Patent Publication Number: US-9893418-B2

Title: Antenna and mobile device therefor

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application is a U.S. National Stage Application under 35 U.S.C. § 371 of PCT Application No. PCT/KR2012/006143, filed Aug. 1, 2012, which claims priority to Korean Patent Application No. 10-2011-0077066, filed Aug. 2, 2011. 
     TECHNICAL FIELD 
     The embodiment relates to an antenna and a mobile device equipped with the antenna, and more particularly, to an antenna which is operated as a loop antenna by connecting a plurality of radiators with each other and a mobile device having the same. 
     BACKGROUND ART 
     Recently, an antenna installed in a mobile communication device is manufactured while focusing on a small size and multi-functions. Although the size of a portable terminal has become small-sized, the portable terminal is requested to support various services such as reproduction of video and audio files or application execution. Thus, the antenna for the portable terminal is also requested to have various functions with a small size. 
     A sub-antenna installed in a portable mobile terminal includes a metal plate antenna having a PIFA (Planar Inverted-F Antenna) structure and a ceramic chip type antenna. Although the performance of the metal plate antenna is lower than that of an external antenna, the metal plate antenna has a merit in that the metal plate antenna can be built in the mobile terminal. However, it is difficult to ensure an installation space for the metal plate antenna due to the large size of the metal plate antenna. Since the design of the metal plate antenna must be changed according to the type of portable devices, there is a problem of increasing the manufacturing cost of the metal plate antenna. 
     Meanwhile, although the ceramic chip type antenna is small in size, the antenna tuning of the ceramic chip type antenna is difficult. In addition, the ceramic chip type antenna is sensitive to external factors due to its narrow bandwidth. Further, the performance of the ceramic chip type antenna is degraded, so it is difficult to fabricate an antenna, which is easily embedded, has a large bandwidth and an excellent performance. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     The embodiment can provide an antenna which can be easily embedded in a portable device and has a large bandwidth. 
     Solution to Problem 
     An antenna according to the embodiment includes a plurality of radiators having a pillar shape; a connecting member for connecting the radiators with each other in series; and a ground member for grounding the radiators connected with each other through the connecting member. 
     Advantageous Effects of Invention 
     The antenna according to the embodiment has a simple structure, can be easily mounted in a small portable device, and has a wide bandwidth. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a view of a module including an antenna according to an embodiment; and 
         FIG. 2  is a view showing an internal structure of the antenna according to the embodiment. 
     
    
    
