Abstract:
An antenna module is disclosed. The antenna module is applied to a mobile communication device and includes a first radiating element and a second radiating element. The first radiating element is disposed on a base board inside the mobile communication device, and one point of the first radiating element is a feed point of the antenna module. The second radiating element is disposed on the base board and is grounded by connecting to a P-sensor inside the mobile communication device. There is a gap between one part of the second radiating element and the first radiating element.

Description:
BACKGROUND 
       [0001]    1. Technology Field 
         [0002]    The present disclosure relates to an antenna module, especially to an antenna module which integrates a proximity sensing function with a communication function. 
         [0003]    2. Description of the Related Art 
         [0004]    Rapid developments in communication technology have led to a flourishing wireless communication industry. Mobile communication devices, such as smart phones, have become essential electronic products for most people. However, due to the miniaturization trend of electronic products, an important issue for product manufacturers is to properly use the limited space inside the mobile communication devices. 
         [0005]    Generally, current mobile communication devices have a sensor pad disposed on one a side of the case of a mobile communication device and close to an antenna module except haying the antenna module, and the sensor pad is used for sensing the approach of a human body. However, when the space where components are disposed is limited, the disposition of the sensor pad may limit the disposition area of the antenna module, which will affect the bandwidth range of the antenna module. 
       SUMMARY 
       [0006]    It is a primary object of the present disclosure to provide an antenna module which integrates a proximity sensing function with a communication function. 
         [0007]    It is another primary object of the present disclosure to provide a mobile communication device having the above antenna module. 
         [0008]    To achieve the above object, the antenna module of the present disclosure is applied to a mobile communication device having a case, a base plate and a proximity sensor, wherein the base plate and the proximity sensor are disposed inside the case. The antenna module of the present disclosure comprises a first radiating element and a second radiating element. The first radiating element is disposed on the base plate and comprises a feed point. The second radiating element is disposed on the base plate and is grounded by electrically connecting to the proximity sensor. A part of the second radiating element and the first radiating element are separated by a distance which is less than a specific distance, such that the first radiating element excites the second radiating element, via capacitive coupling and the proximity sensor senses an induction signal when a conductive object approaches the second radiating element. The induction signal is generated by the sensing of capacitance between the second radiating element and the conductive object. 
         [0009]    Additionally, the present disclosure provides a mobile communication device. The mobile communication device comprises a case, a base plate, a proximity sensor and the above antenna module. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The exemplary embodiment(s) of the present invention will be understood more fully from the detailed description given below and from the accompanying drawings of various embodiments of the invention, which should not be taken to limit the invention to the specific embodiments but are for explanation and understanding only. 
           [0011]      FIG. 1  is a partially exploded diagram of a mobile communication device according to the present invention. 
           [0012]      FIG. 2  is a schematic diagram which shows the connection relationships of each of the components inside a case of the mobile communication device. 
           [0013]      FIG. 3  is a partial schematic diagram of the mobile communication device. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0014]    Please refer to  FIG. 1  to  FIG. 3 , which illustrate the schematic structure of a mobile communication device of the present invention. 
         [0015]    As shown in  FIG. 1  and  FIG. 2 , in one embodiment of the present invention, an antenna module  1  of the present invention is applied to a mobile communication device  90 . In addition to the antenna module  1 , the mobile communication device  90  further comprises a case  91 , a base plate  92 , a ground plane  93 , a proximity sensor  94 , a communication system  95 , a capacitor  96 , a switch element  97 , and an inductance  98 . In a specific embodiment of the present invention, the mobile communication device  90  is a smart phone, but the present invention is not limited to this embodiment. 
         [0016]    In one embodiment of the present invention, the base plate  92  is disposed inside the case  91 . The ground plane  93  is also disposed inside the case  91  and is next to the base plate  92 , wherein the ground plane  93  is a ground plane of all the components of the mobile communication device  90 . 
         [0017]    In one embodiment of the present invention, the proximity sensor  94  is disposed inside the case  91 . The communication system  95  is also disposed inside the case  91  and is electrically connected to the proximity sensor  94 . The communication system  95  comprises a control chip  951  and a power amplifier  952 . The control chip  951  is used for receiving or sending radio frequency signals. The power amplifier  952  is electrically connected to the ground plane  93  and the control chip  951 . The power amplifier  952  is used for amplifying the radio frequency signals sent by the control chip  951 . 
