RFID and Qi device

Abstract

RFID and Qi Device This description relates to a device comprising a frequency demodulator and an amplitude demodulator, the device being configured to use, in a first mode, the two demodulators in parallel and to activate an RFID card mode or a Qi charger mode based on results provided by said demodulators. Figure for the abstract: Fig. 1

Description

Title of the invention: RFID and Qi device technical field

[0001] This description relates generally to electronic devices and more specifically to electronic devices incorporating RFID (radio frequency identification) technology. Prior art

[0002] Contactless technologies are very widespread and are widely used in transportation and access control applications. The trend is to group, as much as possible, functionalities (traditionally hosted by contactless cards or integrated circuit cards, ICs) onto a single device such as a mobile phone. Summary of the invention

[0003] There is a need to improve contactless access devices and more particularly access devices equipped with RFID technology.

[0004] One embodiment overcomes all or part of the disadvantages of known access devices.

[0005] One embodiment provides a device comprising a frequency demodulator and an amplitude demodulator, the device being configured to use, in a first mode, the two demodulators in parallel and to activate an RFID card mode or a Qi charger mode based on results provided by said demodulators.

[0006] One embodiment provides for a method implemented by a device comprising a frequency demodulator and an amplitude demodulator, in which the device uses, in a first mode, the two demodulators in parallel and, in a second mode, the two demodulators successively.

[0007] According to one embodiment, the two frequency and amplitude demodulators also include charge modulators / demodulators.

[0008] According to one embodiment, in a second mode, the two frequency and amplitude demodulators operate successively.

[0009] According to one embodiment, a load modulator of the device is used when the device communicates with an external Type A RFID device configured in reader mode.

[0010] According to one embodiment, said charge modulator is used when the device is charged by an external device and when it emulates an RFID card configured in type A.

[0011] According to one embodiment, an analog Qi head of the device is adapted to frequency modulate or amplitude modulate data when the device is in the second mode, the frequency modulated data being used to communicate with a Qi charging device and the amplitude modulated data being used to communicate with an RFID device configured in card mode.

[0012] According to one embodiment, the amplitude demodulator is used to demodulate a load modulation response from an external type A device configured in card mode.

[0013] According to one embodiment, the amplitude demodulator is used to demodulate a command received from an external device configured in reader mode.

[0014] According to one embodiment, the frequency demodulator is used to demodulate a response received from an external type B device configured in card mode.

[0015] According to one embodiment, the frequency demodulator is used to demodulate a digital ping or any subsequent data packet received from an external load device.

[0016] According to one embodiment, the frequency demodulator is used to demodulate a response received from an external load device.

[0017] According to one embodiment, when an external field is detected on an antenna, it is checked whether the field comes from an RFID device or a Qi device.

[0018] According to one embodiment, the verification is carried out by the emission of periodic interrogation frames in RFID mode and in Qi mode. Brief description of the drawings

[0019] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the accompanying figures, among which:

[0020] [Fig.1] represents, very schematically, an example of a communication system comprising a device incorporating Qi technology, to which, by way of example, the described embodiments apply;

[0021] [Fig.2] represents a chronogram illustrating a mode of operation of the device illustrated in [Fig.1];

[0022] [Fig.3] represents an organizational chart illustrating part of the chronogram illustrated in [Fig.2];

[0023] [Fig.4] represents an example of part of the chronogram illustrated in [Fig.2];

[0024] [Fig.5] represents, schematically and in block form, an embodiment of the communication circuit of the device illustrated in [Fig.1];

[0025] Fig. 6 represents a first example of the operation of the circuit illustrated in [Fig.5];

[0026] [Fig.7] represents another example of part of the chronogram illustrated in [Fig.2];

[0027] [Fig.8] represents a second example of the operation of the circuit illustrated in [Fig.5];

[0028] [Fig.9] represents another example of part of the chronogram illustrated in [Fig.2];

[0029] [Fig. 10] represents a third example of the operation of the circuit illustrated in [Fig. 5];

[0030] [Fig.1 1] represents a fourth example of the operation of the circuit illustrated in [Fig.5];

[0031] [Fig. 12] represents a fifth example of the operation of the circuit illustrated in [Fig. 5];

[0032] [Fig. 13] represents a sixth example of the operation of the circuit illustrated in [Fig. 5]; and

[0033] [Fig. 14] represents another example of part of the chronogram illustrated in [Fig. 2], Description of embodiments

[0034] The same elements have been designated by the same reference numerals in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties.

