Patent Publication Number: US-2013249741-A1

Title: Antenna and Terminal with Anenna

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/CN2011/081703, filed on Nov. 3, 2011, which claims priority to Chinese Patent Application No. 201010555656.1, filed on Nov. 22, 2010, both of which are incorporated herein by reference in their entireties. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not applicable. 
     TECHNICAL FIELD 
     The present invention relates to the field of antenna design, and in particular, to an antenna and a terminal with an antenna. 
     BACKGROUND 
     At present, an antenna used in a terminal with an antenna such as a mobile phone and a data card is mostly a monopole antenna, an inverted-F antenna (IFA) or a planar inverted-F antenna (PIFA), and working frequency bands of each of the antennas are between 824 megahertz (MHz) and 960 MHz and between 1710 MHz and 2170 MHz. 
     In the process of implementing embodiments of the present invention, the inventors found that a high frequency resonance and a low frequency resonance of a conventional antenna may include three frequency bands, which are 1800 frequency band, 1900 frequency band and 2100 frequency band, respectively. As shown in  FIG. 1 , when echo loss of the antenna is tested, in S11 diagram, mark number  1  indicates the low frequency resonance part, mark numbers  3  and  4  indicate the high frequency resonance part, an obvious bump part  2  exists between the high frequency resonance and the low frequency resonance, and the antenna efficiency of the bump part  2  is generally relatively low. So the antenna has a frequency band gap between 960 MHz and 1710 MHz. How to add related applications of frequency bands between 960 MHz and 1710 MHz is a problem required to be solved. 
     SUMMARY 
     An antenna provided by embodiments of the present invention is used for implementing the adding of related applications of frequency bands between 960 MHz and 1710 MHz. 
     To achieve the above objective, embodiments of the present invention adopt the following technical solutions. 
     An antenna, which is a planar antenna, includes an intermediate frequency branch, a high frequency branch and a low frequency branch, where the intermediate frequency branch, the high frequency branch and the low frequency branch are independent of one another, the high frequency branch and the low frequency branch encircle the intermediate frequency branch; a feed point connecting line is disposed on the intermediate frequency branch; a first ground point connecting line is disposed on the high frequency branch; a second ground point connecting line is disposed on the low frequency branch, and the feed point connecting line, the first ground point connecting line and the second ground point connecting line are located at the same side of the antenna. 
     A terminal with an antenna, includes a radio frequency unit, and the radio frequency unit of the terminal with an antenna includes the above antenna. 
     In the antenna and the terminal with an antenna provided by the embodiments of the present invention, the antenna includes an intermediate frequency branch, a high frequency branch and a low frequency branch, where the intermediate frequency branch, the high frequency branch and the low frequency branch are independent of one another, the high frequency branch and the low frequency branch encircle the intermediate frequency branch, the intermediate frequency branch, a feed point connecting line is disposed on the high frequency branch and the low frequency branch, a first ground point connecting line and a second ground point connecting line, respectively, so that three resonances are generated, which are a low frequency resonance, a high frequency resonance and an intermediate resonance, respectively. Therefore, a resonance with a quite wide wide-band is generated. When echo loss of the antenna is tested, an echogram in which no obvious bump exists among the three resonances may be obtained, as shown in  FIG. 2 , so that the antenna not only can work on a frequency band of 824 MHz-960 MHz and a frequency band of 1710 MHz-2170 MHz, but also can work on a frequency band of 960 MHz-1710 MHz. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an S11 diagram for an antenna to perform echo loss testing in the prior art; 
         FIG. 2  is an S11 diagram for an antenna to perform echo loss testing according to an embodiment of the present invention; 
         FIG. 3  is a schematic structural diagram  1  of an antenna according to an embodiment of the present invention; 
         FIG. 4  is a schematic structural diagram  2  of an antenna according to an embodiment of the present invention; 
         FIG. 5  is a schematic structural diagram  1  of an antenna according to another embodiment of the present invention; 
         FIG. 6  is a schematic structural diagram  2  of an antenna according to another embodiment of the present invention; 
         FIG. 7  is a schematic structural diagram  3  of an antenna according to another embodiment of the present invention; 
         FIG. 8  is a schematic structural diagram  4  of an antenna according to another embodiment of the present invention; and 
         FIG. 9  is a block diagram of functions of a mobile phone according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The following clearly describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are merely a part rather than all of the embodiments of the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiment of the present invention without creative efforts shall fall within the protection scope of the present invention. 
     In order to implement the adding of related applications of frequency bands between 960 MHz and 1710 MHz for an antenna, embodiments of the present invention provide an antenna and a terminal with an antenna. 
     As shown in  FIG. 3 , an antenna provided by an embodiment of the present invention is a planar antenna  1  and includes an intermediate frequency branch  11 , a high frequency branch  12  and a low frequency branch  13 , where the intermediate frequency branch  11 , the high frequency branch  12  and the low frequency branch  13  are independent of one another, the high frequency branch  12  and the low frequency branch  13  encircle the intermediate frequency branch  11 ; a feed point connecting line  111  is disposed on the intermediate frequency branch  11 ; a first ground point connecting line  121  is disposed on the high frequency branch  12 ; a second ground point connecting line  131  is disposed on the low frequency branch  13 , and the feed point connecting line  111 , the first ground point connecting line  121  and the second ground point connecting line  131  are located at the same side of the antenna  1 . 