         [0018]    In one embodiment of the present invention, the antenna module  1  comprises a first radiating element  10  and a second radiating element  20 . The first radiating element  10  is disposed on the base plate  92  and comprises a feed point F electrically connected to the power amplifier  952  of the communication system  95  The second radiating element  20  comprises a first radiating portion  21  and a second radiating portion  22 . The first radiating portion  21  is disposed on the base plate  92 , and one end of the first radiating portion  21  and the ground plane  93  are separated by a spacing distance d. The second radiating portion  22  is formed by outwardly extending and binding a side of the first radiating portion  21  twice, and the second radiating portion  22  of the second radiating element  20  forms a part of the case  91  (as shown in  FIG. 3 ). The second radiating element  20  is electrically connected to the proximity sensor  94  so as to electrically connect to the ground plane  93  (i.e., to ground). One part of the first radiating portion  21  of the second radiating element  20  and the first radiating element  10  are separated by a distance g which is less than a specific distance (e.g., 3 mm), such that the second radiating element  20  is excited by the first radiating element  10  via capacitive coupling such that the first radiating element  10  and the second radiating element  20  resonantly generate a low frequency resonant mode haying a bandwidth of approximately 700˜960 Mhz and a high frequency resonant mode having a bandwidth of approximately 1700˜2700 Mhz, both being the bandwidth range covering the 3G/LTE operating frequency band. 
         [0019]    In addition, when a conductive object (e.g., a human face) approaches the second radiating portion  22  of the second radiating element  20 , an induction signal is generated by the sensing of the capacitor between the second radiating element  20  and the conductive object. The proximity sensor  94  can sense the induction signal and inform the control chip  951  of the induction signal after sensing the induction signal, such that the control chip  951  reduces the radiation power of the mobile communication device  1  so as to reduce the effect of radiation generated by the components upon the human body. 
         [0020]    In one embodiment of the present invention, one end of the capacitor  96  is electrically connected to the second radiating element  20 , and another end of the capacitor  96  is electrically connected to the switch element  97 . One of the switch element  97  is electrically connected to the ground plane  93  (i.e., to ground) such that the capacitor  96  can be grounded or not grounded by turning on or off the switch element  97 . In other words, the switch element  97  is used for controlling whether the capacitor  96  is grounded or not grounded. When the switch element  97  is turned on, the capacitor  96  is grounded. In this situation, a resonant path formed by the second radiating element  20  changes the bandwidth of the low frequency resonant mode such that it is in the range of 700˜800 Mhz. When the switch element  97  is turned off, the capacitor  96  is an open circuit and is not grounded. In this situation, another resonant path formed by the second radiating element  20  changes the bandwidth of the low frequency resonant mode such that it is in the range of 869˜960 Mhz. In one specific embodiment of the present invention, the switch element  97  is a single-pole single throw switch, but the present invention is not limited to this embodiment. 
         [0021]    In one embodiment of the present invention, one end of the inductance  98  is electrically connected to the second radiating element  20 , and another end of the inductance  98  is electrically connected to the proximity sensor  94  The inductance  98  is used for preventing radiation signals from escaping to the proximity sensor  94  to prevent degradation of the performance of the radiation signals 
         [0022]    As explained in the description above, the second radiating element  20  of the antenna module  1  of the present invention is not only an emitter of antenna signals but also a sensor pad of the proximity sensor  94  such that the emitter and the sensor pad can be integrated in order to reduce the space required for the disposition of components, such that the disposition of the antenna module  1  is not limited by the location of the sensor pad. This design effectively solves the problem of the above prior art. 
         [0023]    In summary, regardless of the function, the method and result of the present invention are shown to have technical characteristics different from those of the prior arts, and said method and result constitute a significant advance in the field. It is hoped that the examiners will appreciate the novelty of the present invention and grant this patent. However, the aforementioned embodiment is just for illustration of the principle and the result of the present invention and should not be construed to limit the range of the present invention. It will be obvious to those skilled in the art that, based upon the content herein, changes and modifications may be made without departing from the spirit and scope of the present invention. Therefore, the appended claims are intended to encompass within their scope all such changes and modifications as are within the true spirit and scope of the exemplary embodiment(s) of the present invention.