Smartphone antenna in flexible PCB
A thin, flexible antenna module is provided for use in a smartphone. When the antenna module is assembled in the smartphone, the antenna module provides an MST antenna and an NFC antenna. For this, the antenna module includes a flexible PCB containing two coil antennas and further includes a magnetic sheet engaged with flexible PCB. The flexible PCB and the magnetic sheet are attached to each other to form a single body.
1. A smartphone antenna module:
a magnetic sheet comprising a first magnetic sheet portion, a second magnetic sheet portion and a third magnetic sheet portion interposed between the first and second magnetic sheet portions,
a flexible PCB in form of a sheet having a thickness, the flexible PCB comprising a first coil antenna and a second coil antenna; and
a through hole formed through the thickness of the sheet of the flexible PCB such that the flexible PCB comprises a first PCB section and a second PCB section located on an opposite side of the first PCB section across the through hole,
wherein, when viewed in a thickness direction of the flexible PCB, the first coil antenna comprises two or more coiled turns turning around the through hole, and the second coil antenna comprises two or more coiled turns turning around the first coil antenna and the through hole,
wherein no electrical connection is formed between the first coil antenna and the second coil antenna within the flexible PCB,
wherein the flexible PCB and the magnetic sheet are integrated in a single, flexible body, in which the flexible PCB and the magnetic sheet are arranged relative to each other such that:
at least part of the third magnetic sheet portion passes the through hole,
the first magnetic sheet portion is placed over the first PCB section and overlaps, when viewed in the thickness direction, a first coil portion of the first coil antenna formed in the first PCB section of the flexible PCB while not overlapping, when viewed in the thickness direction, a second coil portion of the first coil antenna formed in the second PCB section that is placed across the through hole,
the second magnetic sheet portion is placed under the second PCB section and overlaps, when viewed in the thickness direction, the second coil portion of the first coil antenna formed in the second PCB section of the flexible PCB while not overlapping, when viewed in the thickness direction, the first coil portion of the first coil antenna formed in the first PCB section placed across the through hole, and
the second magnetic sheet portion further overlaps, when viewed in the thickness direction, a second coil portion of the second coil antenna formed in the second PCB section while not overlapping, when viewed in the thickness direction, a first coil portion of the second coil antenna formed in the first PCB section that is placed across the through hole.
2. The smartphone antenna module of claim 1 , wherein the first magnetic sheet portion further overlaps the first coil portion of the second coil antenna that are formed in the first PCB section.
3. The smartphone antenna module of claim 2 , wherein the first magnetic sheet portion extends in a direction away from the second magnetic sheet portion beyond the first coil portion of the second coil antenna.
4. The smartphone antenna module of claim 1 , wherein the first magnetic sheet portion extends in a direction away from the second magnetic sheet portion beyond an edge of the flexible PCB.
5. The smartphone antenna module of claim 1 , wherein the first coil antenna comprises a third portion that does not overlap the magnetic sheet at all.
6. The smartphone antenna module of claim 5 , wherein the first coil antenna comprises a fourth portion that does not overlap the magnetic sheet at all, wherein the first, third, second and fourth portions of the first coil antenna are arranged in order surrounding the through hole.
7. The smartphone antenna module of claim 1 , wherein the second coil antenna comprises a third portion and fourth portion that do not overlap the magnetic sheet at all, wherein the first, third, second and fourth portions of the second coil antenna are arranged in order surrounding the through hole.
8. The smartphone antenna module of claim 1 , wherein the first magnetic sheet portion further overlaps the first coil portion of the second coil antenna that are formed in the first PCB section.
9. The smartphone antenna module of claim 1 , wherein the first magnetic sheet portion has a first width for passing through the through hole without bending thereof whereas the second magnetic sheet portion has a second width for not passing through the through hole without bending thereof.
10. The smartphone antenna module of claim 1 , wherein the through hole has a maximum linear length of an opening thereof, wherein the first magnetic sheet portion has a first width smaller than the maximum linear length whereas the second magnetic sheet portion has a second width larger than the maximum linear length.
11. The smartphone antenna module of claim 1 , wherein the through hole has a maximum linear length of an opening thereof, wherein the first magnetic sheet portion has a first width larger than the maximum linear length whereas the second magnetic sheet portion has a second width larger than the maximum linear length.
12. The smartphone antenna module of claim 1 , wherein the through hole has a maximum linear length of an opening thereof, wherein the first magnetic sheet portion has a first width smaller than the maximum linear length whereas the second magnetic sheet portion has a second width smaller than the maximum linear length.