     As shown in  FIG. 4 , furthermore, in order to reduce the area of the branches, the intermediate frequency branch  11  may be a hollowed-out intermediate frequency branch and the high frequency branch  12  may be a hollowed-out high frequency branch. 
     In the antenna provided by the embodiment of the present invention, the antenna includes an intermediate frequency branch, a high frequency branch and a low frequency branch, where the intermediate frequency branch, the high frequency branch and the low frequency branch are independent of one another, the high frequency branch and the low frequency branch encircle the intermediate frequency branch, the intermediate frequency branch, a feed point connecting line is disposed on the high frequency branch and the low frequency branch, a first ground point connecting line and a second ground point connecting line, respectively, so that three resonances are generated, which are a low frequency resonance, a high frequency resonance and an intermediate resonance, respectively. Therefore, a resonance with a quite wide wide-band is generated. When echo loss of the antenna is tested, an echogram in which no obvious bump exists among the three resonances may be obtained, as shown in  FIG. 2 , so that the antenna not only can work on a frequency band of 824 MHz-960 MHz and a frequency band of 1710 MHz-2170 MHz, but also can work on a frequency band of 960 MHz-1710 MHz. 
     In order to enable persons of skill in the art to understand the technical solutions provided by the embodiment of the present invention more clearly, the antenna provided by the embodiment of the present invention is illustrated below in detail through specific embodiments. 
     As shown in  FIG. 5 , for an antenna provided by another embodiment of the present invention, the antenna  1  is a planar antenna and includes an intermediate frequency branch  11 , a high frequency branch  12  and a low frequency branch  13 , where both the intermediate frequency branch  11  and the high frequency branch  12  are in a surface shape, and the low frequency branch  13  is in a polygonal-line shape. 
     The intermediate frequency branch  11 , the high frequency branch  12  and the low frequency branch  13  are independent of one another, the high frequency branch  12  and the low frequency branch  13  encircle the intermediate frequency branch  11 ; a feed point connecting line  111  is disposed on the intermediate frequency branch  11 ; a first ground point connecting line  121  is disposed on the high frequency branch  12 ; a second ground point connecting line  131  is disposed on the low frequency branch  13 , and the feed point connecting line  111 , the first ground point connecting line  121  and the second ground point connecting line  131  are located at the same side of the antenna. 
     Furthermore, in order to make an antenna bandwidth better, a projection  112  is disposed on the intermediate frequency branch  11  and is located between the high frequency branch  12  and the low frequency branch  13 , thereby separating the high frequency branch  12  from the low frequency branch  13 , a cabling  112  is located at one side of the intermediate frequency branch  11  opposite to the feed point connecting line  111 . 
     Furthermore, in order to reduce the area of the branches, the intermediate frequency branch  11  may be a hollowed-out intermediate frequency branch and the high frequency branch  12  may be a hollowed-out high frequency branch. 
     It should be noted that, the antenna is a passive device closely related to surroundings, on the premise that the intermediate frequency branch, the high frequency branch and the low frequency branch are independent of one another, the high frequency branch and the low frequency branch encircle the intermediate frequency branch, and the feed point connecting line, the first ground point connecting line and the second ground point connecting line are located at the same side of the antenna, the planar structure of the antenna is closely related to the difference of a structural support where the antenna is located. 
     Specifically, the specific shape of each branch of the antenna includes, but is not limited to, the antenna of the following embodiments. 
     (1) The antenna includes an intermediate frequency branch, a high frequency branch and a low frequency branch, where both the intermediate frequency branch and the high frequency branch are in an elongate surface shape, the intermediate frequency branch, the high frequency branch and the low frequency branch are independent of one another, and the high frequency branch and the low frequency branch encircle the intermediate frequency branch. A feed point connecting line is disposed on the intermediate frequency branch; a first ground point connecting line is disposed on the high frequency branch; a second ground point connecting line is disposed on the low frequency branch, and the feed point connecting line, the first ground point connecting line and the second ground point connecting line are located at the same side of the antenna. 
     When both the intermediate frequency branch and the high frequency branch are in an elongate surface shape, the specific shape of each branch of the antenna includes, but is not limited to, the antenna of the following embodiments. 
     (a) As shown in  FIG. 6 , both the intermediate frequency branch  11  and the high frequency branch  12  are rectangular, the intermediate frequency branch  11  and the high frequency branch  12  are arranged side by side, and one relatively short side of the intermediate frequency branch  11  is corresponding to one relatively long side of the high frequency branch  12 . The low frequency branch  13  is in a polygonal-line shape, the polygonal-line low frequency branch  13  may be in a U-shape with a straight bottom, thereby achieving the objective that the low frequency branch and the high frequency branch encircle the intermediate frequency branch therein. 
     In this embodiment, when efficiency testing is performed on the antenna shown in  FIG. 6 , an Antenna Efficiency Table 1 shown in Table 1 is obtained. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Antenna Efficiency Table 1 
               
