Circuit unit for realizing near field communication (NFC), and NFC device

Abstract

A circuit unit for realizing near field communication (NFC), and an NFC device. The circuit unit comprises an NFC antenna, an NFC chip and an excitation circuit, wherein the NFC antenna is connected to the NFC chip; the NFC chip is connected to the excitation circuit; the NFC chip is used for obtaining first energy when the NFC antenna senses a radio frequency field of a user terminal device, and providing part of the first energy to the excitation circuit; and the excitation circuit is used for using the energy obtained from the NFC chip to generate and send an excitation signal, wherein the excitation signal is used for exciting the user terminal device to communicate with a device including the circuit unit.

Description

Circuit unit for implementing near field communication and NFC device

[0001] The present application claims priority to the Chinese patent application No. 2024110630190, filed on August 2, 2024, entitled “Circuit unit for implementing near field communication and NFC device”, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of near field communication technology, and in particular to a circuit unit for implementing near field communication and an NFC device. BACKGROUND

[0003] Near field communication (NFC) technology, as a short-range wireless communication protocol, has been widely applied in many fields such as mobile payment, information interaction, smart home control, access control, identity authentication and identification, electronic ticketing, anti-counterfeiting, etc. The devices participating in NFC can include an NFC initiator device and an NFC target device, wherein the NFC initiator device (also referred to as a master device) needs a power supply device, the master device uses the energy of the power supply device to provide a radio frequency field and sends data to the NFC target device (also referred to as a slave device), and the transmission rate needs to be selected from one of 106kbps, 212kbps or 424kbps. The slave device does not generate a radio frequency field and can not need a power supply device, but uses the radio frequency field generated by the master device to convert into electrical energy to power the circuit of the slave device, receives the data sent by the master device, and uses load modulation technology to transmit the data of the slave device back to the master device at the same transmission rate.

[0004] In actual application, when using a mobile terminal device such as a smart phone as an NFC master device, in order to control power consumption, the NFC master device makes a lot of low-power design on the transmission power of its own card reader, etc. This makes it difficult for the target device at the other end to obtain a good communication success rate by using an active power supply scheme to interact with the mobile terminal device, which is high in power consumption and cost; and if a low-cost passive scheme is used, the communication success rate is often very low. Therefore, the near field communication mode of using a mobile terminal device such as a smart phone as an NFC master device is hindered from large-scale popularization and application.

[0005] Therefore, it is necessary to provide a near field communication scheme with low power consumption and high success rate.

[0006] SUMMARY

[0007] Therefore, the embodiment of the present application provides a circuit unit for implementing near field communication and a NFC device, which are used for improving the success rate of near field communication under low power consumption.

[0008] According to a first aspect of the embodiment of the present application, a circuit unit for implementing near field communication is provided, which comprises a NFC antenna, a NFC chip and an excitation circuit, the NFC antenna is connected with the NFC chip, and the NFC chip is connected with the excitation circuit, wherein the NFC chip is used for obtaining first energy in the case that the NFC antenna senses a radio frequency field of a user terminal device, and providing part of the first energy to the excitation circuit; the excitation circuit is used for generating and emitting an excitation signal by using the energy obtained from the NFC chip, and the excitation signal is used for exciting the user terminal device to communicate with a device comprising the circuit unit.

[0009] According to a second aspect of the embodiment of the present application, a NFC device is provided, which comprises a circuit unit for implementing near field communication, the circuit unit comprises a NFC antenna, a NFC chip and an excitation circuit, the NFC antenna is connected with the NFC chip, and the NFC chip is connected with the excitation circuit, wherein the NFC chip is used for obtaining first energy in the case that the NFC antenna senses a radio frequency field of a user terminal device, and providing part of the first energy to the excitation circuit; the excitation circuit is used for generating and emitting an excitation signal by using the energy obtained from the NFC chip, and the excitation signal is used for exciting the user terminal device to communicate with a device comprising the circuit unit.

