Portable device and near field communication chip
In one embodiment, the antenna arrangement includes a primary antenna having a conductive sidewall; and a loop antenna disposed in and physically separated from the primary antenna. The loop antenna includes a first conductive loop and a capacitor electrically connected between ends of the first conductive loop.
1. A portable device, comprising:
a NFC chip;
a case configured to generate a first magnetic field based on an electrical signal from the NFC chip;
a matching circuit configured to match impedances of the NFC chip and the case; and
a loop antenna physically separated from the NFC chip and the case, and the loop antenna configured to magnetically couple to the case such that the loop antenna forms a second magnetic field in response to the first magnetic field,
wherein the matching circuit includes a transformer,
a loop coil connected to the NFC chip in parallel with the case, the loop coil surrounding the loop antenna.
2. The portable device of claim 1 , further comprising:
an inductor connected between the case and the matching circuit, the inductor configured to reduce an undesired signal component.
3. The portable device of claim 1 , further comprising:
a filter connected between the case and the matching circuit, the filter configured to reduce an undesired signal component.
4. The portable device of claim 1 , further comprising:
a wireless charging circuit electrically connected to the loop antenna, the wireless charging circuit configured to supply power based on the second magnetic field.
5. The portable device of claim 1 , further comprising:
a magnetic secure transmission circuit electrically connected to the loop antenna, the magnetic secure transmission circuit configured to send transmissions via the loop antenna.
6. The portable device of claim 1 , wherein the NFC chip and the loop antenna are in the case.
7. A portable device, comprising:
a case including a conductive material, the case having at least a first terminal;
a near field communication (NFC) device electrically connected to the first terminal of the case, the NFC device configured to provide an electrical signal to the case such that the case radiates a first magnetic field based on the electrical signal;
a loop antenna inside the case, the loop antenna configured to magnetically couple to the case such that the loop antenna forms a second magnetic field in response to the first magnetic field; and
a loop coil connected to the NFC chip in parallel with the case, the loop coil surrounding the loop antenna,
wherein the loop antenna is physically separate from the case and the NFC device.
8. The portable device of claim 7 , wherein the loop antenna includes a conductive loop and a capacitor electrically connected to ends of the conductive loop.
9. The portable device of claim 7 , wherein the loop antenna has one of an elliptical shape and a polygonal shape.
10. The portable device of claim 7 , further comprising:
a display panel connected at a top of the case;
a main board inside the case; and
a processor on the main board, the processor configured to control an operation of the portable device; wherein
the case includes a sidewall portion including the conductive material and a bottom portion including a nonconductive material,
the loop antenna is between the main board and the bottom portion of the case, and
the loop antenna is configured to radiate the second magnetic field in a direction passing through the bottom portion of the case.
11. The portable device of claim 10 , further comprising:
a magnetic sheet between the main board and the loop antenna.
12. The portable device of claim 7 , further comprising:
a display panel connected at a top of the case;
a main board inside the case; and
a processor on the main board, the processor configured to control an operation of the portable device; wherein
the case includes a sidewall portion including the conductive material and a bottom portion including a nonconductive material, and
the loop antenna is between the display panel and the main board, and another second loop antenna is between the main board and the bottom portion of the case,
the loop antenna is configured to radiate the second magnetic field in a first direction passing through the display panel, and
the another second loop antenna is configured to radiate a third magnetic field in a second direction passing through the bottom portion of the case.
13. The portable device of claim 7 , further comprising:
first and second bands attached to the case, the first and second bands being configured to removably attach to one another.
14. The portable device of claim 7 , further comprising:
a display panel at a top of the case.