Patent Publication Number: US-2023141140-A1

Title: Wearable device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 110142010, filed on Nov. 11, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND 
     Technology Field 
     The disclosure relates to a wearable device, and in particular, to a wearable device with an antenna. 
     Description of Related Art 
     For a wearable device to have a fine-looking appearance, the antenna is usually designed inside a metal casing. However, such a way makes it difficult to reduce the size of the wearable device. If the metal casing of the wearable device is used as an antenna, the electromagnetic waves of the antenna are easily absorbed by a human body when the wearable device is worn on the human body, which makes the antenna efficiency difficult to perform well. 
     SUMMARY 
     The disclosure provides a wearable device, which may have a fine-looking appearance and may reduce the probability that the electromagnetic waves of the antenna is absorbed by a human body. 
     The wearable device of the disclosure includes a conductive bottom shell, a conductive frame, an insulating member, and a circuit board. The conductive frame is disposed above the conductive bottom shell and separated from the conductive bottom shell. The conductive frame functions as an antenna and includes a feeding terminal and a first ground terminal. The insulating member is disposed between the conductive bottom shell and the conductive frame, and the insulating member prevents the conductive bottom shell from conducting electricity to the conductive frame. The circuit board is disposed inside the conductive frame, separated from the conductive bottom shell, and disposed between the insulating member and the conductive frame. The feeding terminal and the first ground terminal are electrically connected to the circuit board. 
     In an embodiment of the disclosure, the above-mentioned circuit board includes a first elastic piece and a second elastic piece, the first elastic piece abuts the feeding terminal, and the second elastic piece abuts the first ground terminal. 
     In an embodiment of the disclosure, the above-mentioned conductive frame is adapted to resonate at a first frequency band, and the length from the feeding terminal to the first ground terminal is one-half wavelength of the first frequency band. 
     In an embodiment of the disclosure, the above-mentioned conductive frame includes a second ground terminal, the second ground terminal is electrically connected to the circuit board, and the length from the feeding terminal to the second ground terminal is one-half wavelength of the first frequency band. 
     In an embodiment of the disclosure, the above-mentioned conductive frame includes a second ground terminal, and the second ground terminal is electrically connected to the circuit board. Moreover, the conductive frame is further adapted to resonate at a second frequency band different from the first frequency band, and the length from the feeding terminal to the second ground terminal is one-half wavelength of the second frequency band. 
     In an embodiment of the disclosure, the above-mentioned circuit board includes a third elastic piece, and the third elastic piece abuts the second ground terminal. 
     In an embodiment of the disclosure, the above-mentioned conductive frame includes a slit, so that the conductive frame has an unenclosed annular shape. The conductive frame is adapted to resonate at a second frequency band, and the length from the first ground terminal, the feeding terminal to the slit is one-fourth wavelength of the second frequency band. 
     In an embodiment of the disclosure, the above-mentioned slit is filled with an insulating block. 
     In an embodiment of the disclosure, the above-mentioned insulating member is in an annular shape, and the insulating member is disposed in the gap between the conductive bottom shell and the conductive frame. 
     In an embodiment of the disclosure, the above-mentioned wearable device further includes a screen, which is electrically connected to the circuit board and disposed on the conductive frame. 
     Based on the above, the conductive frame of the wearable device of the embodiment may provide a fine-looking appearance and function as an antenna. The insulating member is disposed between the conductive bottom shell and the conductive frame to separate the conductive bottom shell and the conductive frame. The conductive bottom shell may be configured to reflect the energy of the antenna to converge the energy. In addition, when the wearable device is disposed on the human body, the conductive bottom shell is between the human body and the antenna. The conductive bottom shell may effectively reduce the electromagnetic waves to be absorbed by the human body from the antenna, thereby improving the antenna efficiency. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic top view of a wearable device according to an embodiment of the disclosure. 
         FIG.  2    is a schematic cross-sectional view of the wearable device of  FIG.  1    along lines A and A. 
         FIG.  3    is a plot diagram of frequency vs. S11 for the wearable device of  FIG.  1   . 
         FIG.  4    is a plot diagram of frequency vs. antenna efficiency for the wearable device of  FIG.  1   . 