[0010] An embodiment of the present application can achieve at least the following beneficial effects: by setting the excitation circuit, and using the NFC chip to obtain energy in the case that the NFC antenna senses a radio frequency field of a user terminal device and provide the energy to the excitation circuit, so that the excitation circuit emits an excitation signal for exciting the user terminal device to switch to a standard card detection mode and then perform near field communication, thereby improving the success rate of near field communication in a low power consumption manner. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0012] Fig. 1 is a schematic diagram of an application scenario of a circuit unit for implementing near field communication provided by an embodiment of the present application;

[0013] Fig. 2 is a schematic diagram of a circuit unit for implementing near field communication according to an embodiment of the present application;

[0014] Fig. 3 is a detailed schematic diagram of a circuit unit for implementing near field communication according to an embodiment of the present application;

[0015] Fig. 4 is a schematic diagram of another circuit unit for implementing near field communication according to an embodiment of the present application;

[0016] Fig. 5 is a schematic diagram of still another circuit unit for implementing near field communication according to an embodiment of the present application;

[0017] Fig. 6 is a schematic diagram of yet another circuit unit for implementing near field communication according to an embodiment of the present application;

[0018] Fig. 7 is a schematic diagram of a scenario in which a circuit unit for implementing near field communication according to an embodiment of the present application communicates with a user terminal device operating in an active mode according to an embodiment of the present application;

[0019] Fig. 8 is a schematic diagram of a structure of a metal sheet for an NFC antenna according to an embodiment of the present application;

[0020] Fig. 9 is a schematic diagram of another structure of a metal sheet for an NFC antenna according to an embodiment of the present application;

[0021] Fig. 10 is a schematic diagram of an NFC antenna including a metal sheet and a metal coil according to an embodiment of the present application;

[0022] Fig. 11 is a schematic diagram of another NFC antenna including a metal sheet and a metal coil according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the application. However, it will be apparent to one skilled in the art that the application can be practiced without the specific details set forth in this description. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the application.

[0024] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of one or more embodiments of the application. As used in this disclosure and the appended claims, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0025] It should be understood that, although the terms first, second, etc. can be used herein to describe various information, such information should not be limited to these terms. These terms are only used to differentiate one piece of information from another piece of information. For example, a first can be termed a second, and, similarly, a second can be termed a first, without departing from the scope of one or more embodiments. The word "if' can be interpreted to mean "when" or "upon" or "in response to determining" depending on the context.

[0026] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or authorized by all parties, and the collection, use and processing of related data need to comply with relevant laws, regulations and standards in the relevant region, and provide corresponding operation portal for user to choose authorization or refusal.

[0027] First, the nomenclature involved in one or more embodiments of the present application is explained.

[0028] NFC: Near Field Communication, i.e., near field communication, is a short-range high-frequency radio communication technology.

[0029] NFC active mode: also known as card reader mode. In active mode, the NFC device can act as a card reader to emit a radio frequency field to identify and read / write passive NFC device information. The NFC device in active mode can be referred to as an active NFC device or an NFC master device.

[0030] NFC passive mode: also known as card simulation mode. In passive mode, the NFC device is simulated as a card and can passively respond to the radio frequency field emitted by other devices and be read / written. The NFC device in passive mode can be referred to as a passive NFC device or an NFC slave device.

[0031] LPCD mode: i.e., low power card detection mode or low power card seeking mode, wherein LPCD represents Low Power Card Detection. LPCD is a technology used in NFC technology for efficient detection of proximate contactless smart cards or tags, mainly used to reduce the power consumption of NFC readers when waiting for a smart card or tag to approach. An NFC reader in LPCD mode can periodically send low-power pulses, and when the NFC reader detects a change in signal amplitude on the antenna and exceeds a preset threshold, it can determine that an NFC device is approaching to start further interaction process. Specifically, when a card enters the radio frequency field, the presence of the card will cause changes in the amplitude and phase of the signal, and the LPCD mode can use a software-based card detection mechanism to detect these changes using the LPCD algorithm, and by analyzing the in-phase (I) and quadrature (Q) components of the received signal to determine whether a card is approaching, and further trigger further NFC communication. In portable devices such as mobile phones, LPCD mode is particularly important, and its main advantage is low power consumption. Mobile phones usually need to be on standby for a long time, and frequent activation of NFC functions can significantly consume the battery. LPCD mode allows the mobile phone to continuously detect NFC signals in the background while maintaining a low energy consumption level. Once a card is detected, the mobile phone can quickly switch from low power state to full function state to perform NFC transactions or data exchange.

