Abstract:
A built-in antenna module of a wireless communication terminal is provided. In the antenna module, a substrate is disposed inside a terminal body and has a plurality of electronic parts mounted therein. At least one radiator rib is integrally extended from the terminal body along a predetermined pattern in accordance with properties of the antenna. A radiator line is made of a conductive elastomer which is dispensed and coated onto an upper end of the radiator rib. The radiator line has an end electrically connected to a feeding part of the substrate. The invention simplifies a process for manufacturing the antenna module, thereby improving work productivity and saving manufacturing costs. The invention also allows the antenna to be modified in design more flexibly and the terminal product to be miniaturized.

Description:
CLAIM OF PRIORITY  
       [0001]     This application claims the benefit of Korean Patent Application No. 2005-85709 filed on Sep. 14, 2005 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a built-in antenna module for a wireless telecommunication terminal, more particularly, in which a radiator for transmitting/receiving a signal is formed of a conductive elastomer dispensed on a radiator rib that is integrally injection-molded on a casing of a terminal body, by which the antenna can be assembled easily and quickly and reduced in its occupying space to enhance miniaturization.  
         [0004]     2. Description of the Related Art  
         [0005]     In general, a wireless communication terminal refers to a portable communication device capable of transmitting/receiving voices, texts and image data through wireless communication. The examples include a personal communication service (PCS) terminal, a Personal Digital Assistant (PDA), a smart phone, a next-generation mobile communication (IMT-2000) terminal, a wireless LAN terminal and the like.  
         [0006]     The wireless communication terminal adopts a helical antenna or a dipole antenna to enhance its transmission and reception sensitivity. These are external antennas, which thus are extended out of the wireless terminal.  
         [0007]     The external antennas are advantageously characterized by non-directional radiation. At the same time, they are disadvantageously prone to damage by external force, hardly portable and designed with poor aesthetic appearance.  
         [0008]     To overcome such a problem, plate-shaped built-in antennas such as a micro-strip patch antenna or inverted F-type antenna have been recently adopted in the wireless communication terminal since they can be installed in the terminal without being extended outward.  
         [0009]      FIG. 1  is an exploded view illustrating a conventional built-in antenna which is provided in a wireless communication terminal.  FIG. 2  is a perspective view illustrating a conventional built-in antenna module which is assembled onto a lower casing of a wireless communication terminal. As shown, the antenna module  1  includes a radiator  10  and a base  20 .  
         [0010]     The radiator  10  is made of a conductive material such as a conductive metal so as to transmit and receive a radio wave signal from a base station. To form the radiator  10 , a plate-shaped material is pressurized/perforated in a predetermined pattern.  
         [0011]     The base  20  is made of a non-conductive material which is molded of a non-conductive resin. The base  20  is a fixed structure mounted on a substrate M.  
         [0012]     The base  20  has a plurality of assembly pillars  22  on an upper surface thereof into which assembly holes  12  of the radiator  10  are inserted. This allows the radiator  10  to be fixedly disposed on an outer surface of the base  20 . Also, the base  20  has a plurality of lower assembly steps  24  formed on a lower end thereof corresponding to lower assembly holes  13  on the substrate M.  
         [0013]     The substrate M is mounted on a lower casing  109  which constitutes a terminal body together with an upper casing  108 . A feeding part  15  of the radiator mounted on the base  20  is electrically connected to the base M.  
         [0014]     However, in such a conventional antenna module  1 , to form the radiator  10  in a predetermined pattern, a plate-shaped material is pressurized and then perforated in a predetermined pattern. The radiator  10  processed as just described should be manually assembled onto the base  20  in a separate assembly line in a later process.  
         [0015]     Consequently, a manufacturing process for completely assembling the antenna module is very complicated and cumbersome. This has limitations in enhancing work productivity and reducing manufacturing costs.  
         [0016]     Moreover, when a structure of the base  20  and design of the radiator  10  are changed to modify the radiator, a mold for pressurizing and perforating the plate-shaped material should be replaced. This replacement job inflicts additional costs and wastes a considerable amount of time, not assuring flexible modification in design of the antenna.  