[0035] For the sake of clarity, only the steps and elements useful for understanding the described embodiments have been shown and are detailed. In particular, circuits that are defined by their functions are not structurally detailed.

[0036] Unless otherwise specified, when referring to two elements connected together, this means directly connected without intermediate elements other than conductors, and when referring to two elements connected (in English "coupled") together, this means that these two elements can be connected or linked through one or more other elements.

[0037] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "superior", "inferior", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures.

[0038] Unless otherwise specified, the expressions "approximately", "roughly", and "in the order of" mean within 10%, preferably within 5%.

[0039] In this description, we propose to take advantage of the fact that Qi technology (which corresponds to a standard developed by the Wireless Power Consortium for wireless power transmission) is widely used in new smartphone models. Qi technology is particularly interesting because it operates in a frequency band that includes low frequencies (LF) (100 kHz to 200 kHz). Therefore, this description aims to establish LF communications using RFID technology and some of the components of the circuit dedicated to Qi technology.

[0040] Fig. 1 represents, very schematically, an example of a communication system comprising a device incorporating Qi technology, to which, by way of example, the described embodiments apply.

[0041] The system 11 illustrated in [Fig.1] includes an electronic device 13 adapted to communicate with other electronic devices / appliances using Qi technology and RFID technology.

[0042] According to one embodiment, the device 13 is a mobile phone, for example a smartphone, or a tablet.

[0043] According to the embodiment illustrated in [Fig. 1], the device 13 is adapted to be charged by a Qi charging platform 15 (chargeable mode) or to charge another electronic device 17 equipped with Qi technology (charger mode). In other words, the device 13 is adapted, depending on its external environment, to switch from a charger mode to a chargeable mode. The device 13 can thus operate in charger mode and charge a device in its environment, or in chargeable mode and be charged by a charging device in its environment.

[0044] According to the embodiment illustrated in [Fig. 1], the device 13 is also adapted to communicate with an RFID device configured in card mode 19 and an RFID device configured in reader mode 21. In other words, the device 13 is adapted, depending on its external environment, to switch from reader mode to card mode. The device 13 can thus operate in reader mode and communicate with a device in card mode present in its environment, or in card mode and communicate with a device in reader mode present in its environment.

[0045] According to one application example, the embodiments apply to transport systems and access control, for example to building doors equipped with low frequency (LF) technology.

[0046] Figure 2 represents a timing diagram illustrating one operating mode of the device illustrated in [Fig.1].

[0047] When the device 13 illustrated in [Fig.1] is not in communication, it is in low power or standby mode in order to reduce energy consumption.

[0048] When the device 13 is in standby mode, it must always be able to detect the presence of an RFID reader, an RFID card, a chargeable device or a charging device.

[0049] The chronogram illustrated in [Fig.2] comprises two successive parts I and II, part I corresponding to an operation in which the device 13 is in standby mode and part II corresponding to an operation in which the device 13 is in normal mode, also called interrogation mode.

[0050] According to the embodiment illustrated in [Fig. 2], when the device 13 is in standby mode (Part I), it "probes" its environment with short, periodic emission pulses 23. Two pulses 23 are, for example, separated by a time interval 25. A pulse 23 corresponds to a short emission of a field by the device 13 to detect a possible card-configured device or a chargeable device present within its field. In the event of such detection, the device 13 then wakes up from standby mode and switches to normal mode (Part II). The detection process involves an analysis of the electrical quantities specific to these pulses 23, such as the amplitude or phase, these quantities varying if a card-configured device or a chargeable device is nearby.

[0051] During the intervals 25, the device 13 is in listening mode for devices in player mode or charging devices within range.

[0052] Figure 3 represents a flowchart illustrating part of the chronogram illustrated in Figure 2. More specifically, the flowchart corresponds to an example of the implementation of the listening mode.

