ANTENNA DEVICE AND ASSOCIATED APPARATUS

Abstract

An antenna device for use with a wireless power charging operation and a near-field communication (NFC) operation is formed sets of electrically conductive loops. The sets include a first set of loops configured to form a NFC antenna and a second set of loops. The first and second sets of loops together are configured to form a wireless power charging antenna.

Claims

1. An antenna device for wireless power charging and near-field communication (NFC), comprising: a first pair of nodes configured for connection to an NFC driver circuit; a second pair of nodes configured for connection to a wireless power charging driver circuit; a first electrically conductive loop having a first end connected to a first node of said first pair of nodes and a second end connected to a second node of said first pair of nodes; a first electrically conductive spiral having a first end connected to a first node of said second pair of nodes and a second end connected to the first node of said first pair of nodes; and a second electrically conductive spiral having a first end connected to a second node of said second pair of nodes and a second end connected to the second node of said first pair of nodes; wherein the first electrically conductive loop forms an antenna for near-field communication; and wherein the first electrically conductive spiral, second electrically conductive spiral and first electrically conductive loop form an antenna for wireless power charging.

2. The antenna device according to claim 1, wherein said antenna for near-field communication and said antenna for wireless power charging are configured for concurrent operation.

3. The antenna device according to claim 1, wherein the first electrically conductive loop surrounds the first electrically conductive spiral and the second electrically conductive spiral.

4. The antenna device according to claim 3, wherein windings of the first electrically conductive spiral are interleaved with windings of the second electrically conductive spiral.

5. The antenna device according to claim 1, wherein the first electrically conductive loop comprises a first half-loop connected at a node in series with a second half-loop.

6. The antenna device according to claim 5, wherein said node is a virtual ground.

7. The antenna device according to claim 1, wherein winding of the first electrically conductive loop has a rectangular shape.

8. The antenna device according to claim 1, wherein windings of the first electrically conductive spiral, second electrically conductive spiral and first electrically conductive loop are symmetric about a line of symmetry which passes between the first and second nodes of said first pair of nodes and between the first and second nodes of said second pair of nodes.

9. The antenna device according to claim 1, wherein the antenna for near-field communication is configured for operation at a first frequency, and wherein the antenna for wireless power charging is configured for operation at a second frequency different from the first frequency.

10. The antenna device according to claim 9, wherein the second frequency is lower than the first frequency.

11. The antenna device according to claim 10, wherein the first frequency is equal to 13.56 MHz and the second frequency is in a range of 80 KHz to 300 KHz.

12. The antenna device according to claim 1, further comprising a third electrically conductive spiral having a first end connected to the first node of said second pair of nodes and a second end connected to the second node of said second pair of nodes.

13. An antenna device for wireless power charging and near-field communication (NFC), comprising: a first node; a second node; a third node; a first electrically conductive spiral having a first end connected to the first node and a second end connected to the second node; and a second electrically conductive spiral having a first end connected to the second node and a second end connected to the third node; wherein the first and second nodes are configured for connection to an NFC driver circuit, with the first electrically conductive spiral forming an antenna for near-field communication; wherein the first and third nodes are configured for connection to a wireless power charging driver circuit, with the first electrically conductive spiral and second electrically conductive spiral forming an antenna for wireless power charging.

14. The antenna device according to claim 13, wherein windings of the first electrically conductive spiral and second electrically conductive spiral form an Archimedean spiral.

15. The antenna device according to claim 13, wherein the first node is a common ground node for the NFC driver circuit and the wireless power charging driver circuit.

16. The antenna device according to claim 13, wherein said antenna for near-field communication and said antenna for wireless power charging are configured for concurrent operation.

17. The antenna device according to claim 13, wherein the first electrically conductive spiral surrounds the second electrically conductive spiral.

18. The antenna device according to claim 13, wherein windings of the first electrically conductive spiral and the second electrically conductive spiral have generally circular shapes.