         FIGS.  5  to  7    are schematic top views of various wearable devices according to other embodiments of the disclosure, respectively. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
       FIG.  1    is a schematic top view of a wearable device according to an embodiment of the disclosure. Referring to  FIG.  1   , in the embodiment, a wearable device  100  is, for example, a main body of a smart watch, but the type of the wearable device  100  is not limited thereto. 
       FIG.  2    is a schematic cross-sectional view of the wearable device of  FIG.  1    along lines A and A. Referring to  FIG.  2   , the wearable device  100  of the embodiment includes a conductive bottom shell  110 , a conductive frame  120 , an insulating member  130 , and a circuit board  140 . The conductive frame  120  is disposed above the conductive bottom shell  110  and separated from the conductive bottom shell  110 . In the embodiment, the conductive frame  120  functions as an antenna, and the conductive frame  120  includes a feeding terminal  121  and a first ground terminal  122 . 
     Referring to  FIG.  1   , the conductive frame  120  is adapted to resonate at a first frequency band, and the length of the feeding terminal  121  along the conductive frame  120  to the first ground terminal  122  is one-half wavelength of the first frequency band. The first frequency band is, for example, WiFi 2.4 GHz, but the first frequency band is not limited thereto. That is, the designer may adjust the length from the feeding terminal  121  to the first ground terminal  122  if required, so that the conductive frame  120  may excite at the desired frequency band. 
     In the embodiment, the insulating member  130  is in an annular shape. Please refer to  FIG.  2    again. The insulating member  130  is disposed in the gap between the conductive bottom shell  110  and the conductive frame  120 . Moreover, the insulating member  130  is connected to the conductive bottom shell  110  and the conductive frame  120  to insulate the conductive bottom shell  110  from the conductive frame  120 . Therefore, the conductive bottom shell  110  is not in conduction with the conductive frame  120 , and the current of the conductive frame  120  does not flow to the conductive bottom shell  110 . 
     The circuit board  140  is disposed inside the conductive frame  120  and separated from the conductive bottom shell  110 . That is, the circuit board  140  is not conducted to the conductive bottom shell  110 . In addition, the feeding terminal  121  and the first ground terminal  122  of the conductive frame  120  are electrically connected to the circuit board  140 . 
     Specifically, the circuit board  140  includes a first elastic piece  141  and a second elastic piece  142 . The first elastic piece  141  abuts the feeding terminal  121 , and the second elastic piece  142  abuts the first ground terminal  122 . Certainly, how the feeding terminal  121  and the first ground terminal  122  are electrically connected to the circuit board  140  is not limited thereto. 
     In addition, the wearable device  100  further includes a screen  150 , which is electrically connected to the circuit board  140  and disposed on the conductive frame  120 . In an embodiment, the wearable device  100  may further include a battery, a speaker, or a vibrator, etc., which is not limited to the drawings. Furthermore, in the embodiment, the outer contours of the conductive frame  120 , the conductive bottom shell  110 , and the insulating member  130  have, for example, circular shapes. However, in other embodiments, the outer contours of the conductive frame  120 , the conductive bottom shell  110 , and the insulating member  130  may be square, rectangular, oval, or polygonal. 
     The conductive frame  120  of the wearable device  100  in the embodiment is, for example, a metal frame, which may provide a fine-looking appearance. The conductive frame  120  itself functions as an antenna, and may resonate at the desired frequency band. Therefore, the conductive frame  120  itself has the functions of the housing and the antenna at the same time. Since the conductive frame  120  is the antenna, it is not necessary for the wearable device  100  to have an additional antenna and a holder to support the antenna, the volume of the wearable device  100  may be reduced, or the required elements may be more flexibly placed in the internal space of the wearable device  100 . 
     In addition, the conductive bottom shell  110  may be configured to reflect the antenna&#39;s power from the conductive frame  120 , so that the antenna&#39;s power may be convergent and radiated toward the screen  150 , thereby improving the antenna efficiency. Furthermore, the insulating member  130  is disposed between the conductive bottom shell  110  and the conductive frame  120  to prevent the current of the conductive frame  120  from flowing to the conductive bottom shell  110 . Since the insulating member  130  prevents the conductive frame  120  from conducting electricity to the conductive bottom shell  110 , the conductive bottom shell  110  is not a part of the antenna. When the wearable device  100  is worn on a human body, the conductive bottom shell  110  is between the human body and the antenna. The conductive bottom shell  110  may function as a shielding structure, which may not only improve the antenna efficiency, but also effectively reduce the electromagnetic waves to be absorbed by the human body from the antenna. 
