Patent Publication Number: US-9905909-B2

Title: Antenna module and wireless communication device using same

Description:
FIELD 
     The subject matter herein generally relates to an antenna module and a wireless communication device using same. 
     BACKGROUND 
     Metal housings are widely used for wireless communication devices, such as mobile phones or personal digital assistants (PDAs). Antennas are also important components in the wireless communication devices to receive/transmit wireless signals at different frequencies, such as wireless signals operated in a long term evolution (LTE) band. However, the signal of the antenna located in the metal housing is often shielded by the metal housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the present technology will now be described, by way of example only, with reference to the attached figures. 
         FIG. 1  is an exploded, isometric view of an embodiment of a wireless communication device employing an antenna module. 
         FIG. 2  is an exploded, isometric view of the antenna module of  FIG. 1 . 
         FIG. 3  is a diagrammatic view of the wireless communication device of  FIG. 1 . 
         FIG. 4  is a block diagram of the wireless communication device of  FIG. 1 . 
         FIG. 5  is a scattering parameter graph of the antenna module of  FIG. 1 , showing the antenna module operated in a low-frequency band. 
         FIG. 6  is similar to  FIG. 5 , but showing the antenna module operated in a high-frequency band. 
         FIG. 7  is a total radiating efficiency graph of the antenna module of  FIG. 1 , showing the antenna module operated in a low-frequency band. 
         FIG. 8  is similar to  FIG. 7 , but showing the antenna module operated in a high-frequency band. 
     
    
    
