Patent Publication Number: US-10763573-B2

Title: Antenna structure and wireless communication device using the same

Description:
FIELD 
     The subject matter herein generally relates to an antenna structure and a wireless communication device using the antenna structure. 
     BACKGROUND 
     Antennas are important components in wireless communication devices for receiving and transmitting wireless signals at different frequencies, such as signals in Long Term Evolution Advanced (LTE-A) frequency bands. However, the antenna structure is complicated and occupies a large space in the wireless communication device, which is inconvenient for miniaturization of the wireless communication device. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Implementations of the present disclosure will now be described, by way of example only, with reference to the attached figures. 
         FIG. 1  is an isometric view of an embodiment of a wireless communication device using an antenna structure. 
         FIG. 2  is a circuit diagram of the antenna structure of  FIG. 1 . 
         FIG. 3  is a current path distribution graph of the antenna structure of  FIG. 2 . 
         FIG. 4  is a scattering parameter graph of a first antenna of the antenna structure of  FIG. 1 . 
         FIG. 5  is a gain efficiency graph of the first antenna of the antenna structure of  FIG. 1 . 
         FIG. 6  is a scattering parameter graph of a second antenna of the antenna structure of  FIG. 1 . 
         FIG. 7  is a gain efficiency graph of the second antenna of the antenna structure of  FIG. 1 . 
         FIG. 8  is a scattering parameter graph of a third antenna of the antenna structure of  FIG. 1 . 
         FIG. 9  is a gain efficiency graph of the third antenna of the antenna structure of  FIG. 1 . 
     
    
    
     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 “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 structure and a wireless communication device using same. 
       FIG. 1  illustrates an embodiment of a wireless communication device  200  using an antenna structure  100 . The wireless communication device  200  can be, for example, a mobile phone or a personal digital assistant. The antenna structure  100  can receive and transmit wireless signals. 
     The wireless communication device  200  further includes a substrate  21 . In this embodiment, the substrate  21  is made of dielectric material, for example, epoxy resin glass fiber (FR4) or the like. The substrate  21  includes a first feed point  211 , a second feed point  212 , and a third feed point  214 . The first feed point  211 , the second feed point  212 , and the third feed point  214  are all positioned on the substrate  21  and are spaced apart from each other. The first feed point  211 , the second feed point  212 , and the third feed point  214  are configured to supply current to the antenna structure  100 . 
     In this embodiment, the wireless communication device  200  further includes at least three electronic elements, for example, a first electronic element  217 , a second electronic element  218 , and a third electronic element  219 . The first electronic element  217 , the second electronic element  218 , and the third electronic element  219  are positioned at one side of the substrate  21 . The first electronic element  217 , the second electronic element  218 , and the third electronic element  219  are positioned between the second feed point  212  and the third feed point  214 . 
     In this embodiment, the first electronic element  217  is an audio interface module. The first electronic element  217  is positioned between the first feed point  211  and the third feed point  214  adjacent to the third feed point  214 . The second electronic element  218  is a front camera module. The second electronic element  218  is positioned between the first feed point  211  and the second feed point  212 . The third electronic element  219  is a speaker. The third electronic element  219  is positioned between the first electronic element  217  and the second electronic element  218 . The third electronic element  219  is positioned between the first feed point  211  and the third feed point  214  adjacent to the first feed point  211 . 
     In  FIG. 2 , the antenna structure  100  includes a housing  11 , a first feed portion  12 , a second feed portion  13 , a first ground portion  14 , a third feed portion  15 , a fourth feed portion  16 , and a second ground portion  17 . 
     The housing  11  houses the wireless communication device  200 . The housing  11  includes a side frame  112 . In this embodiment, the side frame  112  is made of metallic material. The side frame  112  is substantially annular. The housing  11  further includes a backboard (not shown). The backboard is positioned on the side frame  112 . The backboard and the side frame  112  cooperatively form a receiving space  114 . The receiving space  114  can receive the substrate  21 , a processing unit, or other electronic components or modules. 
     The side frame  112  includes an end portion  115 , a first side portion  116 , and a second side portion  117 . In this embodiment, the end portion  115  is a top portion of the wireless communication device  200 . The first side portion  116  is spaced apart from and parallel to the second side portion  117 . The end portion  115  has first and second ends. The first side portion  116  is connected to the first end of the end portion  115  and the second side portion  117  is connected to the second end of the end portion  115 . 