       FIG.  3    is a plot diagram of frequency vs. S11 for the wearable device of  FIG.  1   . FIG.  4  is a plot diagram of frequency vs. antenna efficiency for the wearable device of  FIG.  1   . Please refer to  FIGS.  3  and  4   . Comparing the wearable device  100  of the embodiment with a device of which the entire housing is made of metal (i.e., without the insulating member  130 ), the wearable device  100  of the embodiment performs significantly better on S11 and the antenna efficiency in the frequency range of 2400 MHz to 2480 MHz. 
       FIGS.  5  to  7    are schematic top views of various wearable devices according to other embodiments of the disclosure. Please refer to  FIG.  5    first. The main difference between a wearable device  100   a  of this embodiment and the wearable device  100  of  FIG.  1    is that in this embodiment, the conductive frame  120  further includes a second ground terminal  123 , and the second ground terminal  123  is electrically connected to the circuit board  140 . Specifically, the circuit board  140  includes a third elastic piece  143 , and the third elastic piece  143  abuts the second ground terminal  123 . 
     In the embodiment, the length from the feeding terminal  121  to the second ground terminal  123  along the conductive frame  120  is the same as the length from the feeding terminal  121  to the first ground terminal  122  along the conductive frame  120 , and both of the lengths are one-half wavelength of the first frequency band. That is, the first ground terminal  122  and the second ground terminal  123  are symmetrically located on the opposite sides of the feeding terminal  121 . In the embodiment, the wearable device  100   a  may increase the bandwidth of the first frequency band through the above-mentioned design, thereby providing a broadband effect. 
     Referring to  FIG.  6   , the main difference between a wearable device  100   b  of this embodiment and the wearable device  100   a  of  FIG.  5    is that in this embodiment, the length from the feeding terminal  121  to the second ground terminal  124  is different from the length from the feeding terminal  121  to the first ground terminal  122 . A third elastic piece  144  abuts the second ground terminal  124 . In addition to the first frequency band, the conductive frame  120  is further adapted to resonate at the second frequency band different from the first frequency band, and the length from the feeding terminal  121  to the second ground terminal  124  is one-half wavelength of the second frequency band. 
     That is, in the embodiment, the section from the feeding terminal  121  to the first ground terminal  122  may be configured to resonate at the first frequency band, and the section from the feeding terminal  121  to the second ground terminal  124  may be configured to resonate at the second frequency band. Therefore, the wearable device  100   b  of the embodiment may provide multi-band operation. 
     Referring to  FIG.  7   , the main difference between a wearable device  100   c  of this embodiment and the wearable device  100  of  FIG.  1    is that in the embodiment, the conductive frame  120  includes a slit  125 , and the conductive frame  120  has an unenclosed annular shape. The slit  125  is optionally filled with an insulating block  126  to complete the appearance. 
     In the embodiment, in addition to the first frequency band, the conductive frame  120  is further adapted to resonate at the second frequency band different from the first frequency band. The length from the first ground terminal  122 , the feeding terminal  121  to the slit  125  is one-quarter wavelength of the second frequency band. 
     That is, in the embodiment, the section from the feeding terminal  121  to the first ground terminal  122  may be configured to resonate at the first frequency band, and the section from the first ground terminal  122 , the feeding terminal  121  to the slit  125  may be configured to resonate at the second frequency band. Therefore, the wearable device  100   c  of the embodiment may provide multi-band operation. 
     In summary, the conductive frame of the wearable device of the embodiment may provide a fine-looking appearance and function as an antenna. The insulating member is disposed between the conductive bottom shell and the conductive frame to separate the conductive bottom shell and the conductive frame. The conductive bottom shell may be configured to reflect the power of the antenna to make the power convergent. In addition, when the wearable device is worn on a human body, the conductive bottom shell is between the human body and the antenna. The conductive bottom shell may effectively reduce the electromagnetic waves to be absorbed by the human body from the antenna, thereby improving the antenna efficiency.