               
                 Frequency Point Value 
               
            
           
           
               
               
               
            
               
                   
                 Frequency (MHz) 
                 Efficiency (%) 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 824 
                 47.41 
               
               
                   
                 844 
                 51.71 
               
               
                   
                 864 
                 52.74 
               
               
                   
                 884 
                 56.47 
               
               
                   
                 904 
                 55.68 
               
               
                   
                 924 
                 53.53 
               
               
                   
                 944 
                 55.37 
               
               
                   
                 964 
                 57.88 
               
               
                   
                 984 
                 60.03 
               
               
                   
                 1004 
                 58.04 
               
               
                   
                 1024 
                 52.20 
               
               
                   
                 1044 
                 46.83 
               
               
                   
                 1064 
                 40.69 
               
               
                   
                 1084 
                 41.47 
               
               
                   
                 1104 
                 40.98 
               
               
                   
                 1124 
                 41.88 
               
               
                   
                 1144 
                 44.78 
               
               
                   
                 1164 
                 49.43 
               
               
                   
                 1184 
                 53.98 
               
               
                   
                 1204 
                 57.28 
               
               
                   
                 1224 
                 58.68 
               
               
                   
                 1244 
                 61.10 
               
               
                   
                 1264 
                 61.47 
               
               
                   
                 1284 
                 60.49 
               
               
                   
                 1304 
                 60.11 
               
               
                   
                 1324 
                 58.67 
               
               
                   
                 1344 
                 54.20 
               
               
                   
                 1364 
                 54.41 
               
               
                   
                 1384 
                 53.14 
               
               
                   
                 1404 
                 52.33 
               
               
                   
                 1424 
                 51.63 
               
               
                   
                 1444 
                 50.19 
               
               
                   
                 1464 
                 49.78 
               
               
                   
                 1484 
                 51.44 
               
               
                   
                 1504 
                 51.40 
               
               
                   
                 1524 
                 51.23 
               
               
                   
                 1544 
                 51.21 
               
               
                   
                 1564 
                 51.70 
               
               
                   
                 1584 
                 52.31 
               
               
                   
                 1604 
                 54.36 
               
               
                   
                 1624 
                 56.06 
               
               
                   
                 1644 
                 56.78 
               
               
                   
                 1664 
                 59.04 
               
               
                   
                 1684 
                 62.21 
               
               
                   
                 1704 
                 64.48 
               
               
                   
                 1724 
                 67.73 
               
               
                   
                 1744 
                 69.44 
               
               
                   
                 1764 
                 70.20 
               
               
                   
                 1784 
                 71.37 
               
               
                   
                 1804 
                 73.79 
               
               
                   
                 1824 
                 75.95 
               
               
                   
                 1844 
                 76.70 
               
               
                   
                 1864 
                 76.44 
               
               
                   
                 1884 
                 76.25 
               
               
                   
                 1904 
                 74.62 
               
               
                   
                 1924 
                 72.85 
               
               
                   
                 1944 
                 71.84 
               
               
                   
                 1964 
                 70.50 
               
               
                   
                 1984 
                 65.64 
               
               
                   
                 2004 
                 61.51 
               
               
                   