     The side frame  112  further defines a first gap  118  and a second gap  119 . In this embodiment, the first gap  118  is defined in the end portion  115  adjacent to the first side portion  116 . The second gap  119  is defined in the end portion  115  adjacent to the second side portion  117 . The first gap  118  and the second gap  119  both pass through and extend to cut across the side frame  112 . The side frame  112  is divided into three portions by the first gap  118  and the second gap  119 . The three portions are a first radiating portion E 1 , a second radiating portion E 2 , and a third radiating portion E 3 . The first radiating portion E 1 , the second radiating portion E 2 , and the third radiating portion E 3  are spaced apart from each other. 
     In this embodiment, a portion of the side frame  112  between the first gap  118  and the second gap  119  forms the first radiating portion E 1 . A portion of the side frame  112  extending from a side of the first gap  118  away from the first radiating portion E 1  and the second gap  119  forms the second radiating portion E 2 . A portion of the side frame  112  extending from a side of the second gap  119  away from the first radiating portion E 1  and the first gap  118  forms the third radiating portion E 3 . In this embodiment, the second radiating portion E 2  and the third radiating portion E 3  are both grounded. 
     In this embodiment, the first radiating portion E 1  further defines a through hole  120 . The through hole  120  passes through the first radiating portion E 1  and corresponds to the first electronic element  217 . Then, the first electronic element  217  is partially exposed from the through hole  120 . An audio module (for example, an earphone) can be inserted into the through hole  120  and be electrically connected to the first electronic element  217 . 
     In this embodiment, the first gap  118  and the second gap  119  are both filled with insulating material, for example, plastic, rubber, glass, wood, ceramic, or the like. 
     In this embodiment, the first feed portion  12  is positioned in the housing  11  between the second electronic element  218  and the third electronic element  219 . One end of the first feed portion  12  is electrically connected to the first radiating portion E 1 . Another end of the first feed portion  12  is electrically connected to the first feed point  211  through a matching element  121  for feeding current to the first radiating portion E 1 . 
     In this embodiment, the matching element  121  is a 0 ohm resistor, that is, the matching element  121  is at a short-circuit state. In other embodiments, the matching element  121  may be other than the resistor. For example, the matching element  121  may be a capacitor, an inductor, or a combination. 
     In an embodiment, the first feed portion  12  further divides the first radiating portion E 1  into a first resonance section E 11  and a second resonance section E 12 . A portion of the side frame  112  between the first feed portion  12  and the second gap  119  forms the first resonance section E 11 . A portion of the side frame  112  between the first feed portion  12  and the first gap  118  forms the second resonance section E 12 . In one embodiment, the first feed portion  12  is not electrically connected to a middle position of the first radiating portion E 1 , the first resonance section E 11  is longer than the second resonance section E 12 . 
     The second feed portion  13  is positioned in the housing  11  between the second electronic element  218  and the first side portion  116 . One end of the second feed portion  13  is electrically connected to a near field communication (NFC) chip  132  through a matching element  131 , and is grounded through the NFC chip  132 . Another end of the second feed portion  13  is electrically connected to one end of the second resonance section E 12  adjacent to the first gap  118 . 
     In one embodiment, the matching element  131  is an inductor having an inductance of about 39 nH. In other embodiments, the matching element  131  may be other than the inductor. For example, the matching element  131  can be a capacitor, other matching elements, or a combination. 
     The first ground portion  14  is positioned in the housing  11  between the first electronic element  217  and the second side portion  117 . One end of the first ground portion  14  is grounded through a ground element  141 . Another end of the first ground portion  14  is electrically connected to an end of the first resonance section E 11  adjacent to the second gap  119  for grounding the first radiating portion E 1 . 
     In one embodiment, the ground element  141  is an inductor having an inductance of about 5.6 nH. In other embodiments, the ground element  141  may be other than the inductor. For example, the ground element  141  can be a capacitor, other matching elements, or a combination. 
     The third feed portion  15  is positioned in the housing  11 . One end of the third feed portion  15  is electrically connected to the second feed point  212  through a matching element  151 . Another end of the third feed portion  15  is electrically connected to the second radiating portion E 2  for supplying current to the second radiating portion E 2 . 