     DETAILED DESCRIPTION 
     It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the present disclosure. 
     Several definitions that apply throughout this disclosure will now be presented. 
     The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “substantially” is defined to be essentially conforming to the particular dimension, shape, or other feature that the term modifies, such that the component need not be exact. For example, substantially cylindrical means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like. 
     The present disclosure is described in relation to an antenna module and a wireless communication device using same. 
       FIG. 1  illustrates an embodiment of a wireless communication device  200  employing an antenna module  100  (see  FIG. 2 ). The wireless communication device  200  can be a mobile phone or a personal digital assistant, for example (details not shown). The wireless communication device  200  further includes a main portion  21 , a display unit  22 , and a baseboard  23 . 
     The display unit  22  is positioned on one surface of the main portion  21 . The baseboard  23  can be made of a dielectric material, such as glass epoxy phenolic fiber (FR4). The baseboard  23  is positioned inside the main portion  21  and includes a signal feed point  231  and a system grounding plane (not shown). The system grounding plane is configured to ground the antenna module  100 . One side of the baseboard  23  further includes an electronic component  233 . In this embodiment, the electronic component  233  is a universal serial bus (USB) interface module and is electrically connected to the baseboard  23 . 
     The antenna module  100  includes a metallic member  11 , a first radiating portion  12 , a connecting unit  13 , and a switching unit  15  (shown in  FIG. 2 ). The metallic member  11  may be a metallic sheet or a metallic conductive layer formed on a plastic housing through a sputtering manner or the like. As illustrated in  FIG. 3 , in this embodiment, the metallic member  11  is a battery cover of the communication wireless device  200  and is positioned on another surface of the main portion  21  opposite to the display unit  22 . 
     The metallic member  11  is a housing with one end opened and includes a top surface  111 , two opposite first side surfaces  112 , and two opposite second side surfaces  113 . The first side surfaces  112  and the second side surfaces  113  are all located on a peripheral edge of the top surface  111 . In this embodiment, the first side surfaces  112  and the second side surfaces  113  can be flat or curved shape. In this embodiment, the metallic member  11  further defines a slot  115 . The slot  115  is defined on the top surface  111  and extends through the two second side surfaces  113 , such that the metallic member  11  is divided into a first metallic portion  117  and a second metallic portion  118  spaced apart with the first metallic portion  117 . The slot  115  has a width of about 0.5 mm to about 1.5 mm. In this embodiment, the width of the slot  115  is about 0.5 mm. 
     In this embodiment, the first metallic portion  117  of the metallic member  11  acts as a ground portion of the antenna module  100 , and is electrically connected to the system grounding plane of the baseboard  23  through feeder, probe, shrapnel, or the like. The second metallic portion  118  of the metallic member  11  acts as a second radiating portion of the antenna module  100 . 
     In other embodiments, the metallic member  11  further defines an opening  119  (shown in  FIG. 2 ) corresponding to the electronic component  233 . In this embodiment, the opening  119  is defined on one first side surface  112  of the second metallic portion  118 . The electronic component  233  can expose out from the opening  119 , such that a USB device can pass through the opening  119  and be inserted into the electronic component  233 , thereby establishing a connection between the USB device and the wireless communication device  200 . 
     The first radiating portion  12  is located in an interior of the second metallic portion  118  and is spaced apart with the second metallic portion  118 . The first radiating portion  12  is configured to receive a current signal, then the current signal on the first radiating portion  12  can be coupled to the second metallic portion  118  (that is, the second radiating portion of the antenna module  100 ). In this embodiment, a distance between the first radiating portion  12  and the second metallic portion  118  is about 0.5 mm. The first radiating portion  12  includes a feed section  121 , a transition section  123 , and a coupling section  125  connected in that order. The feed section  121  is configured to receive a current signal. The feed section  121  is positioned at a plane parallel to the top surface  111 . In this embodiment, the feed section  121  is substantially a strip. One end of the feed section  121  is electrically connected to the signal feed point  231  through feeder, probe, shrapnel, or the like, thereby feeding current for the antenna module  100 . 
     The transition section  123  is positioned at a plane perpendicular to the top surface  111 . In this embodiment, the transition section  123  is substantially a strip. One end of the transition section  123  is perpendicularly connected to one end of the feed section  121  away from the signal feed point  231 . The other end of the transition section  123  extends towards the top surface  111 . 
