Chip, collision detection method and nfc device for collision detection of rf signals

Abstract

Provided are a near field communication (NFC) device, a method of determining occurrence and non-occurrence of radio frequency (RF) collisions in the NFC device, and an NFC chip. The NFC device includes a front-end circuit including an antenna and a matching network circuit coupled to the antenna, a transmitting circuit that transmits a first RF signal through the front-end circuit, a receiving circuit that receives a second RF signal, the second RF signal being a signal generated by the transmission of the first RF signal through the front-end circuit, a feedback circuit that provides a feedback path from the receiving circuit to the transmitting circuit and extracts a clock having the same frequency as the second RF signal from the second RF signal, and a controller that determines occurrence and non-occurrence of RF collisions with respect to the NFC device based on the clock.

Description

Cross-reference to related applications

[0001] This application claims priority to Korean Patent Application No. 10-2025-0054490, filed on April 25, 2025, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] The embodiments of this disclosure described herein relate to a chip for collision detection of RF signals, a transceiver including the chip, and a method for detecting collisions of RF signals. Background Technology

[0003] Near Field Communication (NFC) is a contactless communication technology that uses a reference frequency (e.g., 13.56 MHz) to send and receive data over short distances. NFC technology supports a polling mode where signals are actively sent and a listening mode where signals are received and responded to. NFC is used in various fields such as payments, authentication, and information sharing.

[0004] When NFC-enabled devices send radio frequency (RF) signals (or radiate RF fields) to each other, there is a possibility of RF signal collisions. When an RF signal collision occurs, it becomes difficult to continue normal NFC operations. Summary of the Invention

[0005] Embodiments of this disclosure provide a chip for RF signal collision detection, a transceiver including the chip, and a method for detecting RF signal collisions.

[0006] According to an embodiment, a near field communication (NFC) device includes: a front-end circuit including an antenna and a matching network circuit coupled to the antenna; a transmitting circuit configured to transmit a first radio frequency (RF) signal through the front-end circuit; a receiving circuit configured to receive a second RF signal generated by transmitting the first RF signal through the front-end circuit; a feedback circuit configured to provide a feedback path from the receiving circuit to the transmitting circuit and to extract a clock having the same frequency as the second RF signal from the second RF signal; and a controller configured to determine whether an RF collision has occurred or not relative to the NFC device based on the clock.

[0007] According to an embodiment, a method for determining whether an RF collision has occurred or not in an NFC device includes: transmitting a first RF signal in a polling mode; extracting a clock from a second RF signal, the second RF signal being a signal generated by transmitting the first RF signal through a matching network circuit of the NFC device; and determining whether an RF collision has occurred or not relative to the NFC device based on the clock.

[0008] According to an embodiment, a near field communication (NFC) chip includes: a transmitting circuit configured to transmit a first radio frequency (RF) signal; a receiving circuit configured to receive a second RF signal defined as a feedback signal of the first RF signal; a feedback circuit configured to provide a feedback path from the receiving circuit to the transmitting circuit and extract a clock having the same frequency as the second RF signal from the second RF signal; and a controller configured to determine whether an RF collision has occurred or not relative to the NFC chip based on the clock.

[0009] Based on the above, a chip for detecting RF signal collisions, a transceiver including the chip, and a method for detecting RF collisions are provided. Attached Figure Description

[0010] The above and other objects and features of this disclosure will become clear from the detailed description of embodiments thereof with reference to the accompanying drawings.

[0011] Figure 1 This is a block diagram illustrating a near field communication (NFC) device according to an embodiment of the present disclosure; Figure 2 This is a circuit diagram illustrating a front-end circuit according to an embodiment of the present disclosure; Figure 3 This is a block diagram illustrating a feedback circuit according to an embodiment of the present disclosure; Figure 4 This is a timing diagram illustrating RF collision prevention operations; Figure 5 This is a timing diagram illustrating RF collision prevention operations according to an embodiment of the present disclosure; Figure 6 This is a flowchart illustrating the RF collision prevention operation of an NFC device according to an embodiment of the present disclosure; Figure 7 This is a flowchart illustrating a method for switching the mode of an NFC device according to an embodiment of the present disclosure; Figure 8 This is a block diagram illustrating a controller according to an embodiment of the present disclosure; Figure 9 This is a block diagram illustrating a chip according to an embodiment of the present disclosure; Figure 10 This is a block diagram illustrating an NFC system according to an embodiment of the present disclosure; Figure 11 This is based on embodiments of the present disclosure. Figure 10 Timing diagram of RF collisions in an NFC system; and Figure 12 This is a block diagram illustrating an electronic device according to an embodiment of the present disclosure. Detailed Implementation

[0012] The embodiments of this disclosure will now be described in detail and clearly to the extent that those skilled in the art can readily implement this disclosure.

[0013] In the following description, the term "coupled" in relation to component A and component B may refer to the physical connection, electrical connection, or both physical and electrical connection between component A and component B.