         [0017]     In addition, as shown in  FIGS. 1 and 2 , the base  20  is a fixed structure assembled between the upper and lower casings  108  and  109 , thereby occupying a certain space. Thus the terminal product is limitedly miniaturizable with reduction in an internal space of the upper and lower casings  108  and  109 .  
       SUMMARY OF THE INVENTION  
       [0018]     The present invention has been made to solve the foregoing problems of the prior art and therefore an object according to certain embodiments of the present invention is to provide a built-in antenna module of a wireless communication terminal which simplifies a manufacturing process thereof to improve work productivity, saves manufacturing costs, and achieves flexible design modification and miniaturization.  
         [0019]     According to an aspect of the invention for realizing the object, there is provided a built-in antenna module of a wireless communication terminal including a substrate disposed inside a terminal body and having a plurality of electronic parts mounted therein; at least one radiator rib integrally extended from the terminal body along a predetermined pattern in accordance with properties of the antenna; and a radiator line made of a conductive elastomer which is dispensed and coated onto an upper end of the radiator rib, the radiator line having an end electrically connected to a feeding part of the substrate.  
         [0020]     Preferably, the radiator rib is a perpendicular rib protruded at a predetermined height from an inner surface of an upper casing during injection-molding thereof, the upper casing constituting the terminal body.  
         [0021]     Preferably, the radiator rib is a perpendicular rib protruded at a predetermined height from an inner surface of a lower casing during injection-molding thereof, the lower casing constituting the terminal body.  
         [0022]     Preferably, the radiator rib has at least one step formed on the upper end thereof, the step having a polygonal cross-section for enabling the radiator line to be formed longer.  
         [0023]     Preferably, the radiator rib has at least one step formed on the upper end thereof, the step having a cup-shaped cross-section for enabling the radiator line to be formed longer.  
         [0024]     Preferably, the radiator rib comprises a conductive elastomer having a volume resistance of 1Ωcm to 1000Ωcm.  
         [0025]     More preferably, the conductive elastomer is formed by adding a conductive metal to a non-conductive elastic resin.  
         [0026]     More preferably, the conductive elastomer has an elastic strength of Hs 5 to Hs 100.  
         [0027]     Preferably, the radiator line has a protrusion protruded from an end thereof corresponding to the feeding part of the substrate, the protrusion being in resilient contact with the feeding part.  
         [0028]     Preferably, the feeding part includes an elastic flap having a free end resiliently contacting a predetermined portion of the radiator line and a fixed end fixed to a fixed hole of the substrate.  
         [0029]     Preferably, the feeding part includes a contact pin having a free end contacting a predetermined portion of the radiator line and a spring member housed in a cylinder casing so that the contact pin is resiliently supported by elastic force of a predetermined magnitude in an upward direction. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]     The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:  
         [0031]      FIG. 1  is an exploded view in which a built-in antenna module is provided in a substrate of a wireless communication terminal according to the prior art;  
         [0032]      FIG. 2  is a perspective view in which a built-in antenna module is assembled onto a lower casing of a wireless communication terminal according to the prior art;  
         [0033]      FIG. 3  is a perspective view illustrating a built-in antenna module of a wireless telecommunication terminal according to the invention;  
         [0034]     FIGS. 4 ( a )-( b ) illustrate an assembly process of a built-in antenna module of a wireless telecommunication terminal according to the invention;  
         [0035]      FIG. 5  illustrates a modified embodiment of a radiator line which is employed in a built-in antenna module of a wireless telecommunication terminal according to the invention, in which (a) is a sawtooth radiator line and (b) is a wave radiator line; and  
         [0036]      FIG. 6  illustrates an embodiment of a feeding part which is employed in a built-in antenna module of a wireless telecommunication terminal according to the invention, in which (a) is an elastic flap-shaped feeding part and (b) is a Fog pin-shaped feeding part. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0037]     Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.  