                 2024 
                 55.41 
               
               
                   
                 2044 
                 50.40 
               
               
                   
                 2064 
                 53.48 
               
               
                   
                 2084 
                 55.71 
               
               
                   
                 2104 
                 53.77 
               
               
                   
                 2124 
                 50.10 
               
               
                   
                 2144 
                 48.35 
               
               
                   
                 2164 
                 47.56 
               
               
                   
                 2170 
                 47.49 
               
               
                   
                 2190 
                 46.16 
               
               
                   
                   
               
            
           
         
       
     
     (b) As shown in  FIG. 7 , the elongate surface shape includes a right-angled trapezoid and a rectangle. At this time, the intermediate frequency branch  11  is a trapezoid, the high frequency branch  12  is a rectangle and a right-angled leg of the intermediate frequency branch  11  is adjacent to one relatively long side of the high frequency branch  12 . The low frequency branch  13  is in a U-shape, and the bottom of the U-shape may be parallel to the oblique leg of the intermediate frequency branch  11 . So an area with a long distance from the ground may be effectively used. 
     When efficiency testing is performed on the antenna shown in  FIG. 7 , the testing results are as shown in Table 2. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Antenna Efficiency Table 2 
               
               
                 Frequency Point Value 
               
            
           
           
               
               
               
            
               
                   
                 Frequency (MHz) 
                 Efficiency (%) 
               
               
                   
                   
               
            
           
           
               
               
               
            
               
                   
                 824 
                 37.48 
               
               
                   
                 844 
                 51.49 
               
               
                   
                 864 
                 58.59 
               
               
                   
                 884 
                 63.56 
               
               
                   
                 904 
                 63.63 
               
               
                   
                 924 
                 60.00 
               
               
                   
                 944 
                 59.75 
               
               
                   
                 960 
                 57.36 
               
               
                   
                 980 
                 56.77 
               
               
                   
                 1010 
                 53.35 
               
               
                   
                 1040 
                 51.44 
               
               
                   
                 1070 
                 46.31 
               
               
                   
                 1100 
                 47.79 
               
               
                   
                 1130 
                 52.49 
               
               
                   
                 1160 
                 56.62 
               
               
                   
                 1190 
                 58.58 
               
               
                   
                 1220 
                 58.07 
               
               
                   
                 1250 
                 55.88 
               
               
                   
                 1280 
                 53.66 
               
               
                   
                 1310 
                 53.42 
               
               
                   
                 1340 
                 53.36 
               
               
                   
                 1370 
                 56.35 
               
               
                   
                 1400 
                 57.66 
               
               
                   
                 1430 
                 61.02 
               
               
                   
                 1460 
                 64.38 
               
               
                   
                 1490 
                 49.88 
               
               
                   
                 1520 
                 58.27 
               
               
                   
                 1550 
                 63.76 
               
               
                   
                 1580 
                 66.47 
               
               
                   
                 1610 
                 64.66 
               
               
                   
                 1640 
                 64.55 
               
               
                   
                 1670 
                 67.24 
               
               
                   
                 1700 
                 67.47 
               
               
                   
                 1730 
                 68.34 
               
               
                   
                 1760 
                 67.66 
               
               
                   
                 1790 
                 67.22 
               
               
                   
                 1820 
                 62.62 
               
               
                   
                 1850 
                 57.53 
               
               
                   
                 1880 
                 70.51 
               
               
                   
                 1910 
                 74.53 
               
               
                   
                 1940 
                 79.82 
               
               
                   
                 1970 
                 80.59 
               
               
                   
                 2000 
                 76.91 
               
               
                   
                 2030 
                 74.06 
               
               
                   
                 2060 
                 71.79 
               
               
                   
                 2090 
                 68.34 
               
               
                   
                 2120 
                 66.63 
               
               
                   
                 2150 
                 65.50 
               
               
                   
                 2170 
                 62.59 
               
               
                   
                   
               
            
           
         
       
