Patent Publication Number: US-11641060-B2

Title: Multi-frequency band antenna

Description:
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS 
     Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. 
     This application is a continuation of, and claims the benefit of priority to, U.S. patent application Ser. No. 16/827,404 filed Mar. 23, 2020, of the same title, which is a continuation of, and claims the benefit of priority to, U.S. patent application Ser. No. 15/689,292 filed Aug. 29, 2017, of the same title, which is a continuation of, and claims the benefit of priority to, U.S. patent application Ser. No. 14/948,226 filed Nov. 20, 2015, of the same title, the contents of each of the foregoing being incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an antenna, especially to a ten-frequency band antenna for enhancing the frequency response of the low-frequency segment and bandwidth of the high-frequency segment. 
     Description of the Related Art 
     The current commercially available planar inverted-F antenna (PIFA) is generally formed by printing metal material (such as copper) on printed circuit board (PCB) with two-dimensional printing technology. Alternatively, metal membrane is pressed into three-dimensional multi frequency band antenna. 
     The multi frequency bands signal transmission/reception can be achieved by changing the two-dimensional radiation patterns or the geometric shape of the three-dimensional radiation bodies. However, the antenna formed on PCB or formed by pressing metal membrane into radiation body need a specific volume to ensure signal transmission/reception quality and prevent signal tuning problem caused by environment. Moreover, the electronic device needs an internal space for arranging the PIFA structure, this causes impact on light weight and compact requirement of the electronic devices. 
     To overcome above problem, the radiation body of the antenna can be fabricated on a rectangular ceramic carrier. As shown in  FIGS.  1  and  2   , the carrier  101  of the antenna  10  has a high-frequency radiator  102  and a low-frequency radiator  103  on the surface thereof and the carrier  101  is fixed on the PCB  20 . The PCB  20  has a ground metal plane  201 , a signal feeding micro strip  202  and a ground wire  203  on two faces thereof, where the signal feeding micro strip  202  connects with the ground wire  203  and the radiator of the carrier  101 . The high-frequency radiator  102  is arranged on the right side of the carrier  101  and the low-frequency radiator  103  is arranged on the left side of the carrier  101 . The antenna  10  is electrically connected to the PCB  20  and the area of the ground metal plane  201  corresponding to the low-frequency radiator  103  is smaller than the area of the ground metal plane  201  corresponding to the high-frequency radiator  102 . Therefore, the low-frequency radiator  103  suffers more to the ground shielding and the frequency response (see label A in  FIG.  2   ) is not satisfactory. Moreover, the bandwidth of the high-frequency radiator  102  is not wide enough (only covering 6 bands as shown by label B in  FIG.  2   ). As a result, the signal transmission/reception quality is poor and signal transmission/reception bandwidth is limited. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to change the position of the high-frequency segment and the low-frequency segment. The low-frequency segment is corresponding to a smaller area portion of the ground metal face on the PCB when the antenna carrier is fixed to the PCB. Therefore, the low-frequency segment is at a free space to enhance frequency response for the low-frequency segment and the bandwidth for the high-frequency segment. 
     It is another object of the present invention to provide blind holes and ribs in the carrier. The blind holes and the ribs can reduce the overall weight of the carrier and prevent warp of the carrier. The area ratio of the blind holes and the volume ratio of the blind holes can be used to adjust the effective dielectric constant of the carrier, thus adjusting resonant frequency and the bandwidth. 
     It is still another object of the present invention to provide an inductor electrically connecting with the ground line and the micro strip to adjust impedance and provide ground for the antenna, thus forming a PIFA dipole antenna. 
     Accordingly the present invention provides a ten-frequency band antenna, comprising: a carrier being a ceramic rectangular body and comprising a front face, a top face, a back face and a bottom face, the carrier having a plurality of blind holes defined on the front face and concave into the carrier, and at least one rib between two adjacent blind holes; a high-frequency segment comprising an inverse n-shaped radiator, a straight shape radiator, a winding radiator and an L-shaped radiator, wherein the high-frequency segment is arranged on left portions of the front face, the top face, the back face and the bottom face of the carrier if viewing at the front face of the carrier; a low-frequency segment comprising a first rectangular radiator, a second rectangular radiator, a third rectangular radiator and a fourth rectangular radiator, wherein the low-frequency segment is arranged on right portions of the front face, the top face, the back face and the bottom face of the carrier if viewing at the front face of the carrier; a printed circuit board (PCB) having a top side, a left slanting side, a slanting bottom side, a right short side, a recessed side and a right long side, the PCB having a first face and a second face, the first face having a first ground metal face and a micro strip, the micro strip having a front section and a rear section, the front section having a through hole, the micro strip having a front portion extended into the first ground metal face such that a gap is defined between the micro strip and the first ground metal face, the first face of the PCB having an opened area with two fixing ends; an area portion of the first ground metal face, which is from the left slanting side to the gap being larger than an area portion of the first ground metal face, which is from the recessed side to the gap, a ground line extended on the smaller area portion of the first ground metal face extended from the recessed side to the gap, a separation defined between the ground line and the rear segment of the micro strip, the first face having an opened area with two fixed ends; an inductor arranged across the separation with one end electrically connecting with the rear section of the micro strip and another end electrically connecting with the ground line, wherein the two fixed ends of the opened area of the first face are fixed to the bottom face of the carrier such that the low-frequency segment is corresponding the recessed side and corresponding to the smaller area portion of the first ground metal face extended from the recessed side to the gap and the low-frequency segment is at a free space to enhance a frequency response of the low-frequency segment, the inverse n-shaped radiator, the straight shape radiator, and the winding radiator couple to each other to enhance a bandwidth of the high-frequency segment. 