     MODE FOR THE INVENTION 
     In the description of the embodiments, it will be understood that, when a layer (or film), a region, a pattern, or a structure is referred to as being “on/over” or “under” another substrate, another layer (or film), another region, another pad, or another pattern, it can be “directly” or over the other substrate, layer (or film), region, pad, or pattern, or one or more intervening layers may also be present. Such a position of the layer has been described with reference to the drawings. 
     Since the thickness and size of each layer shown in the drawings may be modified for the purpose of convenience or clarity of description, the size of elements does not utterly reflect an actual size. 
       FIG. 1  is a view of a module including an antenna according to an embodiment. Referring to  FIG. 1 , the antennas  10  and  10 - 1  according to the embodiment are mounted at both sides of a module  20  and are covered with circuit substrates  16 . Further, the antenna  10  and  10 - 1  may include ground members  15  and  15 - 1  for grounding the antennas  10  and  10 - 1 , respectively. The ground members  15  and  15 - 1 , as shown in  FIG. 1 , may be exposed out of the circuit substrate  16 , or may be covered with the circuit substrate  16 . 
     Meanwhile, the mobile device according to the embodiment may be applied to predetermined devices, such as a portable telephone equipped with the antenna of  FIGS. 1 and 2 , a smart phone, and a game player, which are portable and equipped with a wireless communication module. 
     The shape of the module, the installation place of the antenna, and the number of the antennas may not be limited to those illustrated in  FIG. 1 , and the internal structure of the antenna will be described below. 
       FIG. 2  is a view showing the internal structure of the antenna according to the embodiment. Referring to  FIG. 2 , the antenna  10  according to the embodiment may include a plurality of radiators  11  and  11 - 1  to  11 - 9  having a pillar shape, a connecting member  13  and  13 - 1  to  13 - 8  for connecting the plurality of radiators  11  and  11 - 1  to  11 - 9  with each other in series, and a ground member  15  for grounding the plurality of radiators  11  and  11 - 1  to  11 - 9  connected with each other through the connecting member  13  and  13 - 1  to  13 - 8 . Further, the antenna  10  may further include a plurality parasitic radiators  17  and  17 - 1  to  17 - 4  and a second antenna part  19 . As one example, in  FIG. 2 , a current flows from one radiator  11 - 9  of the plurality of radiators to another radiator  11 . 
     The plurality of radiators  11  and  11 - 1  to  11 - 9  may have a cylindrical shape, respectively. The plurality of radiators  11  and  11 - 1  to  11 - 9  may be disposed to be spaced apart from with each other by a predetermined distance and the connecting member  13  and  13 - 1  to  13 - 8  may connect the plurality of radiators  11  and  11 - 1  to  11 - 9  with each other, such that a current may flow alternatively from an upper end to a lower end of each radiator and vice versa. That is, the current flowing direction may be changed whenever the current flows through the radiator, so that a magnetic field may be formed around the antenna due to the current flowing. The magnetic fields formed by each radiator  11  and  11 - 1  to  11 - 9  are superimposed or overlapped with each other, such that one magnetic field can be formed around the antenna. Further, due to the various current changes by the plurality of radiators, the frequency band of the antenna may be expanded. For example, although a resonant frequency may be determined based on the last radiator  11 , which is grounded from among the plurality of radiators  11  and  11 - 1  to  11 - 9 , the frequency band of the antenna may be more expanded by the connection of the plurality of radiators  11  and  11 - 1  to  11 - 9 . 
     That is, frequency perturbation effect may be utilized through the plurality of radiators  11  and  11 - 1  to  11 - 9 . 
     Meanwhile, the plurality of radiators  11  and  11 - 1  to  11 - 9  may have a polygonal pillar shape, such as a triangle pillar shape, a square pillar shape, and a hexagonal pillar shape, as well as the cylindrical pillar shape. The plurality of radiators  11  and  11 - 1  to  11 - 9  may be formed as a predetermined pillar shape, such that the various changes of the current flowing through the antenna may be induced. 
     The connecting member  13  and  13 - 1  to  13 - 8  may include a plurality of metal plates for connecting adjacent radiators with each other. A current may flow between the radiators through the connecting member  13  and  13 - 1  to  13 - 8 . As shown in  FIG. 2 , a metal plate  13  for connecting two radiators  11  and  11 - 1  to each other connects low sides of the two radiator pillars to each other, and a metal plate  13 - 1  for connecting two radiators  11 - 1  and  11 - 2  to each other connects upper sides of the two radiator pillars to each other. The subsequent metal plates alternately connect the adjacent radiators to each other in the same manner at different horizontal heights of the adjacent radiators. That is, since the metal plates connect the radiators with each other at different horizontal heights of the radiators, the current flowing may be more varied. Thus, the frequency band may be more expanded. 
     Meanwhile, although the connecting members  13  and  13 - 1  to  13 - 8  connect two adjacent radiators to each other in  FIG. 2 , the number of radiators connected through one metal plate is not limited thereto and the connection position is not limited thereto. 
     The ground member  15  may be prepared as a terminal having a predetermined capacitance, such that the usable frequency may be controlled depending on the predetermined capacitance. For example, when an antenna having a usable frequency of 2.4 GHz is fabricated and mounted in a module, the usable frequency of the antenna mounted in the module may vary from the usable frequency of the antenna which is set when the antenna is fabricated. In order to adjust the variation, the ground member  15  is designed to be exposed. Thus, even if the antenna is mounted while being covered with the substrate  16 , the capacitance of the ground member  15  may be adjusted. Thus, the variation of the usable frequency may be compensated. 
     As shown in  FIG. 2 , the plurality parasitic radiators  17  and  17 - 1  to  17 - 4  may be disposed at a lower surface corresponding to an upper surface of the plurality of radiators  11  and  11 - 1  to  11 - 9  covered with the circuit substrate  16 . The parasitic radiators  17  and  17 - 1  to  17 - 4  are not electrically connected to the plurality of radiators  11  and  11 - 1  to  11 - 9 . Unlike the connecting member, each of the plurality of parasitic radiators connects several radiators  11  and  11 - 1  to  11 - 9  to each other at the lower surface of the plurality of radiators  11  and  11 - 1  to  11 - 9 , and the plurality of parasitic radiators may be spaced apart from each other by a predetermined distance. The parasitic radiators are physically connected to and extends between respective ones of the radiators  11  and  11 - 1  to  11 - 9  but are not galvanically connected with radiators  11  and  11 - 1  to  11 - 9 . Thus, the intensity of the magnetic field generated by each of the plurality of radiators  11  and  11 - 1  to  11 - 9  may be maximized. That is, the intensity of the magnetic field generated from the whole area of the antenna may become increased, so that the transmitting and receiving sensitivity of the antenna may be improved. 
     Meanwhile, the antenna  10  according to the embodiment further includes the second antenna part  19 , so that the antenna  10  may be operated as a dual antenna. The second antenna part  19  may be connected to ends of the plurality of parasitic radiators and extended in parallel with the connection direction of the connecting member  13  and  13 - 1  to  13 - 8   
     As described above, according to the embodiment, the installation of the antenna may be easy and the bandwidth is expanded, so that the antenna having the superior performance and the mobile device equipped with the antenna can be provided. 
     Any reference in this specification to one embodiment, an embodiment, example embodiment, etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments. 
     Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.