     In one embodiment, the matching element  151  is a capacitor having an capacitance of about 1.2 pF. In other embodiments, the matching element  151  may be other than the capacitor. For example, the matching element  151  can be an inductor, other matching elements, or a combination. 
     The fourth feed portion  16  is positioned in the housing  11 . One end of the fourth feed portion  16  is electrically connected to one end of the third radiating portion E 3  adjacent to the second gap  119 . Another end of the fourth feed portion  16  is electrically connected to the third feed point  214  through a matching circuit  161  for supplying current to the third radiating portion E 3 . 
     In one embodiment, the matching circuit  161  includes a first matching unit  163  and a second matching unit  165 . One end of the first matching unit  163  is electrically connected to the third feed point  214 . Another end of the first matching unit  163  is electrically connected to the fourth feed portion  16  and one end of the second matching unit  165 . Another end of the second matching unit  165  is grounded. 
     In one embodiment, the first matching unit  163  is a capacitor having a capacitance of about 0.8 pF. The second matching unit  165  is an inductor having an inductance of about 6.2 nH. In other embodiment, the first matching unit  163  and the second matching unit  165  may be other than the capacitor and the inductor. For example, the first matching unit  163  and the second matching unit  165  can be other matching elements or a combination. 
     The second ground portion  17  is positioned in the housing  11 . The second ground portion  17  is spaced apart from the fourth feed portion  16 . One end of the second ground portion  17  is electrically connected to the third radiating portion E 3 . Another end of the second ground portion  17  is grounded for grounding the third radiating portion E 3 . 
     As illustrated in  FIG. 3 , when the first feed portion  12  supplies current, the current flows through the first resonance section E 11  and the first ground portion  14 , then is grounded through the ground element  141  (Per path P 1 ). The first feed portion  12 , the first resonance section E 11 , and the first ground portion  14  cooperatively form a loop antenna to activate a first operating mode and a second operating mode to generate radiation signals in a first radiation frequency band and a second radiation frequency band. 
     In addition, when the first feed portion  12  supplies current, the current flows through the second resonance section E 12 , the second feed portion  13 , and the NFC chip  132 , then is grounded through the NFC chip  132  (Per path P 2 ). The first feed portion  12 , the second resonance section E 12 , and the second feed portion  13  cooperatively form another loop antenna to activate a third operating mode to generate radiation signals in a third radiation frequency band. 
     When the second feed portion  13  supplies current, the current flows through the second resonance section E 12 , the first resonance section E 11 , and the first ground portion  14 , then is grounded through the ground element  141  (Per path P 3 ). The second feed portion  13 , the first radiating portion E 1 , and the first ground portion  14  cooperatively form a loop antenna to activate a fourth operating mode to generate radiation signals in a fourth radiation frequency band. 
     When the third feed portion  15  supplies current, the current flows through the second radiating portion E 2  through the third feed portion  15 , and is grounded (Per path P 4 ). The third feed portion  15  and the second radiating portion E 2  cooperatively form a loop antenna to activate a fifth operating mode to generate radiation signals in a fifth radiation frequency band. 
     When the fourth feed portion  16  supplies current, the current flows through the third radiating portion E 3  through the fourth feed portion  16 , and is grounded through the second ground portion  17  (Per path P 5 ). The fourth feed portion  16 , the third radiating portion E 3 , and the second ground portion  17  cooperatively form a loop antenna to activate a sixth operating mode to generate radiation signals in a sixth radiation frequency band. 
     In this embodiment, the first operating mode is a Long Term Evolution Advanced (LTE-A) low frequency operating mode. The second operating mode and the third operating mode are both a LTE-A middle frequency operating mode. The fourth operating mode is a NFC operating mode. The fifth operating mode includes a global positioning system (GPS) operating mode, a WIFI 2.4/5 GHz operating mode, and a LTE-A high frequency operating mode. The sixth operating mode includes a WIFI 2.4/5 GHz operating mode. 
     In this embodiment, frequencies of the first radiation frequency band are about LTE-A 699-960 MHz. Frequencies of the second radiation frequency band is multiple of the frequencies of the first radiation frequency band. Frequencies of the second radiation frequency band and the third radiation frequency band are about 1805-2170 MHz. Frequencies of the fourth radiation frequency band are about 13.56 MHz. Frequencies of the fifth radiation frequency band include 1575-1605 MHz, 2412-2485 MHz, 5125-5825 MHz, and 2300-2690 MHz. Frequencies of the sixth radiation frequency band include 2412-2485 MHz and 5125-5825 MHz. 