[0014] Figure 1 This is a block diagram illustrating a near field communication (NFC) device according to an embodiment of the present disclosure.

[0015] Reference Figure 1 The NFC device 1000 may include a front-end circuit 1100 and a chip 1200.

[0016] The front-end circuit 1100 may include an antenna containing inductor components and matching network circuitry.

[0017] In this disclosure, an "antenna" may include one or more antenna elements, components, or units, or may have a structure and / or arrangement including antenna elements, components, or units. In some embodiments, an antenna may be configured as a single antenna, and in this case, the transmission or reception of radio frequency (RF) signals can be performed by a single antenna.

[0018] Matching network circuitry (e.g., impedance transformer or resonant circuitry) can be coupled to the antenna. According to some embodiments, the matching network circuitry can be configured to provide impedance matching between the output impedance of chip 1200 and the input impedance of the antenna, or to provide resonance for communication of NFC device 1000 at a specific frequency through a combination of passive components. For example, a specific frequency in NFC device 1000 may be approximately 13.56 MHz.

[0019] Chip 1200 can be coupled to a matching network circuit and configured to process RF signals. Chip 1200 can operate the NFC device 1000 in either polling mode (active mode) or listen mode (passive mode). For example, chip 1200 can operate in either polling mode or listen mode according to a time-division scheme.

[0020] The NFC device 1000 operating in polling mode can be a poller (or initiator, reader, active device, etc.), and the NFC device 1000 operating in listening mode can be a listener (or target). Alternatively, the electronic device can be configured to perform both the roles of poller and listener.

[0021] Polling mode can be defined as a mode for transmitting RF signals. Specifically, polling mode can be defined as a mode in which the NFC device 1000 communicates using its own (or unique) RF frequency (or carrier frequency). In polling mode, the NFC device 1000 can generate or obtain RF signals with an RF frequency and can transmit RF signals.

[0022] The listening mode can be defined as a mode in which the NFC device 1000 responds to external RF signals. Specifically, the listening mode can be defined as a mode in which the NFC device 1000 responds to RF signals sent from another NFC device, rather than generating and sending RF signals as in polling mode. In listening mode, the NFC device 1000 can receive RF signals from another NFC device. For example, the NFC device 1000 operating in listening mode can respond to RF signals based on a load modulation scheme.

[0023] In some embodiments, chip 1200 may include a transmitting (Tx) circuit 1210, a receiving (Rx) circuit 1220, a feedback circuit 1230, and a controller 1240.

[0024] Tx circuit 1210 can transmit a first RF signal RF1 via a matching network circuit. In some embodiments, Tx circuit 1210 can receive a processed and / or modulated baseband signal from controller 1240, up-convert the baseband signal to a reference frequency to obtain the first RF signal RF1 or oscillate the first RF signal RF1, and amplify the first RF signal RF1. Tx circuit 1210 can apply the amplified first RF signal RF1 to front-end circuit 1100.

[0025] Rx circuit 1220 can receive a second RF signal RF2 via a matching network circuit, the second RF signal being defined as a signal fed back (e.g., generated) as a result of the transmission of the first RF signal RF1 through the matching network circuit. Rx circuit 1220 can apply the second RF signal RF2 to feedback circuit 1230.

[0026] In the following, in this disclosure, "first RF signal RF1" is defined as an RF signal provided from Tx circuit 1210 to front-end circuit 1100 (and matching network circuit), and "second RF signal RF2" is defined as an RF signal provided from front-end circuit 1100 (and matching network circuit) to Rx circuit 1220. Second RF signal RF2 may be a signal generated as a result of the transmission of first RF signal RF1 through the matching network circuit included in front-end circuit 1100 and fed back to Rx circuit 1220.

[0027] In some embodiments, when the NFC device 1000 operates in listening mode, the Rx circuit 1220 can receive a received signal from the front-end circuit 1100 and can process the received received signal (e.g., low-noise amplification, frequency down-conversion, etc.).

[0028] Feedback circuit 1230 provides a feedback path from Rx circuit 1220 to Tx circuit 1210, and can extract clock CLK (i.e., clock CLK signal) from the second RF signal RF2 and send the extracted clock CLK to controller 1240. The extracted clock CLK has the same frequency as the second RF signal RF2. In this embodiment, the feedback path can be defined as the path through which the signal is fed back to Tx circuit 1210 via Rx circuit 1220 and feedback circuit 1230. Feedback circuit 1230 can provide a closed loop for Tx circuit 1210, matching network circuit, and Rx circuit 1220 via the feedback path.

[0029] The feedback circuit 1230 can apply the clock CLK extracted from the second RF signal RF2 to the controller 1240.

