Abstract:
Provided is a portable terminal which is provided with a first case, a second case, and a connecting section which connects together the first case and the second case, and has less deterioration of antenna sensitivity. The portable terminal has the first case ( 2 ), the second case ( 3 ), the connecting section ( 4 ), a first circuit section ( 32 ) disposed in the first case ( 2 ), a first conductive section ( 31 ) disposed in the first case ( 2 ), a second conductive section ( 33 ) disposed in the second case ( 3 ), a third conductive section ( 34 ) disposed in the connecting section ( 4 ), and a first electronic component ( 61 ) disposed adjacent to the first conductive section ( 31 ) in the length direction of the first case ( 2 ) in the first case ( 2 ). The first length (X 1 ), which is obtained from the sum of the path length of the signals in the band of a first frequency (f 1 ) in the first conductive section ( 31 ) and the path length of the signals in the band of the first frequency (f 1 ) in the first electronic component ( 61 ), is substantially the same as the second length (X 2 ), which is obtained from the sum of the path length of the signals in the band of the first frequency (f 1 ) in the second conductive section ( 33 ) and the path length of the signals in the band of the first frequency (f 1 ) in the third conducive section ( 34 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS: 
     This application is the National Stage of International Application No. PCT/JP2010/057221, filed Apr. 23, 2010, which claims the benefit of Japanese Application No. 2009-107183, filed Apr. 24, 2009, the entire contents of both of which are incorporated by reference herein. 
     FIELD OF THE INVENTION 
     The present invention relates to a mobile terminal device such as a cellular telephone device. 
     BACKGROUND OF THE INVENTION 
     Conventionally, as a mobile terminal device, a cellular telephone device of a folder type has been known, which includes a first body, a second body, and a connecting portion connecting the first body and the second body, and which is configured so as to be capable of transitioning to an opened state and a closed state via the connecting portion depending on the usage aspects. A cellular telephone device of such a folder type has a communication function to perform communication externally via an antenna. 
     For example, Patent Document 1 proposes a cellular telephone device, in which one of a first conductive portion disposed in the first body and a second conductive portion disposed in the second body can be utilized as an antenna, by feeding power to one of the first conductive portion and the second conductive portion and by grounding the other one (in a ground state). 
     Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2007-104468 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     However, in the cellular telephone device proposed in Patent Document 1, a connecting portion is disposed between the first body and the second body. Accordingly, a third conductive portion disposed in the connecting portion also functions as a part of the antenna or a part of the ground. 
     Accordingly, in a cellular telephone device in which a length of the first conductive portion in the first body is substantially identical to a length of the second conductive portion in the second body, for example, the length of the first conductive portion in the first body is different from a length obtained by summation of the length of the second conductive portion in the second body and a length of a third conductive portion in the connecting portion. In this case, the electrical length of the ground and the electrical length of the antenna are not balanced. Accordingly, this brings about a problem of deteriorating the antenna sensitivity. 
     In a mobile terminal device including a first body, a second body, and a connecting portion connecting the first body and the second body, an object of the present invention is to provide a mobile terminal device that suppresses deterioration of the antenna sensitivity. 
     Means for Solving the Problems 
     The present invention relates to a mobile terminal device, including: a first body; a second body; a connecting portion that connects the first body and the second body; a first circuit unit that is disposed in the first body, and includes a ground unit, a power feed unit and a signal processing unit that is connected to the power feed unit and processes a signal in a first frequency band; a first conductive portion that is disposed in the first body, and is connected to one of the ground unit or the power feed unit; a second conductive portion that is disposed in the second body; a third conductive portion that is disposed in the connecting portion, and is connected to the second conductive portion and the other one of the ground unit or the power feed unit; and a first electronic component that is disposed adjacently to the first conductive portion in the first body, and is connected at high frequency to the first conductive portion, in which a first length, which is obtained by summation of a path length of a signal in the first frequency band in the first conductive portion and a path length of a signal in the first frequency band in the first electronic component, is substantially identical to a second length, which is obtained by summation of a path length of a signal in the first frequency band in the second conductive portion and a path length of a signal in the first frequency band in the third conductive portion. 
     Moreover, it is preferable that the first conductive portion is connected to the ground unit; the third conductive portion is connected to the power feed unit; the first length is a path length of a signal in the first frequency band from a contact point, where the first conductive portion is in contact with the ground unit, to the first electronic component; and the second length is a path length of a signal in the first frequency band from a contact point, where the third conductive portion is in contact with the power feed unit, to the second conductive portion. 
     In addition, it is preferable that the first conductive portion is formed so as to be elongated in a longitudinal direction of the first body; the second conductive portion is formed so as to be elongated in a longitudinal direction of the second body; the first electronic component is formed so as to be elongated in a width direction that is orthogonal to the longitudinal direction of the first body; and one end of the first electronic component in the width direction is connected to the first conductive portion. 
     Furthermore, it is preferable that the first electronic component is an antenna element resonating with a signal in a second frequency band, and the mobile terminal device further includes: a second circuit unit that is connected to the first electronic component, and processes a signal in the second frequency band resonated by the first electronic component; a first suppression unit that is disposed so as to be interposed between the first conductive portion and the first electronic component, and suppresses passage of a signal in a frequency band different from the first frequency band; and a second suppression unit that is disposed so as to be interposed between the first electronic component and the second circuit unit, and suppresses passage of a signal in a frequency band different from the second frequency band. 
     Moreover, it is preferable that the mobile terminal device further includes: a second electronic component that is disposed adjacently to the second conductive portion in the longitudinal direction of the second body in the second body, and is connected at high frequency to the second conductive portion, a first selection unit that is configured so as to be capable of selecting a state where the first conductive portion and the first electronic component are connected at high frequency, or a state where the first conductive portion and the first electronic component are cut off at high frequency; a second selection unit that is configured so as to be capable of selecting a state where the second conductive portion and the second electronic component are connected at high frequency, or a state where the second conductive portion and the second electronic component are cut off at high frequency; and a control unit that controls connection or cutoff of the first selection unit, and connection or cutoff of the second selection unit. 