     In this embodiment, the first feed portion  12 , the second feed portion  13 , the first radiating portion E 1 , and the first ground portion  14  cooperatively form a first antenna. The third feed portion  15  and the second radiating portion E 2  form a second antenna. The fourth feed portion  16 , the third radiating portion E 3 , and the second ground portion  17  cooperatively form a third antenna. The first antenna is a diversity antenna and a NFC antenna. The second antenna is a diversity antenna, a GPS antenna, and a WIFI 2.4/5 GHz antenna. The third antenna is a WIFI 2.4/5 GHz antenna. 
     In the first antenna, the first feed portion  12 , the second feed portion  13 , the first radiating portion E 1 , and the first ground portion  14  form the diversity antenna. The second feed portion  13 , the first radiating portion E 1 , and the first ground portion  14  form the NFC antenna. 
     When the first antenna works at the third radiation frequency band, the first antenna is grounded through the second feed portion  13 . When the first antenna works at the fourth radiation frequency band, the second feed portion  13  supplies current to the first antenna. That is, the second feed portion  13  can simultaneously serve as a ground of the diversity antenna and a signal feed point of the NFC antenna. 
       FIG. 4  illustrates a scattering parameter graph of the first antenna of the antenna structure  100 .  FIG. 5  illustrates a gain efficiency graph of the first antenna of the antenna structure  100 .  FIG. 6  illustrates a scattering parameter graph of the second antenna of the antenna structure  100 .  FIG. 7  illustrates a gain efficiency graph of the second antenna of the antenna structure  100 .  FIG. 8  illustrates a scattering parameter graph of the third antenna of the antenna structure  100 .  FIG. 9  illustrates a gain efficiency graph of the third antenna of the antenna structure  100 . 
     In views of  FIG. 4  to  FIG. 9 , a working frequency of the antenna structure  100  can cover 699-960 MHz, 1710-2690 MHz, 1575-1605 MHz, and 5125-5825 MHz. That is, the antenna structure  100  may work at corresponding LTE-A low, middle, and high frequency bands, frequency bands of GPS, NFC, and WIFI 2.4/5 GHz. When the antenna structure  100  works at these frequency bands, the antenna structure  100  has a good radiating efficiency, which satisfies antenna design requirements. 
     As described above, the antenna structure  100  defines the first gap  118  and the second gap  119 , then the side frame  112  is divided into a first radiating portion E 1  and a second radiating portion E 2 . The antenna structure  100  further includes the first feed portion  12 , the second feed portion  13 , the first ground portion  14 , and the third feed portion  15 . The current from the first feed portion  12  flows through the first resonance section E 11  of the first radiating portion E 1  and is further grounded through the first ground portion  14  to activate the first operating mode to generate radiation signals in the LTE-A low frequency band and the second operating mode to generate radiation signals in a first LTE-A middle frequency band. 
     The current of the first feed portion  12  further flows through the second resonance section E 12  of the first radiating portion E 1 , and is grounded through the second feed portion  13  to activate the third operating mode to generate radiation signals in a second LTE-A middle frequency band. The current of the third feed portion  15  flows through the second radiating portion E 2 , and the second radiating portion E 2  generates radiation signals in the LTE-A high frequency band. That is, the wireless communication device  200  can use carrier aggregation (CA) technology of LTE-A to receive or send wireless signals at multiple frequency bands simultaneously. 
     In addition, in this embodiment, the second antenna and the third antenna can generate or receive radiation signals of WIFI 2.4/5 GHz, the antenna structure  100  can realize WIFI Multi-input Multi-output (MIMO) function. That is, the antenna structure  100  can fully meet receiving and transmitting functions of LTE/GSM/UMTS, GPS 1575 MHz, Wi-Fi MIMO 2.4/5 GHz, NFC 13.56 MHz bands, required for 4G LTE handsets, which includes reception and transmission functions of frequency bands of 700/850/900/1800/1900/2100/2300/2500 MHz, GPS 1575 MHz, Wi-Fi 2.4/5 GHz, and NFC 13.56 MHz, and also has a 3CA function and a Wi-Fi MIMO function. 
     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 structure and the wireless communication device. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present disclosure 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.