Patent Publication Number: US-7225003-B2

Title: Mobile terminal including first and second housings and an antenna

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   The present application is a Continuation of U.S. application Ser. No. 10/181,445, filed on Jul. 26, 2002, now U.S. Pat. No. 7,031,762, which is a National Stage of PCT/JP00/09373 filed on Dec. 28, 2000, the entire contents of both of which are incorporated herein by reference. 

   TECHNICAL FIELD 
   The present invention relates to a mobile terminal, and more specifically, to a mobile terminal as represented by a mobile phone. 
   BACKGROUND ART 
   The use of mobile phones has been spreading rapidly these days. Under such circumstances, the development regarding prevention of transmission gain degradation is proceeding.  FIG. 27  is a perspective view of a conventional mobile phone. Referring to  FIG. 27 , a housing  402  of a mobile wireless radio as a mobile phone is divided into a first unit  402   a  having a receiver unit, and a second unit  402   b  without a receiver unit. The second unit  402   b  is foldably connected to the lower portion of the first unit  402   a  by a folding unit  402   c . An aerial  401  as an antenna is formed to project upwardly toward the first unit  402   a  from an upper end surface  423  of the second unit  402   b  of the housing  402  of the mobile radio. 
   In the above mentioned conventional mobile phone, however, the following problems are involved. 
   First, since the antenna is extending from the housing and exposed, it tends to contact with user&#39;s fingers. In such a case, a problem arises that the antenna gain degrades under the effect of fingers. 
   Further, though there is the first unit  402   a  between a user&#39;s head and the aerial  401 , the action of the first unit  402   a  serving as a shielding plate for electromagnetic waves decreases due to the wide distance between the first unit  402   a  and the aerial  401 . As a result, the aerial is affected by the user&#39;s head, and thus the antenna gain tends to be degraded. 
   In addition, when the mobile phone is placed on a conductive material such as a metal board, a problem arises that antenna gain of the aerial  401  is degraded under the effect of the metal board, which in turn degrades speech quality. 
   Therefore, an object of the present invention is to solve the problems described above, and to provide a mobile terminal that can alleviate degradation of antenna gain. 
   DISCLOSURE OF THE INVENTION 
   A mobile terminal according to the present invention includes a first housing having one end and the other end, a second housing having one end and the other end, with that one end being pivotally mounted to the first housing, and a first antenna element accommodated in one end of the first housing. The other end of the second housing pivots toward or away from the other end of the first housing. Upon use, the other end of the second housing is distanced from the other end of the first housing and held in close proximity to a user&#39;s head. Upon use, the first housing is disposed relative to the second housing so that the second housing intervenes between the first antenna element and the user&#39;s head. 
   In thus formed mobile terminal, the first antenna element is accommodated in the first housing. Thus the first antenna element will not be affected by the contact with fingers, and therefore degradation of the antenna gain is prevented. Further, even when the mobile terminal is placed on a metal board, the antenna gain will not degrade since the first housing intervenes between the first antenna element and the metal board. Additionally, since the second housing intervenes between the first antenna element and the user&#39;s head upon use, and the distance between the first antenna element and the second housing is shortened, the second housing shields the electromagnetic wave transmitted to/received by the first antenna element. Therefore, the antenna element will not be affected by the user&#39;s head and thus degradation of the antenna gain can be prevented. 
   Preferably, the first antenna element includes at least one type of antenna selected from the group consisting of a monopole antenna, a dipole antenna, a plate antenna, an inverted F type antenna, and a loop antenna. 
   Preferably, the first antenna element is accommodated between a portion of the first housing to which one end of the second housing is connected, and one end of the first housing. 
   Preferably, the first housing includes a first surface facing to the user&#39;s head and a second surface opposing to the first surface, and the first antenna element is accommodated close to the first surface. Thus, since the first antenna element is accommodated close to the position distanced from the second surface which is to contact with fingers, that the first antenna element is protected from the effect of the user. As a result, further stable antenna gain can be attained. 
   Preferably, a conductive plate with constant potential is accommodated close to the second surface. Thus, the first antenna element is less affected by fingers in contact with the second surface. 
   Preferably, the mobile terminal further includes a second antenna element at the other end of the second housing. 
   Preferably, the first housing includes either one of a liquid crystal display unit indicating text information or an operation unit to be pressed by fingers for operation. The second housing includes the other one of the liquid crystal display unit or the operation unit. 
   Preferably, the operation unit includes a substrate extending from one end to the other end within the first housing, and the first antenna element is provided on the substrate. 
   Preferably, the second housing is conductive. Thus, the second housing has an effect to shield electromagnetic wave, thus the antenna is less likely affected by the user&#39;s head, and degradation of antenna gain is prevented. 
   The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic side view of a mobile phone according to a first embodiment of the present invention. 
       FIG. 2  shows the mobile phone illustrated in  FIG. 1  in a compact form. 
       FIG. 3  is a schematic side view of a mobile phone according to a second embodiment of the present invention. 
       FIG. 4  is a schematic side view of a mobile phone according to a third embodiment of the present invention. 
       FIG. 5  is a schematic side view of a mobile phone according to a fourth embodiment of the present invention. 
       FIG. 6  is a schematic side view of a mobile phone according to a fifth embodiment of the present invention. 
       FIG. 7  is a schematic side view of a mobile phone according to a sixth embodiment of the present invention. 
       FIG. 8  is a schematic side view of a mobile phone according to a seventh embodiment of the present invention. 
       FIG. 9  is a schematic side view of a mobile phone according to an eighth embodiment of the present invention. 
       FIG. 10  is a schematic side view of a mobile phone according to a ninth embodiment of the present invention. 
       FIG. 11  is a schematic side view of a mobile phone according to a tenth embodiment of the present invention. 
       FIG. 12  is a schematic view of antennas used in a mobile phone of the present invention. 
       FIG. 13  is a schematic view of antennas used in a mobile phone of the present invention. 
       FIG. 14  is a schematic view of antennas used in a mobile phone of the present invention. 
       FIG. 15  is a schematic view of antennas used in a mobile phone of the present invention. 
       FIG. 16  is a schematic view of antennas used in a mobile phone of the present invention. 
       FIG. 17  is a schematic view of antennas used in a mobile phone of the present invention. 
       FIG. 18  is a schematic view of antennas used in a mobile phone of the present invention. 
       FIG. 19  shows relation between a mobile phone and coordinate axes. 
       FIG. 20  shows relation between a mobile phone and coordinate axes. 
       FIG. 21  shows a process of measuring a radiation pattern on x-z plane. 
       FIG. 22  shows a process of measuring a radiation pattern on x-z plane. 
       FIG. 23  shows a process of measuring a radiation pattern on x-z plane. 
       FIG. 24  is a graph showing antenna gain with a mobile phone according to the present invention. 
       FIG. 25  is a graph showing antenna gain with an index finger placed on an antenna element. 
       FIG. 26  is a graph showing antenna gain with a conventional mobile phone. 
       FIG. 27  is a perspective view showing a conventional mobile phone. 
   