[0053] In the event that the device 13 detects a field (block 61, Field detected), it activates (block 63, Go to active mode) by exiting sleep mode and responds to the reader or charger device according to the technology detected.

[0054] More specifically, the device 13 comprises two demodulators, one demodulator adapted to demodulate on-off keying (OOK) and one demodulator adapted to demodulate frequency shift keying (FSK). The device 13 is in normal mode when both demodulators are triggered simultaneously (block 65, Start OOK and FSK demodulators).

[0055] In order to respond to the reading or loading device, the device 13 detects the technology of the device within range, and more specifically the type of modulation on which it is based. Thus, the device 13 detects either on-off (OOK) modulation (block 67, OOK detected) or frequency-shift keying (FSK) modulation (block 73, FSK detected).

[0056] The response of device 13 is adapted to the type of modulation detected by the device.

[0057] If a type A is detected, based on the start of a frame, in addition to the modulation OK, device 13 responds by sending a response with load modulation according to the RFID standard (block 69, Type A detected based on Start of Frame: Send answer with Load Modulation according to RFID standard).

[0058] If a type B is detected, based on the start of a frame, in addition to OOK modulation, the device 13 responds by activating the field after an extinction of detection and responding in accordance with the RFID standard using FSK modulation (block 71, Type B detected based on Start of Frame: Turn on field after field off detection and answer according to RFID standard using FSK).

[0059] If an FSK modulation is detected, the device 13 responds by sending a response with the load modulation in accordance with the Qi standard (block 75, Qi charger: Answer with Load Modulation according to Qi standard).

[0060] According to the embodiment illustrated in [Fig. 2], in normal mode (part II), the device 13 transmits periodic polling frames 27, during which it generates a field intended for devices in card mode or chargeable devices within range. The periodic polling frame 27 can be repeated several times before returning to standby mode if no device in card mode has responded. The purpose of these periodic frames (polling loop) is to determine the type of external device based on the type of transmitted frames to which the external device responds.

[0061] A frame 27 is, for example, made up of a succession of two emission pulses 29 and 31, pulse 29 (LF RFID REQUEST) being configured to generate a field understandable by devices in card mode and pulse 31 (Reverse QI / Reverse Qi) being configured to generate a field understandable by chargeable devices.

[0062] In other words, during a frame 27, the device 13 successively implements two emission pulses 29 and 31, each representative of a type of technology (Qi or RFID). The types of technologies targeted by the pulses are successively RFID technology and Qi technology.

[0063] Figure 4 shows an example of an enlargement of part of the chronogram illustrated in Figure 2. More specifically, Figure 4 shows a chronogram of a frame 27.

[0064] According to the embodiment illustrated in [Fig. 4], the pulse 29 comprises a guard time followed by two successive requests, each representing either Type A or Type B. Each request, between the first request (OOK Type A Command) and the second request (OOK Type B Command), is followed by a timeout 33 (Timeout for reception of the response). During the timeout 33, the device 13 waits for the response from devices in Type A card mode within its range or from devices in Type B card mode.

[0065] According to the embodiment illustrated in [Fig.4], the pulse 29 and the pulse 31 are separated by a reset time.

[0066] According to the embodiment illustrated in [Fig. 4], the pulse 31 comprises a guard time followed by a request representative of Qi technology (digital ping). The request is followed by a timeout 33 (timeout for reception of the response). During the timeout 33, the device 13 waits for the response from the devices to be charged within its field.

[0067] According to the embodiment illustrated in [Fig.4], before pulse 29, between pulses 29 and 31, and after pulse 31, the device 13 is in listening mode.

[0068] According to one embodiment, each pulse 23 has a duration of between 50 ps and 100 ps, ​​for example on the order of 70 ps, ​​and each pulse 29, 31 has a duration of between 50 ms and 100 ms, for example on the order of 70 ms. The interval 25 and the waiting time 33 have a duration of between 200 ms and 1 s.

[0069] Fig. 5 represents schematically and in block form an embodiment of the communication circuit 35 of the device 13 illustrated in Fig. 1.

