Abstract:
An antenna apparatus for a mobile communication terminal to achieve better portability and to prevent damage from careless handling by a user. The antenna is installed inside a main body of the mobile terminal, to render more room for accommodating its components. The antenna apparatus includes the main body having therein a main board, a keypad assembly provided with a plurality of key tops formed exposedly on the upper surface of the main body, and an antenna section disposed, between the main board and the keypad assembly, opposite to and in the vicinity of the lower end of the main body. The antenna section is comprised of an antenna sheet disposed underneath the keypad assembly.

Description:
CLAIM OF PRIORITY  
         [0001]    This application claims priority to an application entitled “Antenna Apparatus for Mobile Communication Terminal” filed in the Korean Industrial Property Office on Dec. 6, 2002 and assigned the application serial No. 2002-77167, the contents of which are incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to a mobile wireless communication terminal and, in particular, to an antenna apparatus for use in mobile wireless communication terminals such as mobile phones, hand-held personal computers, personal digital assistants (PDAs), etc.  
           [0004]    2. Description of the Related Art  
           [0005]    In recent years, mobile communication systems that are in common use by a great number of mobile subscribers have extended their available services to include paging service, mobile phone calling, short message service (SMS) to a mobile banking service system, and further up to a multi-media service such as motion picture service and the like. The tremendous growth of the mobile communication systems with a diversity of service functions has led to the need to make more use of an integrated type of wireless terminal devices such as PDAs and the like, which serve as both a personal computer and a mobile communication terminal equipment, e.g. mobile phone, because a conventional mobile phone is to some degree limited in the extent of its functions.  
           [0006]    Referring to FIG. 1, there is shown a schematic front view of a conventional mobile communication terminal  100 , that is to say, e.g. a PDA. As seen in the front view, the mobile communication terminal  100  is provided with a display unit  101  in its front, under which a keypad assembly  105  is arranged and above which a speaker  109  is disposed. As the keypad generally has a limit in the scope of data capable of inputting as an input means, the display unit  101  may be implemented as an input device using a touch screen. On one side of an upper end of the mobile terminal  100  is disposed an antenna  107  and on an other side of the upper end of the mobile terminal  100  is disposed a camera module  111 , of which photographing angle is adjustable by an adjusting knob  113  disposed on one side of the upper end of the mobile terminal  100  and adjacent to the camera module  111 .  
           [0007]    Referring then to FIGS. 2 and 3, the keypad  105  is comprised of a silicon keypad  151  provided with a plurality of key buttons  151   a  projecting to the outside of the mobile terminal  100 , and a flexible printed circuit board  153  for the keypad. The flexible printed circuit board  153  is provided with electrical contacts corresponding to the plurality of key buttons  151   a  and is adapted to generate a set of electrical signals S for supplying to a main board  157  of the mobile terminal according to the manipulation of the key buttons  151   a  by a user. The flexible printed circuit board  153  is connected to a data cable  153   b  for transferring the electrical signal S to the main board  157 . The keypad is disposed on a cover  155  mounted to protect the main board  157 . Further, a respective key button  151   a  of the silicon keypad  151  may be preferably attached at its upper surface to a plastic material (not sown) or the like for offering more pleasant touch to the users.  
           [0008]    In the meantime, the tremendous increase of data and information transferred using the mobile communication terminal, as during a multi-media content service, essentially demands high-speed data transmission in the mobile communication service system. Hence, a diversity antenna has been proposed in the art as one preferred solution for improving the data transfer rate as well as the quality of data transfer.  