     According to one aspect of the present invention, an area ratio of the blind holes on the front face and a volume ratio of the blind holes with respect to the carrier is adjustable to adjust an effective dielectric constant of the carrier, thus adjusting resonant frequency and the bandwidth. 
     According to another aspect of the present invention, the area ratio of the blind holes on the front face is 30%-50%. 
     According to still another aspect of the present invention, the area ratio of the blind holes on the front face is 40%. 
     According to still another aspect of the present invention, the volume ratio of the blind holes with respect to the carrier is 20%-30%. 
     According to still another aspect of the present invention, the volume ratio of the blind holes with respect to the carrier is 24%. 
     According to still another aspect of the present invention, the inverse n-shaped radiator has a first straight line portion, a second straight line portion and an L shaped portion, the first straight line portion is arranged on edges of the front face, the top face, the back face and the bottom face of the carrier, a portion of the first straight line portion on the bottom is used as fixed point for PCB. 
     According to still another aspect of the present invention, the straight shape radiator electrically connects to one side of the second straight line portion, the straight shape radiator is arranged on edges of the front face and the bottom face of the carrier, one end of the straight shape radiator is adjacent to the winding radiator for coupling and a portion of the straight shape radiator arranged on the bottom face is used as signal feeding point. 
     According to still another aspect of the present invention, one end of the winding radiator electrically connects with one end of the second straight line portion and another end of the winding radiator electrically connects with low-frequency segment such that a short side of the L-shaped radiator of the inverse n-shaped radiator is coupling to the winding radiator. 
     According to still another aspect of the present invention, pitches of the winding radiator are around 0.15 mm-0.3 mm to provide LC resonance with 2400 MHZ to about 2700 MHZ resonant frequency. 
     According to still another aspect of the present invention, the L-shaped radiator is arranged on the front face and bottom face of the carrier, the short side of the L-shaped radiator is parallel to the straight shape radiator, a long side of the of the L-shaped radiator is vertical to the straight shape radiator and parallel to the winding radiator, the long side of the of the L-shaped radiator provides ground point. 
     According to still another aspect of the present invention, the high-frequency segment provides a fourth frequency band, a fifth frequency band, a sixth frequency band, a seventh frequency band, an eighth frequency band, a ninth frequency band and a tenth frequency band, and the fourth frequency band, the fifth frequency band, the sixth frequency band, the seventh frequency band, the eighth frequency band, the ninth frequency band and the tenth frequency band are within 1710 MHZ to about 6000 MHZ. 
     According to still another aspect of the present invention, the high-frequency segment provides a first frequency band, a second frequency band, and a third frequency band, and the first frequency band, the second frequency band, and the third frequency band are within 700 MHZ to about 960 MHZ. 
     According to still another aspect of the present invention, the second face has a second ground metal face, the through hole is opened to the second ground metal face and electrically connects with a signal feeding end of a coaxial cable, the second ground metal face electrically connects with a ground end of the coaxial cable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosed example itself, however, may be best understood by reference to the following detailed description of the present disclosed example, which describes an exemplary embodiment of the present disclosed example, taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    shows a conventional multi-band antenna; 
         FIG.  2    shows the reflection loss of the conventional multi-band antenna in  FIG.  1   ; 
         FIG.  3    shows the front perspective view of the carrier of the ten-frequency band antenna according to the present invention; 
         FIG.  4    shows the top perspective view of the carrier of the ten-frequency band antenna according to the present invention; 
         FIG.  5    shows the back perspective view of the carrier of the ten-frequency band antenna according to the present invention; 
         FIG.  6    shows the back perspective view of the carrier of the ten-frequency band antenna according to the present invention; 
         FIG.  7    shows expanded view of the metal radiators of the carrier of the ten-frequency band antenna according to the present invention; 
         FIG.  8    shows the exploded view of the ten-frequency band antenna and the PCB; 
         FIG.  9    shows the backside view of the ten-frequency band antenna and the PCB; 
         FIG.  10    shows the electric connection of the ten-frequency band antenna and the PCB; and 
         FIG.  11    shows the reflection loss curve of the ten-frequency band antenna of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG.  3    shows the front perspective view of the carrier of the ten-frequency band antenna according to the present invention;  FIG.  4    shows the top perspective view of the carrier of the ten-frequency band antenna according to the present invention;  FIG.  5    shows the back perspective view of the carrier of the ten-frequency band antenna according to the present invention;  FIG.  6    shows the back perspective view of the carrier of the ten-frequency band antenna according to the present invention; and  FIG.  7    shows expanded view of the metal radiators of the carrier of the ten-frequency band antenna according to the present invention. The ten-frequency band antenna according to the present invention comprises a carrier  1 , a high-frequency segment  2 , and a low-frequency segment  3 . 