[0070] The communication circuit 35 is connected to an antenna 37 via a matching circuit 39. The communication circuit 35 can also be connected to an application processor 41 (AP) and / or a safety element 43 (SE).

[0071] According to the embodiment illustrated in [Fig.3], the communication circuit 35 comprises: - a controller 45 (CONTROLLER), for example, a microcontroller or a microprocessor intended to manage the exchanges between the different elements of the circuit 35; - a wireless RFID reader receiver / transmitter 47 (RFID RW UART) connected to the controller 45 and intended to encode / decode data in reader mode; - an RFID card emulation receiver / transmitter 49 (RFID CE UART) connected to the controller 45 and intended to encode / decode data in card mode; - an analog receiver / transmitter head Qi 51 (Qi receiver / transmitter Analog font end) connected to the adaptation circuit 39, intended to shape the received signals and to transmit; - a transmission / emission circuit 53 (TX Drivers) intended to amplify, in transmission, the signals supplied by the controller 45 to the analog head Qi 51; - a frequency demodulator and a charge modulator / demodulator (also called backscatter) 55 (Qi Demodulator LM / FSK), between the analog head Qi 51 and the controller 45, intended to frequency demodulate the signal received by the analog head Qi 51; - a load modulator 57, between the controller 45 and the adaptation circuit 39, to assign an external field in RFID card mode or in mode Qi charger; and - an amplitude demodulator and charge modulator / demodulator 59 (RFID Demodulator OOK / LM), between the adaptation circuit 39 and the controller 45, adapted to demodulate the received signal in the reader and RFID card modes, respectively.

[0072] According to one embodiment, the controller 45 includes coding circuits dedicated to Qi technology.

[0073] Figures 6 to 14 show six examples of the operating method of the circuit 35 depending on the external circuit that it detects or that detects it. In each of Figures 6 to 14, the components that are not used during the example of use shown have not been illustrated.

[0074] Fig. 6 represents a circuit 35 while the device 13 detects and communicates, in reader mode, with a type A LF low frequency device configured in card mode.

[0075] Fig. 7 represents a timing diagram of an example of a frame 27 in the circuit 35 of Fig. 6.

[0076] According to the embodiment illustrated in Figures 6 and 7, when the device 13 detects an external type A device configured in card mode and communicating at low frequency (LF), the device 13 operates in reader mode.

[0077] In such a mode, the application processor operates (link a)I) the low-frequency RFID reader wireless application using the controller 45.

[0078] The controller 45 uses the RFID reader wireless receiver / transmitter 47 to build low frequency RFID reader wireless commands or LF RFID RW (link a)II commands).

[0079] The controller 45 uses the transmission / transmission circuit 53 and the analog head 51 to generate the LF RFID RW commands in accordance with type A, using on / off modulation (OOK Type A command a)III, [Fig.7]) (link a)III).

[0080] The responses (LM Tag responses, [Fig.7]) from the external device in card mode intended for device 13 are demodulated using charge demodulation via the RFID demodulator 59 (link a)IV).

[0081] According to one embodiment, not illustrated, the responses from the external device in card mode intended for device 13 are demodulated by the Qi 55 demodulator.

[0082] The controller 45 then uses the RFID reader wireless receiver / transmitter 47 to decode the responses from the external device in card mode (link a)V) and to forward the corresponding data to the application processor 41 (link a)VI).

[0083] During this operating process, the controller 45 can use the security element 43 to implement any necessary cryptographic operation.

[0084] After establishing contact between device 13 and the device within range, the latter They communicate with each other by sending successive commands and responses.

[0085] Fig. 8 represents the circuit 35 while the device 13 detects and communicates, in reader mode, with a type B LF low frequency device configured in card mode.

[0086] Figure [Fig.9] represents a timing diagram of an example of a frame 27 in the circuit 35 of Figure [Fig.8],

[0087] According to the embodiment illustrated in [Fig.8], the detection of an external device of type B configured in card mode is carried out after a lack of response to a request of type A.

[0088] According to the embodiment illustrated in [Fig.8], when the device 13 detects an external device of type B configured in card mode and communicating at low frequency LF, the device 13 operates in reader mode.

[0089] In such a mode, the application processor operates (link b)I) the low-frequency RFID reader wireless application using the controller 45.