   BEST MODES FOR CARRYING OUT THE INVENTION 
   (First Embodiment) 
     FIG. 1  is a side view of a mobile phone according to a first embodiment of the present invention. Referring to  FIG. 1 , the mobile phone  1   a  as a mobile terminal according to the present invention includes a lower housing  10  as a first housing having one end  10   a  and the other end  10   b , an upper housing  20  as a second housing having one end  20   a  pivotally connected to the lower housing  10 , and a monopole antenna  30  as a first antenna element accommodated close to one end  10   a  of the lower housing  10 . The other end of the upper housing  20  pivots toward and away from the other end  10   b  of the lower housing  10 . The mobile phone  1   a  is used in close proximity to a user&#39;s head with the other end  20   b  of the upper housing  20  being distanced from the other end  10   b  of the lower housing  10 . Upon use, the lower housing  10  is disposed relative to the upper housing  20  so that the upper housing  20  intervenes between the monopole antenna  30  and the user&#39;s head  100 . 
   The mobile phone  1   a  includes the lower housing  10  and the upper housing  20  connected to the lower housing  10 . In the one end  10   a  of the lower housing  10 , the monopole antenna  30  is accommodated. The monopole antenna  30  is accommodated between a portion of the lower housing  10  to which the upper housing  20  is connected and one end  10   a  of the lower housing  10 . The lower housing  10  is made with plastics, and the monopole antenna  30  is accommodated within the space thereof. A feed point  31  is provided at one end of the monopole antenna  30 . The lower housing  10  includes a first surface  10   c  facing to the user&#39;s head  100 , and a second surface  10   d  opposing thereto. The monopole antenna  30  is provided at the middle point between the first surface  10   c  and the second surface  10   d.    
   The first surface  10   c  is provided with an axis  32 . A monopole antenna  30  is provided between the portion to which the axis  32  is mounted and the one end  10   a . The other end  10   b  of the lower housing  10  is provided with a plurality of push buttons  11  as an operation unit to be pressed with fingers for operation. Manual pressing of the push buttons  11  allows input of information such as telephone numbers. 
   One end  20   a  of the upper housing  20  is pivotally connected to the lower housing  10  via the axis  32 . The upper housing  20  extends from one end  20   a  to the other end  20   b . As materials for structuring the upper housing  20 , not only insulating material such as plastics, but also conductive materials with high performance of shielding electromagnetic waves such as magnesium can be employed. It is also possible to plate the surface of the plastics with highly conductive materials. The first surface  20   c  of the upper housing  20  is provided with a liquid crystal display device  21  as a liquid crystal display unit for displaying text information. Text information will appear on the liquid crystal display device to be viewed by the user. The second surface  20   d  of the upper housing  20  is disposed opposite to the first surface  20   c  and upon use as illustrated in  FIG. 1  it will face to the lower housing  10 . Both of the first surface  10   c  of the lower housing  10  and the first surface  20   c  of the upper housing  20  are in close proximity to the user&#39;s head  100 . 
     FIG. 2  illustrates the mobile phone of  FIG. 1  in a compact form for easier accommodation. Referring to  FIG. 2 , when the mobile phone  1   a  is to be made compact, the upper housing  20  pivots toward the lower housing  20  so that the first surface  20   c  of the upper housing  20  and the first surface  10   c  of the lower housing  10  face to each other. Thus, by flipping the upper housing  20 , the overall size of mobile phone can be made compact for easier accommodation. 
   In thus formed mobile phone  1   a , the monopole antenna  30  is accommodated in the lower housing  10 . Accordingly, since the monopole antenna  30  will not contact with fingers, the degradation of antenna gain can be prevented and stable antenna gain can be obtained. 
   Since the monopole antenna  30  is accommodated in the lower housing  10 , even when the mobile phone  1   a  is dropped, the monopole antenna  30  will not be damaged and thus mechanical strength can also be attained. 
   Further, when the mobile phone  1   a  is placed on a metal board, since the second surface  10   d  of the lower housing  10  intervenes between the monopole antenna  30  and the metal board, the antenna characteristics can be prevented from degradation and becomes stable. As a result, speech quality will not be degraded. 