[0032] Standard card detection mode: or normal card detection mode or normal card seeking mode. In order to improve the rate and success rate of NFC communication, usually the NFC reader is in full function state when performing NFC communication, i.e., standard card detection mode. In actual application, in LPCD mode and standard card detection mode, the NFC reader (such as mobile terminal device) will emit a 13.56 MHz sine wave, the difference between LPCD mode and standard card detection mode is that the transmission time and amplitude of the sine wave are different. For example, in LPCD mode, the pulse width is usually us level, while in standard card detection mode, the pulse width is usually tens of ms level.

[0033] NFC tag: full name Near Field Communication tag, is a small device based on near field communication technology, which can realize data exchange between devices in a short distance. NFC tag usually includes a microchip and an antenna, the chip stores information (such as ID, URL, etc.), and the antenna is responsible for receiving and sending data. NFC tag is a passive device that can work without external power supply. In actual application, when an NFC reader (such as a smart mobile device supporting NFC function) approaches an NFC tag, the magnetic field generated by the NFC reader will be inducted by the antenna of the tag, thereby generating enough power to activate the chip in the tag, so that the tag can send the information stored in it.

[0034] NFC technology has been widely applied in many fields such as mobile payment, information interaction, smart home control, access control, identity authentication and identification, electronic ticketing, anti-counterfeiting and the like. For example, in the field of mobile payment, the payment method based on NFC technology is currently booming both at home and abroad.

[0035] In the mobile payment scenario, the mainstream NFC-based payment method at present is to make the cash register device as the payee end as a card reader working in active mode to achieve payment by reading the information passively simulated on the mobile device as the payer end. However, the electronic wallet used by consumers is provided by the mobile device manufacturer, and users need to open various wallets according to the requirements of the mobile device manufacturer in order to use the NFC payment function of the mobile device, which is not only inconvenient to manage, but also has information security risks. Moreover, not all mobile device models currently support the function of simulating passive cards such as financial payment, so the large-scale popularization and application of the NFC payment method with the mobile device working in passive mode are limited. Therefore, it is necessary to make the mobile device work in active mode.

[0036] However, the NFC payment method with the mobile device working in active mode also has some problems in practice. Specifically, the mobile device is usually powered by a battery and is very sensitive to power consumption. In order to control power consumption, many low-power designs are usually made to the transmission power of the card reader itself, such as setting the LPCD mode. For example, the phone usually turns off the card reading function when it is off screen, and most phones will automatically enter the LPCD mode after a period of time after the screen is turned on. When the mobile device in the LPCD mode is close to the opposite NFC target device, it can be switched to the standard card detection mode. In actual application, when the mobile device senses that the intensity change of the radio frequency signal it transmits is greater than or equal to a preset threshold due to the sensing of the opposite NFC target device, the mobile device will be awakened from the LPCD mode and enter the standard card detection mode. However, in the LPCD mode, the signal intensity emitted by the mobile device is weak, and the amplitude of the transmitted radio frequency signal will be reduced compared with the standard card detection mode. Therefore, the influence amplitude of the opposite NFC target device on the signal will also be reduced, so that the mobile device cannot determine whether there is an NFC target device around by the change amplitude of the signal, and thus cannot get the correct judgment result and cannot switch to the standard card detection mode, which further reduces the success rate of the mobile device sensing the NFC target device, and affects the success rate of near field communication and the user experience.

[0037] Taking a smart phone as an NFC master device and a cash register device for near field communication as an example, in the related art, only active devices can obtain a good communication success rate when interacting with the smart phone. However, the active cash register device has high power consumption, high design complexity, high cost, and high offline laying cost, and is not conducive to wide promotion. The communication success rate of a low-cost and passive payment solution is often very low (for example, the communication success rate of the current passive payment solution is less than 70%, and for some mobile devices, the communication success rate is even less than 50%), and the low success rate also hinders the promotion of the payment mode.

[0038] In view of this, in the embodiments of the present specification, a low-power near field communication solution applied to an NFC slave device is provided. By setting an excitation circuit, and providing part of the energy obtained by the NFC chip in the case that the NFC antenna induces the radio frequency field of the user terminal device to the excitation circuit, and then sending an excitation signal by the excitation circuit to excite the user terminal device and the NFC slave device to communicate. In this way, the near field communication success rate can be improved with low power consumption and low cost, thereby promoting the production and popularization of convenient NFC payment products as NFC slave devices.