     In addition, the present invention relates to a mobile terminal device, including: a first body; a second body; a connecting portion that connects the first body and the second body; a first circuit unit that is disposed in the first body, and includes a ground unit, a power feed unit and a signal processing unit that is connected to the power feed unit and processes a signal in a first frequency band; a first conductive portion that is disposed in the first body, and is connected to one of the ground unit or the power feed unit; a second conductive portion that is disposed in the second body; a third conductive portion that is disposed in the connecting portion, and is connected to the second conductive portion and the other one of the ground unit or the power feed unit; and a first electronic component that is disposed adjacently to the first conductive portion in the longitudinal direction of the first body in the first body, and is connected at high frequency to the first conductive portion; and a second electronic component that is disposed adjacently to the second conductive portion in the longitudinal direction of the second body in the second body, and is connected at high frequency to the second conductive portion, in which a third length, which is a path length of a signal in the first frequency band in the first conductive portion, is substantially identical to a fourth length, which is obtained by summation of a path length of a signal in the first frequency band in the second conductive portion and a path length of a signal in the first frequency band in the third conductive portion; and a fifth length, which is obtained by summation of the third length and a length along a longitudinal direction of the first electronic component, is substantially identical to a sixth length, which is obtained by summation of the fourth length and a length along a longitudinal direction of the second electronic component. 
     Furthermore, it is preferable that the first conductive portion is connected to the ground unit; the third conductive portion is connected to the power feed unit; the third length is a path length of a signal in the first frequency band from a contact point, where the first conductive portion is in contact with the ground unit, to a contact point, where the first conductive portion is in contact with the first electronic component; the fourth length is a path length of a signal in the first frequency band from a contact point, where the third conductive portion is in contact with the power feed unit, to the second conductive portion; the fifth length is a path length of a signal in the first frequency band from a contact point, where the first conductive portion is in contact with the ground unit, to the first electronic component; and the sixth length is a path length of a signal in the first frequency band from a contact point, where the third conductive portion is in contact with the power feed unit, to the second electronic component. 
     Moreover, it is preferable that the first conductive portion is formed so as to be elongated in a longitudinal direction of the first body; the second conductive portion is formed so as to be elongated in a longitudinal direction of the second body; the first electronic component is formed so as to be elongated in a width direction that is orthogonal to the longitudinal direction of the first body, and one end of the first electronic component in the width direction of the first body is connected to the first conductive portion; and the second electronic component is formed so as to be elongated in a width direction that is orthogonal to the longitudinal direction of the second body, and one end of the second electronic component in the width direction of the second body is connected to the second conductive portion. 
     In addition, it is preferable that the first electronic component is an antenna element resonating with a signal in a second frequency band, and the mobile terminal device further includes: a second circuit unit that is connected to the first electronic component, and processes a signal in the second frequency band resonated by the first electronic component; a first suppression unit that is disposed so as to be interposed between the first conductive portion and the first electronic component, and suppresses passage of a signal in a frequency band different from the first frequency band; and a second suppression unit that is disposed so as to be interposed between the first electronic component and the second circuit unit, and suppresses passage of a signal in a frequency band different from the second frequency band. 
     Furthermore, it is preferable that the mobile terminal device further includes: a first selection unit that is configured so as to be capable of selecting a state where the first conductive portion and the first electronic component are connected at high frequency, or a state where the first conductive portion and the first electronic component are cut off at high frequency; a second selection unit that is configured so as to be capable of selecting a state where the second conductive portion and the second electronic component are connected at high frequency, or a state where the second conductive portion and the second electronic component are cut off at high frequency; and a control unit that controls connection or cutoff of the first selection unit, and connection or cutoff of the second selection unit. 
     Effects of the Invention 
     According to the present invention, in a mobile terminal device including a first body, a second body, and a connecting portion connecting the first body and the second body, it is possible to provide a mobile terminal device that suppresses deterioration of the antenna sensitivity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing an appearance of a cellular telephone device according to the present invention in an opened state; 
         FIG. 2  is a front view schematically showing the opened state of the cellular telephone device in a first embodiment; 
         FIG. 3  is a circuit diagram showing a first suppression unit and a second suppression unit in the first embodiment; 
         FIG. 4  is a graph showing electrical characteristics of the first suppression unit in the first embodiment; 
         FIG. 5  is a graph showing electrical characteristics of the second suppression unit in the first embodiment; 
         FIG. 6  is a front view schematically showing an opened state of a cellular telephone device in a second embodiment; and 
         FIG. 7  is a block diagram showing a configuration of control of the cellular telephone device in the second embodiment. 
     
    
    
     EXPLANATION OF REFERENCE NUMERALS 
       1  cellular telephone device (mobile terminal device) 
       2  operation unit side body (first body) 
       3  display unit side body (second body) 
       4  connecting portion 
       22  receiver (second electronic component) 
       31  first conductive portion 
       32  first circuit unit 
       33  second conductive portion 
       34  third conductive portion 
       35  ground unit 
       36  power feed unit 
       37  signal processing unit 
       42  first suppression unit 
       43  second suppression unit 
       51  first selection unit 
       52  second selection unit 
       61  antenna element (first electronic component) 
     X 1  first length 
     X 2  second length 
     f 1  first frequency 
     f 2  second frequency 
     DETAILED DESCRIPTION OF THE INVENTION 
     Descriptions are provided hereinafter regarding an embodiment of the present invention with reference to the drawings. A basic structure of a cellular telephone device  1  as a mobile terminal device according to a first embodiment is described with reference to  FIG. 1 .  FIG. 1  is a perspective view showing an appearance of the cellular telephone device  1  in an opened state. 
     As shown in  FIG. 1 , the cellular telephone device  1  as a mobile terminal device includes: an operation unit side body  2  as a first body shaped like a substantially rectangular parallelepiped; and a display unit side body  3  as a second body shaped like a substantially rectangular parallelepiped. Each of the operation unit side body  2  and the display unit side body  3  has a shape elongated in a longitudinal direction A. 
     The operation unit side body  2  and the display unit side body  3  are connected so as to be openable and closable via a connecting portion  4  including a hinge mechanism. More specifically, an upper end portion of the operation unit side body  2  and a lower end portion of the display unit side body  3  are connected via the connecting portion  4 . As a result, the cellular telephone device  1  is configured so as to be capable of forming opened/closed states by relatively moving the operation unit side body  2  and the display unit side body  3  connected via the hinge mechanism. 