     The carrier  1  is a ceramic rectangular body with a front face  11 , a top face  12 , a back face  13  and a bottom face  14 . The front face  11  has a plurality of blind holes  15  defined thereon and each two blind holes have a rib  16  therebetween. The blind holes  15  and each rib  16  can reduce the overall weight of the carrier  1  and prevent warp of the carrier  1 . The area ratio of the blind holes  15  on the front face  11  and the volume ratio of the blind holes  15  with respect to the carrier  1  can be used to adjust the effective dielectric constant of the carrier  1 , thus adjusting resonant frequency and the bandwidth. The area ratio of the blind holes  15  on the front face  11  is around 30%-50%, and more particularly can be 40%. The volume ratio of the blind holes  15  with respect to the carrier  1  is 20%-30% and more particularly can be 24%. Moreover, the shape and the symmetric degree of the blind holes  15  can also be adjusted. 
     When viewing from the front face  11  of the carrier  1 , the high-frequency segment  2  is arranged on the left side of the carrier  1  and has an inverse π-shaped radiator  21 , a straight shape radiator  22 , a winding radiator  23  and an L-shaped radiator  24 . The inverse L-shaped radiator  21  has a first straight line portion  211 , a second straight line portion  212  and an π-shaped portion  213 . 
     The first straight line portion  211  is arranged on edges of the front face  11 , the top face  12 , the back face  13  and the bottom face  14 . The portion of the first straight line portion  211  on the bottom face  14 , namely the bottom first straight line portion  211   a  is used as fixed point for PCB (not shown). The second straight line portion  212  of the inverse n-shaped radiator  21  connects with the straight shape radiator  22  at one edge thereof. The straight shape radiator  22  is arranged on the front face  11  and the bottom face  14 , respectively. One end of the straight shape radiator  22  is adjacent to the winding radiator  23  such that the coupling therebetween provides 4900 MHZ to about 6000 MHZ bandwidth. The straight shape radiator  22  arranged on the bottom face  14  is used as signal feeding point. One end of the winding radiator  23  electrically connects with one end of the second straight line portion  212  and another end of the winding radiator  23  electrically connects with low-frequency segment  3 . The short side  213   a  of the L shaped portion  213  and the winding radiator  23  have coupling therebetween to provide 3500 MHZ bandwidth. The pitches of the winding radiator  23  are around 0.15 mm-0.3 mm to provide LC resonance with 2400 MHZ to about 2700 MHZ resonant frequency. The L-shaped radiator  24  is arranged on the front face  11  and the bottom face  14 . The short side  241  of the L-shaped radiator  24  is parallel to the straight shape radiator  22 , the long side  242  of the L-shaped radiator  24  is vertical to the straight shape radiator  22  and parallel to the winding radiator  23 . In the shown embodiment, the longer side  242  of the L-shaped radiator  24  is used as ground end. In the shown embodiment, high-frequency segment  2  provides the fourth frequency band, the fifth frequency band, the sixth frequency band, the seventh frequency band, the eighth frequency band, the ninth frequency band and the tenth frequency band. The frequency range of the fourth frequency band, the fifth frequency band, the sixth frequency band, the seventh frequency band, the eighth frequency band, the ninth frequency band and the tenth frequency band is between 1710 MHZ and 6000 MHZ, and can be used in GSM, WCDMA, WIFI, LTE, WIMAX and 802.11ac communication system. 
