EP3154125B1

EP3154125B1 - Eight-frequency band antenna

Info

Publication number: EP3154125B1
Application number: EP16175515.2A
Authority: EP
Inventors: Ronan Quinlan
Original assignee: Taoglas Ltd Taiwan
Current assignee: Taoglas Group Holdings Ltd
Priority date: 2015-10-06
Filing date: 2016-06-21
Publication date: 2020-04-08
Anticipated expiration: 2036-06-21
Also published as: EP3154125A1; TWI563735B; TW201714354A

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention 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 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.
WO 2014 058926 A1 discloses an antenna capable of operating among all LTE bands, and also capable of operation among all remote side cellular applications, such as GSM, AMPS, GPRS, CDMA, WCDMA, UMTS, and HSPA among others. The antenna provides a low-cost alternative to active-tunable antennas suggested in the prior art for the same multi-platform objective.
US 8 779 988 B2 discloses a surface mount device multiple-band antenna module, which includes a substrate and a carrier. The substrate has a first grounding metal surface and a first micro-strip line on a side thereof. The first grounding metal surface has a second micro-strip line connected thereto. There is a space between the first micro-strip line and the second micro-strip line. The substrate has a second grounding metal surface on the other side thereof. The carrier is made of ceramic material with high dielectric constant, which has a first radiative metal portion, a second radiative metal portion and a third radiative metal portion. The carrier is electrically connected with the substrate. The joint of the first radiative metal portion and the second radiative metal portion is electrically connected to the first micro-strip line. The third radiative metal portion is electrically connected to the second micro-strip line. Thus, the multiple-band antenna module is obtained.

SUMMARY OF THE INVENTION

The invention is defined by the independent claim. Optional features are set out in the dependent claims.
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 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 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.

BRIEF DESCRIPTION OF DRAWING

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 invention.
Fig. 4 shows the top perspective view of the carrier of the eight-frequency band antenna according to the present invention.
Fig. 5 shows the back perspective view of the carrier of the eight-frequency band antenna according to the present invention.
Fig. 6 shows the back perspective view of the carrier of the eight-frequency band antenna according to the present invention.
Fig. 7 shows expanded view of the metal radiators of the carrier of the eight-frequency band antenna according to the present invention.
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 invention.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 3 shows the front perspective view of the carrier of the eight-frequency band antenna according to the present invention; Fig. 4 shows the top perspective view of the carrier of the eight-frequency band antenna according to the present invention; Fig. 5 shows the back perspective view of the carrier of the eight-frequency band antenna according to the present invention; Fig. 6 shows the back perspective viewof the carrier of the eight-frequency band antenna according to the present invention; and Fig. 7 shows expanded view of the metal radiators of the carrier of the eight-frequency band antenna according to the present invention. The eight-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 rectagular 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 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 frond 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 a is used as fixed point for PCB. The bottom of the double-T shaped radiator 21 electrically connects with one end of a short side 221 of the first L-shaped radiator 22, which is arranged on the back face 13. The other end of 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. In the shown embodiment, 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 pitches of the winding radiator 24 are around 0.15 mm -0.3 mm to provide LC resonance with 2400 MHz ∼ 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 longe 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 MHz, 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 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 to 10 show the exploded view, the backside view and the electric connection of the eight-frequency band antenna and the PCB. 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 4a, a left slanting side 4b, a bottom slanting side 4c, a right short side 4d, a recessed side 4e and a right long side 4f. Moreover, the PCB 4 hasa 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 4b to the gap 45, is larger than the area portion 432 of the first ground metal face 43, which is from the recessed side 4e 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 4e 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 botton 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 botton face 14 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 4e 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 prsent 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 4e 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 prsent invention has better frequency response for the low-frequency segment 3 (mark C) and higher bandwidth for the high-frequency segment 2 (mark D). Morover, 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 700MHZ and 960MHZ, 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 ∼ 2500 MHz and used in WIFI communication and the eighth frequency band with frequency range 2600 MHz ∼ 2700 MHz used in LTE communication.

Claims

An eight-frequency band antenna, comprising:
a carrier (1) comprising a front face (11), a top face (12), a back face (13) and a bottom face (14), the carrier (1) having a plurality of blind holes (15) defined on the front face (11) and concave into the carrier (1) and at least one rib (16) between two adjacent blind holes (15);

a high-frequency segment (2) arranged on the front face (11), the top face (12), the back face (13), and the bottom face (14) of the carrier (1) comprising a double-T shaped radiator (21), a first L-shaped radiator (22), a straight shaped radiator (23), a winding radiator (24), and a second L-shaped radiator (25); and

a low-frequency segment (3) arranged on the front face (11), the top face (12), the back face (13) and the bottom face (14) of the carrier (1),