     In other words, the cellular telephone device  1  can be arranged into an opened state where the operation unit side body  2  and the display unit side body  3  are apart from each other, and into a folded state where the operation unit side body  2  and the display unit side body  3  are contacting each other, by relatively rotating (pivoting) the operation unit side body  2  and the display unit side body  3 , which are connected via the connecting portion  4 . 
     An outer surface of the operation unit side body  2  is configured with a front case  2   a  and a rear case  2   b . An operation key set  11  and a microphone  12  are each exposed on the front case  2   a  side of the operation unit side body  2 , in which the microphone  12  serves as a sound input unit to which sound produced by a user of the cellular telephone device  1  during a phone call is input. 
     The operation key set  11  is configured with: function setting operation keys  13  for operating various functions such as for various settings, a telephone number directory function and a mail function; input operation keys  14  for inputting the digits of a telephone number, characters for mail, and the like; and a selection operation key  15  for performing selection of the various operations, scrolling up, down, left and right, etc. Predetermined functions are assigned (key assignment) to each key configuring the operation key set  11  in accordance with the opened/closed state of the operation unit side body  2  and the display unit side body  3 , various modes, and the type of application that is running. An operation corresponding to a function assigned to each key is executed by the user depressing each key. 
     The microphone  12  is disposed to an outer end side (lower end side) that is opposite to the connecting portion  4  side in the longitudinal direction A of the operation unit side body  2 . In other words, the microphone  12  is disposed to one outer end side of the cellular telephone device  1  in the opened state. 
     An interface (not illustrated) for communicating with an external device (for example, a host device) is disposed on one side face of the operation unit side body  2 . Side keys, to which predetermined functions are assigned, and an interface (not illustrated), where external memory is inserted and removed, are disposed on another side face of the operation unit side body  2 . When not in use, each interface is covered with a cap. 
     An outer surface of the display unit side body  3  is configured with a front case  3   a  and a rear case  3   b . On the front case  3   a  of the display unit side body  3 , a display unit  21  for displaying a variety of information, and a receiver  22  that outputs sound of the other party of a phone call are disposed so as to be exposed to the outside. Here, the display unit  21  is configured with a liquid crystal display panel, a drive circuit that drives the liquid crystal display panel, a light source unit such as a backlight that irradiates light from the back face side of the liquid crystal display panel, etc. 
     Next, internal structures of the operation unit side body  2  and the display unit side body  3  are described with reference to  FIGS. 2 to 5 .  FIG. 2  is a front view schematically showing the opened state of the cellular telephone device in the first embodiment.  FIG. 3  is a circuit diagram showing a first suppression unit and a second suppression unit in the first embodiment.  FIG. 4  is a graph showing electrical characteristics of the first suppression unit in the first embodiment.  FIG. 5  is a graph showing electrical characteristics of the second suppression unit in the first embodiment. 
     It should be noted that, regarding components inside the operation unit side body  2 ,  FIG. 2  only shows a first conductive portion  31 , a first circuit unit  32 , a second circuit unit  41 , an antenna element  61  as a first electronic component, etc. Moreover, regarding components inside the display unit side body  3 ,  FIG. 2  only shows a second conductive portion  33 . In addition, regarding components inside the connecting portion  4 ,  FIG. 2  only shows a third conductive portion  34 . However,  FIG. 2  does not limit each internal structure of the operation unit side body  2 , the display unit side body  3  and the connecting portion  4 . 
     Furthermore, as a virtual manner of illustration,  FIG. 2  shows a connection state by way of a connecting wire(s) connecting the first conductive portion  31 , the second conductive portion  33 , the third conductive portion  34 , the antenna element  61 , the first circuit unit  32 , the second circuit unit  41 , etc. It should be noted that, in the present embodiment, the connecting wire(s) in  FIG. 2  is illustrated for describing a connection state of each unit, and shall be excluded when describing a path length of a signal later, for convenience of explanation. 
     As shown in  FIG. 2 , the first conductive portion  31 , the first circuit unit  32 , the antenna element  61 , the second circuit unit  41 , the first suppression unit  42  and the second suppression unit  43  are included inside the operation unit side body  2 , more specifically between the front case  2   a  and the rear case  2   b .In the present embodiment, the first conductive portion  31 , the second circuit unit  41 , the first suppression unit  42  and the second suppression unit  43  are each disposed on the circuit board  50 . 
     The first conductive portion  31  is a ground pattern formed on the circuit board  50 . The first conductive portion  31  is formed so as to be elongated in the longitudinal direction A of the operation unit side body  2 . 
     The first circuit unit  32  includes a ground unit  35 , a power feed unit  36 , and a signal processing unit  37  that is connected to the ground unit  35  and the power feed unit  36 . 
     The ground unit  35  is connected to an end portion of the first conductive portion  31 , on the connecting portion  4  side thereof in the longitudinal direction A. As a result, the ground unit  35  is connected at high frequency to the first conductive portion  31 . The power feed unit  36  is connected at high frequency to the third conductive portion  34  disposed in the connecting portion  4 . In addition, the ground unit  35  and the power feed unit  36  are disposed adjacently to each other in the first circuit unit  32 . Moreover, the third conductive portion  34  is connected at high frequency to the second conductive portion  33  disposed in the display unit side body  3 . In other words, the power feed unit  36  is connected so as to be capable of feeding power to the second conductive portion  33  and the third conductive portion  34 . The power feed unit  36  is connected to the signal processing unit  37 . The signal processing unit  37  is connected to the power feed unit  36 , and performs processing of signals in a first frequency f 1  band. In addition, the signal processing unit  37  is configured with: a radio circuit including an RF circuit; a matching circuit; a control circuit; and the like. 
     The antenna element  61  is disposed in an end portion (a lower end portion shown in  FIG. 2 ) opposite to the connecting portion  4  in the operation unit side body  2 . The antenna element  61  is disposed adjacently to the first conductive portion  31  in the longitudinal direction A of the operation unit side body  2 . 
     The antenna element  61  is formed of a conductive material. The antenna element  61  is formed so as to be rectangular in a planar view, and is formed so as to be elongated in a direction B that is orthogonal to the longitudinal direction A of the operation unit side body  2 . Here, the direction orthogonal to the longitudinal direction A of the operation unit side body  2  refers to a width direction B (a horizontal direction shown in  FIG. 2 ) of the operation unit side body  2 . Furthermore, the width direction B of the operation unit side body  2  coincides with a longitudinal direction of the antenna element  61 . In this way, the antenna element  61  is disposed such that the longitudinal direction of the antenna element  61  is in parallel with the width direction B of the operation unit side body  2 . 
