Patent Publication Number: US-2015061948-A1

Title: Electronic device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of TW application serial No. 102131342, filed on Aug. 30, 2013. The entirety of the above-mentioned patent applications are hereby incorporated by reference herein and made a part of specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an electronic device and, more particularly, to an electronic device including an antenna. 
     2. Description of the Related Art 
     in order to maintain the wireless communication quality of as portable device, an antenna with good efficiency is needed. The portable device usually includes a dipole antenna or a monopole antennal disposed outside the device or integrated in the portable device. However, it is not easy to integrate the antenna to the portable device due to its large size. 
     Conventionally, the antenna is designed to adapt to different communication system by switching multiple matching circuits and radiating structures. However, an additional switch or a bias circuit is needed, which makes the antenna manufacture more complicated and the cost is increased. 
     A planar inverted F antenna (PIFA) is usually used as an internal antenna which is integrated in the portable device. As the portable device becomes lighter, smaller, and thinner, the space for laying the antenna becomes smaller. Since many components in the portable device is made of metal and the distance between the antenna and the metal components is short. The electric field of the antenna concentrates easily and the radiation loss of the antenna increases. Thus, it is more difficult to design an antenna which can operate at multiband communication system. 
     BRIEF SUMMARY OF THE INVENTION 
     An electronic device is provided. 
     The electronic device includes a first conducting element, a second conducting element and a multiband antenna. The multiband antenna includes a first radiating part and a first coupling metal part. At least a part of the first radiating part is disposed between the first conducting element and the second conducting element. The first coupling metal part parallels to the first radiating part and is connected to a ground. 
     In sum, the affection on the antenna due to metal components in a portable device can be reduced, and the antenna can operate at more and wider frequency bands. 
     These and other features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram showing an electronic device in the first embodiment; 
         FIG. 2  is a side view of the electronic device in  FIG. 1 ; 
         FIG. 3  is a top view of the electronic device in  FIG. 1 ; 
         FIG. 4  is a schematic diagram showing an electronic device in the second embodiment; 
         FIG. 5  is a schematic diagram showing an electronic device in the third embodiment; 
         FIG. 6  is a schematic diagram showing an electronic device in the fourth embodiment; 
         FIG. 7  is a schematic diagram showing an electronic device in the fifth embodiment; and 
         FIG. 8  is a schematic diagram showing an electronic device in the sixth embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       FIG. 1  is a schematic diagram showing an electronic device in a first embodiment. As shown in  FIG. 1 , the electronic device includes a first conducting element  310 , a second conducting element  320  and a multiband antenna  100 . The multiband antenna  100  includes a first radiating part  105  and a first coupling metal part  200 . The first radiating part  105  is disposed between the first conducting element  310  and the second conducting element  320 . Since the sizes of the first conducting element  310  and the second conducting element  320  may be different, at least a part of the first radiating part  105  is disposed between the first conducting element  310  and the second conducting element  320 . The first coupling metal part  200  parallels to the first radiating part  105  and a ground point  204  is disposed at one end of the first coupling metal part  200 . 
     The multiband antenna  100  includes a first metal part  101 , a second metal part  102  and a third metal pan  103 . The first metal part  101  parallels to the second metal part  102 . One of the first metal part  101  and the second metal part  102  is used for signal feed-in, and the other one is connected to the ground. That means, when the first metal part  101  is used for signal feed-in, the second metal part  102  is connected to the ground. On the contrary, when the first metal part  101  is connected to the ground, the second metal part  102  is used for signal feed-in. In an embodiment, when the electronic device is applied to a portable device (such as a mobile phone), one of the first metal part  101  and the second metal part  102  is electrically connected to a signal line of a transceiver for signal feed-in, and the other one is electrically connected to a system ground of the portable. The third metal part  103  is connected between the first metal part  101  and the second metal part  102 . The first metal pan  101 , the second metal part  102  and the third metal part  103  forms an U shape, and an opening of the U shape which is formed by the first metal part  101 , the second metal part  102  and the third metal part  103  extends towards the third metal part  103  to form a groove  104 . Thus, if the length of the first metal part  101  and the second metal pan  102  increases, the length of the groove  104  also increases, and the length of the groove  104  can be changed to make the impedance of the multiband antenna  100  conform to a constant value (such as 50 Ω). 