[0030] In some embodiments, the feedback circuit 1230 can obtain a delayed clock DCLK (i.e., a delayed clock DCLK signal) by setting a phase value based on the phase delay of the extracted clock CLK. The feedback circuit 1230 can then provide the obtained delayed clock DCLK to the Tx circuit 1210.

[0031] In some embodiments, the Tx circuit 1210 may generate a first RF signal RF1 or cause the first RF signal RF1 to oscillate based on a delayed clock DCLK provided from the feedback circuit 1230. The first RF signal RF1 may have a frequency that varies according to a set phase value. For example, if the delayed clock DCLK is delayed by a first phase value from the clock CLK, the frequency of the first RF signal RF1 may change (up or down) to a frequency value corresponding to the first phase value.

[0032] When a closed loop including the aforementioned feedback path is formed, any changes that may occur in the second RF signal RF2 are directly reflected in the acquisition or oscillation of the first RF signal RF1. For example, assuming an RF collision occurs between NFC device 1000 and another NFC device (or another poller), the frequency of the signal oscillating through the closed loop including the antenna may fluctuate during an RF collision. In the open-loop case, NFC device 1000 operates based on a fixed oscillation frequency, therefore, the frequency of the oscillation signal does not fluctuate. Conversely, in the closed-loop case, the frequency of the oscillation signal may fluctuate due to RF collisions, and the level of the oscillation signal may vary depending on the difference between the oscillation frequency and the resonant frequency of the matching network circuit.

[0033] In some embodiments, since the NFC device 1000 oscillates the first RF signal RF1 based on a clock CLK extracted through a closed loop, the frequencies of the first RF signal RF1 and the second RF signal RF2 corresponding to the first RF signal RF1 may fluctuate due to RF interference. Therefore, the frequency of the clock CLK extracted by the feedback circuit 1230 may also fluctuate in response to the frequency fluctuation of the second RF signal RF2.

[0034] The controller 1240 can detect whether an RF collision has occurred by detecting frequency fluctuations in the first RF signal RF1 and the second RF signal RF2. The controller 1240 can detect RF collisions relative to the NFC device 1000 based on the clock CLK.

[0035] In some embodiments, the controller 1240 may receive a clock CLK from the feedback circuit 1230 and may obtain the frequency of the clock CLK. When the frequency of the obtained clock CLK falls outside a set range relative to a reference frequency, the controller 1240 may determine that an RF collision has been detected. The set range may be set differently to include the reference frequency. According to some embodiments, the reference frequency may be the same as the specific frequency described above, or it may be a frequency defined relative to the delayed clock DCLK.

[0036] Based on the detection of an RF conflict, the controller 1240 can switch the operating mode of the NFC device 1000 from polling mode to listening mode. Therefore, the NFC device 1000 can avoid RF conflicts with another NFC device and can operate in listening mode. Alternatively, based on the absence of a detected RF conflict, the controller 1240 can maintain the operating mode of the NFC device 1000 in polling mode.

[0037] The NFC device 1000 according to the above embodiment may have a structure that obtains the first RF signal RF1 through a closed loop or oscillates the first RF signal RF1, thus enabling it to detect RF collisions. Furthermore, when an RF collision is detected, the NFC device 1000 may switch its operating mode to a listening mode; therefore, the NFC device 1000 can actively respond to RF collisions and improve compatibility with other NFC devices.

[0038] Figure 2 This is a circuit diagram showing a front-end circuit 1100 according to an embodiment of the present disclosure.

[0039] Reference Figure 2 The front-end circuit 1100 may include an antenna ANT and a matching network circuit 1110. The antenna ANT may be implemented as a coil. The two ends of the antenna ANT may be coupled to a first node N1 and a second node N2, respectively.

[0040] The matching network circuit 1110 may include a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6 and a seventh capacitor C7, a first inductor L1, a second inductor L2, a first resistor R1 and a second resistor R2.

[0041] The first capacitor C1 can be coupled to the first node N1 and the second node N2. The second capacitor C2 can be coupled to the first node N1 and the third node N3, and the third capacitor C3 can be coupled to the second node N2 and the fourth node N4. One end of the fourth capacitor C4 can be coupled to the third node N3, and the other end of the fourth capacitor C4 can be grounded. One end of the fifth capacitor C5 can be coupled to the fourth node N4, and the other end of the fifth capacitor C5 can be grounded.

[0042] The first inductor L1 can be coupled to the third node N3 and the first terminal T1, and the second inductor L2 can be coupled to the fourth node N4 and the second terminal T2. The first terminal T1 and the second terminal T2 can be coupled to the Tx circuit 1210 according to the above embodiment (see...). Figure 1 ).

[0043] The first resistor can be coupled to the first node N1 and one end of the sixth capacitor C6, and the second resistor can be coupled to the second node N2 and one end of the seventh capacitor C7. One end of the sixth capacitor C6 can be coupled to the first resistor, and the other end of the sixth capacitor C6 can be coupled to the third terminal T3. One end of the seventh capacitor C7 can be coupled to the second resistor, and the other end of the seventh capacitor C7 can be coupled to the fourth terminal T4. The third terminal T3 and the fourth terminal T4 can be coupled to the Rx circuit 1220 according to the above embodiment (see...). Figure 1 ).