         [0038]      FIG. 3  is a perspective view illustrating a built-in antenna module of a wireless telecommunication terminal according to the invention.  FIG. 4  illustrates an assembly process of a built-in antenna module of a wireless telecommunication terminal according to the invention.  
         [0039]     As shown in  FIGS. 3 and 4 , in the built-in antenna module  100  of the invention, a radiator is simply and quickly installed thereon without undergoing pressurization and perforation, thereby saving manufacturing costs. The built-in antenna module  100  includes a radiator rib  110 , a radiator line and a feeding part  130 .  
         [0040]     The radiator rib  110  is a vertical structure integrally disposed on an inner surface of an upper or lower casing  108  or  109  which is injection-molded. The upper and lower casings  108  and  109  are assembled together to constitute a terminal body.  
         [0041]     The radiator rib  110  is a perpendicular rib member made of a conductive resin. The radiator rib  110  is protruded at a predetermined height from the inner surface of the upper or lower casing  108  or  109  which is injection-molded along a predetermined pattern. The pattern is designed in advance in view of characteristics of the antenna and reception sensitivity.  
         [0042]     Also, the radiator line  120  is made of a conductive elastomer which is dispensed (not illustrated) and coated onto an upper end of the radiator rib  110 . Here, as just described, the radiator rib  110  is disposed in the upper or lower casing  108  or  109  in accordance with properties of the antenna. This allows a signal to be transmitted and received from the base station.  
         [0043]     The conductive elastomer of the radiator line  120  is manufactured by adding a conductive metal element such as gold, silver and bronze to a non-conductive elastic resin such as a silicone rubber. Preferably, in producing the conductive elastomer, a weight ratio of the non-conductive elastic resin is adjusted such that the radiator line  120  has an elastic strength of Hs 5 to Hs 100. Also, preferably, a weight ratio of the conductive metal element is adjusted such that the radiator line  12  has a volume resistance of 1Ωcm to 1000Ωcm.  
         [0044]     Moreover, preferably, the radiator line  120  has a protrusion  125  on one end thereof corresponding to the feeding part  130  of the substrate M so that the protrusion  125  is in resilient contact with the feeding part  130 .  
         [0045]     The radiator rib  110  where the radiator line  120  is disposed is made of a non-conductive resin, which is the same material as the injection-molded upper and lower casings  108  and  109 . This non-conductive resin has a dielectric constant of at least 1.  
         [0046]     Meanwhile, as shown in  FIG. 3 , the radiator line  120  may be coated on the upper end of the flat radiator rib  110  but not limited thereto. Preferably, the radiator line  120  is formed longer to maximize transmission and reception capabilities of the antenna.  
         [0047]     Accordingly, as shown in  FIG. 5 ( a ), the radiator rib  110  has at least one step having a polygonal cross-section formed on the upper end thereof, thereby forming a sawtooth radiator line  120   a . Also, as shown in  FIG. 5 ( b ), the radiator rib  110  has at least one step having a cup-shaped cross-section on an upper end thereof, thereby forming a wave radiator line  120   b.    
         [0048]     The substrate M has at least one feeding part  130  formed thereon corresponding to a side end of the radiator line  120  to be electrically connected to the radiator line  120 .  
         [0049]     As shown in  FIG. 6 ( a ), the feeding part  130  is structured as an elastic flap  131  in which a free end is in resilient contact with a predetermined portion of the radiator line  120  and a fixed end is fixed in a fixed hole  106  of the substrate M. Alternatively, as shown in  FIG. 6 ( b ), the feeding part  130  includes a contact pin  133  having a free end contacting a predetermined portion of the radiator line  120  and a spring member  132  housed in a cylinder casing  134  so that the contact pin is resiliently supported by elastic force of a predetermined magnitude in a direction of the radiator line  120 .  
         [0050]     To configure the antenna module  100  as just described, the radiator rib  120  is an integral perpendicular rib member protruded at a predetermined height from an inner surface of an upper or lower casing  108  or  109  during injection-molding thereof. The upper and lower casings  108  and  109  are injection-molded of a non-conductive resin by a mold (not illustrated) to constitute a terminal body.  