     An end portion of the antenna element  61  in the longitudinal direction (the width direction B of the operation unit side body  2 ) is connected at high frequency to the first conductive portion  31 . Moreover, the antenna element  61  is configured as an antenna element resonating with a signal in a second frequency f 2  band, and functions as a radiating element of the antenna. It should be noted that the second frequency f 2  band will be described later. 
     The second circuit unit  41  is connected at high frequency to the antenna element  61 . The second circuit unit  41  processes signals in the second frequency f 2  band that is resonated by the antenna element  61 . 
     The first suppression unit  42  is disposed so as to be interposed between the first conductive portion  31  and the antenna element  61 . The first conductive portion  31  is connected at high frequency to the antenna element  61  via the first suppression unit  42 . The first suppression unit  42  suppresses signals in frequency bands different from the first frequency f 1  band. In other words, the first suppression unit  42  allows passage of only signals in the first frequency f 1  band, and suppresses passage of signals in other frequency bands. The first suppression unit  42  is configured such that the resonance frequency thereof is the first frequency f 1  band. 
     As shown in  FIG. 3 , the first suppression unit  42  is configured with a first capacitor C 1  and a first coil L 1 . The first frequency (resonance frequency) f 1  is determined by the following equation (1), and impedance Z 1  is determined by the following equation (2).
 
 f 1=½π√( L 1  C 1)  (1)
 
 Z 1= jωL 1+1/( jωC 1)  (2)
 
     where ω=2πf 1   
     As shown in  FIG. 4 , the first suppression unit  42  has characteristics obtained in a graph of impedance Z 1 , in which the resonance frequency thereof is the first frequency f 1  band. In the first suppression unit  42 , the impedance Z 1  is 0Ω in the first frequency f 1  band. In addition, in the first suppression unit  42 , the impedance Z 1  is inductive impedance or capacitive impedance in the other frequency bands. Accordingly, the first suppression unit  42  allows passage of signals in the first frequency f 1  band, and functions as a bandpass filter that suppresses passage of signals in the other frequency bands. For example, in a case of CDMA (Code Division Multiple Access) communication that utilizes signals in an 800 MHz band as the first frequency f 1  band, the first suppression unit  42  is configured with the first capacitor C 1  and the first coil L 1 , in which the impedance Z 1  is 0Ω in the 800 MHz band as the first frequency f 1  band. 
     The first suppression unit  42  is disposed so as to be interposed between the first conductive portion  31  and the antenna element  61 . Furthermore, in the first suppression unit  42 , the impedance Z 1  is 0Ω in the first frequency f 1  band. Accordingly, the first suppression unit  42  allows passage of signals in the first frequency f 1  band, and suppresses passage of signals in the other frequency bands. As a result, in the first suppression unit  42 , the antenna element  61  is connected to the first conductive portion  31 , in the first frequency f 1  band. In this way, the antenna element  61  is connected to the ground unit  35  of the first circuit unit  32  via the first conductive portion  31  as a ground pattern. 
     Moreover, the second suppression unit  43  is disposed so as to be interposed between the antenna element  61  and the second circuit unit  41 . The antenna element  61  is connected at high frequency to the second circuit unit  41  via the second suppression unit  43 . The second suppression unit  43  suppresses passage of signals in frequency bands different from the second frequency f 2  band. In other words, the second suppression unit  43  allows passage of signals in the second frequency f 2  band, and suppresses passage of signals in the other frequency bands. The second suppression unit  43  is configured such that the resonance frequency thereof is the second frequency f 2  band. 
     More specifically, as shown in  FIG. 3 , the second suppression unit  43  is configured with a second capacitor C 2  and a second coil L 2 . The second frequency (resonance frequency) f 2  is determined by the following equation (3).
 
 f 2=½π√( L 2  C 2)  (3)
 
     In addition, impedance Z 2  is determined by the following equation (4).
 
 Z 2= jωL 2+1/( jωC 2)  (4)
 
     where ω=2πf 2   
     Accordingly, as shown in  FIG. 5 , the second suppression unit  43  has characteristics obtained in a graph of impedance Z 2 , in which the resonance frequency is the second frequency f 2  band. In other words, in the second suppression unit  43 , the impedance Z 2  is 0Ω in the second frequency f 2  band. Furthermore, in the second suppression unit  43 , the impedance Z 2  is inductive impedance or capacitive impedance in the other frequency bands. Accordingly, the second suppression unit  43  allows passage of signals in the second frequency f 2  band, and functions as a bandpass filter that suppresses passage of signals in the other frequency bands. For example, in a case of GPS (Global Positioning System) communication that utilizes signals in a 1575 MHz band as the second frequency f 2  band, the second suppression unit  43  is configured with the second capacitor C 2  and the second coil L 2 , in which the impedance Z 2  is 0Ω in the 1575 MHz band as the second frequency f 2  band. 
     As shown in  FIGS. 2  to.  5 , the second suppression unit  43  is disposed so as to be interposed between the antenna element  61  and the second circuit unit  41 . Moreover, in the second suppression unit  43 , the impedance Z 2  is 0Ω in the second frequency f 2  band. Accordingly, the second suppression unit  43  allows passage of signals in the second frequency f 2  band, and suppresses passage of signals in the other frequency bands. As a result, in the second suppression unit  43 , the antenna element  61  is connected at high frequency to the second conductive portion  41  in the second frequency f 2  band. 
     In addition, as shown in  FIG. 2 , the second conductive portion  33  is a ground pattern formed on the circuit board disposed inside the display unit side body  3 . The second conductive portion  33  is formed so as to be elongated in the longitudinal direction A of the display unit side body  3 . 
     Furthermore, the third conductive portion  34  is configured with a conductive portion disposed inside the connecting portion  4 . The third conductive portion  34  is formed so as to be elongated in the longitudinal direction A of the display unit side body  3 . The third conductive portion  34  is disposed on an end portion side in the direction B, which is orthogonal to the longitudinal direction A of the display unit side body  3  in the connecting portion  4 , in parallel with the longitudinal direction A of the display unit side body  3 . The end portion of the third conductive portion  34  on the display unit side body  3  side is connected to the end portion in the longitudinal direction A of the second conductive portion  33 . The end portion of the third conductive portion  34  on the operation unit side body  2  side is connected to the power feed unit  36  of the first circuit unit  32 . As a result, the third conductive portion  34  is connected at high frequency to the second conductive portion  33 , and is also connected at high frequency to the power feed unit  36  of the first circuit unit  32 . 