[0044] The first resistor, the sixth capacitor C6, the second resistor, and the seventh capacitor C7 can provide attenuation for the RF signal received from the antenna ANT. According to some embodiments, the first and second resistors can be omitted.

[0045] In the above Figure 2 The antenna ANT and matching network circuit 1110 shown in the front-end circuitry 1100 are merely examples, and the embodiments disclosed herein should not be limited thereto or thereby restricted. The antenna ANT and matching network circuit 1110 can be configured or implemented in various ways to provide resonance and impedance matching for a specific frequency to the NFC device 1000.

[0046] Figure 3 This is a block diagram illustrating a feedback circuit according to an embodiment of the present disclosure.

[0047] Reference Figure 3The feedback circuit 1230 may include a clock (i.e., clock signal) extraction circuit 1231 and a delay unit 1232.

[0048] The clock extraction circuit 1231 can receive the second RF signal RF2 from the Rx circuit 1220. The clock extraction circuit 1231 can extract a clock CLK from the second RF signal RF2, which is a digital signal with the same frequency as the second RF signal RF2. For example, the clock extraction circuit 1231 can extract a clock CLK with logic high and logic low levels from the second RF signal RF2 based on a preset voltage threshold. The clock extraction circuit 1231 can provide the extracted clock CLK to the controller 1240 and the delay unit 1232.

[0049] The delay unit 1232 can delay the phase of the provided clock CLK by a set phase value, and can obtain a delayed clock DCLK. According to various embodiments, the delay unit 1232 can be implemented as a delay chain in which one or more inverters or buffers are connected in series, or can be implemented in various other forms that can delay the phase of the clock CLK.

[0050] Delay unit 1232 can provide a delayed clock DCLK to Tx circuit 1210. The first RF signal RF1 (refer to...) is obtained or oscillated by Tx circuit 1210. Figure 1 The frequency can vary depending on the level of the phase value of the clock CLK delay.

[0051] In some embodiments, the controller 1240 can control the setting of a phase value. The controller 1240 can provide a control signal CS to the delay unit 1232 for setting the phase value. In this case, the delay unit 1232 can delay the phase of the clock CLK by the phase value controlled by the control signal CS.

[0052] According to the above embodiments, the frequency of the RF signal obtained or oscillated by the Tx circuit 1210 of the NFC device 1000 may differ from a specific frequency depending on the delay clock DCLK. Therefore, the NFC device 1000 can transmit an RF signal with a frequency different from a specific frequency transmitted by another NFC device. When the frequencies of the RF signals transmitted by multiple NFC devices 1000 are the same (e.g., a specific frequency), RF collisions may not be detected. The NFC device 1000 according to this disclosure can transmit an RF signal with a frequency different from a specific frequency; therefore, the NFC device 1000 can further improve its performance in detecting RF collisions.

[0053] Figure 4 This is a timing diagram illustrating RF collision prevention operations.

[0054] Reference Figure 4The NFC device can support RF collision avoidance (RFCA) to prevent RF collisions, and the controller can control the Tx circuit in response to RFCA.

[0055] First, NFC devices can be used in segment T. IDT During this period, it waits without sending an RF signal. Here, segment T... IDT This can be defined as an initial delay time during which the NFC device waits to check for the presence of an external RF signal. The NFC device can operate in segment T. IDT The presence of external RF signals is detected during this period.

[0056] When in segment T IDT When no external RF signal is detected during the period, the NFC device has segment T RFW2 Additional waiting time. In this embodiment, segment T RFW2 It can be defined as the additional time an NFC device waits before acquiring or transmitting an RF signal, and can be based on a segment T as a unit of waiting time. RFW1 To define. For example, segment T RFW2 It can be derived from the expression "n×T" RFW1 The definition is as follows: In this expression, n is a randomly generated integer. Therefore, NFC devices can probabilistically avoid RF collisions with each other.

[0057] When the NFC device is in segment T IDT and T RFW2 When no external RF signal is detected, the NFC device can activate the RF field. In other words, when no external RF signal is detected, the NFC device can operate in polling mode. The NFC device can activate the RF field and radiate an RF field with a specific frequency through its antenna.

[0058] NFC devices can be used in segment T IRFG RF field is activated during this period. Segment T IRFG It can be the initial RF generation time, and can be defined as the minimum time that needs to be waited after the RF field is activated and before the data is sent.

[0059] NFC devices can be used in segment T IRFG Then a request is sent. This request may include frames for communicating with nearby NFC devices.

[0060] exist Figure 4 In the case of NFC device segment T RFW2 When they are set to the same value, RF conflicts are difficult to avoid.

