 7] <85> The apparatus according to claim 5 or 6, further comprising a hinge part between the connector and the body part so that the connector can be rotated and bended.

[Claim 8] <86> The apparatus according to claim 5, further comprising a cap removable from the body part whose internal hollow space can receive the connector.

[Claim 9] <87> The apparatus according to claim 8, further comprising a connection string for appending the apparatus to the mobile communication terminal, the connection string being connected to the strap-typed DMB antenna apparatus, <88> wherein the connection string passes through the cap and is connected to the mobile communication terminal.

[Claim 10] <89> The apparatus according to claim 5, wherein both ends of the flexible circuit board come in contact with each other, and the both ends of the circuit board is united and fixed by the body part.

[Claim 11] <90> A mobile communication terminal comprising a strap-typed DMB antenna for receiving DMB signals; a signal processing part for converting the DMB signals to baseband image signals! and a display part for displaying the image signals, the strap-typed DMB antenna apparatus comprising: <9i> a flexible circuit board folded in an extending direction thereof; <92> an electrically conductive radiator for receiving DMB signals which is printed on one side of the flexible circuit board; and <93> a sliding tab capable of sliding in the extending direction of the folded circuit board, uniting the folded circuit board, <94> wherein a frequency band of the DMB signals received by the radiator is changed by sliding the sliding tab.