Patent Publication Number: US-2022224009-A1

Title: Multi-frequency band antenna

Description:
PRIORITY 
     This application is a continuation of, and claims the benefit of priority to, U.S. patent application Ser. No. 16/685,843 filed Nov. 15, 2019, and entitled “Eight-Frequency Band Antenna”, which is a continuation of, and claims the benefit of priority to, U.S. patent application Ser. No. 16/172,098 filed Oct. 26, 2018 of the same title, which is a continuation of, and claims the benefit of priority to, U.S. patent application Ser. No. 14/948,237 filed Nov. 20, 2015 of the same title, the contents of each of the foregoing being incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Field of the Disclosure 
     The present disclosure relates to an antenna, especially to an eight-frequency band antenna for enhancing the frequency response of the low-frequency segment and bandwidth of the high-frequency segment. 
     Description of Prior 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  FIG. 1  and  FIG. 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 
     In one aspect, a multi-frequency band antenna is disclosed. It is one object of the present disclosure 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 disclosure to provide blind holes and ribs in the carrier. The blind holes and the ribs can reduce the overall weight of the carrier  1  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 disclosure 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 disclosure provides an eight-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 arranged on left portions of the front face, the top face, the back face and the bottom face of the carrier if viewing from the front face of the carrier; a low-frequency segment arranged on right portions of the front face, the top face, the back face and the bottom face of the carrier if viewing from 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 section 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 and to enhance a bandwidth of the high-frequency segment. 
     According to one aspect of the present disclosure, 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 disclosure, the area ratio of the blind holes on the front face is 30%-50%. 
     According to still another aspect of the present disclosure, the area ratio of the blind holes on the front face is 40%. 
     According to still another aspect of the present disclosure, the volume ratio of the blind holes with respect to the carrier is 20%-30%. 
     According to still another aspect of the present disclosure, the volume ratio of the blind holes with respect to the carrier is 24%. 
     According to still another aspect of the present disclosure, the high-frequency segment has a double-T shaped radiator, a first L-shaped radiator, a straight shape radiator, a winding radiator and a second L-shaped radiator, the double-T shaped radiator being arranged on of the front face, the top face, the back face and the bottom face of the carrier, and a portion of the double-T shaped radiator, which is arranged on the on the bottom face being used as fixed point for PCB, a bottom part of the double-T shaped radiator electrically connects with one end of a short side of the first L-shaped radiator is arranged on the bottom face, the other end of the short side of the first L-shaped radiator electrically connects with the straight shape radiator arranged on the front face and the bottom face, the straight shape radiator electrically connecting with the micro strip, a long side of the first L-shaped radiator arranged on the top face and the back face coupled to the winding radiator arranged on the top face and the back face, the second L-shaped radiator being arranged on the front face and the bottom face, a short side of the second L-shaped radiator being parallel to the straight shape radiator, a long side of the second L-shaped radiator being vertical to the straight shape radiator and parallel to the winding radiator, the long side of the second L-shaped radiator electrically connected with the ground line. 
     According to still another aspect of the present disclosure, the high-frequency segment provides a fourth frequency band, a fifth frequency band, a sixth frequency band, a seventh frequency band, and an eighth frequency band, and the fourth frequency band, the fifth frequency band, the sixth frequency band, the seventh frequency band, and the eighth frequency band are within 1710 MHZ about 2700 MHZ. 
     According to still another aspect of the present disclosure, pitches of the winding radiator are around 0.15 mm about 0.3 mm to provide LC resonance with 2400 MHZ about 2700 MHZ resonant frequency. 
     According to still another aspect of the present disclosure, the low-frequency segment comprising a first rectangular radiator, a second rectangular radiator, a third rectangular radiator and a fourth rectangular radiator arranged respectively the front face, the top face, the back face and the bottom face of the carrier and having different areas, the third rectangular radiator arranged on the back face is fixed point with the PCB. 
     According to still another aspect of the present disclosure, the low-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 about 960 MHZ. 
     According to still another aspect of the present disclosure, 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 coefficients of the multi-band antenna in  FIG. 1 . 
         FIG. 3  shows the front perspective view of the carrier of the eight-frequency band antenna according to the present disclosure. 
         FIG. 4  shows the top perspective view of the carrier of the eight-frequency band antenna according to the present disclosure. 
         FIG. 5  shows the back perspective view of the carrier of the eight-frequency band antenna according to the present disclosure. 
         FIG. 6  shows the back perspective view of the carrier of the eight-frequency band antenna according to the present disclosure. 