[0061] Figure 5 This is a timing diagram illustrating RF collision prevention operation according to an embodiment. Hereinafter, for ease of explanation, details related to... Figure 4 Describe those same detailed descriptions.

[0062] Reference Figure 5 Due to the NFC device in segment T IDT and T RFW2 If no external RF signal is detected during the RF field activation, an RF collision may occur at time point tcol. As an example, when segment T of the NFC device... RFW2 Set as segment T with another NFC device RFW2 At the same time, since both NFC devices have their RF fields turned on, an RF conflict may occur.

[0063] After the RF field is activated, the NFC device can extract a clock (i.e., a clock signal) from the RF field according to the above embodiments, and can detect RF collisions based on the extracted clock. For example, the NFC device can determine that an RF collision has been detected when the frequency of the clock falls outside a set range relative to a reference frequency.

[0064] When an RF conflict is detected, the NFC device can shut down the RF field and operate in listening mode.

[0065] Even in RFCA segment T RFW2 If set to the same configuration, the NFC device according to the above embodiment can also detect RF conflicts and switch the operating mode to listening mode, thus improving compatibility with other NFC devices.

[0066] Figure 6 This is a flowchart illustrating the RF collision prevention operation of an NFC device according to an embodiment of the present disclosure.

[0067] Reference Figure 6 The NFC device sends a first RF signal in polling mode (S110). The NFC device performs RFCA according to the above embodiment (see reference). Figure 4 and Figure 5 It can operate in polling mode.

[0068] In operation S120, the NFC device extracts the clock of the second RF signal. The extracted clock has the same frequency as the second RF signal. As described above, the second RF signal is defined as a signal generated by transmitting the first RF signal through the matching network circuit included in the NFC device, and is fed back to the Rx circuit included in the NFC device.

[0069] In operation S130, the NFC device detects an RF collision relative to itself based on the clock extracted in operation S120. For example, in operation S130, the NFC device monitors the frequency of the extracted clock and determines that an RF collision has been detected when the clock frequency fluctuates. For example, when the frequency of the clock extracted in operation S130 falls outside a set range relative to a reference frequency, the NFC device determines that an RF collision has been detected.

[0070] In some embodiments, the method may further include obtaining a delayed clock by setting a phase value based on a phase delay of the clock, and obtaining a first RF signal based on the delayed clock. In this case, the NFC device may oscillate the first RF signal based on the delayed clock.

[0071] NFC devices can detect RF collisions by using the operating method according to the above embodiments.

[0072] Figure 7 This is a flowchart illustrating a method for switching the mode of an NFC device according to an embodiment of the present disclosure.

[0073] Reference Figure 7 The NFC device sets the polling mode (S210) and sends an RF signal (S220). In operation S230, the NFC device determines whether to terminate the polling mode.

[0074] When it is determined that the polling mode should be maintained (indicated as "No" in operation S230), the NFC device determines whether an RF collision has occurred (e.g., an RF collision is detected) or no RF collision has occurred (e.g., no RF collision is detected) (S240). When an RF collision occurs (e.g., an RF collision is detected) (indicated as "Yes" in S240), the NFC device sets a listening mode and terminates the polling mode (S250). For example, the NFC device switches its operating mode to listening mode based on the detection of an RF collision.

[0075] NFC devices operating in listening mode stop generating, acquiring, and sending RF signals, and instead receive or respond to RF signals from external NFC devices.

[0076] Alternatively, when no RF collision occurs (e.g., no RF collision is detected) (indicated as "No" in S240), the NFC device returns to operation S220 and sends an RF signal. For example, the NFC device maintains its operating mode in polling mode based on the absence of detected RF collision.

[0077] NFC devices can detect RF collisions and actively respond to RF collisions by operating according to the methods described in the above embodiments.

[0078] Figure 8This is a block diagram illustrating a controller according to an embodiment of the present disclosure.

[0079] Reference Figure 8 The controller 1240 may include a modulator 1241, a demodulator 1242, a processor 1243, and a memory 1244.

[0080] Modulator 1241 can receive and modulate transmission data TD from processor 1243. As an example, modulator 1241 can modulate transmission data TD based on a modulation scheme such as amplitude shift keying (ASK), on / off keying (OOK), binary phase shift keying (BPSK), etc. The modulated signal MS is provided to Tx circuit 1210.

[0081] Demodulator 1242 can receive the received signal RS from Rx circuit 1220 and demodulate the received signal RS to obtain received data RD. Demodulator 1242 can demodulate the received signal RS according to a demodulation scheme corresponding to the modulation scheme used by modulator 1241.

[0082] The processor 1243 can be coupled to the memory 1244 and can control the overall operation of the chip and the NFC device.