[0039] FIG. 1 is a schematic diagram of an application scenario of a circuit unit for implementing near field communication provided by the embodiments of the present specification.

[0040] As shown in FIG. 1, when a mobile terminal device 100 with NFC function is close to an NFC tag 201 or a cash register terminal device 202 with NFC function, near field communication can occur between the mobile terminal device 100 and the NFC tag 201 or the cash register terminal device 202, so that the mobile terminal device 100 can obtain information provided by the NFC tag 201 or the cash register terminal device 202. In this process, the mobile terminal device 100 works in an active mode, and the NFC tag 201 or the cash register terminal device 202 works in a passive mode.

[0041] Although the NFC master device initiating the NFC communication is a smart phone type mobile terminal device 100 in FIG. 1, the NFC master device in the actual application of the solution of the present specification can include but is not limited to smart wearable devices such as smart watches, smart glasses, etc. Although the NFC slave device is the NFC tag 201 or the cash register terminal device 202 in FIG. 1, the NFC slave device in the actual application of the solution of the present specification can include but is not limited to electronic door locks, payment code plates, entry / exit gate machines, etc.

[0042] In actual application, the NFC master device such as the mobile terminal device 100 can emit a radio frequency field, and the NFC slave device such as the NFC tag 201 or the payment terminal device 202 can respond to the near field communication signal emitted by the NFC master device and send service information to the mobile terminal device 100 when the NFC slave device senses the near field communication signal. The service information can be different according to application scenarios. For example, in a payment scenario, the service information can include payment order information; for another example, in an ordering scenario, the service information can include a uniform resource locator for opening an ordering page; for still another example, in product traceability, the service information can include product description information.

[0043] The circuit unit for implementing near field communication provided by the scheme of the embodiments of the present specification can be installed in the NFC slave device such as the NFC tag 201 or the payment terminal device 202 as shown in FIG. 1. The NFC device provided by the scheme of the embodiments of the present specification can be used as the NFC tag 201 or the payment terminal device 202 as shown in FIG. 1.

[0044] In the scheme provided by the embodiments of the present specification, in the circuit unit for implementing near field communication, the energy recycling capability of the NFC chip itself for the radio frequency field of the user terminal device close by is utilized, and the recycled energy is provided to the excitation module, and the user terminal device is excited by the excitation module, so that the user terminal device can sense the presence of the NFC slave device (containing the circuit unit provided by the embodiments of the present specification) and further perform normal near field communication with the NFC slave device.

[0045] In one or more embodiments of the present specification, a circuit unit for implementing near field communication is provided.

[0046] FIG. 2 shows a schematic diagram of a circuit unit 300 for implementing near field communication provided by the embodiments of the present specification.

[0047] As shown in FIG. 2, specifically, the circuit unit 300 for implementing near field communication can include an NFC antenna 301, an NFC chip 302, and an excitation circuit 303, the NFC chip 302 can be connected with the NFC antenna 301, and the NFC chip 302 can be connected with the excitation circuit 303.

[0048] The NFC chip 302 and the NFC antenna 301 connected therewith can have the capability of signal sending and receiving, and signal modulation and demodulation. Specifically, the NFC chip 302 and the NFC antenna 301 connected therewith can work in a passive mode and directly communicate with a user terminal device (for example, a smart phone) working in an active mode at the opposite end.

[0049] The communication carrier frequency of NFC (Near Field Communication) technology is 13.56 MHz. This frequency is standardized worldwide, so that NFC devices of different manufacturers can be compatible with each other. The 13.56 MHz frequency is selected to ensure efficient and secure data exchange within a short distance (usually a few centimeters to about 20 centimeters). The radio frequency field with a communication carrier frequency of 13.56 MHz has the ability to provide an energy field. The radio frequency field transmitted by the NFC master device working in the active mode can usually provide energy for the NFC slave device. The NFC slave device working in the passive mode can work directly and complete communication with the NFC master device through the energy provided by the NFC master device. In the embodiments of the present specification, the NFC chip 302 and the NFC antenna 301 connected thereto can be provided by commercially available commodity chips, such as NXP NTAG5LINK chip, Fudan Micro FM11NT082C chip, and related chips of ST and other manufacturers, without being limited to these examples.