     In the cellular telephone device  1  in the first embodiment described above, a first length X 1  (X 1   a +X 1   b ), which is obtained by summation of a length X 1   a  (a path length of a signal in the first frequency f 1  band) of the first conductive portion  31  in the longitudinal direction A of the operation unit side body  2  and a length X 1   b  (a path length of a signal in the first frequency f 1  band) of the antenna element  61  in the longitudinal direction (the width direction B of the operation unit side body  2 ), is substantially equal to a second length X 2  (X 2   a +X 2   b ), which is obtained by summation of a length X 2   a  (a path length of a signal in the first frequency f 1  band) of the second conductive portion  33  in the longitudinal direction A of the display unit side body  3  and a length X 2   b  (a path length of a signal in the first frequency f 1  band) of the third conductive portion  34  in the longitudinal direction A of the display unit side body  3  (X 1 =X 2 ) (see  FIG. 2 ). 
     Here, the first length X 1  (X 1   a +X 1   b ) is described in detail. 
     As shown in  FIG. 2 , the length X 1   a  (a path length of a signal in the first frequency f 1  band) of the first conductive portion  31  in the longitudinal direction A of the operation unit side body  2  is a path length in the first conductive portion  31  along the longitudinal direction A of the operation unit side body  2 , and is a path length of a signal in the first frequency f 1  band from an end portion of the first conductive portion  31  on the connecting portion  4  side to the other end portion thereof on the opposite side from the connecting portion  4 . Moreover, the length X 1   b  (a path length of a signal in the first frequency f 1  band) of the antenna element  61  in the longitudinal direction (the width direction B of the operation unit side body  2 ) is a path length in the antenna element  61  along the longitudinal direction (the width direction B of the operation unit side body  2 ), and is a path length of a signal in the first frequency f 1  band from one end portion of the antenna element  61  to the other end portion thereof. 
     In other words, the first length X 1  (X 1   a +X 1   b ) is a path length of a signal in the first frequency f 1  band from a contact point, where the first conductive portion  31  is in contact with the ground unit  35 , to the antenna element  61 . 
     In addition, the second length X 2  (X 2   a +X 2   b ) is described in detail. 
     The length X 2   a  (a path length of a signal in the first frequency f 1  band) of the second conductive portion  33  in the longitudinal direction A of the display unit side body  3  is a path length in the second conductive portion  33  along the longitudinal direction A of the display unit side body  3 , and is a path length of a signal in the first frequency f 1  band from an end portion of the second conductive portion  33  on the connecting portion  4  side to the other end portion thereof on the opposite side from the connecting portion  4 . Furthermore, the length X 2   b  (a path length of a signal in the first frequency f 1  band) of the third conductive portion  34  in the longitudinal direction A of the display unit side body  3  is a path length in the third conductive portion  34  along the longitudinal direction A of the display unit side body  3 , and is a path length of a signal in the first frequency f 1  band from an end portion of the third conductive portion  34  on the display unit side body  3  side to the other end portion thereof on the operation unit side body  2  side. 
     In other words, the second length X 2  (X 2   a +X 2   b ) is a path length of a signal in the first frequency f 1  band from a contact point, where the third conductive portion  34  is in contact with the power feed unit  36 , to the second conductive portion  33 . 
     Moreover, the second conductive portion  33  in the display unit side body  3  and the third conductive portion  34  in the connecting portion  4  are electrically connected to the power feed unit  36 . Accordingly, the second conductive portion  33  and the connecting portion  4  function as a radiating element of the antenna. In the operation unit side body  2 , the first conductive portion  31  and the antenna element  61  are electrically connected to the ground unit  35 . As a result, the first conductive portion  31  and the antenna element  61  function as a ground unit of the antenna. Therefore, the entirety of the display unit side body  3 , the operation unit side body  2  and the connecting portion  4  configures a single antenna (for example, a dipole antenna). 
     Here, descriptions are provided for operations in the cellular telephone device  1  of the first embodiment. 
     First, with reference to  FIGS. 2 to 5 , descriptions are provided for a case in which a signal in the first frequency f 1  band is input into the cellular telephone device  1 . 
     As shown in  FIGS. 2 to 5 , in a case in which a signal in the first frequency f 1  band is input into the cellular telephone device  1 , the first suppression unit  42  allows passage of the signal in the first frequency f 1  band. In other words, the first conductive portion  31  is connected at high frequency to the antenna element  61 . Accordingly, since the first conductive portion  31  is electrically connected to the ground unit  35 , the first conductive portion  31  and the antenna element  61  function as a ground unit of the antenna. In addition, the second conductive portion  33  and the third conductive portion  34  function as a radiating element of the antenna. On the other hand, the second suppression unit  43  suppresses passage of signals in frequency bands different from the second frequency f 2  band. Accordingly, the second suppression unit  43  suppresses passage of signals in the first frequency f 1  band. In other words, in the first frequency f 1  band, the antenna element  61  is unlikely to be connected at high frequency to the second circuit unit  41 . 
     In addition, the signal processing unit  37  of the first circuit unit  32  performs predetermined processing on signals in the first frequency f 1  band fed from the power feed unit  36 . 
     In this way, the entirety of the display unit side body  3  and the operation unit side body  2  configures a single antenna (for example, a dipole antenna). 
     Next, descriptions are provided for a case in which a signal in the second frequency f 2  band is input into the cellular telephone device  1 . 
     As shown in  FIGS. 2 to 5 , in a case in which a signal in the second frequency f 2  band is input into the cellular telephone device  1 , the first suppression unit  42  suppresses passage of signals in frequency bands different from the first frequency f 1  band. Accordingly, the first suppression unit  42  suppresses passage of signals in the second frequency f 2  band. In other words, in the second frequency f 2  band, the antenna element  61  is unlikely to be connected at high frequency to the first circuit unit  42 . Therefore, since the antenna element  61  is connected to the second circuit unit  41 , the antenna element  61  functions as a radiating element of the antenna. On the other hand, the second suppression unit  43  allows passage of signals in the second frequency f 2  band. In other words, in the second frequency f 2  band, the antenna element  61  is connected at high frequency to the second circuit unit  41 . In addition, the second circuit unit  41  connected to the antenna element  61  performs predetermined processing on signals in the second frequency f 2  band that is resonated by the antenna element  61 . 
