NFC device and implementation method thereof
By adopting dual-loop antenna arrangement and phase control methods in NFC devices, the problem of antenna coverage in large areas and uneven magnetic fields in wireless charging applications is solved, and communication performance and charging efficiency are improved.
Patent Information
- Application Number
- CN202411777593.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-01-02
- Filing Date
- 2024-12-05
- Publication Date
- 2025-07-04
AI Technical Summary
The antenna of the NFC device used in wireless charging applications is difficult to cover larger areas, resulting in uneven magnetic fields and affecting communication performance.
A dual loop antenna arrangement is adopted, including single-ended NFC antennas of the external and internal loops, and are fed in phase and out-of-phase through different transmitters, periodically switching the operating state to achieve magnetic field uniformity.
Through dual-loop antenna arrangement and phase control, a more uniform magnetic field distribution of the NFC device is achieved, and communication capability and wireless charging efficiency are improved.
Smart Images
Figure CN120263230A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a Near Field Communication (NFC) device. In addition, the present disclosure relates to a corresponding method of implementing an NFC device. Background Art
[0002] Compared with NFC devices for typical NFC applications such as contactless transactions, NFC devices for wireless charging applications face different challenges. More specifically, compared with the antennas of NFC devices for typical NFC applications, the antennas of NFC devices for wireless charging applications should cover a larger area. In fact, it may be difficult to achieve these antennas covering a larger area. Summary of the Invention
[0003] According to a first aspect of the present disclosure, there is provided a Near Field Communication (NFC) device, comprising: an antenna arrangement including a first NFC antenna and a second NFC antenna, wherein the first NFC antenna forms a first loop of the antenna arrangement and wherein the second NFC antenna forms a second loop of the antenna arrangement; a first transmitter operatively coupled to the first NFC antenna, wherein the first transmitter is configured to feed the first NFC antenna; a second transmitter operatively coupled to the second NFC antenna, wherein the second transmitter is configured to feed the second NFC antenna.
[0004] In one or more embodiments, the first loop is an outer loop of the antenna arrangement, and the second loop is an inner loop of the antenna arrangement.
[0005] In one or more embodiments, the first NFC antenna is physically separated from the second NFC antenna.
[0006] In one or more embodiments, the first NFC antenna and the second NFC antenna are single-ended antennas.
[0007] In one or more embodiments, the NFC device is configured to operate in a first operating state and a second operating state, wherein: in the first operating state, the first transmitter feeds the first NFC antenna with a first signal, and the second transmitter feeds the second NFC antenna with a second signal, wherein the phase of the first signal is substantially the same as the phase of the second signal; in the second operating state, the first transmitter feeds the first NFC antenna with a third signal, and the second transmitter feeds the second NFC antenna with a fourth signal, wherein the phase of the third signal is substantially different from the phase of the fourth signal.
[0008] In one or more embodiments, the difference between the phase of the third signal and the phase of the fourth signal is 180 degrees or approximately 180 degrees.
[0009] In one or more embodiments, the NFC device is configured to periodically switch between a first operating state and a second operating state.
[0010] In one or more embodiments, a charging device includes the NFC device according to any of the preceding technical solutions.
[0011] In one or more embodiments, the charging device is a Qi-based charging device.
[0012] According to a second aspect of the present disclosure, a method of implementing a Near Field Communication (NFC) device is contemplated, which includes: providing an antenna arrangement for the NFC device, wherein the antenna arrangement includes a first NFC antenna and a second NFC antenna, wherein the first NFC antenna forms a first loop of the antenna arrangement and wherein the second NFC antenna forms a second loop of the antenna arrangement; providing a first transmitter for the NFC device operatively coupled to the first NFC antenna, wherein the first transmitter is configured to feed the first NFC antenna; providing a second transmitter for the NFC device operatively coupled to the second NFC antenna, wherein the second transmitter is configured to feed the second NFC antenna.
[0013] In one or more embodiments, the first loop is an outer loop of the antenna arrangement, and the second loop is an inner loop of the antenna arrangement.
[0014] In one or more embodiments, the first NFC antenna is physically separated from the second NFC antenna.
[0015] In one or more embodiments, the first NFC antenna and the second NFC antenna are single-ended antennas.