[0083] Processor 1243 can control memory 1244 and execute at least one instruction stored in memory 1244 to implement the description, functions, processes, proposals, methods, and / or operation flowcharts of this disclosure. Furthermore, processor 1243 can provide operations according to various embodiments of this disclosure based on instructions stored in memory 1244. Additionally, processor 1243 can process information stored in memory 1244 to generate data.

[0084] The processor 1243 can select the operating mode of the NFC device (such as polling mode and listening mode) and control the Tx circuit 1210, Rx circuit 1220, modulator 1241 and / or demodulator 1242 according to the selected mode.

[0085] For example, processor 1243 can enable or disable the RF field according to the selected mode. Processor 1243 can perform RFCA to enable the RF field according to the above embodiments. For example, processor 1243 can generate or obtain transmission data TD and can provide transmission data TD to modulator 1241. For example, processor 1243 can receive received data RD from demodulator 1242 and can extract valid data from received data RD, or can perform cyclic redundancy check (CRC) verification.

[0086] The processor 1243 can store the acquired or processed data in the memory 1244, or can read the data stored in the memory 1244.

[0087] In some embodiments, the processor 1243 may receive a clock CLK from the feedback circuit according to the above embodiments and may detect RF collisions based on the clock CLK. For example, the processor 1243 may obtain the frequency of the provided clock CLK and may determine that an RF collision has been detected when the frequency of the clock CLK fluctuates. Whether the frequency of the clock CLK fluctuates can be determined by a comparison operation between the frequency of the clock CLK and a reference frequency or by a comparison operation between the frequency of the clock CLK and a set range relative to the reference frequency.

[0088] In some embodiments, when the NFC device operates in polling mode, the processor 1243 may detect RF collisions based on the clock CLK, and when an RF collision is detected, the processor 1243 may switch the operating mode of the NFC device from polling mode to listening mode. Alternatively, when no RF collision is detected, the processor 1243 may maintain the operating mode of the NFC device in polling mode.

[0089] The memory 1244 may be connected to the processor 1243 and may store various information related to the operation of the processor 1243. For example, the memory 1244 may store software code including at least one instruction for performing some or all of the processes controlled by the processor 1243 or for implementing the description, function, process, proposal, method and / or operation flowchart of this disclosure.

[0090] According to the above embodiment, the controller 1240 can detect RF conflicts based on the clock CLK, and can improve compatibility with other NFC devices by switching modes when an RF conflict is detected.

[0091] Figure 9 This is a block diagram illustrating a chip according to an embodiment of the present disclosure. Hereinafter, for ease of explanation, details related to... Figure 1 Those same detailed descriptions.

[0092] Reference Figure 9 In addition to the Tx circuit 1210, Rx circuit 1220, feedback circuit 1230 and controller 1240, chip 1200a may also include a reference clock generation circuit 1250.

[0093] According to various embodiments, the reference clock generation circuit 1250 can generate a reference clock RCLK, which can be used to generate a specific frequency required by the NFC device. For example, the reference clock generation circuit 1250 can be implemented as a crystal oscillator, an RC oscillator, a frequency divider, etc. The reference clock generation circuit 1250 can provide the reference clock RCLK to the Tx circuit 1210 and the controller 1240.

[0094] In some embodiments, the Tx circuit 1210 may receive a reference clock RCLK from the reference clock generation circuit 1250 and may oscillate an initial RF signal based on the reference clock RCLK. After oscillating the initial RF signal, the Tx circuit 1210 may oscillate the RF signal based on a delayed clock DCLK. In this case, the reference clock RCLK may be a clock matched to a specific frequency. For example, the Tx circuit 1210 may initially oscillate the RF signal at a specific frequency, and then may oscillate the RF signal at a frequency matched to the delayed clock DCLK.

[0095] In some embodiments, the controller 1240 may use a provided reference clock RCLK to detect RF collisions. The controller 1240 may compare a reference clock RCLK matched to a specific frequency with a clock CLK, and may determine that an RF collision has been detected when the clock CLK falls outside a set range of the reference clock RCLK.

[0096] The operation of the reference clock generation circuit 1250 according to the embodiment is merely illustrative, and this disclosure should not be limited thereto or construed as such. For example, as Figure 1 As shown, an NFC device can be configured to initially oscillate at a specific frequency without a separate reference clock RCLK, or the NFC device can operate in response to a reference clock RCLK applied from an external source.

[0097] Figure 10 This is a block diagram illustrating an NFC system according to an embodiment of the present disclosure.

[0098] Reference Figure 10 According to some embodiments, the NFC system 2000 may include a first NFC device 2100 and a second NFC device 2200. The first NFC device 2100 and the second NFC device 2200 may perform near-field communication with each other based on an NFC scheme. For example, the first NFC device 2100 may operate in both polling and listening modes, and the second NFC device 2200 may operate in both polling and listening modes, or may operate only in polling mode. The second NFC device 2200, which may operate only in polling mode, may be the poller (or initiator, reader, or active device).