   Additionally, since the distance between the monopole antenna  30  and the upper housing  20  is short, the upper housing  20  will shield electromagnetic waves. As a result, the monopole antenna  30  can be protected from the effect of the user&#39;s head  100 . Thus, degradation of the antenna gain can be prevented. 
   (Second Embodiment) 
     FIG. 3  is a schematic side view of a mobile phone according to a second embodiment of the present invention. Referring to  FIG. 3 , the mobile phone  1   b  according to the second embodiment of the present invention is different from the mobile phone  1   a  according to the first embodiment in that monopole antenna  30  is provided near the first surface  10   c  in the lower housing  10 . 
   Thus structured mobile phone  1   b  primarily has the same effect as the mobile phone  1   a  according to the first embodiment. Further, since the monopole antenna  30  is disposed remotely from the second surface  10   d  of the lower housing  10  to which fingers may contact, degradation of antenna gain can further be alleviated. Additionally, with a thin type of lower housing  10 , degradation of antenna gain due to the effect of fingers can be prevented as well. 
   (Third Embodiment) 
     FIG. 4  is a schematic side view of a mobile phone according to a third embodiment of the present invention. Referring to  FIG. 4 , the mobile phone  1   c  according to the third embodiment of the present invention is different from the mobile phone  1   a  according to the first embodiment in that monopole antenna  30  is provided at one end  10   a  of the lower housing  10 , i.e., at the top surface. The monopole antenna  30  extends approximately orthogonal to the direction to which the lower housing  10  extends. 
   Thus structured mobile phone  1   c  also has the same effect as the mobile phone  1   a  according to the first embodiment. Further, since the monopole antenna  30  is attached at the top surface of the lower housing  10 , the attachment area of the antenna can be made smaller. 
   (Fourth Embodiment) 
     FIG. 5  is a schematic side view of a mobile phone according to a fourth embodiment of the present invention. Referring to  FIG. 5 , a mobile phone  1   d  according to the fourth embodiment of the present invention is different from the mobile phone  1   a  according to the first embodiment in that the provided monopole antenna  30  is bent. Such monopole antenna  30  is in the composite form of antennas described in the first to third embodiments. 
   Thus structured mobile phone  1   d  also has the same effect as the mobile phone  1   a  according to the first embodiment. 
   (Fifth Embodiment) 
     FIG. 6  is the schematic side view of a mobile phone according to a fifth embodiment of the present invention. Referring to  FIG. 6 , the mobile phone  1   e  according to the fifth embodiment of the present invention is different from the mobile phone  1   a  according to the first embodiment in that a metal plate  34  as a ground with constant potential is provided between the monopole antenna  30  and the second surface  10   d . The metal plate  34  prevents the monopole antenna  30  from affected by user&#39;s finger  80 . 
   Thus structured mobile phone  1   d  also has the same effect as the mobile phone  1   a  according to the first embodiment. Further, by placing the metal plate  34  to be the ground in the portion possibly contacted by fingers, the effect upon contact can further be reduced. 
   (Sixth Embodiment) 
     FIG. 7  is the schematic side view of a mobile phone according to a sixth embodiment of the present invention. Referring to  FIG. 7 , the mobile phone  1   f  according to the sixth embodiment of the present invention is different from the mobile phone  1   a  according to the first embodiment in that a vibrator  35  is provided near the monopole antenna  30 , which is connected to a substrate  37  via a coil  36 . The vibrator  35  can be replaced with other components. The coil  36  is provided between the vibrator  35  and the substrate  37 , thus vibrator is less likely affected by high frequency waves which is input to/output from the monopole antenna  30 . 
   Thus structured mobile phone  1   f  also has the same effect as the mobile phone  1   a  according to the first embodiment. Further, by attaching components such as the vibrator near the antenna, the mobile phone  1   f  can be made compact. Additionally, the vibrator can be enclosed by a material with high conductivity to oscillate as an antenna element itself. 
   (Seventh Embodiment) 
     FIG. 8  is the schematic side view of a mobile phone according to a seventh embodiment of the present invention. Referring to  FIG. 8 , the mobile phone  1   g  according to the seventh embodiment of the present invention is different from the mobile phone  1   a  according to the first embodiment in that a hole  10   h  for a strap is provided in the lower housing  10 , with the monopole antenna  30  being provided around it. The hole is shown prismatic, but it may be formed as cylindrical as well. 