[0016] In one or more embodiments, the method further includes configuring the NFC device to operate in a first operating state and a second operating state, wherein: in the first operating state, the first transmitter feeds the first NFC antenna with a first signal, and the second transmitter feeds the second NFC antenna with a second signal, wherein the phase of the first signal is substantially the same as the phase of the second signal; in the second operating state, the first transmitter feeds the first NFC antenna with a third signal, and the second transmitter feeds the second NFC antenna with a fourth signal, wherein the phase of the third signal is substantially different from the phase of the fourth signal.
[0017] In one or more embodiments, the difference between the phase of the third signal and the phase of the fourth signal is 180 degrees or approximately 180 degrees. Description of the Drawings
[0018] Embodiments will be described in detail with reference to the accompanying drawings.
[0019] Figure 1Shows an example of an NFC device.
[0020] Figure 2 Shows antenna performance.
[0021] Figure 3 Shows magnetic field measurement.
[0022] Figure 4 Shows an illustrative embodiment of an NFC device.
[0023] Figure 5 Shows an illustrative embodiment of a method of implementing an NFC device.
[0024] Figure 6A Shows an illustrative embodiment of an NFC device operating in a first operating state.
[0025] Figure 6B Shows an illustrative embodiment of an NFC device operating in a second operating state.
[0026] Figure 7A Shows the antenna arrangement performance in the first operating state.
[0027] Figure 7B Shows the antenna arrangement performance in the second operating state.
[0028] Figure 8A Shows the magnetic field measurement in the first operating state.
[0029] Figure 8B Shows the magnetic field measurement in the second operating state.
[0030] Figure 9 Shows an exemplary implementation of an NFC device.
[0031] Figure 10 Shows an actual implementation of an NFC device. Detailed Description
[0032] Figure 1An example of an NFC device 100 is shown. The NFC device includes an NFC antenna 102, a first transmitter 104 operatively coupled to one end of the NFC antenna 102, and a second transmitter 106 operatively coupled to the other end of the NFC antenna 102. As mentioned above, compared with NFC devices for typical NFC applications, NFC devices for wireless charging applications face different challenges. More specifically, compared with the antennas of NFC devices for typical NFC applications, the antennas of NFC devices for wireless charging applications should cover a larger area. In fact, it may be difficult to make these antennas cover a larger area. For example, compared with typical NFC reader-oriented applications, the NFC antenna for a Qi-based charger design with a so-called NFC card protection function should cover a larger area. However, the relatively large size of the antenna may result in a weaker magnetic field at its center. Therefore, an internal loop is often added to the antenna. In Figure 1 the example shown, the NFC antenna 102 includes an internal loop and an external loop connected to each other, thereby forming a single antenna that covers a larger area compared with an antenna without an internal loop. By providing the internal loop for the NFC antenna 102, the magnetic field flowing through the center of the NFC antenna 102 can be effectively increased. However, Figure 1 the antenna design shown in may be affected by the weakening of the magnetic field between the two loops. This is caused by the orientation of the currents flowing through the two loops, which may result in destructive interference of the magnetic fields between the two loops. Therefore, the magnetic field of the NFC antenna 102 may become uneven as a whole, which may lead to poor performance of the NFC device 100.
[0033] Figure 2 and 3 show Figure 1 the performance 200 of the NFC antenna shown in, respectively, magnetic field measurements 300 performed on a specific area covered by this antenna, which indicate the performance. It should be noted that the magnetic field measurements in the measurement area 308 are expressed in volts (V). An NFC antenna with a large pore size may suffer from a weak magnetic field flowing through its center. Therefore, it may be challenging to detect a phone or tag with a small-sized NFC antenna placed at this center. To improve the detection ability, one or more internal loops can be placed close to the center of the antenna, as Figure 1 shown in. Using the Biot-Savart law, the magnetic field of this structure can be analyzed. The currents of the two loops have the same direction, which results in constructive interference at the center of the antenna. However, the magnetic field between the loops may also suffer from destructive interference, thus resulting in a weak field (i.e., a blind spot) between the two loops. This may in turn reduce the ability to communicate with a phone or tag at the edge of the antenna.
[0034] Now discuss the NFC device and the corresponding method of implementing the NFC device, which specifically promotes an increase in the performance of the NFC device by generating a more uniform magnetic field.