[0099] When both the first NFC device 2100 and the second NFC device 2200 are operating in polling mode, the first NFC device 2100 may activate its RF field and emit a first signal SIG1, and the second NFC device 2200 may activate its RF field and emit a second signal SIG2. For example, the first NFC device 2100 may acquire or generate and emit the first signal SIG1 having the same frequency as or relative to a reference frequency defined by a delayed clock. For example, the second signal SIG2 may have the specific frequency. When the first signal SIG1 has a frequency defined relative to the delayed clock, the performance of RF collision detection can be further improved.

[0100] In some embodiments, the first NFC device 2100 may include a front-end circuit 2110 and a chip 2120, and may perform RF collision detection operations (see reference). Figures 1 to 9 The first NFC device 2100 may include a closed-loop CL for detecting RF collisions. Through the closed-loop CL, a first signal SIG1 may oscillate according to the clock of an internally fed-in first signal SIG1 (e.g., the second RF signal mentioned above).

[0101] In some embodiments, an RF collision may occur when the first NFC device 2100 and the second NFC device 2200 transmit signals to each other. When an RF collision occurs, a change may occur in the first signal SIG1, and this change may also be reflected in the signal fed back through the closed-loop CL. The first NFC device 2100 may detect the RF collision from the frequency change of the first signal SIG1, and when an RF collision is detected, the operating mode of the first NFC device 2100 may switch to a listening mode.

[0102] In some embodiments, the second NFC device 2200 may only support polling mode. The first NFC device 2100 may initially transmit a first signal SIG1 in polling mode. Since the second NFC device 2200 does not recognize the first signal SIG1 transmitted by the first NFC device 2100, the second NFC device 2200 may also transmit a second signal in polling mode. In this case, RF collisions may occur, and changes may occur in the first signal SIG1. As described above, the first NFC device 2100 can avoid RF collisions by detecting RF collisions from frequency changes in the first signal SIG1 and subsequently switching its operating mode to listening mode upon detecting an RF collision.

[0103] Therefore, the NFC system 2000 can detect and subsequently avoid (e.g., remove) RF collisions between NFC devices.

[0104] Figure 11 This is based on embodiments of the present disclosure. Figure 10Timing diagram of RF collisions in an NFC system.

[0105] Reference Figure 11 Each of the first signal SIG1 and the second signal SIG2 can be emitted at a constant level until the RF collision time point tcol. The reference frequency fREF, which serves as the frequency of the first signal SIG1, can also be maintained at a constant value until the RF collision time point tcol.

[0106] After the RF collision time point tcol, the strengths of both the first signal SIG1 and the second signal SIG2 fluctuate as the signals overlap. In this case, the reference frequency fREF can also fluctuate after the RF collision time point tcol. For example, when an RF collision occurs, the reference frequency fREF of the first NFC device 2100 with a closed loop can fluctuate after the RF collision time point tcol, and the first NFC device 2100 can detect the RF collision through this fluctuation. For example, the first NFC device 2100 can determine that an RF collision has been detected when the reference frequency fREF fluctuates beyond a set range SR relative to the reference frequency fREF.

[0107] Figure 12 This is a block diagram illustrating an electronic device according to an embodiment of the present disclosure.

[0108] Reference Figure 12 The electronic device 3000 may include an application processor (AP) 3100, an NFC device 3400, a memory 3200, a user interface 3300, and a power supply 3500.

[0109] For example, the electronic device 3000 can be any mobile system, such as a mobile phone, smartphone, personal digital assistant (PDA), portable multimedia player (PMP), digital camera, music player, portable game console, navigation system, laptop computer, etc.

[0110] The AP 3100 can control the overall operation of the electronic device 3000. For example, the AP 3100 can run applications that provide internet browsers, games, videos, etc. The AP 3100 may include a single core or multiple processor cores (multi-core).

[0111] The memory 3200 can store data required for the operation of the electronic device 3000. For example, the memory 3200 can store a boot image or firmware used to start the electronic device 3000, and can store output data to be sent to an external device (e.g., an NFC-enabled external device) and received input data, such as data received from an external device.

[0112] User interface 3300 may include one or more input devices (such as keypad or touch screen) and / or one or more output devices (such as speaker or display device).

[0113] The NFC device 3400 can send output data stored in the memory 3200 to an external device via NFC, receive input data from an external device via NFC, and store input data in the memory 3200. The NFC device 3400 may include front-end circuitry 3410 and a chip 3420.

[0114] In some embodiments, chip 3420 may include collision detector 3421. Collision detector 3421 may perform RF collision detection operations according to the above embodiments (see [reference]). Figure 6 and Figure 7 In some embodiments, the collision detector 3421 may extract a clock with the same frequency as the second RF signal and may detect RF collisions relative to the NFC device 3400 based on the extracted clock, wherein the second RF signal is defined as a feedback signal of the first RF signal.

[0115] Power supply 3500 can supply the power required for the operation of electronic device 3000.