   Thus structured mobile phone  1   g  also has the same effect as the mobile phone  1   a  according to the first embodiment. 
   (Eighth Embodiment) 
     FIG. 9  is the schematic side view of a mobile phone according to a eighth embodiment of the present invention. Referring to  FIG. 9 , the mobile phone  1   h  according to the present invention is different from the mobile phone  1   a  according to the first embodiment in that a monopole antenna  50  is also provided at the other end  20   b  of the upper housing  20 . The monopole antenna  50  is connected to the feed point  51 . The monopole antenna  50  is not necessarily be accommodated in the upper housing  20 , and it may be projected from the upper housing  20 . Further, the monopole antenna  50  can be provided at either side of the first surface  20   c  or the second surface  20   d  of the upper housing  20 . 
   Thus structured mobile phone  1   h  also has the same effect as the mobile phone  1   a  according to the first embodiment. Further, whether the mobile phone  1   h  is in use or in the folded form, the distance between the monopole antenna  30  and the monopole antenna  50  are long; in other words, these antennas are kept separated in either case. As a result, degradation of the antenna effect can be prevented, alleviating troubles upon transmission. Further, the monopole antenna  50  may be a monopole antenna  30  at the same frequency band (e.g., a diversity antenna). Additionally, it may be an antenna for other systems (Bluetooth or Global Positioning System, GPS). 
   (Ninth Embodiment) 
     FIG. 10  is the schematic side view of a mobile phone according to a ninth embodiment of the present invention. Referring to  FIG. 10 , the mobile phone  1   i  according to the ninth embodiment of the present invention is different from the mobile phone  1   a  according to the first embodiment in that an operation unit includes an extended substrate  37 , and a feed point  31  and a strip antenna  230  are formed thereon. 
   Thus structured mobile phone  1   h  also has the same effect as the mobile phone  1   a  according to the first embodiment. Further, by extending the substrate of the operation unit and forming the antenna thereon, the cost reduction can be contemplated. 
   (Tenth Embodiment) 
     FIG. 11  is the schematic side view of a mobile phone according to a tenth embodiment of the present invention. Referring to  FIG. 11 , the mobile phone  1   j  according to the tenth embodiment of the present invention is different from the mobile phone  1   a  according to the first embodiment in that the monopole antenna  30  is accommodated close to one end  520   a  of an upper housing  520 . In particular, the mobile phone  1   j  as a mobile terminal according to the present invention includes an upper housing  520  as a first housing having one end  520   a  and the other end  520   b , a lower housing  510  as a second housing having one end  510   a  pivotally mounted to the upper housing  520 , and a monopole antenna  30  as a first antenna element accommodated close to the one end  520   a  of the upper housing  520 . The other end  510   b  of the lower housing  510  pivots toward and away from the other end  520   b  of the upper housing  520 . The mobile phone  1   j  is used with the other end  510   b  of the lower housing  510  being distanced from the other end  520   b  of the upper housing  520  and in close proximity to the user&#39;s head  100 . Upon use, the lower housing  510  is disposed relative to the upper housing  520  so that the lower housing  510  intervenes between the monopole antenna  30  and the user&#39;s head  100 . The upper housing  520  has a first surface  520   c  and a second surface  520   d , while the lower housing  510  has a first surface  510   c  and a second surface  510   d.    
   Thus structured mobile phone  1   j  also has the same effect as the mobile phone  1   a  according to the first embodiment. 
   (Eleventh Embodiment) 
     FIGS. 12 to 18  illustrate antennas used in the mobile phones according to the present invention. Referring to  FIG. 12 , in the mobile phone according to the present invention, a meanderline antenna  130  as a monopole antenna may be used in place of monopole antenna  30  shown in  FIGS. 1 to 11 . 
   Referring to  FIG. 13 , in the mobile phone according to the present invention, a helical antenna  131  as a monopole antenna may be used in place of monopole antenna  30  shown in  FIGS. 1 to 11 . 
   Referring to  FIG. 14 , in the mobile phone according to the present invention, a zigzag antenna  132  as a monopole antenna may be used in place of monopole antenna  30  shown in  FIGS. 1 to 11 . 
   Referring to  FIG. 15 , in the mobile phone according to the present invention, a plate antenna  133  such as a patch antenna or a short patch antenna may be used in place of monopole antenna  30  shown in  FIGS. 1 to 11 . 