13. The smartphone antenna module of claim 1 , wherein the first coil antenna comprises a first inner terminal and a first outer terminal, wherein the flexible PCB further comprises a PCB connector for electrically connecting the first coil antenna to a first counterpart connector of a smartphone, wherein the PCB connector is electrically connected to the first inner terminal and the first outer terminal.
14. The smartphone antenna module of claim 13 , wherein the flexible PCB further comprises a connection line interconnecting the first inner terminal and the PCB connector, wherein the connection line crosses over the first coil antenna and the second coil antenna.
15. The smartphone antenna module of claim 13 , wherein the second coil antenna comprises a second inner terminal and a second outer terminal, wherein the PCB connector is also for electrically connecting the second coil antenna to a second counterpart connector of the smartphone, wherein the PCB connector is also electrically connected to the second inner terminal and the second outer terminal.
16. A smartphone comprising:
a display module comprising a display surface;
the smartphone antenna module of claim 1 ; and
a rear wall facing away from the display surface and made of a non-magnetic material,
wherein the magnetic sheet is arranged generally parallel to the rear wall.
17. The smartphone of claim 16 , wherein at least part of the first magnetic sheet portion is interposed between the rear wall and the first PCB section whereas at least part of the second PCB section is interposed between the rear wall and the second magnetic sheet portion.
18. The smartphone of claim 16 , wherein the first coil antenna is connected to a first smartphone circuit for magnetic secure transmission (MST) using a frequency range of 85-100 KHz, wherein the second coil antenna is connected to a second smartphone circuit for near field communication (NFC) using 13.56 MHz.
19. A smartphone antenna module:
a magnetic sheet comprising a first magnetic sheet portion, a second magnetic sheet portion and a third magnetic sheet portion interposed between the first and second magnetic sheet portions,
a flexible PCB in form of a sheet having a thickness, the flexible PCB comprising a first coil antenna, a second coil antenna and a third coil antenna; and
a through hole formed through the thickness of the sheet of the flexible PCB such that the flexible PCB comprises a first PCB section, and a second PCB section located on an opposite side of the first PCB section across the through hole,
wherein, when viewed in a thickness direction of the flexible PCB, the first coil antenna comprises two or more coiled turns turning around the through hole, and the second coil antenna comprises two or more coiled turns turning around the first coil antenna, the third coil antenna and the through hole,
wherein no electrical connection is formed between the first coil antenna and the second coil antenna within the flexible PCB, no electrical connection is formed between the third coil and the first coil antenna within the flexible PCB, and no electrical connection is formed between the third coil and the second coil antenna within the flexible PCB,
wherein the flexible PCB and the magnetic sheet are integrated in a single, flexible body, in which the flexible PCB and the magnetic sheet are arranged relative to each other such that:
at least part of the third magnetic sheet portion passes the through hole,
the first magnetic sheet portion is placed over the first PCB section and overlaps, when viewed in the thickness direction, a first coil portion of the first coil antenna formed in the first PCB section of the flexible PCB while not overlapping, when viewed in the thickness direction, a second coil portion of the first coil antenna formed in the second PCB section that is placed across the through hole,
the second magnetic sheet portion is placed under the second PCB section and overlaps, when viewed in the thickness direction, the second coil portion of the first coil antenna formed in the second PCB section of the flexible PCB while not overlapping, when viewed in the thickness direction, the first coil portion of the first coil antenna formed in the first PCB section that is placed across the through hole, and
the second magnetic sheet portion further overlaps, when viewed in the thickness direction, a second coil portion of the second coil antenna formed in the second PCB section while not overlapping, when viewed in the thickness direction, a first coil portion of the second coil antenna formed in the first PCB section that is placed across the through hole.
20. The smartphone antenna module of claim 19 , wherein, when viewed in a thickness direction of the flexible PCB, the third coil antenna comprises more than one coiled turns encircling around the first coil antenna and the through hole.
21. A smartphone comprising:
a display module comprising a display surface;
the smartphone antenna module of claim 19 ; and
a rear wall facing away from the display surface and made of a non-magnetic material, wherein the magnetic sheet is arranged generally parallel to the rear wall.
22. The smartphone of claim 21 , wherein the first coil antenna is connected to a first smartphone circuit and configured for magnetic secure transmission (MST) using a frequency range of 85-100 KHz, wherein the second coil antenna is connected to a second smartphone circuit and configured for near field communication (NFC) using 13.56 MHz, wherein the third coil antenna is connected to a third smartphone circuit and configured for wireless charging the smartphone.