19. The antenna device according to claim 13, wherein the antenna for near-field communication is configured for operation at a first frequency, and wherein the antenna for wireless power charging is configured for operation at a second frequency different from the first frequency.

20. The antenna device according to claim 19, wherein the second frequency is lower than the first frequency.

21. The antenna device according to claim 20, wherein the first frequency is equal to 13.56 MHz and the second frequency is in a range of 80 KHz to 300 KHz.

22. The antenna device according to claim 13, further comprising a third electrically conductive spiral having a first end connected to the first node and a second end connected to the third node.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Other advantages and features of the invention will appear on examination of the detailed description of embodiments, in no way restrictive, and the appended drawings in which:

[0063] FIG. 1, previously described, illustrates an NFC antenna and a Qi antenna according to the prior art; and

[0064] FIG. 2 shows a mobile phone incorporating an example of an apparatus comprising an antenna device for wireless power charging and/or near-field communication;

[0065] FIGS. 3 and 4 illustrate a first embodiment of the antenna device for wireless power charging and/or near-field communication;

[0066] FIGS. 5 and 6 illustrate a second embodiment of the antenna device for wireless power charging and/or near-field communication;

[0067] FIG. 7 illustrates a third embodiment of the antenna device for wireless power charging and/or near-field communication; and

[0068] FIG. 8 illustrates a fourth embodiment of the antenna device for wireless power charging and/or near-field communication.

DETAILED DESCRIPTION

[0069] Reference is made to FIG. 2 which shows a mobile phone 8 incorporating an example of an apparatus 9 comprising an antenna device 10 for wireless power charging and/or near-field communication NFC connected to a wireless power charging driver circuit 11 and a NFC driver circuit 12.

[0070] Although the apparatus 9 is incorporated in a mobile phone, the apparatus can be incorporated in any mobile device operating wireless power charging and/or near-field communication NFC.

[0071] FIGS. 3 and 4 illustrate a first embodiment of the antenna device 10 for wireless power charging and/or near-field communication NFC.

[0072] The antenna device 10 comprises two sets of electrically conductive loops 13 and 14, a first set of loops 13 being configured to form a NFC antenna and the first 13 and second 14 sets of loops being configured together to form a wireless power charging antenna.

[0073] The second set of loops 14 is surrounded by the first set of loops 13. The two sets of loops are connected together.

[0074] The first and second sets of loops 13 and 14 form a rectangle.

[0075] The first 13 and second 14 sets of loops comprise at each end a connecting point 15, 16 and 17, 18, respectively.

[0076] The connecting points 17 and 18 of the second set of loops 14 are localized in the center of the second set of loops.

[0077] The connecting points 15 and 16 of the first set of loops 13 are connected with terminals of a NFC driver circuit 12 and the connecting points 17 and 18 are connected with terminals of a wireless power charging driver circuit 11.

[0078] The second set of loops 14 comprises a first part comprising three loops comprising half-loops 14a to 14f extending around the center of the antenna device 10 in a clockwise direction starting from the connecting point 17 to a connecting point 19, and a second part comprising half-loops 14g to 14l extending around the center of the antenna device 10 in a clockwise direction starting from a connecting point 20 at the free end of the half-loop 14g to the connecting point 17.

[0079] The connecting points 19 and 20 are connected to the connecting points 15 and 16.

[0080] The half-loop 14g crosses over the half-loop 14f at point 21, the half-loop 14h crosses under the half-loop 14e at point 22, the half-loop 14i crosses over the half-loop 14d at point 23, the half-loop 14j crosses under the half-loop 14c at point 24, the half-loop 14k crosses over the half-loop 14b at point 25 and the half-loop 14l crosses under the half-loop 14a at point 26.

[0081] The first set of loops 13 comprises two loops comprising four half-loops 13a, 13b, 13c and 13d extending around the second set of loops 14 in a clockwise direction starting from the connecting point 19 to the connecting point 20.