     
     According to Table 1 and Table 2, it may be obtained that the working efficiencies of 824 MHz-2170 MHz of the antennas are all over 40%, so that the antenna not only can work on a frequency band of 824 MHz-960 MHz and a frequency band of 1710 MHz-2170 MHz, but also can work on a frequency band of 960 MHz-1710 MHz. 
     It should be noted that, when the intermediate frequency branch is in an elongate surface shape, one side of the intermediate frequency branch adjacent to the low frequency branch may be in an arc shape or polygonal-line shape, which is not described again herein. 
     (2) As shown in  FIG. 8 , the antenna  1  includes an intermediate frequency branch  11 , a high frequency branch  12  and a low frequency branch  13 , where the intermediate frequency branch  11  is in a square shape, the high frequency branch  12  is in an elongate surface shape, the low frequency branch  13  is in an polygonal-line shape, the intermediate frequency branch  11 , the high frequency branch  12  and the low frequency branch  13  are independent of one another, the intermediate frequency branch  11  and the high frequency  12  are arranged side by side, one side of the intermediate frequency branch  11  is adjacent to one relatively long side of the high frequency branch  12 , and the high frequency branch  12  and the low frequency branch  13  encircle the intermediate frequency branch  11 . A feed point connecting line  111  is disposed on the intermediate frequency branch  11 ; a first ground point connecting line  121  is disposed on the high frequency branch  12 ; a second ground point connecting line  131  is disposed on the low frequency branch  13 , and the feed point connecting line  111 , the first ground point connecting line  121  and the second ground point connecting line  131  are located at the same side of the antenna  1 . 
     In addition, in the above embodiment, the low frequency branch  13  may also be in a U-shape with an arc-shaped bottom instead of being in a polygonal-line shape. 
     In the antenna provided by the embodiment of the present invention, the antenna includes an intermediate frequency branch, a high frequency branch and a low frequency branch, the intermediate frequency branch, the high frequency branch and the low frequency branch are independent of one another, the high frequency branch and the low frequency branch encircle the intermediate frequency branch, the intermediate frequency branch, a feed point connecting line is disposed on the high frequency branch and the low frequency branch, a first ground point connecting line and a second ground point connecting line, respectively, so that three resonances are generated, which are a low frequency resonance, a high frequency resonance and an intermediate resonance, respectively. Therefore, a resonance with a quite wide wide-band is generated, and no obvious bump exists among the three resonances, so that the antenna not only can work on a frequency band of 824 MHz-960 MHz and a frequency band of 1710 MHz-2170 MHz, but also can work on a frequency band of 960 MHz-1710 MHz. 
     A terminal with an antenna provided by the embodiment of the present invention includes a radio frequency unit, where the radio frequency unit of the terminal with an antenna includes an antenna, and the antenna includes an intermediate frequency branch, a high frequency branch and a low frequency branch, where the intermediate frequency branch, the high frequency branch and the low frequency branch are independent of one another, the high frequency branch and the low frequency branch encircle the intermediate frequency branch; a feed point connecting line is disposed on the intermediate frequency branch; a first ground point connecting line is disposed on the high frequency branch; a second ground point connecting line is disposed on the low frequency branch, and the feed point connecting line, the first ground point connecting line and the second ground point connecting line are located at the same side of the antenna. 
     In this embodiment, both the intermediate frequency branch and the high frequency branch are in a surface shape and the low frequency branch is in a polygonal-line shape. 
     As shown in  FIG. 9 , taking a mobile phone terminal as an example, a conventional mobile phone terminal mainly includes: a central processing unit, a radio frequency unit and a base band circuit, where the radio frequency unit and the base band circuit are coupled with the central processing unit. Besides, the conventional mobile phone terminal further includes a subscriber identity module (SIM) card connected to the central processing unit, a storage device (such as flash memory and random-access memory (RAM)), a short message module and a liquid-crystal display (LCD) screen, and so on. The mobile phone of the embodiment of the present invention adopts the above antenna structure. 
     In the terminal with an antenna provided by the embodiment of the present invention, the antenna includes an intermediate frequency branch, a high frequency branch and a low frequency branch, where the intermediate frequency branch, the high frequency branch and the low frequency branch are independent of one another, the intermediate frequency branch, a feed point connecting line is disposed on the high frequency branch and the low frequency branch, a first ground point connecting line and a second ground point connecting line, respectively, so that three resonances are generated, which are a low frequency resonance, a high frequency resonance and an intermediate resonance, respectively. Therefore, a resonance with a quite wide wide-band is generated, and no obvious bump exists among the three resonances, so that the antenna not only can work on a frequency band of 824 MHz-960 MHz and a frequency band of 1710 MHz-2170 MHz, but also can work on a frequency band of 960 MHz-1710 MHz. 
     The antenna and the terminal with an antenna provided by the embodiments of the present invention can be applied to a device using an antenna for communication. 
     The foregoing descriptions are merely specific embodiments of the present invention, but are not intended to limit the protection scope of the present invention. Any variation or replacement readily figured out by persons skilled in the art within the technical scope disclosed in the present invention shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.