     The first radiating part  105  of the multiband antenna  100  is connected to one end of the second metal part  102  which is not connected to the third metal part  103 . the first radiating part  105  is coplanar with and perpendicularperpendicular to the second metal part  102 , extends away from the groove  104  and it is along the first conducting element  310  and the second conducting element  320 . The extending length of the first radiating part  105  can be changed to adjust a first frequency corresponding to a resonance mode. When the first radiating part  105  is shorter, the first frequency is higher. 
     When the multiband antenna  100  operates, the first radiating pan  105  resonates to transmit or receive an electromagnetic signal. The end of the first radiating part  105  which is not connected to the second metal part  102  is easily shielded by the first conducting element  310 , and the communication efficiency of the multiband antenna  100  is affected.  FIG. 2  is a side view of the electronic device in  FIG. 1 . As shown in  FIG. 1  and  FIG. 2 , the electronic device includes the first coupling metal part  200 . The first coupling, metal part  200  is disposed in parallel with the first radiating part  105  and there is a distance  201  (about 0.1 mm to 1 mm) therebetween. The first coupling metal part  200  is near the end of the first radiating part  105  which is not connected to the second metal part  102 , and the ground point  204  is connected to the ground. Thus, the first coupling metal part  200  and the first radiating part  105  can electromagnetically couple to each other and resonate at a second frequency. Due to the frequency bands corresponding to the first frequency and the second frequency, the electronic device can be applied at multiple frequency bands via the multiband antenna  100 . In the embodiment, the frequency bands corresponding to the first frequency and the second frequency can be changed by adjusting the length of the first radiating part  105  and the first coupling metal part  200 . When the frequency hands corresponding to the first frequency and the second frequency are overlapped, a broader frequency band is generated to enable the electronic device to be applied at multiple frequency bands via the multiband antenna  100 . 
     In the embodiment, in order to avoid affection from grounded metal components, when the first coupling metal part  200  and the first radiating part  105  are coupled to each other, the ground point  204  formed on the first coupling metal part  200  is not disposed at the orthographic projection part of the first radiating part  105  at the first coupling metal pan  200 .  FIG. 3  is a top view of the electronic device in  FIG. 1 . As shown in  FIG. 3 , the orthographic projection of the first radiating part  105  is at a section  202  of the first coupling metal part  200 , and the ground point  204  is at another section  203  of the first coupling metal part  200 . 
     As shown in  FIG. 1 , in the embodiment, the first metal part  101 , the second metal part  102  and the third metal part  103  are attached to a casing (not shown) of the electronic device to fax the multiband antenna  100 , and the surfaces of the first metal pan  101 , the second metal part  102  and the third metal part  103  are determined by the attaching surface. Thus, the first metal part  101 , the second metal part  102  and the third metal pan  103  may be arc elements, flat elements or any other elements with continuous surfaces. 
       FIG. 4  is a schematic diagram showing an electronic device in the second embodiment. As shown in  FIG. 4 , when the electronic device is applied to a portable device (such as a mobile phone), the first conducting element  311  is a signal connector with a metal casing, such as a universal serial bus (USB) signal connector, a high-definition multimedia interface (HDMI) or a micro-USB signal connector. The metal casing protects the signal connector and is connected to the ground to avoid external interference or static electricity affection. 