[0090] The controller 45 uses the RFID reader wireless receiver / transmitter 47 to build low frequency RFID reader wireless commands or LF RFID RW (link b)II commands).

[0091] The controller 45 uses the transmission / transmission circuit 53 and the analog head 51 to generate the LF RFID RW commands in accordance with type B, by generating a magnetic field, using on / off amplitude modulation (OOK Type B command b)III, [Fig.9]) (link b)III).

[0092] After the command is generated, the device 13 stops its magnetic field and waits for a response from the external device.

[0093] The responses from the external device in card mode intended for device 13 (FSK Type B Responses, [Fig.9]) are demodulated using frequency shift demodulation (FSK demodulation) via the Qi 55 demodulator (link b)IV).

[0094] The controller 45 then uses the RFID reader wireless receiver / transmitter 47 to decode the responses from the external device in card mode (link b)V) and to forward the corresponding data to the application processor 41 (link b)VI).

[0095] During this operating process, the controller 45 can use the security element 43 to implement any necessary cryptographic operation.

[0096] After establishing contact between device 13 and the device within range, they communicate with each other by sending successive commands and responses.

[0097] Fig. 10 represents the circuit 35 while the device 13 detects and communicates, in card mode, with a type A LF low frequency device configured in reader mode.

[0098] According to the embodiment illustrated in [Fig. 10], when the device 13 detects a external type A device configured in reader mode and communicating at low frequency LF, device 13 operates in card mode.

[0099] In such a mode, the application processor operates (link c)I) the low-frequency RFID card emulation application using the controller 45.

[0100] Commands from the external device in reader mode intended for device 13 are demodulated via RFID demodulator 59 (link c)II), using on / off amplitude demodulation.

[0101] The controller 45 then uses the RFID card emulation receiver / transmitter 49 to decode the commands from the external device (link c)III) and uses the RFID card emulation receiver / transmitter 49 to construct the responses (link c)IV).

[0102] The controller 45 uses the charge modulator 57 to generate the response in accordance with type A with the device in player mode via the matching circuit 39, using FSK (c)V link modulation).

[0103] During this operating process, the controller 45 can use the security element 43 to implement any necessary cryptographic operation.

[0104] Figure 11 shows circuit 35 while device 13 detects and communicates, in card mode, with a type B LF low frequency device configured in reader mode.

[0105] According to the embodiment illustrated in [Fig.1 1], when the device 13 detects an external type B device configured in reader mode and communicating at low frequency LF, the device 13 operates in card mode.

[0106] In such a mode, the application processor operates (link d)I) the low-frequency RFID card emulation application using the controller 45.

[0107] Commands from the external device in reader mode intended for device 13 are demodulated using on / off demodulation via RFID demodulator 59 (link d)II).

[0108] The controller 45 then uses the RFID card emulation receiver / transmitter 49 to decode the commands from the external device (link d)III) and uses the RFID card emulation receiver / transmitter 49 to construct the responses (link d)IV).

[0109] The controller 45 uses the transmit / transmit circuit 53 and the analog head 51 to generate the response in accordance with type B with the device in player mode via the matching circuit 39, using frequency shift modulation (FSK modulation) (d)V link).

[0110] During this operating process, the controller 45 can use the security element 43 to implement any necessary cryptographic operation.

[0111] Figure 12 shows circuit 35 while device 13 detects and is charged via a charging device.

[0112] According to the embodiment illustrated in [Fig. 12], when the device 13 detects a External Qi charger device, device 13 operates in chargeable mode.

[0113] In such a mode, the analog Qi ping from the external device in charger mode intended for device 13 is demodulated, using FSK modulation via the Qi demodulator 55, and decoded by the controller 45 (link e)I).

[0114] The controller 45 uses the load modulator 57 to generate the responses via the matching circuit 39 (link e)II).

[0115] Next, the device 13 is loaded and the controller 45 communicates monitoring data to the application processor 41 (link e)III).

[0116] During this operating process, the controller 45 can use the security element 43 in case it is necessary to perform authentication.

[0117] Fig. 13 represents circuit 35 while device 13 detects and charges a chargeable device.