         FIG. 7  shows a planar view of the metal radiators of the carrier of the eight-frequency band antenna according to the present disclosure. 
         FIG. 8  shows the exploded view of the eight-frequency band antenna and the PCB. 
         FIG. 9  shows the backside view of the eight-frequency band antenna and the PCB. 
         FIG. 10  shows the electric connection of the eight-frequency band antenna and the PCB. 
         FIG. 11  shows the reflection loss curve of the eight-frequency band antenna of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 3  shows the front perspective view of the carrier  1  of the eight-frequency band antenna  100  according to the present disclosure;  FIG. 4  shows the top perspective view of the carrier  1  of the eight-frequency band antenna  100  according to the present disclosure;  FIG. 5  shows the back perspective view of the carrier  1  of the eight-frequency band antenna  100  according to the present disclosure;  FIG. 6  shows the back perspective view of the carrier  1  of the eight-frequency band antenna  100  according to the present disclosure; and  FIG. 7  shows a planar view of the metal radiators of the carrier  1  of the eight-frequency band antenna  100  according to the present disclosure. The eight-frequency band antenna  100  according to the present disclosure 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 which form a three-dimensional cavity in the carrier  1  and each two blind holes have at least one rib  16  therebetween. The blind holes  15  and the ribs  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 a double-T shaped radiator  21 , a first L-shaped radiator  22 , a straight shape radiator  23 , a winding radiator  24  and a second L-shaped radiator  25 . The double-T shaped radiator  21  is arranged on edges of the front face  11 , the top face  12 , the back face  13  and the bottom face  14 , and is used as fixed point for PCB  4 . The bottom of one T of the double-T shaped radiator  21  electrically connects with one end of a short side  221  of the first L-shaped radiator  22 . The double-T shaped radiator  21  is arranged on the bottom face  14  and the back face  13 . The short side  221  of the first L-shaped radiator  22  electrically connects with the straight shape radiator  23  arranged on the front face  11  and the bottom face  14 . The long side  222  of the first L-shaped radiator  22  is positioned on two surfaces of the carrier  1  adjacent the winding radiator  24 . In the embodiment shown, the straight shape radiator  23  functions as signal feeding point. The long side  222  of the first L-shaped radiator  22 , which is arranged on the top face  12  and the back face  13  couples to the winding radiator  24 , which is arranged on the top face  12  and the back face  13 . The winding radiator  24  has an L-shaped gap along a length adjacent the first rectangular radiation body  31  and the second rectangular radiation body  32 . The pitches of the winding radiator  24  are around 0.15 mm about 0.3 mm to provide LC resonance with 2400 MHZ about 2700 MHZ resonant frequency. The second L-shaped radiator  25  is arranged on the front face  11  and the bottom face  14 . The short side  251  of the second L-shaped radiator  25  is parallel to the straight shape radiator  23 , the long side  252  of the second L-shaped radiator  25  is vertical to the straight shape radiator  23  and parallel to the winding radiator  24 . In the shown embodiment, the longer side  252  of the second L-shaped radiator  25  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 and the eighth frequency band. The frequency range of the fourth frequency band, the fifth frequency band, the sixth frequency band, the seventh frequency band and the eighth frequency band is between 1710 MHZ and 2700, and can be used in GSM, WCDMA, WIFI, and LTE 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 top face  12 , the back face  13 , the bottom face  14 , and the front face  11  of the carrier  1 . 
     The third rectangular radiation body  33  of the low-frequency segment  3  provides fixing points with the printed circuit board. In the embodiment shown, 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 eight-frequency band antenna and the PCB  4 . The eight-frequency band antenna further comprises a PCB  4  fixed to the carrier  1  and the PCB has, in connection sequence, 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 portion  211  of the double-T shaped radiator  21  on the on the bottom face  14  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 portion  211  of the double-T shaped radiator  21  on the on the bottom face  14  and the third rectangular radiation body  33  respectively. The straight shape radiator  23  on the bottom face  14  electrically connects the micro strip  44 . The long side  222  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 disclosure. 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 eight-frequency band antenna of the present disclosure has better frequency response for the low-frequency segment  3  (reflection loss over frequency C) and higher bandwidth for the high-frequency segment  2  (reflection loss over frequency D). 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, and can be used in LTE and GMS communication. 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 and can be used in GSM and WCDMA communication. The high-frequency segment  2  provides the seventh frequency band with frequency range 2400 MHZ about 2500 MHZ and used in WIFI communication and the eighth frequency band with frequency range 2600 MHZ about 2700 MHZ used in LTE communication. 
     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.