           [0009]    Referring now to FIG. 4, which illustrates a front view of a mobile wireless communication terminal  200 , e.g. a PDA, with such a diversity antenna  203  of the prior art, being further provided with an additional, second antenna  203  mainly used for the diversity receiving function. The front surface of the mobile terminal  200  includes a display unit  201 , below which display unit  201  and keypad assembly  205  are disposed, and above which a speaker  209  is disposed. On one side of the upper end of the mobile terminal  200  is positioned a first antenna  207  for a general transmitting/receiving function, while on the other side of the upper end the second diversity antenna  203  is positioned for the diversity receiving function. Here, the second diversity antenna  203  in the signal receiving operation of the mobile terminal serves to prevent fading phenomena by means of receiving radio waves separately from the first antenna, wherein the fading phenomenon is referred to as a physical phenomenon that significant degradation of signal strength or quality, or transfer rate or the like that is mainly owing to the physical change in medium through which radio waves pass, the diffraction of radio waves or the phase difference between more than one receiving path of the radio waves transmitted from the same origination. That is to say, a combination of two signals each received through the first and second antennas  207  and  203  enables effective detection of an optimal receiving signal, so as to prevent the fading phenomenon to obtain better quality of signal. This will also be quite helpful to achieve remarkable improvement of transfer rate in the mobile communication system.  
           [0010]    Meanwhile, FIG. 5 shows a front view of a mobile wireless communication terminal  300 , e.g. a PDA, with the diversity receiving antenna  303  arranged in such a way that it extends downwardly from the opposite, i.e. lower, end of the mobile terminal  300 , so that the second antenna is positioned apart from the first antenna  307  enough to carry out the diversity receiving function efficiently. The remaining components of the mobile terminal  300 , inclusive of a display unit  301 , a keypad assembly  305 , a speaker  309 , a camera module  311  and so on, may be arranged in a similar way to the foregoing construction described with reference to FIGS.  1  to  4 .  
           [0011]    However, the conventional type of mobile communication terminal as described above has a disadvantage that it may be not only inconvenient for some users to carry owing to such a protrusion of the second antenna from a main body of the mobile communication terminal, but also it may be subject to damage should the user happen to drop it down onto a hard floor carelessly. Further, such an antenna apparatus has some degree of limitation in design since it has a protrusion part extending outwardly from the main body of the mobile terminal. Furthermore, in the design of the mobile communication terminal with the diversity antenna apparatus, it will technically not be easy for a designer to ensure a space for adequately accommodating the diversity antenna apparatus inside the mobile communication terminal because its interior parts are essentially to be configured very compactly in a limited spacing.  
         SUMMARY OF THE INVENTION  
         [0012]    It is, therefore, an object of the present invention to provide an antenna apparatus for a mobile communication terminal, being capable of achieving better portability and being less prone to damage of the antenna apparatus from careless handling.  
           [0013]    It is another object of the present invention to provide an antenna apparatus for a mobile communication terminal capable of being installed inside a main body of the mobile communication terminal, so as to render more room for accommodating its components.  
           [0014]    Accordingly, to achieve the above objects of the present invention, an antenna apparatus for a mobile communications terminal includes a main body serving as a housing for the mobile communication terminal, said main body having therein a main board, a keypad assembly provided with a plurality of key tops formed on the upper surface of the main body, and an antenna section disposed between the main board and the keypad assembly, opposite to and in the vicinity of the lower end of the main body.  
           [0015]    According to a second aspect of the present invention, an antenna apparatus for a mobile communication terminal includes a main body serving as a housing for the mobile communication terminal, said main body having therein a main board, a keypad assembly provided with a plurality of key tops exposed on the top surface of the main body, a first antenna disposed in vicinity of the upper end section of the mobile communication terminal for use in the signal receiving/transmitting function of a radio frequency signal through the mobile communication terminal, and a second antenna disposed between the main board and the keypad assembly, opposite to and in the vicinity of the lower end of the main body.  
           [0016]    Preferably, the second antenna is comprised of at least one antenna sheet arranged underneath the keypad assembly between the main board and the keypad assembly, in such a way that, on said antenna sheet, a predetermined antenna pattern of a conductive material is formed.  
           [0017]    Preferably, the antenna apparatus further includes a flexible printed circuit board for the keypad assembly arranged between the main board and the keypad assembly, including a plurality of contacts for generating an electrical signal for inputting to the main board according to each operation of a plurality of key buttons arranged in the keypad assembly, at least one antenna sheet inserted between the flexible printed circuit board and the main board, or between the flexible printed circuit board and the keypad assembly, wherein the antenna sheet is provided thereon with a predetermined antenna pattern consisting of a conductive material.  