         [0051]     The at least one radiator rib  120  is disposed on at least one of the upper and lower casings  108  and  109  corresponding to the feeding part  130  of the substrate M where electronic parts are mounted.  
         [0052]     Further, the radiator rib  110  formed during injection-molding of the upper and lower casings  108  and  109  is shaped according to pre-set antenna characteristics and reception sensitivity. The radiator rib  120  may have at least one step having a polygonal cross-section or a cup-shaped cross-section formed on an upper end thereof, thereby enabling the radiator line  120  to be formed longer.  
         [0053]     Subsequently, a conductive paint  105  for shielding EMI is coated on an inner surface of the upper and lower casings  108  and  109  or an outer surface of the substrate M to be electrically connected to a ground part (not illustrated) of the substrate M. This shields a harmful external electromagnetic wave from entering the terminal body and militating against electronic products.  
         [0054]     With the conductive paint for shielding EMI coated, a dispenser (not illustrated) filled with a conductive elastomer is disposed just over the radiator rib  110  to dispense a liquid conductive elastomer along an upper end of the radiator rib  110 . Here, the liquid conductive elastomer is manufactured by combining an elastic resin and a conductive metal element. This allows a radiator line  120  to be formed on the upper end of the radiator rib  110  to radiate a signal to the outside and receive an external signal.  
         [0055]     The conductive elastomer dispensed onto the radiator rib  110  is naturally cured or UV-cured. For the natural curing, the conductive elastomer is kept at a room temperature during a predetermined time. Meanwhile, for the UV-curing, the conductive elastomer is irradiated with ultra violet ray to shorten a curing time.  
         [0056]     Subsequently, upon curing the radiator line  120  made of the conductive elastomer, the upper and lower casings  108  and  109  are vertically assembled together. Then the substrate M assembled on the lower casing  109  is electrically connected to the radiator line  120  by the feeding part  130 .  
         [0057]     That is, the protrusion  125  formed on one end of the radiator line  120  corresponds one-by-one to the feeding part  130  of the substrate M so that the radiator line  120  resiliently contacts the feeding part  130 .  
         [0058]     As shown in  FIG. 6 ( a ), in a case where the feeding part  130  is the elastic flap  131  connected to the substrate M, the free end of the elastic flap  131  is in resilient contact with and electrically connected to a conductive elastomer corresponding to the protrusion  125  of the radiator line  120 , thereby allowing a signal to be transmitted and received.  
         [0059]     Moreover, as shown in  FIG. 6  ( b ), in a case where the feeding part  130  is structured of a Fog pin-shaped contact pin  133  and a spring member  132  elastically supporting the contact pin, the contact pin  133  has an end in resilient contact with and electrically connected to an end of the radiator line  120 , thereby enabling transmission and reception of the signal.  
         [0060]     As set forth above, according to preferred embodiments of the invention, a wireless telecommunication terminal has a radiator rib on an inner surface thereof when upper and lower casings of a terminal body are injection-molded. Also, the terminal has a conductive elastomer dispensed on an upper end thereof to contact a feeding part of the substrate. Therefore the invention obviates a need for a cumbersome and complicated process of pressurizing and perforating a plate-shaped material to form a separate radiator, and assemble the radiator on an outer surface of a base and then the base assembled with the radiator onto a casing, as in the prior art. Meanwhile, the invention allows a radiator rib to be integrally formed on an inner surface of the casing and a radiator line to be installed thereon more easily and conveniently. This simplifies a manufacturing process of the antenna module, thereby reducing manufacturing costs and enhancing design flexibility of the antenna.  
         [0061]     In addition, according to the invention, a base is not installed in an inner space between the upper and lower casings as in the prior art. This allows the antenna module to occupy significantly less space than the prior art, thereby ensuring the terminal product to be designed in a smaller size.  
         [0062]     While the present invention has been shown and described in connection with the preferred embodiments, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention as defined by the appended claims.