[0035] Figure 4 An illustrative embodiment of an NFC device 400 is shown. The NFC device 400 includes an antenna arrangement, which in turn includes a first NFC antenna 402 and a second NFC antenna 404. The first NFC antenna 402 forms a first loop of the antenna arrangement. In addition, the second NFC antenna 404 forms a second loop of the antenna arrangement. Additionally, the NFC device 400 includes a first transmitter 406 operatively coupled to the first NFC antenna 402, wherein the first transmitter 406 is configured to feed the first NFC antenna 402. Further, the NFC device 400 includes a second transmitter 410 operatively coupled to the second NFC antenna 404, wherein the second transmitter 410 is configured to feed the second NFC antenna 404. By providing the NFC device 400 with an antenna arrangement having two separate loops formed by the first NFC antenna 402 and the second NFC antenna 404, and by feeding the separate loops with different transmitters 406, 410, the NFC device 400 can generate a more uniform magnetic field. In a practical implementation, the first transmitter 406 is operatively coupled to one end of the first NFC antenna 402, and the other end of the NFC antenna 402 is coupled to ground 408. In addition, in a practical implementation, the second transmitter 410 is operatively coupled to one end of the second NFC antenna 404, and the other end of the NFC antenna 404 is coupled to ground 412.
[0036] In one or more embodiments, the first loop is an outer loop of the antenna arrangement, and the second loop is an inner loop of the antenna arrangement. In this way, the NFC device is promoted to generate a more uniform magnetic field. In one or more embodiments, the first NFC antenna is physically separated from the second NFC antenna. In this way, the NFC device is further promoted to generate a more uniform magnetic field. In a practical implementation, the first NFC antenna and the second NFC antenna are single-ended antennas.
[0037] In one or more embodiments, the NFC device is configured to operate in a first operating state and a second operating state, wherein: in the first operating state, a first transmitter feeds a first NFC antenna with a first signal, and a second transmitter feeds a second NFC antenna with a second signal, wherein the phase of the first signal is substantially the same as the phase of the second signal; in the second operating state, the first transmitter feeds the first NFC antenna with a third signal, and the second transmitter feeds the second NFC antenna with a fourth signal, wherein the phase of the third signal is substantially different from the phase of the fourth signal. In this way, further promoting the NFC device to generate a more uniform magnetic field. Specifically, by alternating between the first operating state and the second operating state, a more uniform magnetic field can be obtained. In a practical implementation, the difference between the phase of the third signal and the phase of the fourth signal is 180 degrees or approximately 180 degrees. In addition, in a practical implementation, the NFC device is configured to periodically switch between the first operating state and the second operating state. The currently disclosed NFC device can be advantageously used in charging devices, such as Qi-based charging devices.
[0038] Figure 5 Illustrative embodiments of a method 500 for implementing an NFC device are shown. Method 500 includes the following steps. At 502, an antenna arrangement is provided for the NFC device, wherein the antenna arrangement includes a first NFC antenna and a second NFC antenna, wherein the first NFC antenna forms a first loop of the antenna arrangement and wherein the second NFC antenna forms a second loop of the antenna arrangement. At 504, a first transmitter operatively coupled to the first NFC antenna is provided for the NFC device, wherein the first transmitter is configured to feed the first NFC antenna. In addition, at 506, a second transmitter operatively coupled to the second NFC antenna is provided for the NFC device, wherein the second transmitter is configured to feed the second NFC antenna. As mentioned above, by providing the NFC device with an antenna arrangement having two separate loops formed by the first NFC antenna and the second NFC antenna, and feeding the separate loops with different transmitters, the NFC device can generate a more uniform magnetic field.
[0039] Figure 6A and 6BIllustrative embodiments of an NFC device operating in a first operating state 600 and a second state 614 are shown. The NFC device includes two separate antenna loops fed by two separate transmitters. In addition, each antenna is connected to a single-ended source and is thus not differential. By changing the phase difference between the two antennas, for example, changing between in-phase (0° phase difference) and out-of-phase (180° phase difference), two different operating states can be achieved. When the two antennas are fed in-phase, the magnetic fields generated by the two antennas result in constructive interference at the center. When the two antennas are fed out-of-phase, the magnetic fields generated by the two antennas result in constructive interference between the two loops (i.e., at the edges of the antenna arrangement). By alternating between these two operating states (e.g., by periodically switching between the states), a uniform magnetic field can be achieved throughout the entire area covered by the antenna arrangement.
