Abstract:
An antenna assembly includes a looped but open metallic antenna and a flat ceramic antenna within the loop of the metallic antenna. The metallic antenna includes a first end portion and a second end portion at two ends. The ceramic antenna is surrounded by the metallic antenna. The first end portion is connected to the ceramic antenna and the second end is a free end, and the output power of wireless signals thusly radiated is increased at given frequencies.

Description:
FIELD 
       [0001]    The subject matter herein generally relates to an antenna assembly and a communication device having the antenna assembly. 
       BACKGROUND 
       [0002]    Antennas are widely used in communication devices, such as mobile phones and remote controllers, to radiate wireless signals. However, a communication device usually comprises a metallic casing for housing the antenna which may seriously degrade the radiation efficiency of the antenna and further limit an effective radiation distance of the antenna. Therefore, there is room for improvement within the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    Implementations of the present technology will now be described, by way of example only, with reference to the attached figures. 
           [0004]      FIG. 1  is an isometric view of a first exemplary embodiment of a communication device. 
           [0005]      FIG. 2  is an isometric view of an antenna assembly of the communication device of  FIG. 1 . 
           [0006]      FIG. 3  is similar to  FIG. 1 , but showing a second exemplary embodiment of an antenna assembly. 
           [0007]      FIG. 4  is an isometric view of an antenna assembly of the communication device of  FIG. 2 . 
           [0008]      FIG. 5  is a diagram showing a relationship between radiating frequencies and radiating output powers of a previous communication device which only comprises a ceramic antenna. 
           [0009]      FIG. 6  is a diagram showing a relationship between radiating frequencies and radiating output powers of the communication device of  FIG. 1  or  FIG. 3 . 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    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 exemplary embodiments described herein. However, it will be understood by those of ordinary skill in the art that the exemplary 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 exemplary embodiments described herein. The drawings are not necessarily to scale and the proportions of certain sections have been exaggerated to better illustrate details and features of the present disclosure. 
         [0011]    Several definitions that apply throughout this disclosure will now be presented. 
         [0012]    The term “substantially” is defined to be essentially conforming to the 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. 
         [0013]      FIG. 1  illustrates a first exemplary embodiment of a communication device  10 . The communication device  10  may be a remote controller having wireless communication functionality. The remote controller may be used to control a to-be-controlled device (not shown), such as a projector, a television, a set-top box, or a game machine, to perform actions. 
         [0014]    Also referring to  FIG. 2 , the communication device  10  comprises an antenna assembly  100 , a metallic casing  110 , and a front cover  101 . The metallic casing  110  is hollow, and comprises a front end portion  111  facing the to-be-controlled device when the communication device  10  is in use. The front cover  101  covers the front portion  111 , thereby defining a receiving space  112  to receive the antenna assembly  100 . 
         [0015]    The antenna assembly  100  comprises a metallic antenna  120  and a ceramic antenna  130 . The metallic antenna  120  and the ceramic antenna  130  are positioned adjacent to and facing the front cover  101 . Thus, the wireless signals from the metallic antenna  120  can directly radiate out from the front portion  111 . 
         [0016]    The metallic antenna  120  is curved and has two ends, one end comprises a first end portion  121  and another end comprises a second end portion  122 . The metallic antenna  120  further comprises a turning point  123  positioned between the first end portion  121  and the second end portion  122 . A portion of the metallic antenna  120  positioned between the second end portion  122  and the turning point  123  is attached to an inner periphery of the front portion  111 . The remaining portion of the metallic antenna  120  positioned between the first end portion  121  and the turning point  123  protrudes from the inner periphery of the front portion  111  into the receiving space  112 . The metallic antenna  120  may be made of copper or silver. 
         [0017]    The ceramic antenna  130  may be substantially flat. The ceramic antenna  130  is surrounded by the metallic antenna  120 . The first end portion  121  is connected to the ceramic antenna  130 . The second end portion  122  is a free end. In at least one exemplary embodiment, the ceramic antenna  130  is connected to the first end portion  121  by soldering for example. 
         [0018]    In at least one exemplary embodiment, an annular flange  1110  protrudes from the inner periphery of the front portion  111 . The metallic antenna  120  is supported by the annular flange  1110 . Thus, if a portion of the wireless signals radiates away from the front portion  111 , the portion of the wireless signals may be reflected by the annular flange  1110  towards the front portion  111 . Thus, attenuation of the wireless signals can be reduced. 