the double-T shaped radiator (21) being arranged on the front face (11), the top face (12), the back face (13) and the bottom face (14) of the carrier (1), a portion (211) of the double-T shaped radiator (21), which is arranged on the bottom face (14), being usable as a fixed point for a printed circuit board (4), and a bottom part of the double-T shaped radiator (21) electrically connects with one end of a short side (221) of the first L-shaped radiator (22), which is arranged on the back face (13) of the carrier (1), and wherein the eight-frequency band antenna further comprises:
a printed circuit board (4) having, in connection sequence, a top side (4a), a left slanting side (4b), a slanting bottom side (4c), and a right long side (4f), a recessed side (4e), and a right short side (4d), the printed circuit board (4) having a first face (41) and a second face (42), the first face (41) having a first ground metal face (43) covering a portion of the first face (41) and a micro strip (44), the micro strip (44) having a front section (441) and a rear section (442), the front section (441) of the micro strip (44) having a through hole (443) and the front section (441) extends into the first ground metal face (43) such that a gap (45) is defined between the micro strip (44) and the first ground metal face (43), and further wherein the first ground metal face (43) is positioned adjacent a part of the left slanting side (4b) and the recessed side (4e),

an area portion (431) of the first ground metal face (43), which is from the left slanting side (4b) to the gap (45) being larger than an area portion (432) of the first ground metal face (43), which is from the recessed side (4e) to the gap (45), a ground line (46) extended on the smaller area portion (432) of the first ground metal face (43) extended from the recessed side (4e) to the gap (45), a separation (47) defined between the ground line (46) and the rear section (442) of the micro strip (44), the first face (41) having an opened area not covered by the first ground metal face (43) and having two fixed ends (48), the opened area being positioned adjacent to the top side (4a), the other part of the left slanting side (4b) and the right short side (4d);

an inductor (5) arranged across the separation (47) with one end electrically connecting with the rear section (442) of the micro strip (44) and another end electrically connecting with the ground line (46),

wherein the two fixed ends (48) of the opened end area of the first face (41) are fixed to the bottom face (14) of the carrier (1) such that the low-frequency segment (3) is corresponding the recessed side (4e) and corresponding to the smaller area portion (432) of the first ground metal face (43) extended from the recessed side (4e) to the gap (45) and the low-frequency segment (3) is at a free space to enhance a frequency response of the low-frequency segment (3) and to enhance a bandwidth of the high-frequency segment (2).
The eight-frequency band antenna in claim 1, wherein an area ratio of the blind holes (15) on the front face (11) and a volume ratio of the blind holes (15) with respect to the carrier (1) is adjustable to adjust an effective dielectric constant of the carrier (1), thus adjusting resonant frequency and a bandwidth.
The eight-frequency band antenna in claim 2, wherein the area ratio of the blind holes (15) on the front face (11) is 30%-50%.
The eight-frequency band antenna in claim 3, wherein the area ratio of the blind holes (15) on the front face (11) is 40%.
The eight-frequency band antenna in claim 2, wherein the volume ratio of the blind holes (15) with respect to the carrier (1) is 20%-30%.
The eight-frequency band antenna in claim 5, wherein the volume ratio of the blind holes (15) with respect to the carrier (1) is 24%.
The eight-frequency band antenna in claim 1, wherein the other end of 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 straight shape radiator (23) electrically connecting with the micro strip (44), a long side (222) of the first L-shaped radiator (22), which is arranged on the top face (12) and the back face (13) of the carrier (1), is coupled to the winding radiator (24), which is arranged on the top face (12) and the back face (13) of the carrier (1), the second L-shaped radiator (25) being arranged on the front face (11) and the bottom face (14), a short side (251) of the second L-shaped radiator (25) being parallel to the straight shape radiator (23), a long side (252) of the second L-shaped radiator (25) being vertical to the straight shape radiator (23) and parallel to the winding radiator (24), the long side (252) of the second L-shaped radiator (25) being electrically connected with the ground line (46).
The eight-frequency band antenna in claim 1, wherein the high-frequency segment (2) 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-2700 MHz.
The eight-frequency band antenna in claim 8, wherein pitches of the winding radiator (24) are 0.15 mm-0.3 mm to provide LC resonance with 2400 MHz - 2700 MHz resonant frequency.
The eight-frequency band antenna in claim 8, the low-frequency segment (3) further comprising:
a first rectangular radiator (31), a second rectangular radiator (32), a third rectangular radiator (33) and a fourth rectangular radiator (34) arranged respectively the front face (11), the top face (12), the back face (13) and the bottom face (14) of the carrier (1) and having different areas, the third rectangular radiator (33) arranged on the bottom face (14) is connected by a fixed end (48) to a printed circuit board (4).
The eight-frequency band antenna in claim 10, wherein the low-frequency segment (3) 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 - 960 MHz.
The eight-frequency band antenna in claim 1, wherein the second face (42) has a second ground metal face (43'), wherein a through hole (443) is opened to the second ground metal face (43') and electrically connects with a signal feeding end of a coaxial cable, the second ground metal face (43') electrically connects with a ground end of the coaxial cable.
The eight-frequency band antenna of claim 1, wherein the high-frequency segment (2) is arranged on left portions of the front face (11), the top face (12), the back face (13), and the bottom face (14) of the carrier (1) if viewing from the front face (11) of the carrier (1), and/or wherein the low-frequency segment (3) is arranged on right portions of the front face (11), the top face (12), the back face (13), and the bottom face (14) of the carrier (1) if viewing from the front face (11) of the carrier (1).