     In this way, the antenna element  61  configures an antenna. According to the cellular telephone device  1  of the first embodiment described above, the following effects are achieved. 
     In the cellular telephone device  1 , the first conductive portion  31  and the antenna element  61  of the operation unit side body  2  are connected to the ground unit  35  of the first circuit unit  32 , and the second conductive portion  33  of the display unit side body  3  and the third conductive portion  34  of the connecting portion  4  are connected at high frequency to the power feed unit  36 . Accordingly, the entirety of the operation unit side body  2 , the display unit side body  3  and the connecting portion  4  configures a single antenna (for example, a dipole antenna). As a result, the antenna sensitivity of the cellular telephone device  1  can be improved. 
     Furthermore, the cellular telephone device  1  is configured such that the first circuit unit  32  and the antenna element  61  are disposed in the operation unit side body  2 . Accordingly, the length for functioning as a radiating element of the antenna and the length for functioning as a ground unit of the antenna can be favorably balanced. As a result, the antenna sensitivity of the cellular telephone device  1  can be improved. 
     Moreover, a configuration is employed (X 1 =X 2 ) such that the first length X 1  (X 1   a +X 1   b ), which is obtained by summation of the length X 1   a  of the first conductive portion  31  in the longitudinal direction A of the operation unit side body  2  and the length X 1   b  of the antenna element  61  in the longitudinal direction (the width direction B of the operation unit side body  2 ), is substantially equal to the second length X 2  (X 2   a +X 2   b ), which is obtained by summation of the length X 2   a  of the second conductive portion  33  in the longitudinal direction A of the display unit side body  3  and the length X 2   b  of the third conductive portion  34  in the longitudinal direction A of the display unit side body  3 . As a result, the length for functioning as a radiating element of the antenna is substantially equal to the length for functioning as a ground unit of the antenna. Therefore, it is possible to improve the antenna sensitivity of the antenna (for example, a dipole antenna) configured with the entirety of the operation unit side body  2 , the display unit side body  3  and the connecting portion  4 . 
     In addition, the cellular telephone device  1  includes the first suppression unit  42  and the second suppression unit  43 . Accordingly, in a case of using an antenna configured with the entirety of the operation unit side body  2 , the display unit side body  3  and the connecting portion  4 , in which the antenna element  61  serves as a part of the components, and in a case of using the antenna element  61  as an antenna, the antenna can function as an antenna compatible with frequency bands corresponding to signals in different frequency bands, respectively. More specifically, in a case in which the antenna element  61  is used as a shared antenna compatible with a plurality of frequency bands, the first suppression unit  42  and the second suppression unit  43  make it possible to cause the antenna to function as an antenna (for example, a dipole antenna) configured with the entirety of the operation unit side body  2 , the display unit side body  3  and the connecting portion  4 , or as an antenna (for example, a GPS antenna) in which the antenna element functions as an antenna radiating element. The first suppression unit  42  and the second suppression unit  43  contribute to so-called multiband compatibility of the cellular telephone device  1 . 
     Next, descriptions are provided for the cellular telephone device  1  according to a second embodiment with reference to  FIGS. 6 and 7 .  FIG. 6  is a front view schematically showing an opened state of the cellular telephone device in the second embodiment.  FIG. 7  is a block diagram showing a configuration of control of the cellular telephone device in the second embodiment. As a virtual manner of illustration, regarding components inside the operation unit side body  2 ,  FIG. 6  only shows the first conductive portion  31 , the first circuit unit  32 , the antenna element  61 , a first selection unit  51 , etc. Furthermore, regarding components inside the display unit side body  3 , only the second conductive portion  33 , a second selection unit  52 , a receiver  22 , etc. are shown. Moreover, regarding an internal structure of the connecting portion  4 , only the third conductive portion  34  is shown. However,  FIGS. 6 and 7  do not limit each internal structure of the operation unit side body  2 , the display unit side body  3  and the connecting portion  4 . 
     In addition, as a virtual manner of illustration,  FIG. 6  shows a connection state by way of a connecting wire(s)connecting the first conductive portion  31 , the second conductive portion  33 , the third conductive portion  34 , the antenna element  61 , the receiver  22 , the first circuit unit  32 , the second circuit unit  41 , etc. It should be noted that, in the present embodiment, the connecting wire(s) in  FIG. 6  is shown for describing a connection state of each unit, and shall be excluded when describing a path length of a signal later, for convenience of explanation. 
     The cellular telephone device  1  in the second embodiment has a configuration similar to that of the cellular telephone device  1  in the first embodiment, except for including the receiver  22  as a second electronic component, the first selection unit  51 , and the second selection unit  52 , and except for the proportion of each length of the first conductive portion  31 , the second conductive portion  33  and the third conductive portion  34 . Therefore, the second embodiment is mainly described with regard to the receiver  22 , the first selection unit  51  and the second selection unit  52 , as well as the proportion of each length of the first conductive portion  31 , the second conductive portion  33  and the third conductive portion  34 ; and descriptions of other components are omitted. 
     As shown in  FIGS. 6 and 7 , the cellular telephone device  1  includes the receiver  22 , the first selection unit  51 , the second selection unit  52 , and the control unit  55 . It should be noted that the control unit  55  is included in the signal processing unit  37 . 
     The receiver  22  and the second selection unit  52  are disposed inside the display unit side body  3 . The second selection unit  52  is disposed on the circuit board. The first selection unit  51  is disposed on the circuit board  50  inside the operation unit side body  2 . 
     The receiver  22  is disposed to an end side (an upper side shown in  FIG. 6 ) that is opposite to the connecting portion  4  in the display unit side body  3 . The receiver  22  is disposed adjacently to the second conductive portion  33  in the longitudinal direction A of the display unit side body  3 . 