     The coupling section  125  is positioned at a plane parallel to the top surface  111 . In this embodiment, the coupling section  125  is substantially a strip. The coupling section  125  is perpendicularly connected to the end of the transition section  123  away from the feed section  121  and extends towards the two second side surfaces  113 . 
     In other embodiments, the coupling section  125  can also be positioned at a plane where the transition section  123  is positioned, that is, the coupling section  125  can be coplanar with the transition section  123  and only to ensure that the first radiating portion  12  is spaced apart with the second metallic portion  118 . The coupling section  125  is spaced apart from the top surface  111  and/or the first side surfaces  112 . In addition, the feed section  121 , the transition section  123 , and the coupling section  125  are not limited to be strips, which can also be other shape. For example, the feed section  121  is substantially L-shaped. Two sides of the transition section  123  define a plurality of openings, then the transition section  123  is substantially square-wave shaped. The coupling section  125  is substantially a strip, but only extends towards one of the second side surfaces  113 . 
     In this embodiment, the connecting unit  13  includes five connecting portions  131 ,  132 ,  133 ,  134 ,  135 . The connecting portions  131 ,  132 ,  133  function as low-frequency connecting portions and the connecting portions  134 ,  135  function as high-frequency connecting portions. The five connecting portions  131 - 135  are all positioned at one edge of the second metallic portion  118  near the opening  115  and are electrically connected between the second metallic portion  118  and the switching unit  15 . 
     It can be understood that the five connecting portions  131 - 135  can be flexible printed circuit (FPC) or other conductive structures. Also, a number of the connecting portions is not limited to be five, which can be adjusted according to a need of the user. For example, the connecting unit  13  includes four connecting portions. One connecting portion acts as a high-frequency connecting portion, and the other connecting portions act as low-frequency connecting portions. It can be understood that when only a high-frequency band or a low-frequency band of the antenna module  100  needs to be adjusted, the low-frequency connecting portion or the high-frequency connecting portion can be omitted, that is, only one or more than one high-frequency connecting portions or only one or more than one low-frequency connecting portions are needed. 
     As illustrated in  FIG. 2 , in this embodiment, the switching unit  15  includes two conductive portions  151  and five switches S 1 , S 2 , S 3 , S 4 , S 5 . The conductive portions  151  may be FPC or a flex and rigid combination board. The two conductive portions  151  are positioned on the first metallic portion  117  and are electrically connected to the first metallic portion  117 . The switches S 1 -S 5  are divided into two groups and each group is positioned on one corresponding conductive portion  151 . The switches S 1 -S 5  are electrically connected to the first metallic portion  117  through the conductive portions  151  and are electrically connected to corresponding high-frequency connecting portions and corresponding low-frequency connecting portions. For example, the switches S 1 -S 4  are positioned on one conductive portion  151  and are electrically connected to the first metallic portion  117  through the one conductive portion  151 . The switches S 1 -S 4  establish a corresponding one-to-one electronic connection with the connecting portions  131 - 134 . The switch S 5  is positioned on the other conductive portion  151  and is electrically connected to the first metallic portion  117  through that conductive portion  151 . The switch S 5  establishes an electronic connection with the corresponding connecting portion  135 . 
     Then, when the switches S 1 -S 5  are turned on or turned off, the first metallic portion  117  connects with or disconnects with the second metallic portion  118  at different locations, thereby forming different current paths. The antenna module  100  therefore can works at different frequency bands, and which can effectively adjust a bandwidth of the antenna module  100 . In this embodiment, each of the switches S 1 -S 5  corresponds to a different frequency band. When one of the switches S 1 -S 5  is turned on and the other switches are turned off, the antenna module  100  can works at the frequency band corresponding to the switch that is turned on. 
     For example, as illustrated at table  1 , when the switch S 1  is turned on, other switches S 2 , S 3 , S 4 , S 5  are turned off, the antenna module  100  can work at a first frequency band, that is LTE band17 (704-746 MHz). When the switch S 2  is turned on, other switches S 1 , S 3 , S 4 , S 5  are turned off, the antenna module  100  can work at a second frequency band, that is GSM850 (824-894 MHz). When the switch S 3  is turned on, other switches S 1 , S 2 , S 4 , S 5  are turned off, the antenna module  100  can work at a third frequency band, that is GSM900 (880-960 MHz). When the switch S 4  is turned on, other switches S 1 , S 2 , S 3 , S 5  are turned off, the antenna module  100  can work at a fourth frequency band, that is LTE band7 (2300-2690 MHz). When the switch S 5  is turned on, other switches S 1 , S 2 , S 3 , S 4  are turned off, the antenna module  100  can work at a fifth frequency band, that is GSM1800/1900/UMTS2100 (1710-2170 MHz). 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 relationship between frequency bands of the antenna 
               