   Referring to  FIG. 16 , in the mobile phone according to the present invention, an inverted F type antenna  134  may be used in place of monopole antenna  30  shown in  FIGS. 1 to 11 . 
   Referring to  FIG. 17 , in the mobile phone according to the present invention, a loop antenna  135  may be used in place of monopole antenna  30  shown in  FIGS. 1 to 11 . 
   Referring to  FIG. 18 , in the mobile phone according to the present invention, a dipole antenna  136  may be used in place of monopole antenna  30  shown in  FIGS. 1 to 11 . 
   Next, radiation characteristics of the mobile phone according to the present invention and a conventional mobile phone were compared.  FIGS. 19 and 20  show relation between the mobile phone and coordinate axes. Note that  FIG. 19  is a rear view of the mobile phone, while  FIG. 20  is a side view thereof. First, a mobile phone  1   a  according to the present invention was prepared as shown in  FIGS. 19 and 20 . The mobile phone  1   a  includes a lower housing  10  and an upper housing  20 . At one end  10   a  of the lower housing  10 , a monopole antenna  30  in accommodated. 
   The direction to which the monopole antenna  30  extends is +Z direction. Further, from left to right direction in  FIG. 19  is +Y direction. The direction from depth toward the plane of  FIG. 19  is +X direction. 
     FIGS. 21 to 23  illustrate a process of measuring a radiation pattern in the X-Z plane. First, referring to  FIG. 21 , the mobile phone  1   a  shown in  FIGS. 19 and 20  was placed on a table  150 . Here, the placement was done such that the +Z direction and +X direction are orthogonal to the vertical direction indicated by an arrow  140 . Thus, +Y direction is approximately parallel to the perpendicular direction represented by the arrow  140 . The table  150  can be rotated in the direction indicated by an arrow R. A user was present near the first plane  10   c  and  20   c.    
   In such a state in which the mobile phone  1   a  was placed on the table  150 , radio wave at the frequency of 940 MHz was radiated from a radio transceiver unit via the monopole antenna  30  at a prescribed power. At the same time, the table was rotated in the direction indicated by the arrow R. Thus, a radio wave as indicated by the arrow  151  was radiated. The field intensity of the radio wave was measured by a measuring antenna  160 , and the field intensity of vertically polarized wave in the direction indicated by an arrow V and horizontally polarized wave in the direction indicated by an arrow H was determined. 
   Referring to  FIG. 22 , a dipole antenna  170  was placed on the table  150 . A feed point  171  was provided at the middle portion of the dipole antenna  170  and connected to a coaxial cable  172 . The coaxial cable  172  was connected to the prescribed radio transceiver unit. The dipole antenna  170  extends approximately parallel to the perpendicular direction indicated by the arrow  140 . By turning the table  150  in the direction indicated by the arrow R, and applying similar power to the dipole antenna  170  as applied to the mobile phone  1   a  by the radio transceiver unit illustrated in  FIG. 21 , radio wave as indicated by an arrow was radiated from the dipole antenna  170  at the frequency of 940 MHz. Thus, the radio wave indicated by the arrow  152  was radiated from the dipole antenna  170 . The radio wave is a vertically polarized wave in the direction indicated by an arrow V. The field intensity of the radio wave was measured by a measuring antenna  160 . 
   Referring to  FIG. 23 , the dipole antenna  170  was placed on the table  150 . The dipole antenna was placed so that it extends orthogonal to the vertical direction indicated by the arrow  140 . The feed point  171  was provided at the middle portion of the dipole antenna  170  and connected to the coaxial cable  172 . By turning the table  150  in the direction indicated by the arrow R, and applying similar power to the dipole antenna  170  as applied to the mobile phone  1   a  by the radio transceiver unit illustrated in  FIG. 21 , radio wave as indicated by an arrow  153  was radiated from the dipole antenna  170  at the frequency of 940 MHz. The radio wave was a horizontally polarized wave in the direction indicated by an arrow H. The field intensity of the radio wave was measured by the measuring antenna  160 . 
   Based on the data acquired in the process described with reference to  FIGS. 21 to 23 , an antenna element radiation pattern was determined. The result is shown in  FIG. 24 . 
   In  FIG. 24 , solid line  301  indicates gain of vertically polarized wave of radio wave radiated by the monopole antenna  30  shown in  FIG. 21  for the field intensity of the vertically polarized wave radiated by the dipole antenna  170  in the process shown in  FIG. 22 . The gain was determined by the following equation:
 