     The receiver  22  is formed of a metallic conductive material. The receiver  22  is formed so as to be substantially oval in a planar view. Furthermore, the receiver  22  is formed so as to be elongated in the direction B that is orthogonal to the longitudinal direction A of the display unit side body  3 . Here, the direction B orthogonal to the longitudinal direction A of the display unit side body  3  refers to the width direction B (the horizontal direction shown in  FIG. 6 ) of the display unit side body  3 . Moreover, the width direction B of the display unit side body  3  coincides with the longitudinal direction of the receiver  22 . In this way, the receiver  22  is disposed such that the longitudinal direction of the receiver  22  is in parallel with the width direction B of the display unit side body  3 . 
     In addition, an end portion of the receiver  22  in the longitudinal direction of the receiver  22  (the width direction B of the display unit side body  3 ) is connected at high frequency to the conductive portion  33 . 
     The first selection unit  51  selectively makes changes between a state where the first conductive portion  31  and the antenna element  61  are connected at high frequency, and a state where the first conductive portion  31  and the antenna element  61  are cut off at high frequency. The second selection unit  52  selectively makes changes between a state where the second conductive portion  33  and the receiver  22  are connected at high frequency, and a state where the second conductive portion  33  and the receiver  22  are cut off at high frequency. 
     As shown in  FIG. 7 , the control unit  55  controls connection or cutoff of the first selection unit  51 , and controls connection or cutoff of the second selection unit  52 . 
     Here, with reference to  FIGS. 6 and 7 , descriptions are provided for control of the first selection unit  51  and the second selection unit  52  by the control unit  55 . 
     As shown in  FIG. 7 , the control unit  55  can switch between a first state in which both the first selection unit  51  and the second selection unit  52  select a cutting off state, and a second state in which both the first selection unit  51  and the second selection unit  52  select a connecting state. 
     In a state in which the control unit  55  has switched to the first state, the first conductive portion  31  functions as a ground unit of the antenna. Furthermore, the second conductive portion  33  and the third conductive portion  34  integrally function as a radiating element of the antenna. 
     In this case, a third length X 3  (a path length of a signal in the first frequency f 1  band) of the first conductive portion  31  in the longitudinal direction A of the operation unit side body  2  is substantially equal to a fourth length X 4  (X 4   a +X 4   b ) that is obtained by summation of a length X 4   a  (a path length of a signal in the first frequency f 1  band) of the second conductive portion  33  in the longitudinal direction A of the display unit side body  3  and a length X 4   b  (a path length of a signal in the first frequency f 1  band) of the third conductive portion  34  in the longitudinal direction A of the display unit side body  3  (X 3 =X 4 ). Accordingly, the fourth length X 4 , which is obtained by summation of the length X 4   a  of the second conductive portion  33  that functions as a radiating element of the antenna and the length X 4   b  of the third conductive portion  34 , is substantially equal to the third length X 3  of the first conductive portion  31  that functions as a ground unit of the antenna. 
     Here, the third length X 3  is described in detail. As shown in  FIG. 6 , the third length X 3  (a path length of a signal in the first frequency f 1  band) of the first conductive portion  31  in the longitudinal direction A of the operation unit side body  2  is a path length in the first conductive portion  31  along the longitudinal direction A of the operation unit side body  2 , and is a path length of a signal in the first frequency f 1  band from an end portion of the first conductive portion  31  on the connecting portion  4  side to the other end portion thereof on the opposite side from the connecting portion  4 . 
     In other words, the third length X 3  is a path length of a signal in the first frequency f 1  band from a contact point, where the first conductive portion  31  is in contact with the ground unit  35 , to a contact point, where the first conductive portion  31  is in contact with the antenna element  61 . 
     Moreover, the fourth length X 4  (X 4   a +X 4   b ) is described in detail. 
     The length X 4   a  (a path length of a signal in the first frequency f 1  band) of the second conductive portion  33  in the longitudinal direction A of the display unit side body  3  is a path length in the second conductive portion  33  along the longitudinal direction A of the display unit side body  3 , and is a path length of a signal in the first frequency f 1  band from an end portion of the second conductive portion  33  on the connecting portion  4  side to the other end portion thereof on the opposite side from the connecting portion  4 . In addition, the length X 4   b  (a path length of a signal in the first frequency f 1  band) of the third conductive portion  34  in the longitudinal direction A of the display unit side body  3  is a path length in the third conductive portion  34  along the longitudinal direction A of the display unit side body  3 , and is a path length of a signal in the first frequency f 1  band from an end portion of the third conductive portion  34  on the display unit side body  3  side to the other end portion thereof on the operation unit side body  2  side. 
     In other words, the fourth length X 4  (X 4   a +X 4   b ) is a path length of a signal in the first frequency f 1  band from a contact point, where the third conductive portion  34  is in contact with the power feed unit  36 , to the second conductive portion  33 . 
     In a state in which the control unit  55  has switched to the second state, the first conductive portion  31  and the antenna element  61  integrally function as a ground unit of the antenna. Furthermore, the receiver  22 , the second conductive portion  33  and the third conductive portion  34  integrally function as a radiating element of the antenna. 
     In this case, connection is established such that a fifth length X 5  (X 3 +X 5   b ), which is obtained by summation of the third length X 3  (X 5   a  (a path length of a signal in the first frequency f 1  band)) and a length X 5   b  (a path length of a signal in the first frequency f 1  band) of the antenna element  61  in the longitudinal direction (the width direction B of the operation unit side body  2 ), is substantially equal to a sixth length X 6 , which is obtained by summation of the fourth length X 4  (X 6   a  (a path length of a signal in the first frequency f 1  band)) and a length X 6   b  (a path length of a signal in the first frequency f 1  band) of the receiver  22  in the longitudinal direction (the width direction B of the display unit side body  3 ) (X 5 =X 6 ). Accordingly, the sixth length X 6  (X 4 +X 6   b ), which is obtained by summation of the fourth length X 4  for functioning as a radiating element of the antenna and the length X 6   b  of the receiver  22 , is substantially equal to the fifth length X 5 , which is obtained by summation of the third length X 3  for functioning as a ground unit of the antenna and the length X 5   b  of the antenna element  61 . 
     Here, the fifth length X 5  (X 3 +X 5   b ) is described in detail. 