[0082] The half-loop 13c crosses under the half-loop 13a at point 27.

[0083] As illustrated on FIG. 4, the first set of loops 13 is connected between the first and second parts of the second set of loops 14.

[0084] The connecting points 15 and 16 of the first set of loops are connected to loops 14f and 14g of the second set of loops 14 so that the loops of both sets of loops are connected in series.

[0085] The connecting points 19 and 20 of both set of loops are disposed symmetrically in relation to a center axis A parallel to the larger dimension of the rectangle.

[0086] The half-loops 14a and 14l, 14b and 14k, 14c and 14j, 14d and 14i, 14e and 14h, 14f and 14g, 13a and 13d, 13b and 13c have the same length and are symmetrical with respect to the axis A.

[0087] During NFC and Qi operations, a current I flows in a current path from connecting point 17 to connecting point 18 via the half-loops 14a to 14f, 13a to 13d and 14g to 14l and a current I flows in a current path from connecting point 15 to connecting pint 16 via half-loops 13a to 13d.

[0088] The half-loops 14a to 14f, 13a and 13b generate a magnetic field which is countered by a magnetic field generated by the half-loops 13c, 13d and 14g to 14l.

[0089] A virtual ground GND is created between the half-loops 13b and 13c avoiding high voltage conditions.

[0090] The symmetrical topology of the antenna device creates a virtual ground avoiding high voltage conditions so that the NFC signal is not corrupted.

[0091] The NFC antenna is configured to communicate with a NFC circuit at a first frequency and the wireless power charging antenna is configured to communicate with a wireless power charging circuit at a second frequency.

[0092] The wireless power charging antenna can operate in a receiving or emitting mode.

[0093] The first frequency is equal to 13.56 MHz and the second frequency is in the range of 80 KHz to 300 KHz.

[0094] Due to symmetrical antenna device 10 topology and as the first and second frequencies are far enough apart from each other, the NFC antenna and the wireless power charging antenna are capable to operate concurrently.

[0095] The antenna device 10 can also operates as an NFC antenna or as a wireless power charging antenna.

[0096] For example, the first embodiment of the antenna device 10 is included in a square having a side equal to 53.5 mm and both antennas are made of a wire having a thickness of 2 mm.

[0097] FIGS. 5 and 6 illustrate a second embodiment of the antenna device 10 for wireless power charging and/or near-field communication NFC.

[0098] The antenna device 10 comprises two sets of electrically conductive loops 28 and 29. A first set of loops 28 is configured to form a NFC antenna and the first 28 and second 29 sets of loops being configured to form together a wireless power charging antenna.

[0099] The second set of loops 29 is surrounded by the first set of loops 28.

[0100] The first set of loops 28 comprises at each end a connecting point 30 and 31, and the second set of loops is connected in series with the first set of loops 28 at the connecting point 30.

[0101] The second set of loops 28 comprises a connecting point 32 at its free end.

[0102] The first and second sets of loops form an Archimedean spiral, the connecting point 32 being inside the Archimedean spiral.

[0103] The connecting point 32 inside the Archimedean spiral is connected with the wireless power charging driver circuit 11, the connecting point 30 of both set of loops is connected with a NFC driver circuit and the connecting point 31 outside the Archimedean spiral is connected with a common ground of the driver circuits 11 and 12.

[0104] The wireless power charging antenna and the NFC antenna are sharing the same ground connection connected at point 31.

[0105] The Archimedean spiral is acting as a voltage divider, the first part of the voltage divider being the first set of loops 28 and the second part of the voltage divider being the second set of loops 29.

[0106] Thus, the voltage difference at the output of the NFC antenna and the wireless power charging antenna is reduced so that the NFC antenna can operate in proximity of the wireless power charging antenna.

[0107] The NFC antenna is configured to communicate with a NFC circuit at the first frequency and the wireless power charging antenna is configured to communicate with a wireless power charging circuit at the second frequency.