(gain)=20×log 10 (field intensity of the vertically polarized wave from the monopole antenna 30/field intensity of the vertically polarized wave from the dipole antenna 170)
 
   Dotted line  302  indicates gain of horizontally polarized wave of radio wave radiated by the monopole antenna  30  shown in  FIG. 21  for the field intensity of the horizontally polarized wave radiated by the dipole antenna  170  in the process shown in  FIG. 23 . The gain was determined by the following equation:
 
(gain)=20×log 10 (field intensity of the horizontally polarized wave from the monopole antenna 30/field intensity of the horizontally polarized wave from the dipole antenna 170)
 
   Meanwhile, one scale shown in  FIGS. 24 to 26  indicates 10 dB. The mean gain of both vertically and horizontally polarized waves (cross polarization ratio, XPR=6 dB) was determined to be −14.73 dBd. Additionally, the peak value of the gain was −4.27 dBd. 
   Next, in the process shown in  FIG. 21 , the lower housing  10  was in contact with a user&#39;s hand at the portion distanced from the monopole antenna  30  by 2 mm. The body of the user was near the first surfaces  10   c  and  20   c . Under such a condition, the table  150  shown in  FIG. 21  was rotated in the direction of the arrow R and a prescribed power from the radio transceiver unit was applied to the monopole antenna  30  to radiate radio wave. Under such a condition, the table was rotated in the direction of the arrow R and similar power as described in the process with reference to  FIG. 21  was applied to the mobile phone  1   a  from the radio transceiver unit, then radio wave at the frequency of 940 MHz was radiated. The field intensity of vertically and horizontally polarized waves of the radio wave were measured by the measuring antenna  160 . 
     FIG. 25  shows a radiation pattern with a user&#39;s hand in contact with the lower housing  10  placed near the monopole antenna  30 . In  FIG. 25 , solid line  311  indicates gain of field intensity of vertically polarized wave of radio wave radiated by the mobile phone  1   a  with a user&#39;s hand in contact with the lower housing  10  near the monopole antenna  30  for the field intensity of the vertically polarized wave measured in the process shown in  FIG. 22 . The gain was determined by the following equation:
 (gain)=20×log 10 (field intensity of the vertically polarized wave from the mobile phone 1 a  with a user&#39;s hand in contact with the lower housing  10  near the monopole antenna 30/field intensity of the vertically polarized wave from the dipole antenna 170) 
   Dotted line  312  indicates gain of field intensity of horizontally polarized wave of radio wave radiated by the mobile phone  1   a  with a user&#39;s hand in contact with the lower housing  10  near the monopole antenna  30  for the field intensity of the horizontally polarized wave measured in the process shown in  FIG. 23 . The gain was determined by the following equation:
 