         [0019]    In at least one exemplary embodiment, the metallic antenna  120  is electrically insulated from the metallic casing  110 . An anodizing treatment can be applied to the metallic casing  110  to form an oxidation film (not shown) which electrically insolates the metallic casing  110  from the metallic antenna  120 . 
         [0020]    In at least one exemplary embodiment, the metallic casing  110  comprises a supporting structure  140 . The ceramic antenna  130  is supported and fixed by the supporting structure  140 . The supporting structure  140  may be a printed circuit board. 
         [0021]      FIGS. 3 and 4  illustrates a second exemplary embodiment of an antenna assembly  200 . The communication device  20  comprises an antenna assembly  200 , a metallic casing  210 , and a front cover  201 . The metallic casing  210  is hollow, and comprises a front end portion  211  facing the to-be-controlled device when the communication device  20  is in use. The front cover  201  covers the front portion  211 , thereby defining a receiving space  212  to receive the antenna assembly  200 . 
         [0022]    The antenna assembly  200  comprises a metallic antenna  220  and a ceramic antenna  230 . The metallic antenna  220  and the ceramic antenna  230  are positioned adjacent to and facing the front cover  201 . Thus, the wireless signals from the metallic antenna  220  can directly radiate out from the front portion  211 . 
         [0023]    The metallic antenna  220  is curved and has two ends, one end comprises a first end portion  221  and another end comprises a second end portion  222 . The metallic antenna  220  further comprises a turning point  223  positioned between the first end portion  221  and the second end portion  222 . A portion of the metallic antenna  220  positioned between the second end portion  222  and the turning point  223  is attached to an inner periphery of the front portion  211 . The remaining portion of the metallic antenna  220  positioned between the first end portion  221  and the turning point  223  protrudes from the inner periphery of the front portion  211  into the receiving space  212 . 
         [0024]    The metallic antenna  220  is an enamel wire which comprises a metallic wire and an insulated layer wrapped around the metallic wire. In this exemplary embodiment, at least one bent portion  224  is formed between the second end portion  222  and the turning point  223 , thereby changing a radiation field of the antenna assembly  200 , and preventing the insulated layer from affecting the wireless signals from the metallic antenna  220 . 
         [0025]    The ceramic antenna  230  may be substantially flat. The ceramic antenna  230  is surrounded by the metallic antenna  220 . The first end portion  221  is connected to the ceramic antenna  230 . The second end portion  222  is a free end. In at least one exemplary embodiment, the ceramic antenna  230  is connected to the first end portion  221  by soldering for example. 
         [0026]    In at least one exemplary embodiment, an annular flange  2110  protrudes from the inner periphery of the front portion  211 . The metallic antenna  220  is supported by the annular flange  2110 . Thus, if a portion of the wireless signals radiates away from the front portion  211 , the portion of the wireless signals may be reflected by the annular flange  2110  towards the front portion  211 . Thus, attenuation of the wireless signals can be reduced. 
         [0027]    In at least one exemplary embodiment, the metallic antenna  220  is electrically insulated from the metallic casing  210 . An anodizing treatment can be applied to the metallic casing  210  to form an oxidation film (not shown) which electrically insolates the metallic casing  210  from the metallic antenna  220 . 
         [0028]    In at least one exemplary embodiment, the metallic casing  210  comprises a supporting structure  240 . The ceramic antenna  230  is supported and fixed by the supporting structure  240 . The supporting structure  240  may be a printed circuit board. 
         [0029]    A relationship between radiating frequencies and radiating output powers of a communication device comprising only a ceramic antenna is illustrated in  FIG. 5 . A comparison of the communication devices  10  and  20  is also illustrated in  FIG. 6 .  FIGS. 5 and 6  show the test results, which illustrate that the communication devices  10  and  20  have higher radiating output powers than the previous communication devices. 
         [0030]    The exemplary embodiments shown and described above are only examples. Many details are often found in the art such as the other features of a 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 detail, especially in matters of shape, size, and arrangement of the sections 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 exemplary embodiments described above may be modified within the scope of the claims.