[0116] According to an embodiment, the electronic device 3000 can detect and subsequently avoid RF conflicts with another device by using an NFC device 3400 capable of detecting RF conflicts.

[0117] Although embodiments of this disclosure have been described, it should be understood that this disclosure is not intended to be limited to these embodiments, but rather that various changes and modifications can be made by those skilled in the art within the spirit and scope of this disclosure as claimed in the appended claims. Therefore, the subject matter disclosed should not be limited to any single embodiment described herein, and the scope of the inventive concept should be determined based on the appended claims.

Claims

1. A near-field communication device, comprising: The front-end circuitry includes an antenna and a matching network circuitry coupled to the antenna. A transmitting circuit configured to transmit a first radio frequency signal via the front-end circuit; A receiving circuit configured to receive a second radio frequency signal, the second radio frequency signal being a signal generated by transmitting the first radio frequency signal through the front-end circuit; A feedback circuit is configured to provide a feedback path from the receiving circuit to the transmitting circuit and to extract a clock having the same frequency as the second radio frequency signal from the second radio frequency signal. as well as A controller is configured to determine, based on the clock, whether a radio frequency conflict has occurred or not relative to the near-field communication device.

2. The near-field communication device according to claim 1, wherein, The controller is configured to switch the operating mode of the near-field communication device from polling mode to listening mode in response to determining that the radio frequency conflict has occurred.

3. The near-field communication device according to claim 2, wherein, The polling mode is defined as the mode of transmitting the first radio frequency signal, and the listening mode is defined as the mode of the near-field communication device responding to an external radio frequency signal.

4. The near-field communication device according to claim 3, wherein, The controller is configured to maintain the operating mode of the near-field communication device in the polling mode in response to determining that no radio frequency conflict has occurred.

5. The near-field communication device according to claim 1, wherein, The feedback circuit is configured to provide a closed loop relative to the transmitting circuit, the matching network circuit, and the receiving circuit via the feedback path.

6. The near-field communication device according to claim 1, wherein, The feedback circuit is configured to obtain a delayed clock based on setting a phase value by delaying the phase of the clock, and to provide the delayed clock to the transmitting circuit.

7. The near-field communication device according to claim 6, wherein, The transmitting circuit is configured to oscillate the first radio frequency signal based on the delayed clock.

8. The near-field communication device according to claim 7, wherein, The first radio frequency signal has a frequency that varies according to the set phase value.

9. The near-field communication device according to claim 6, wherein, The controller is configured to control the set phase value.

10. The near-field communication device according to claim 1, wherein, The controller is configured to determine that the radio frequency conflict has occurred when the frequency of the clock falls outside a set range relative to a reference frequency.

11. A method for determining whether radio frequency collisions have occurred or not in a near-field communication device, comprising: Send the first radio frequency signal in polling mode; The clock is extracted from a second radio frequency signal, which is a signal generated by transmitting the first radio frequency signal through the matching network circuit of the near-field communication device; as well as The occurrence and non-occurrence of the radio frequency conflict relative to the near-field communication device are determined based on the clock.

12. The method of claim 11, further comprising, in response to determining that the radio frequency conflict has occurred, switching the operating mode of the near-field communication device from the polling mode to the listening mode.

13. The method of claim 11, further comprising maintaining the operating mode of the near-field communication device in the polling mode in response to determining that no radio frequency conflict has occurred.

14. The method of claim 11, further comprising: A delayed clock is obtained by setting a phase value based on the phase delay of the clock. as well as The first radio frequency signal is oscillated based on the delayed clock.

15. The method according to claim 14, wherein, The first radio frequency signal has a frequency that varies according to the set phase value.

16. The method according to claim 11, wherein, The radio frequency conflict is determined to have occurred when the frequency of the clock falls outside a set range relative to the reference frequency.

17. A near-field communication chip, comprising: A transmitting circuit configured to transmit a first radio frequency signal; A receiving circuit configured to receive a second radio frequency signal that is defined as a feedback signal of the first radio frequency signal; A feedback circuit is configured to provide a feedback path from the receiving circuit to the transmitting circuit and to extract a clock having the same frequency as the second radio frequency signal from the second radio frequency signal. as well as A controller configured to determine whether radio frequency conflicts have occurred or not relative to the near-field communication chip based on the clock.

18. The near-field communication chip according to claim 17, wherein, The controller is configured to switch the operating mode of the near-field communication chip from polling mode to listening mode in response to determining that the radio frequency conflict has occurred.

19. The near-field communication chip according to claim 18, wherein, The controller is configured to maintain the operating mode of the near-field communication chip in the polling mode in response to determining that no radio frequency conflict has occurred.

20. The near-field communication chip according to claim 17, wherein, The controller is configured to determine that the radio frequency conflict has occurred when the frequency of the clock falls outside a set range relative to a reference frequency.

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