(gain)=20×log 10 (field intensity of the horizontally polarized wave from the mobile phone 1 a  with a user&#39;s hand in contact with the lower housing 10 near the monopole antenna 30/field intensity of the horizontally polarized wave from the dipole antenna 170)
 
   From  FIG. 25 , mean gain of vertically and horizontally polarized waves (XPR=6 dB) was determined to be a preferable value of −15.33 dBd. Peak value of the gain was −4.55 dBd. 
   Accordingly, it can be appreciated that high transmission gain is acquired in the present invention. 
   Next, with the conventional mobile wireless radio shown in  FIG. 27 , according to the same process as described with reference to  FIG. 21 , axis Z and axis X are horizontally directed, while axis Y is placed on the table  150  so as to be parallel to the vertical direction. A person was present opposite to the aerial  401  of the mobile transceiver. Under such a condition, the table was rotated in the direction indicated by the arrow R, while radio wave at the frequency of 940 MHz was radiated via the aerial  401 . Simultaneously, similar power as applied to the monopole antenna  30  by the radio transceiver unit was applied to the aerial  401 . Vertically and horizontally polarized waves of thus radiated radio waves were measured by the measuring antenna  160 .  FIG. 26  shows a radiation pattern for such a conventional antenna. In  FIG. 26 , solid line  321  indicates gain of field intensity of vertically polarized wave of radio wave radiated by the aerial  401  according to the step described with reference to  FIG. 21  for the field intensity of the vertically polarized wave measured in the process shown in  FIG. 22 . The gain was determined by the following equation:
 
(gain)=20×log 10 (field intensity of the vertically polarized wave from the aerial 401/field intensity of the vertically polarized wave from the dipole antenna 170)
 
   Dotted line  322  indicates gain of horizontally polarized wave of radio wave radiated by the aerial  401  according to the step described with reference to  FIG. 21  for the field intensity of the horizontally polarized wave measured in the process shown in  FIG. 23 . The gain was determined by the following equation:
 
(gain)=20×log 10 (field intensity of the horizontally polarized wave from the aerial 401/field intensity of the horizontally polarized wave from the dipole antenna 170)
 
   According to  FIG. 26 , it can be appreciated that gain of vertically and horizontally polarized waves are both decreased. From  FIG. 26 , the mean gain was determined to be −21.35 dBd. Additionally, peak value of gain was −13.41 dBd. 
   INDUSTRIAL APPLICABILITY 
   The mobile terminal according to the present invention can be utilized in the field of mobile phone.