[0040] Figure 7A and 7B The performance 700 of the antenna arrangement in a first operating state 700 and a second operating state 702 is shown respectively. Specifically, the performance of an antenna arrangement according to the present disclosure having two separate antenna loops fed by two separate transmitters is shown. In the first operating state, the center of the antenna arrangement is covered, while in the second operating state, the edges of the antenna arrangement are covered (i.e., the area between the two loops). As mentioned above, by alternating between the two operating states, a uniform magnetic field can be achieved throughout the entire area covered by the antenna arrangement.
[0041] Figure 8A and 8B Magnetic field measurements in a first operating state 800 and a second operating state 812 are shown respectively. Specifically, the magnetic field measurements of an antenna arrangement according to the present disclosure having two separate antenna loops fed by two separate transmitters are shown. It should be noted that the magnetic field measurements in the measurement area 810 are expressed in volts (V). By alternating between the two operating states, the magnetic field throughout the entire area covered by the antenna arrangement can become more homogeneous.
[0042] Figure 9 An exemplary implementation of an NFC device 900 is shown. Specifically, a typical implementation of an NFC device for wireless charging applications is shown. The NFC device 900 includes an NFC reader integrated circuit (IC) 902, which is operatively coupled to an NFC antenna 906 through a matching circuit 904. As explained with reference to Figure 1 As explained, the NFC antenna 906 includes an internal loop and an external loop connected to each other, thereby forming a single antenna that covers a larger area compared to an antenna without an internal loop. Specifically, the NFC antenna 906 is a differential antenna, and more specifically, an antenna fed differentially by two separate transmitters. As mentioned above with reference toFigure 1 As mentioned, such a design may be affected by the weakening of the magnetic field between the two loops. This is caused by the orientation of the currents flowing through the two loops, which may result in destructive interference of the magnetic fields between the two loops. As a result, the magnetic field of the NFC antenna 906 may become non-uniform overall, which may lead to poor performance of the NFC device 900.
[0043] Figure 10 An actual implementation of the NFC device 1000 is shown. Specifically, a possible implementation of the NFC device according to the present disclosure is shown. The NFC device 1000 includes an NFC reader IC 1002, which is operatively coupled to separate NFC antennas 1006, 1008 through a matching circuit 1004. More specifically, the NFC antennas 1006, 1008 form separate loops of the antenna arrangement included in the NFC device 1000. In this case, two separate transmitters are used to feed the two single-ended NFC antennas 1006, 1008. The two transmitters can be controlled separately, which enables precise control of the phase difference between them. Therefore, in-phase and out-of-phase operating states can be easily achieved using this implementation.
[0044] It should be noted that the above embodiments have been described with reference to different subject matters. Specifically, some embodiments may have been described with reference to method-type claims, while other embodiments may have been described with reference to device-type claims. However, those skilled in the art will understand from the above that, unless otherwise stated, any combination of features related to different subject matters, in particular the combination of features of method-type claims and features of device-type claims, in addition to any combination of features belonging to one type of subject matter, is also considered to be disclosed together with this document.
[0045] In addition, it should be noted that the drawings are schematic. In different figures, like or identical elements are denoted by the same reference numerals. In addition, it should be noted that, in order to provide a concise description of the illustrative embodiments, implementation details that are customary for those skilled in the art may not have been described. It should be understood that, in the development of any such implementation, as in any engineering or design project, numerous implementation-specific decisions must be made in order to achieve the specific goals of the developer, such as compliance with system-related and business-related constraints, which may vary between different implementations. In addition, it should be understood that such development work may be complex and time-consuming, but is merely routine for those skilled in the art in design, manufacturing, and production.