           [0018]    According to a third aspect of the present invention, an antenna apparatus for a mobile communication terminal includes a main body having therein a main board, a keypad assembly provided with a plurality of key tops formed on the top surface of the main body, a flexible printed circuit board for the keypad assembly, arranged between the main board and the keypad assembly, for generating an electrical signal for inputting to the main board according to each operation of a plurality of key buttons arranged in the keypad assembly, and at least one antenna means inserted between the flexible printed circuit board and the main board, or between the flexible printed circuit board and the keypad assembly.  
           [0019]    Advantageously, the antenna means further comprises at least one antenna sheet inserted between the flexible printed circuit board and the main board, or between the flexible printed circuit board and the keypad assembly, and a predetermined antenna pattern consisting of a conductive material coated on the antenna sheet.  
           [0020]    Advantageously, the antenna means is one selected from a group comprised of a planar inverted F-type antenna, a meander antenna with plural curvatures, a loop antenna, or a wired antenna. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    The foregoing and other features and advantages of the invention will be apparent from the following detailed description of preferred embodiments as illustrated in the accompanying drawings, wherein same reference characters refer to the same parts or components throughout the various views. The drawings are not necessarily to scale, but the emphasis instead is placed upon illustrating the principles of the invention, wherein:  
         [0022]    [0022]FIG. 1 illustrates a front view of a conventional mobile communication terminal;  
         [0023]    [0023]FIG. 2 illustrates an exploded perspective view of a keypad assembly of the conventional mobile communication terminal shown in FIG. 1;  
         [0024]    [0024]FIG. 3 illustrates a schematic sectional side view of the keypad assembly according to the conventional mobile communication terminal shown in FIG. 2;  
         [0025]    [0025]FIG. 4 illustrates a front view of another conventional mobile communication terminal provided with a diversity antenna;  
         [0026]    [0026]FIG. 5 illustrates a front view of still another conventional mobile communication terminal provided with a diversity antenna;  
         [0027]    [0027]FIG. 6 illustrates a front view of a mobile communication terminal having an antenna apparatus according to a preferred embodiment of the present invention;  
         [0028]    [0028]FIG. 7 illustrates an exploded perspective view of a keypad assembly and an antenna apparatus of the mobile communication terminal shown in FIG. 6;  
         [0029]    [0029]FIG. 8 illustrates an antenna pattern formed for the antenna apparatus of the mobile communication terminal shown in FIG. 7;  
         [0030]    [0030]FIG. 9 illustrates a partial sectional view of the keypad assembly and the antenna apparatus of the mobile communication terminal shown in FIG. 7;  
         [0031]    [0031]FIG. 10 illustrates a front view of a mobile communication terminal having an antenna apparatus according to another preferred embodiment of the present invention; and  
         [0032]    [0032]FIG. 11 illustrates a front view of a mobile communication terminal having an antenna apparatus according to still another preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]    In the following description, for purposes of explanation rather than limitation, specific details are set forth such as the particular architecture, interfaces, techniques, etc., in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments, which depart from these specific details. For the purpose of simplicity and clarity, detailed descriptions of well-known devices and methods are omitted to avoid obscuring the description of the present invention with unnecessary detail.  
         [0034]    Referring now to FIG. 6, a structure of an antenna apparatus  460  will be described according to a preferred embodiment of the present invention. FIG. 6 illustrates a front view of a mobile communication terminal  400 , e.g. a PDA, provided with the antenna apparatus  460  according to the present invention. The antenna apparatus  460  is disposed in the vicinity of the keypad  405 , underlying the same, as viewed from the front of the mobile terminal  400 . The mobile terminal  400  is provided on its front with a display unit  401 , beneath which a keypad assembly  405  is arranged and above which a speaker  409  is disposed. On an upper end of the mobile terminal  400  is disposed a camera module  411 , of which a photographing angle is adjustable by an adjusting knob  413 , disposed on one side of the upper end of the mobile terminal  400 . The display unit  401  may be configured in such a way that it has the largest possible display area within the entire top surface of a main body of the mobile terminal  400 , so as to enable viewing a motion picture or using video phone thereon with more ease. Therefore, the keypad assembly  405  is preferably provided with only those essentially required basic key buttons  451   a  (FIG. 7) such as “menu” key, “power” on/off key and so on, and the display unit  401  may be formed of a touch screen, which enables use as an input device for entering a variety of data into the mobile terminal.  