     As described above, the third length X 3  is a path length of a signal in the first frequency f 1  band from the ground unit  35  to the first conductive portion  31 . Moreover, the length X 5   b  (a path length of a signal in the first frequency f 1  band) of the antenna element  61  in the longitudinal direction (the width direction B of the operation unit side body  2 ) is a path length in the antenna element  61  along the longitudinal direction (the width direction B of the operation unit side body  2 ), and is a path length of a signal in the first frequency f 1  band from one end portion of the antenna element  61  to the other end portion thereof. 
     In other words, the fifth length X 5  (X 3 +X 5   b ) is a path length of a signal in the first frequency f 1  band from a contact point, where the first conductive portion  31  is in contact with the ground unit  35 , to the antenna element  61 . 
     In addition, the sixth length X 6  (X 4 +X 6   b ) is described in detail. 
     As described above, the fourth length X 4  is a path length of a signal in the first frequency f 1  band from the power feed unit  36  via the third conductive portion  34  to the second conductive portion  33 . Furthermore, the length X 6   b  (a path length of a signal in the first frequency f 1  band) of the receiver  22  in the longitudinal direction (the width direction B of the display unit side body  3 ) is a path length in the receiver  22  along the longitudinal direction (the width direction B of the display unit side body  3 ), and is a path length of a signal in the first frequency f 1  band from one end portion of the receiver  22  to the other end portion thereof. 
     In other words, the sixth length X 6  (X 4 +X 6   b ) is a path length of a signal in the first frequency f 1  band from a contact point, where the third conductive portion  34  is in contact with the power feed unit  36 , to the receiver  22 . 
     According to the cellular telephone device  1  of the second embodiment described above, the following effects are achieved. 
     The control unit  55  controls the first selection unit  51  and the second selection unit  52 . The control unit  55  is configured so as to be capable of switching between a connection state in which the third length X 3  of the first conductive portion  31  in the longitudinal direction A of the operation unit side body  2  is substantially equal to the fourth length X 4 , which is obtained by summation of the length X 4   a  of the second conductive portion  33  in the longitudinal direction A of the display unit side body  3  and the length X 4   b  of the third conductive portion  34  in the longitudinal direction A of the display unit side body  3  (X 3 =X 4 ), and a connection state in which the fifth length X 5 , which is obtained by summation of the third length X 3  (X 5   a ) and the length X 5   b  of the antenna element  61  in the longitudinal direction (the width direction B of the operation unit side body  2 ), is substantially equal to the sixth length X 6 , which is obtained by summation of the fourth length X 4  (X 6   a ) and the length X 6   b  of the receiver  22  in the longitudinal direction (the width direction B of display unit side body  3 ) (X 5 =X 6 ). 
     Accordingly, the length for functioning as a radiating element of the antenna is substantially equal to the length for functioning as a ground unit of the antenna, in either cases of switching to the state in which the fifth length X 5  is substantially equal to the sixth length X 6  (X 5 =X 6 ) or the state in which the third length X 3  is substantially equal to the fourth length X 4  (X 3 =X 4 ). Therefore, it is possible to improve the antenna sensitivity of the antenna (for example, a dipole antenna) configured with the entirety of the operation unit side body  2  and the display unit side body  3 . 
     Moreover, the fifth length X 5  and the sixth length X 6  (X 5 =X 6 ) are configured so as to be longer than the third length X 3  and the fourth length X 4  (X 3 =X 4 ), respectively (X 3 =X 4 &lt;X 5 =X 6 ). Accordingly, it is possible to establish compatibility with not only frequencies used in the third length X 3  and the fourth length X 4 , but also with frequencies used in the fifth length X 5  and the sixth length X 6 . More specifically, in a case in which the fifth length X 5  and the sixth length X 6  are configured so as to be longer than the third length X 3  and the fourth length X 4  (X 3 =X 4 &lt;X 5 =X 6 ), respectively, the fifth length X 5  and the sixth length X 6  are lengths for functioning as a radiating element of the antenna that is compatible with frequencies lower than the frequencies that the third length X 3  and the fourth length X 4  are compatible with. Therefore, the cellular telephone device  1  can be made compatible with different frequencies only by the control unit  55  controlling the first selection unit  51  and the second selection unit  52 . 
     Although the preferable embodiments have been described above, the present invention is not limited to the aforementioned embodiments, and can be implemented as various embodiments. 
     For example, although the present embodiment is configured such that the first conductive portion  31  is connected to the ground unit  35  of the first circuit unit  32 , and the third conductive portion  34  is connected to the power feed unit  36  of the first circuit unit  32 , it may be configured such that the first conductive portion  31  is connected to the power feed unit  36  of the first circuit unit  32 , and the third conductive portion  34  is connected to the ground unit  35  of the first circuit unit  32 . 
     In addition, although the receiver  22  is used as the second electronic component that is connected to the second conductive portion  33  in the present embodiment, the present invention is not limited thereto. In other words, a microphone, IrDA (Infrared Data Association), a camera, an external connector or the like may be used as the electronic component. 
     Furthermore, although the first conductive portion  31  and the second conductive portion  33  are configured with the circuit board in the present embodiment, the present invention is not limited thereto. In other words, the first conductive portion  31  and the second conductive portion  33  may be configured with a shielding case or the like. Moreover, the path lengths of signals in the first frequency f 1  band or the second frequency f 2  band may appropriately vary depending on the position of the contact point where the power feed unit  36  or the ground unit  35  is in contact with any of the conductive portions, or the shapes of the conductive portions; and the present embodiment merely represents one aspect of the invention. In other words, the path lengths of signals in the first frequency f 1  band or the second frequency f 2  band can be appropriately changed by changing the position of the contact point where the power feed unit  36  or the ground unit  35  is in contact with any of the conductive portions, or the shape of the conductive portions, in accordance with design. 
     In the cellular telephone device  1  of the present embodiment, the first frequency f 1  band is for signals in a frequency band utilized for CDMA (Code Division Multiple Access) communication, and the second frequency f 2  band is for signals in a frequency band utilized for GPS (Global Positioning System) communication; however, it is not limited thereto. For example, it is possible to establish compatibility with signals of terrestrial digital broadcasting, signals of wireless LAN, signals of RFID, etc. 
     In addition, although the present invention is applied to the cellular telephone device  1  as a mobile terminal device in the present embodiment, it is not limited thereto. In other words, the present invention may be applied to a mobile terminal device such as a PHS (Personal Handyphone System), a PDA (Personal Digital Assistant), a portable navigation device, a notebook PC or the like.