     When viewing from the front face  11  of the carrier  1 , the low-frequency segment  3  is arranged on the right side of the carrier  1  and has a first rectangular radiation body  31 , a second rectangular radiation body  32 , a third rectangular radiation body  33  and a fourth rectangular radiation body  34 , where each of the rectangular radiation bodies has different area and is respectively arranged on the front face  11 , the top face  12 , the back face  13  and the bottom face  14  of the carrier  1 . The third rectangular radiation body  33  provides fixing points with the printed circuit board. In the shown embodiment, the low-frequency segment  3  provides the first frequency band, the second frequency band, and the third frequency band. The frequency range of the first frequency band, the second frequency band, and the third frequency band is between 700 MHZ and 960 MHZ, and can be used in LTE and GMS communication system. 
       FIGS.  8 - 10    show the exploded view, the backside view and the electric connection of the ten-frequency band antenna and the PCB. The ten-frequency band antenna further comprises a PCB  4  fixed to the carrier  1  and the PCB has a top side  4   a , a left slanting side  4   b , a bottom slanting side  4   c , a right short side  4   d , a recessed side  4   e  and a right long side  4   f  Moreover, the PCB  4  has a first face  41  and a second face  42 . The first face  41  has a first ground metal face  43  and a micro strip  44 . 
     The micro strip  44  has a front section  441  and a rear section  442 . The front section  441  has a through hole  443  and extends into the first ground metal face  43  such that a gap  45  is defined between the front section  441  and the first ground metal face  43 . Moreover, the area portion  431  of the first ground metal face  43 , which is from the left slanting side  4   b  to the gap  45 , is larger than the smaller area portion  432  of the first ground metal face  43 , which is from the recessed side  4   e  to the gap  45 . 
     Moreover, a ground line  46  is extended on the smaller area portion  432  of the first ground metal face  43 , which is from the recessed side  4   e  to the gap  45 . The ground line  46  is parallel to the rear section  442  of the micro strip  44 . A separation  47  is defined between the ground line  46  and the rear section  442  of the micro strip  44 . An inductor  5  is connected between the ground line  46  and the rear section  442  of the micro strip  44  and cross the separation  47  to adjust impedance and provide ground for the antenna, thus forming a PIFA dipole antenna. The opened area of the first face  41  has two corresponding fixed ends  48  for fixed connection with the bottom first straight line portion  211   a  and the third rectangular radiation body  33 . 
     The second face  42  further has a second ground metal face  43 ′, where the through hole  443  is opened to the second ground metal face  43 ′ and electrically connects with a signal feeding end (not shown) of a coaxial cable. The second ground metal face  43 ′ electrically connects with the ground end of the coaxial cable. 
     When the carrier  1  is fixed to the PCB  4 , the two fixed ends  48  are fixed to the bottom first straight line portion  211   a  and the third rectangular radiation body  33  respectively. The straight shape radiator  22  on the bottom face  14  electrically connects the micro strip  44 . The long side  242  of the L-shaped radiator  24  electrically connects with the ground line  46 . After fixing the carrier  1 , the low-frequency segment  3  is arranged on the opened area and corresponding to the recessed side  4   e  of the PCB  4  and corresponding to the smaller area portion  432  of the first ground metal face  43  such that the low-frequency segment  3  is located at a free space to enhance the frequency response of the low-frequency segment  3 . 
       FIG.  11    shows the reflection loss curve of the ten-frequency band antenna of the present invention. With reference also to  FIG.  10   , after fixing the carrier  1  to the PCB  4 , the low-frequency segment  3  is arranged on the opened area and corresponding to the recessed side  4   e  of the PCB  4  and the smaller area portion  432  of the first ground metal face  43  such that the low-frequency segment  3  is at a free space with less shielding. The ten-frequency band antenna of the present invention has better frequency response for the low-frequency segment  3  and higher bandwidth for the high-frequency segment  2 . Moreover, the low-frequency segment  3  provides the first frequency band, the second frequency band, and the third frequency band. The frequency range of the first frequency band, the second frequency band, and the third frequency band is between 700 MHZ and 960 MHZ, as indicated by mark C in  FIG.  11   . The high-frequency segment  2  provides the fourth frequency band, the fifth frequency band, and the sixth frequency band with frequency range between 1710 MHZ and 2710 MHZ, as indicated by mark D in  FIG.  11   . The high-frequency segment  2  provides the seventh frequency band with frequency range 2400 MHZ to about 2500 MHZ and the eighth frequency band with frequency range 2600 MHZ to about 2700 MHZ, as indicated by mark D in  FIG.  11   . The high-frequency segment  2  provides the ninth frequency band with frequency range 3500 MHZ to about 3700 MHZ, as indicated by mark E in  FIG.  11   . The high-frequency segment  2  provides the tenth frequency band with frequency range 4900 MHZ to about 6000 MHZ, as indicated by mark F in  FIG.  11   . 
     The foregoing descriptions of embodiments of the disclosed example have been presented only for purposes of illustration and description. They are not intended to be exhaustive or to limit the disclosed example to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the disclosed example. The scope of the disclosed example is defined by the appended.