         [0035]    Referring to FIGS.  7  to  9 , a detailed description to the keypad  405  and the antenna apparatus  460  is provided. FIG. 7 illustrates an exploded perspective view of the keypad assembly  405  and the antenna apparatus  460  of the mobile communication terminal  400  shown in FIG. 6, and FIG. 8 illustrates an example of an antenna pattern  465  formed by the antenna apparatus  460  of the mobile communication terminal shown in FIG. 7. Further, FIG. 9 illustrates a partial sectional view of the keypad assembly  405  and the antenna apparatus  460  of the mobile communication terminal shown in FIG. 7. As shown in these figures, on a main board  457  accommodated within the mobile terminal  400  is a cover  455 . The keypad assembly  405  and the antenna apparatus  460  are configured in such a way that a silicon keypad  451 , a first antenna sheet  460   a,  a flexible printed circuit board  453  for the keypad and a second antenna sheet  460   b  are sequentially stacked on the cover  455 .  
         [0036]    The silicon keypad  451  is positioned as the topmost surface of a main body of the mobile terminal  400  over the antenna apparatus  460 , with its key tops protruded. The flexible printed circuit board  453  is provided with a plurality of contacts  453   a  so as to generate an electrical signal S supplied to the main board  457  depending upon the operation of respective key buttons  451   a  arranged on the keypad  451 . The electrical signal S produced from the contacts  453   a  of the flexible printed circuit board  453  is supplied to the main board  457  through a data cable  453   b.  The first antenna sheet  460   a  is inserted between the silicon keypad  451  and the flexible printed circuit board  453 , while the second antenna sheet  460   b  is inserted between the cover  455  and the flexible printed circuit board  453 . Here, there will be no need to put together both of the first antenna sheet  460   a  and the second antenna sheet  460   b,  but instead of both, only one of the two antenna sheets may be selectively employed depending upon the characteristic of the mobile terminal in use.  
         [0037]    The first and second antenna sheets  460   a  and  460   b  are, in themselves, capable of performing the function of an antenna, and on these first and second antenna sheets  460   a  and  460   b  may be formed the antenna pattern  465  having a topology such as shown in FIG. 8. Using the antenna pattern  465 , a planar inverted F-type antenna, a meander antenna formed of curvatures and the like may be constructed. Further, it should be appreciated that, besides the above antenna pattern, other types of antenna may be implemented using a suitable wire or the like.  
         [0038]    The first and second antenna sheets  460   a  and  460   b  are provided with ground lines  463   a  and  463   b  connected to a ground of the mobile terminal  400  and the antenna pattern  465 , and power supply lines  461   a  and  461   b  for supplying electrical power F. The mobile terminal  400  carries out data transmitting/receiving operations with a base station through the antenna apparatus  460  which may be provided with both of the first antenna sheet  460   a  and the second antenna sheet  460   b,  or either one of the two antenna sheets according to the characteristic of the mobile terminal in use. In addition, using the antenna apparatus  460  equipped within the mobile terminal  400 , a diversity antenna of the mobile terminal can be configured according to the present invention.  
         [0039]    Referring now to FIGS. 10 and 11, a front view of a mobile communication terminal having the antenna apparatus according to other preferred embodiments of the present invention are shown. As shown in FIG. 10, the mobile terminal  500  with a diversity antenna, having on its front a display unit  501 , beneath which a keypad assembly  505  is positioned and above which a speaker  509  is disposed. The mobile terminal  500  further includes a first antenna  507  disposed in upper end and a second antenna  560  disposed underlying the keypad  505  on a lower end that is opposite to the first antenna  507 . Also in the upper end of the mobile terminal  500  is disposed a camera module  511 , with a photographing angle adjustable by an adjusting knob  513  disposed on one side of the upper end of the mobile terminal  500 . Here, the display unit  401  may be configured in such a way that it has the largest possible area within the entire top surface of a main body of the mobile terminal  500  so as to enable viewing a motion picture or using a video phone thereon with more ease.  