       FIG. 5  is a schematic diagram showing an electronic device in the third embodiment. As shown in FIG:  5 , the first radiating part  105  is perpendicularly connected to one end of the second metal part  102 , and the electronic device further includes a second radiating part  106 . The second radiating part  106  is connected to the other end of the second metal part  102 , which is coplanar and perpendicular to the second metal part  102 , and it parallels to the first radiating part  105 . The first radiating part  105  and the second radiating part  106  are disposed at two sides of the first conducting element  311 , respectively. The extending length of the second radiating pan  106  can be changed to adjust a frequency band corresponding to a third frequency, and the second radiating part  106  can resonate at the third frequency. The length of the first radiating part  105  can be changed to adjust the first frequency, the coupling effect between the first coupling metal part  200  and the first radiating part  105  can be changed to adjust the second frequency, and the length of the second radiating pan  106  can be changed to adjust the third frequency. Thus, the electronic device can be applied to multiband communication system via the multiband antenna  100   a.    
     In the embodiment, the frequency bands corresponding to the first frequency, the second frequency and the third frequency can be changed by adjusting the length of the first radiating part  105 , the first coupling metal part  200  and the second radiating part  106 . When the frequency bands generated by the first frequency, the second frequency and the third frequency are overlapped or close to each other, a broader frequency band is formed. Thus, the electronic device can be applied to a broader band via the multiband antenna  100   a , or the frequency bands are adjusted to meet different communication demands. 
       FIG. 6  is a schematic diagram showing an electronic device in the fourth embodiment. As shown in  FIG. 6 , the multiband antenna  100   b  further includes a second coupling metal part  210 . The second coupling metal part  210  is connected to the first coupling metal part  200 , coplanar and perpendicular to the first coupling metal pan  200 , and the second coupling metal part  210  extends along the second conducting element  321 , but it does not contact with the second conducting element  321 . An extending length of the second coupling metal part  210  from the ground point  204  can be adjusted to generate the frequency band when the second coupling metal part  210  resonates at a fourth frequency. 
       FIG. 7  is a schematic diagram showing an electronic device in the fifth embodiment. As shown in  FIG. 7 , the first coupling metal part  220  of the multiband antenna  100   c  is formed by a metal bar cut from the surfaces  312  and  313  of the metal casing of the first conducting element  311   a . The metal bar cut from a part  314  at the surfaces  312  and  313  of the metal casing is folded and extends away from the first conducting element  311   a . The end part of the metal bar parallels to the first radiating part  105  and does not contact with the first radiating, part  105 . The end part of the metal bar is close to the end of the first radiating part  105 , and when the first coupling metal part  220  and the first radiating part  105  couple to each other and resonate at the second frequency, the first coupling metal part  220  can be formed by the metal bar. The metal casing of the first conducting element  311   a  is connected to the ground, and thus the first coupling metal part  220  is connected to the ground via the metal casing of the first conducting element  311   a . The electronic device and the first conducting element  311   a  can be integrated to a nodule and applied to a portable device. 
       FIG. 8  is a schematic diagram showing an electronic device in the sixth embodiment. As shown in  FIG. 8 , the electronic device further includes an output module  322 , and the first conducting element  311   b  is disposed in the output module  322 . For example, the first conducting element  311   b  may be a loudspeaker coil or a camera, and the output module  322  may be a loudspeaker module or a camera module. When the electronic device is applied to a portable device, the output module  322  may include a nonmetal casing, such as a loudspeaker box or a plastic camera casing, to cover the first conducting element  311   b , and the size of the second conducting element  321  is larger that of the first conducting element  311   b . The first coupling metal part  230  of the multiband antenna  100   d  is fixed at the output module  322 , and it is connected to the ground via the ground point thereon. The first coupling metal part  230  parallels to the first radiating part  105 , but does not contact with the first radiating part  105 . The first coupling metal part  230  is dose to one end of the first radiating pan  105 , and thus they can couple to each other and resonate at the second frequency. 
     Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, the disclosure is not for limiting the scope. Persons having ordinary skill in the art may make various modifications and changes without departing, from the scope. Therefore, the scope of the appended claims should not be limited to the description of the preferred embodiments described above.