[0050] In the embodiments of the present specification, considering that the user terminal device can be in the LPCD mode and it is difficult to communicate successfully and difficult to be woken up, in order to improve the success rate of communication, the energy recovered by the NFC chip 302 working in the passive mode can be provided to the excitation circuit 303, and the excitation circuit 303 transmits an active radio frequency field to excite the user terminal device, so that the user terminal device switches to the standard card detection mode and performs near field communication data interaction, thereby improving the success rate of near field communication.

[0051] As shown in FIG. 2, the excitation circuit 303 is arranged in the circuit unit 300 for implementing near field communication. Specifically, the NFC chip 302 can be electrically connected with the excitation circuit 303, so that the NFC chip 302 can provide part of the energy recovered by the NFC antenna 301 based on the close radio frequency field to the excitation circuit 303, so that the excitation circuit 303 works. In actual application, the NFC chip 302 can output the recovered energy to the excitation circuit 303 through, for example, the VOUT pin.

[0052] Further, the NFC chip 302 can be used to obtain first energy in the case that the NFC antenna 301 senses the radio frequency field of the user terminal device, and provide part of the first energy to the excitation circuit 303. The excitation circuit 303 can be used to generate and emit an excitation signal using the energy obtained from the NFC chip 302, and the excitation signal is used to excite the user terminal device to communicate with the device containing the circuit unit 300.

[0053] Further, in the circuit unit 300, the NFC antenna 301 can be connected with the excitation circuit 303; and the excitation circuit 303 can be configured to radiate the excitation signal to the user terminal device through the NFC antenna.

[0054] In one or more embodiments of the present specification, the NFC chip 302 can be communicatively connected with the excitation circuit 303. Specifically, the NFC chip 302 can sense the field intensity state of the user terminal device through the NFC antenna 301, and output a related signal (e.g., an interrupt signal) to the excitation circuit 303.

[0055] More specifically, the NFC chip 302 can also be configured to send an interrupt signal to the excitation circuit 303 when the NFC antenna 301 senses that the radio frequency field of the user terminal device is close; accordingly, the excitation circuit 303 can be specifically configured to generate and send an excitation signal based on the signal characteristics of the interrupt signal when it is determined that the user terminal device is in the low-power card detection mode; the excitation signal is used to switch the user terminal device in the low-power card detection mode to the standard card detection mode.

[0056] FIG. 3 shows a detailed schematic diagram of a circuit unit 300 for implementing near field communication according to an embodiment of the present specification.

[0057] As shown in FIG. 3, the circuit unit 300 for implementing near field communication can include a NFC antenna 301, a NFC chip 302, and an excitation circuit 303, and further, the excitation circuit 303 can include a controller 3031 and a signal generator 3032. When the controller 3031 detects a related interrupt signal and the condition is necessary, it can control the signal generator 3032 to start field radiation excitation through a hardware enable signal, thereby awakening the user terminal device at the opposite end.

[0058] Optionally, the controller 3031 can control the signal generator 3032 to start field radiation excitation based on the interrupt signal judging that the user terminal device at the opposite end is in the LPCD state.

[0059] Specifically, the controller 3031 can be configured to use the energy obtained from the NFC chip 302 to determine whether the user terminal device is in the low-power card detection mode according to the signal characteristics of the interrupt signal, and send a hardware enable signal to the signal generator 3032 when the user terminal device is in the low-power card detection mode. Accordingly, the signal generator 3032 can be configured to use the energy obtained from the NFC chip 302 to generate and send the excitation signal in response to the hardware enable signal.

[0060] In actual application, the NFC chip 302 can be electrically connected with the excitation circuit 303 to provide energy for the excitation circuit 303. Specifically, the NFC chip 302 can be electrically connected with the controller 3031 and the signal generator 3032 respectively to provide energy for the controller 3031 and the signal generator 3032 respectively.