[0108] The wireless power charging antenna can operate in a receiving or emitting mode.

[0109] Due to the same ground connection of both antennas and as the first and second frequencies are far enough apart from each other, the NFC antenna and the wireless power charging antenna are capable to operate concurrently.

[0110] The antenna device 10 can also operates as an NFC antenna or as a wireless power charging antenna.

[0111] For example, the second embodiment of the antenna device 10 is included in a square having a side equal to 53.5 mm and both antennas are made of a wire having a thickness of 2 mm.

[0112] The inductance value of the first set of loops 13, 28 is in the range 500 nH to 1.5 H with a resistance in the range 0.2 to 3 , and the number of loops is preferably in the range 1 to 6.

[0113] The inductance value of the second set of loops 14, 29 is in the range 6 H to 24 H with a resistance in the range 0.01 to 0.2 , and the number of loops is preferably in the range 12 to 24 according to the value of power to be transferred or received.

[0114] The first embodiment of the antenna device 10 illustrated on FIGS. 3 and 4 permits to transfer more power than the second embodiment of the antenna device illustrated on FIGS. 5 and 6.

[0115] In other embodiments, the mobile phone can comprise an antenna device 10 comprising at least one antenna device 10 according to the first and/or second embodiment illustrated on FIGS. 3 to 6, and at least one NFC antenna device and/or Qi antenna device illustrated on FIG. 1.

[0116] Embodiments of the antenna device 10 comprising the first and second sets of loops 13, 14, 28 and 29 and the Qi antenna device 3 illustrated on FIG. 1 are described in what follows.

[0117] A third embodiment of the antenna device 10 for wireless power charging and/or near-field communication NFC combining the first and second set of loops 28, 29 as illustrated on FIGS. 5 and 6 with the second antenna 3 configured for Qi non contact power transfer is illustrated on FIG. 7.

[0118] The first and second sets of loops 28 and 29 form the Archimedean spiral.

[0119] The antenna device 10 further comprises three terminals 33, 34 and 35.

[0120] The first terminal 33 is connected with the second terminal 7 of the second antenna 3, with the connecting point 31 outside the Archimedean spiral and with the common ground of the driver circuits 11 and 12.

[0121] The second terminal 34 is connected with the wireless power charging driver circuit 11, with the connecting point 32 inside the Archimedean spiral and with the first terminal 6 of the second antenna 3.

[0122] The third terminal 35 is connected with the NFC driver circuit 12.

[0123] FIG. 8 illustrates a fourth embodiment of the antenna device 10 for wireless power charging and/or near-field communication NFC.

[0124] The antenna device 10 comprises the second antenna 3 configured for Qi non contact power transfer and the first and second sets of loops 13 and 14 forming a rectangle.

[0125] The antenna device 10 further comprises two terminals 36 and 37.

[0126] The first terminal 36 is connected with the second terminal 7 of the second antenna 3, with the connecting point 18 of the second set of loops 14 and with the wireless power charging driver circuit 11.

[0127] The second terminal 37 is connected with the wireless power charging driver circuit 11, with the connecting point 17 of the second set of loops 14 and with the first terminal 6 of the second antenna 3.

[0128] The connecting points 15 and 16 of the first set of loops are connected with the NFC driver circuit 12.

[0129] In another embodiment, the antenna device 10 comprises the first antenna 2 and/or the second antenna 3 and at least the first and second sets of loops in a rectangular form or forming an Archimedean spiral.

[0130] Conventional antennas could be combined with at least one antenna device for wireless power charging and/or near-field communication NFC to interoperate with various mobile device antennas.

[0131] Multiple antennas could be used to establish the best NFC connection between a reader and the mobile device 8 due to different NFC antennas location in the mobile device 8.

[0132] Advantageously, the antenna device for wireless power charging and/or near-field communication NFC can be used on power transmitter and power receiver devices.