[0046] Finally, it should be noted that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The measures recited in the claims can be implemented by means of hardware including several distinct elements and / or by means of a suitably programmed processor. In a device claim reciting several means, several of these means can be implemented by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
[0047] List of reference signs
[0048] 100 NFC device
[0049] 102 NFC antenna
[0050] 104 First transmitter
[0051] 106 Second transmitter
[0052] 200 Antenna performance
[0053] 300 Magnetic field measurement
[0054] 302 NFC antenna
[0055] 304 First transmitter
[0056] 306 Second transmitter
[0057] 308 Measurement area
[0058] 400 NFC device
[0059] 402 First NFC antenna
[0060] 404 Second NFC antenna
[0061] 406 First transmitter
[0062] 408 Ground
[0063] 410 Second transmitter
[0064] 412 Ground
[0065] 500 Method of implementing an NFC device
[0066] 502 provides an antenna arrangement for an NFC device, wherein the antenna arrangement includes a first NFC antenna and a second NFC antenna, wherein the first NFC antenna forms a first loop of the antenna arrangement and wherein the second NFC antenna forms a second loop of the antenna arrangement
[0067] 504 provides a first transmitter operatively coupled to the first NFC antenna, wherein the first transmitter is configured to feed the first NFC antenna
[0068] 506 provides a second transmitter operatively coupled to the second NFC antenna, wherein the second transmitter is configured to feed the second NFC antenna
[0069] 600 An NFC device operating in a first operating state
[0070] 602 First NFC antenna
[0071] 604 Second NFC antenna
[0072] 606 First transmitter
[0073] 608 Ground
[0074] 610 Second transmitter
[0075] 612 Ground
[0076] 614 An NFC device operating in a second operating state
[0077] 700 Antenna arrangement performance in the first operating state
[0078] 702 Antenna arrangement performance in the second operating state
[0079] 800 Magnetic field measurement in the first operating state
[0080] 802 First NFC antenna
[0081] 804 Second NFC antenna
[0082] 806 First transmitter
[0083] 808 Ground
[0084] 810 Measurement area
[0085] 812 Magnetic field measurement in the second operating state
[0086] 900 Exemplary embodiment of an NFC device
[0087] 902 NFC reader IC
[0088] 904 Matching Circuit
[0089] 906 NFC Antenna
[0090] 1000 Practical Implementation of NFC Device
[0091] 1002 NFC Reader IC
[0092] 1004 Matching Circuit
[0093] 1006 NFC Antenna
[0094] 1008 NFC Antenna.
Claims
1. A Near Field Communication (NFC) device, characterized in that, Comprising: An antenna arrangement including a first NFC antenna and a second NFC antenna, wherein the first NFC antenna forms a first loop of the antenna arrangement and wherein the second NFC antenna forms a second loop of the antenna arrangement; A first transmitter operatively coupled to the first NFC antenna, wherein the first transmitter is configured to feed the first NFC antenna; A second transmitter operatively coupled to the second NFC antenna, wherein the second transmitter is configured to feed the second NFC antenna.
2. The NFC device according to claim 1, wherein The first loop is an outer loop of the antenna arrangement, and wherein the second loop is an inner loop of the antenna arrangement.
3. The NFC device according to any one of the preceding claims, characterized in that, The first NFC antenna is physically separated from the second NFC antenna.
4. The NFC device according to any one of the preceding claims, characterized in that, The first NFC antenna and the second NFC antenna are single-ended antennas.
5. The NFC device according to any one of the preceding claims, characterized in that, The NFC device is configured to operate in a first operating state and a second operating state, wherein: In the first operating state, the first transmitter feeds the first NFC antenna with a first signal and the second transmitter feeds the second NFC antenna with a second signal, wherein the phase of the first signal is substantially the same as the phase of the second signal; In the second operating state, the first transmitter feeds the first NFC antenna with a third signal and the second transmitter feeds the second NFC antenna with a fourth signal, wherein the phase of the third signal is substantially different from the phase of the fourth signal.
6. The NFC device according to claim 5, characterized in that, The difference between the phase of the third signal and the phase of the fourth signal is 180 degrees or approximately 180 degrees.
7. The NFC device according to claim 5 or 6, characterized in that, The NFC device is configured to periodically switch between the first operating state and the second operating state.
8. A charging device, characterized in that, Comprising the NFC device according to any one of the preceding claims.
9. The charging device according to claim 8, characterized in that, The charging device is a Qi-based charging device.
10. A method for implementing a Near Field Communication (NFC) device, characterized in that, The method includes: Providing an antenna arrangement for the NFC device, wherein the antenna arrangement includes a first NFC antenna and a second NFC antenna, wherein the first NFC antenna forms a first loop of the antenna arrangement and wherein the second NFC antenna forms a second loop of the antenna arrangement; Providing a first transmitter for the NFC device operatively coupled to the first NFC antenna, wherein the first transmitter is configured to feed the first NFC antenna; Providing a second transmitter for the NFC device operatively coupled to the second NFC antenna, wherein the second transmitter is configured to feed the second NFC antenna.