               
                 module and states of the switches 
               
            
           
           
               
               
               
            
               
                   
                 Switch 
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Frequency bands 
                 S1 
                 S2 
                 S3 
                 S4 
                 S5 
               
               
                   
                   
               
               
                   
                 LTE band17 
                 on 
                 off 
                 off 
                 off 
                 off 
               
               
                   
                 GSM850 
                 off 
                 on 
                 off 
                 off 
                 off 
               
               
                   
                 GSM900 
                 off 
                 off 
                 on 
                 off 
                 off 
               
               
                   
                 LTE band7 
                 off 
                 off 
                 off 
                 on 
                 off 
               
               
                   
                 GSM1800/1900/UMTS2100 
                 off 
                 off 
                 off 
                 off 
                 on 
               
               
                   
                   
               
            
           
         
       
     
     In other embodiments, a number of the conductive portions  151  is not limited to be two, it can also be one, then the switches S 1 -S 5  are all positioned on the conductive portion  151 . 
       FIG. 4  illustrates that the wireless communication device  200  further includes a processing unit  25 , a radio frequency (RF) transceiving unit  26 , a matching unit  27 , and a filtering unit  28 . The processing unit  25  is positioned on the baseboard  23  and is electrically connected to the display unit  22 , the RF transceiving unit  26 , and the switches S 1 -S 5 . The processing unit  25  is configured to output control signals to the switches S 1 -S 5  positioned on the conductive portions  151  to turn on or turn off the switches S 1 -S 5 . 
     The matching unit  27  is electrically connected to the signal feed point  231  and the RF transceiving unit  26 . The matching unit  27  is configured to match an impedance of the antenna module  100  for optimizing performance of the antenna module  100 . 
     The filtering unit  28  includes a high-pass filtering unit  281  and a low-pass filtering unit  283 . The high-pass filtering unit  281  and the low-pass filtering unit  283  are both electrically connected to the RF transceiving unit  26  and the matching unit  27  for separating the high-frequency portion and the low-frequency portion of RF signals transmitted from the antenna module  100  and RF signals received by the antenna module  100 . 
     When current is input to the signal feed point  231 , the current flows to the first radiating portion  12 , and is coupled to the second metallic portion  118  from the first radiating portion  12 . The second metallic portion  118  and the first metallic portion  117  cooperatively activate a plurality of resonating modes through the slot  115  therebetween. In addition, the processing unit  25  outputs a corresponding controlling signal to the switching unit  15  to turn on or turn off the switches S 1 -S 5 , thereby adjusting a bandwidth of the antenna module  100 . In this embodiment, the antenna module  100  can at least work at communication systems of LTE band17 (704-746 MHz), GSM850 (824-894 MHz), GSM900 (880-960 MHz), LTE band7 (2300-2690 MHz), and GSM1800/1900/UMTS2100 (1710-2170 MHz). 
       FIG. 5  illustrates a scattering parameter graph of the antenna module  100 , showing the antenna module  100  in a low frequency band.  FIG. 6  illustrates a scattering parameter graph of the antenna module  100 , showing the antenna module  100  in a high frequency band. Curve  51  illustrates a working frequency of the antenna module  100  when the switch S 3  is turned on and the other switches S 1 , S 2 , S 4 , S 5  are turned off. Curve  52  illustrates a working frequency of the antenna module  100  when the switch S 2  is turned on and the other switches S 1 , S 3 , S 4 , S 5  are turned off. Curve  53  illustrates a working frequency of the antenna module  100  when the switch S 1  is turned on and the other switches S 2 , S 3 , S 4 , S 5  are turned off. Curve  61  illustrates a working frequency of the antenna module  100  when the switch S 4  is turned on and the other switches S 1 , S 2 , S 3 , S 5  are turned off. Curve  62  illustrates a working frequency of the antenna module  100  when the switch S 5  is turned on and the other switches S 1 , S 2 , S 3 , S 4  are turned off. 
     In view of the curves  51 - 53  and  61 - 62 , the antenna module  100  has good performance when operating at LTE band17 (704-746 MHz), GSM850 (824-894 MHz), GSM900 (880-960 MHz), LTE band7 (2300-2690 MHz), and GSM1800/1900/UMTS2100 (1710-2170 MHz). 
       FIG. 7  illustrates a total radiating efficiency graph of the antenna module  100 , showing the antenna module  100  in a low frequency band.  FIG. 8  illustrates a total radiating efficiency graph of the antenna module  100 , showing the antenna module  100  in a high frequency band. Curve  71  illustrates a total radiating efficiency of the antenna module  100  when the switch S 3  is turned on and the other switches S 1 , S 2 , S 4 , S 5  are turned off. Curve  72  illustrates a total radiating efficiency of the antenna module  100  when the switch S 2  is turned on and the other switches S 1 , S 3 , S 4 , S 5  are turned off. Curve  73  illustrates a total radiating efficiency of the antenna module  100  when the switch S 1  is turned on and the other switches S 2 , S 3 , S 4 , S 5  are turned off. Curve  81  illustrates a total radiating efficiency of the antenna module  100  when the switch S 4  is turned on and the other switches S 1 , S 2 , S 3 , S 5  are turned off. Curve  82  illustrates a total radiating efficiency of the antenna module  100  when the switch S 5  is turned on and the other switches S 1 , S 2 , S 3 , S 4  are turned off. 
     In view of the curves  71 - 73  and  81 - 82 , when the antenna module  100  operates at LTE band17 (704-746 MHz), GSM850 (824-894 MHz), GSM900 (880-960 MHz), LTE band7 (2300-2690 MHz), and GSM1800/1900/UMTS2100 (1710-2170 MHz), the total radiating efficiency of the antenna module  100  is above 60%, which satisfies design standard of the antenna. 
     The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of the antenna module and the wireless communication device. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the details, especially in matters of shape, size and arrangement of the parts within the principles of the present disclosure up to, and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.