         [0040]    The first antenna  507  serves as a main antenna of the mobile terminal  500 , for carrying out the transmitting/receiving of radio waves, while the second antenna  560  serves as a sub antenna of the mobile terminal, for carrying out the diversity receiving function, being configured in such a way that the silicon keypad  451 , the first antenna sheet  460   a,  the flexible printed circuit board  453  for keypad and a second antenna sheet  460   b  are sequentially stacked on the cover  455 , as in FIGS. 7 and 9.  
         [0041]    Here, it will be also appreciated by one of ordinary skill in the art that, contrary to the above construction, the second antenna  560  may be configured to serve as a main antenna of the mobile terminal  500 , for carrying out the transmitting/receiving of radio waves, while the first antenna  507  serves as a sub antenna of the mobile terminal, for carrying out the diversity receiving function.  
         [0042]    Referring then to FIG. 11, the mobile terminal  600  with the diversity antenna is provided in its front with a display unit  601 , beneath which display unit a keypad assembly  605  is positioned and above which a speaker  609  is disposed. The mobile terminal  600  further includes a first antenna  607  disposed in its upper end underlying the speaker  609 , and a second antenna  660  underlying the keypad  605  and disposed in the lower end, opposite to the first antenna  607 . On the upper end of the mobile terminal  600  is further disposed a camera module  611 , with a photographing angle adjustable by an adjusting knob  613  disposed on one side of the mobile terminal  600 .  
         [0043]    The first antenna  607  accommodated within the upper end of the mobile terminal  600  may be configured with the first or second antenna sheet  460   a  or  460   b,  having topology as shown in FIG. 8, using either one of a planar inverted F-type antenna, a meander antenna with plural curvatures, a loop antenna, a chip-type antenna, etc., which best meets the requirements for a particular preferred embodiment. The first antenna  607  serves as a main antenna of the mobile terminal  600 , for carrying out the transmitting/receiving of radio waves, while the second antenna  660  serves as a sub antenna of the mobile terminal, for carrying out the diversity receiving function, the second antenna being configured in such a way that the silicon keypad  451 , the first antenna sheet  460   a,  the flexible printed circuit board  453  for keypad and the second antenna sheet  460   b  are sequentially stacked on the cover  455 , as seen in FIGS. 7 and 8. Further, apart from the antenna apparatus having the antenna pattern formed on the first or second antenna sheet  460   a  and  460   b,  this antenna apparatus may be implemented using a preferred one of various kinds of antennas such as a planar inverted F-type antenna, a curved antenna with plural curvatures, a loop antenna, or a chip type antenna, etc. depending upon the requirements or characteristic of the mobile terminals in use. The second antenna serves as a sub antenna of the mobile terminal for achieving the diversity receiving function.  
         [0044]    In the meantime, it will be appreciated by one of ordinary skill in the art that contrary to the above configuration of the first and second antennas, the second antenna  660  may be configured to serve as a main antenna of the mobile terminal  600 , for carrying out the transmitting/receiving of radio waves, while the first antenna  607  serves as a sub antenna of the mobile terminal, for carrying out the diversity receiving function.  
         [0045]    As apparent from the foregoing description, it will be understood that the mobile communication terminal according to the present invention is configured in such a way that the antenna apparatus is accommodated underlying the keypad assembly or together with the same within the mobile communication terminal such as, e.g., mobile phone or PDA, thereby achieving more easy built-in design and preventing damage to the antenna due to any external impact. Moreover, where the aforementioned pattern antenna is combined with an external type of antenna, it will be considerably easier for its designers to meet the design rule to ensure enough isolating distance in between the aforementioned antenna and the external antenna. Furthermore, introduction of such a diversity receiving function to either one of the two antennas according to the present invention will cause to achieve significant improvement of the quality of signal and speed of data transfer in the mobile communication terminals.  
         [0046]    While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes and modifications may be made, and equivalents may be substituted for elements thereof without departing from the true scope of the present invention. Therefore, it is intended that the present invention not be limited to the particular embodiments disclosed, instead, it is intended that the present invention include all embodiments falling within the scope of the appended claims.