[0061] The NFC chip 302 can be communicatively connected with the excitation circuit 303 to output an interrupt signal to the excitation circuit 303. Specifically, the NFC chip 302 can be communicatively connected with the controller 3031 and output an interrupt signal to the controller 3031. In turn, a preset judgment process can be performed by the controller 3031, and in a case where it is determined that the excitation signal needs to be transmitted, a hardware enable signal is output to the signal generator 3032 to make the signal generator 3032 transmit the excitation signal.

[0062] In actual application, the NFC chip 302 can communicate with the controller 3031 through an I2C, SPI or other communication interface. In specific implementation, a software program can be injected into the NFC chip 302, so that when the NFC chip 302 obtains a signal of a nearby radio frequency field based on the induction of the NFC antenna 301, an interrupt signal is output to the controller 3031, so that the controller 3031 can learn the characteristics of the radio frequency field.

[0063] Taking the Fudan Micro FM11NT082C chip as an example, when the NFC chip 302 detects a field strength change, a high-level interrupt can be output to the controller 3031 through an Interrupt Request (IRQ) pin to establish communication between the NFC chip 302 and the controller 3031.

[0064] Specifically, the characteristics of the field strength signal of the radio frequency field transmitted by the user terminal device can be carried in the interrupt signal.

[0065] In actual application, the signal characteristics of the interrupt signal can include at least one of pulse width, time period or pulse amplitude, without being limited thereto. In actual application, the judgment of whether the user terminal device is in the low-power card detection mode can specifically include: judging whether the user terminal device is in the low-power card detection mode according to at least one of the pulse width, time period or pulse amplitude of the interrupt signal.

[0066] Specifically, the signal feature of the terminal request information transmitted by the NFC chip 302 can be used to reflect the feature of the radio frequency field of the user terminal device. When the user terminal device is in different card detection states, the features of the transmitted radio frequency field are different, and thus the features of the interrupt signals generated by the NFC chip and transmitted to the controller 3031 are different.

[0067] For example, compared with the standard card detection mode, when the user terminal device is in the LPCD mode, the pulse width of the signal of the transmitted radio frequency field is shorter, and correspondingly, the pulse width of the interrupt signal is shorter. For another example, compared with the standard card detection mode, when the user terminal device is in the LPCD mode, the time period of the signal of the transmitted radio frequency field is longer, and correspondingly, the time period of the interrupt signal is longer. For still another example, compared with the standard card detection mode, when the user terminal device is in the LPCD mode, the pulse amplitude of the signal of the transmitted radio frequency field is weaker, and correspondingly, the pulse amplitude of the interrupt signal is weaker.

[0068] Further, in order to save energy, the controller 3031 can control the signal generator 3032 to start the field radiation excitation again in a case where it is determined that the information in the NFC chip 302 is not read.

[0069] In actual application, if the NFC chip communicates successfully with the user terminal device and the information in the NFC chip 302 is read by the user terminal device, the NFC chip will output corresponding flag information according to the program setting of the NFC chip. In actual application, when the controller 3031 receives the interrupt signal, the flag information can be read from the NFC chip through a communication interface (for example, an I2C, SPI or the like), and then whether the communication is successful can be known based on the flag information.

[0070] Specifically, the controller 3031 can also be used to determine whether the user terminal device communicates successfully with the NFC chip 302 based on the flag information obtained from the NFC chip 302 by using the energy obtained from the NFC chip 302, and send a hardware enable signal to the signal generator 3032 in a case where the user terminal device is in the low-power card detection mode and the user terminal device does not communicate successfully with the NFC chip 302. Correspondingly, the signal generator 3032 can generate and send the excitation signal by using the energy obtained from the NFC chip 302 in response to the hardware enable signal.

[0071] That is, the excitation circuit 303 can be specifically used to generate and send the excitation signal in a case where it is determined that the user terminal device is in the low-power card detection mode and the NFC chip does not communicate successfully with the user terminal device based on the signal feature of the interrupt signal.

[0072] In one or more embodiments of the present specification, in order to further improve the energy recovery efficiency of the energy provided by the NFC master device working in the active mode, an energy recovery circuit can be further provided.

[0073] FIG. 4 shows a schematic diagram of another circuit unit 310 for implementing near field communication according to an embodiment of the present specification.