[0118] The [Fig. 14] represents a timing diagram of an example of a frame 27 in the circuit 35 of the [Fig. 13].

[0119] According to the embodiment illustrated in Figures 13 and 14, the detection of a chargeable device is carried out after a lack of response to an RFID request (frame 27).

[0120] According to the embodiment illustrated in [Fig.13], when the device 13 detects an external Qi device in chargeable mode, the device 13 operates in charger mode.

[0121] In such a mode, the controller 45 sends, using FSK modulation (link f)I), the digital Qi ping (Digital ping f)I, [Fig. 14]) using the transmission / transmission circuit 53.

[0122] The response from the external device (LM Answer from the device to be charged, [Fig. 14]) is demodulated using a charge demodulator 55 via the Qi demodulator 51 (link f)II) and decoded by the controller (link f)III).

[0123] Next, the device 13 charges the device within range and the controller 45 communicates monitoring data to the application processor 41 (link f)III).

[0124] During this operating process, the controller 45 can use the security element 43 in case authentication is required.

[0125] After contact is established between device 13 and the device within range, they both communicate by sending successive commands and responses. Any subsequent data packet received from an external charging device can then be demodulated by the charge demodulator 55.

[0126] According to the embodiments described, during phase I illustrated in [Fig.2], the device 13 is adapted to use the Qi demodulator and the RFID demodulator in parallel, whereas, during phase II, the device 13 is adapted to use the Qi demodulator and the RFID demodulator successively.

[0127] One advantage of the described embodiments is that they make it possible to combine, in the same circuit, LF RFID and Qi technologies.

[0128] Various embodiments and variations have been described. A person skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will become apparent to a person skilled in the art.

[0129] Finally, the practical implementation of the embodiments and variants described is within the reach of a person skilled in the art, based on the functional indications given above.

Claims

Demands

1. Contactless access device comprising a frequency demodulator (55) and an amplitude demodulator (59), the device being configured to use, in a first mode (I), the two demodulators in parallel and to activate an RFID card mode or a Qi charger mode based on results provided by said demodulators.

2. Device according to claim 1, wherein the two frequency and amplitude demodulators also comprise charge modulators / demodulators.

3. Device according to claim 1 or 2, wherein, in a second mode, the two frequency and amplitude demodulators operate successively.

4. Device according to any one of claims 1 to 3, wherein a charge modulator (57) of the device is used when the device communicates with an external Type A RFID device configured in reader mode.

5. Device according to claim 4, wherein said charge modulator (57) is used when the device is charged by an external device and when it emulates a type A configured RFID card.

6. Device according to any one of claims 1 to 5, wherein an analog Qi head (51) of the device is adapted to frequency modulate or amplitude modulate data when the device is in the second mode, the frequency modulated data being used to communicate with a Qi charging device and the amplitude modulated data being used to communicate with an RFID device configured in card mode.

7. Device according to any one of claims 1 to 6, wherein the amplitude demodulator (59) is used to demodulate a charge modulation response from an external Type A device configured in card mode.

8. Device according to any one of claims 1 to 7, wherein the amplitude demodulator (59) is used to demodulate a command received from an external device configured in reader mode.

9. A device according to any one of claims 1 to 8, wherein the frequency demodulator (55) is used to demodulate a response received from an external type B device configured in map mode.

10. Device according to any one of claims 1 to 9, wherein the frequency demodulator (55) is used to demodulate a digital ping or any subsequent data packet received from an external charging device.

11. Device according to any one of claims 1 to 10, wherein the frequency demodulator (55) is used to demodulate a response received from an external load device.

12. A device according to any one of claims 1 to 11, wherein when it detects an external field on an antenna, it checks whether the field is from an RFID device or a Qi device.

13. Device according to claim 12, wherein the verification is carried out by the emission of periodic interrogation frames in RFID mode and in Qi mode.

14. Method implemented by a contactless access device comprising a frequency demodulator (55) and an amplitude demodulator (59), wherein the device uses, in a first mode (I), the two demodulators in parallel and, in a second mode (II), the two demodulators successively.

15. Method according to claim 14 applied to a device according to any one of claims 1 to 13.

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