[0074] As shown in FIG. 4, the circuit unit 310 for implementing near field communication can include an NFC antenna 301, an NFC chip 302, and an excitation circuit 303, and further can include a conditioning circuit 304, which can be connected with the NFC antenna 301, and the conditioning circuit 304 can be connected with the excitation circuit 303. Specifically, the conditioning circuit 304 can be configured to obtain a second energy when the NFC antenna 301 senses the radio frequency field of the user terminal device, and provide at least part of the second energy to the excitation circuit 303.

[0075] Specifically, the 13.56 MHz sine wave sensed by the NFC antenna can be output to the excitation circuit 303 in the back stage for use by the conditioning circuit 304. The conditioning circuit 304 can be electrically connected with the excitation circuit 303, and more specifically, can be electrically connected with the controller 3031 and the signal generator 3032 to provide energy to the controller 3031 and the signal generator 3032.

[0076] In one or more embodiments of the present specification, considering that the field period of the LPCD is particularly short, an energy supply module can be optionally additionally provided to supplement the power supply of the excitation circuit 303 as a special period to ensure the completion of a communication period.

[0077] FIG. 5 shows a schematic diagram of another circuit unit 320 for implementing near field communication according to an embodiment of the present specification.

[0078] As shown in FIG. 5, the circuit unit 320 for implementing near field communication can include an NFC antenna 301, an NFC chip 302, an excitation circuit 303, and a conditioning circuit 304, and further can include an energy supply module 305, which is connected with the excitation circuit 303 and configured to provide a third energy to the excitation circuit 303.

[0079] Optionally, the energy supply module 305 can be set as a chargeable module. In the case that the chargeable energy supply module 305 is set, the energy recycled by the NFC chip 302 and the trimming circuit 304 can be provided to the chargeable energy supply module 305, and then provided to the excitation circuit 303 when needed, so as to improve the energy utilization efficiency. In addition, the chargeable energy supply module 305 can have an external charging interface, so as to obtain additional energy.

[0080] In actual application, the energy supply module 305 can be specifically set as a button cell, a lithium battery, etc.

[0081] It should be noted that, in the embodiment of the present specification, the scheme of setting the energy supply module 305 for providing additional energy for the excitation circuit 303 is different from the scheme of the active NFC chip in the related art. In the active NFC chip in the related art, a power supply directly used for supplying power to the NFC chip is usually set, instead of further setting a supplementary power supply for supplying power to the excitation circuit 303 on the basis of setting the excitation circuit 303. Moreover, in the embodiment of the present specification, the energy supply module 305 plays a role of the supplementary power supply, and is used as a bottom solution. In other words, even in the case that the energy supply module 305 is not used, the driving of the excitation circuit 303 can still be realized through the recycling of the energy inducted by the NFC antenna, and then the wake-up of the peer device can be realized, and the near field communication success rate can be improved.

[0082] In one or more embodiments of the present specification, another antenna can also be set, for radiating the excitation signal generated by the excitation circuit 303.

[0083] FIG. 6 shows a schematic diagram of another circuit unit 330 for realizing near field communication provided by the embodiment of the present specification.

[0084] As shown in FIG. 6, the circuit unit 330 for realizing near field communication can include the NFC antenna 301, the NFC chip 302 and the excitation circuit 303, and further, the circuit unit 330 can also include a second NFC antenna 306, the second NFC antenna 306 being connected with the excitation circuit 303; the excitation circuit 303 is used for radiating the excitation signal to the user terminal device through the second NFC antenna 306.

[0085] Unlike the embodiment shown in Fig. 2, in the embodiment shown in Fig. 6, the excitation signal can be radiated by the additionally set NFC antenna. By setting the second NFC antenna 306 to radiate the excitation signal, on the one hand, the design is simpler without complex time division multiplexing design, and the signal transmission efficiency is also higher; on the other hand, since the antenna is additionally set, compared with multiplexing the original existing antenna, the shape, position, etc. of the second NFC antenna can be more flexibly set, so as to more greatly improve the radiation intensity of the excitation signal, better inductively couple with the device of the user terminal equipment at the opposite end, so as to further improve the probability of waking up the user terminal equipment from the LPCD mode, and further improve the near field communication success rate.

[0086] As shown in Fig. 6, it is an optimization based on the embodiment shown in Fig. 2, and the excitation signal transmitted by the NFC antenna 301 is replaced by the second NFC antenna 306. Optionally, the excitation signal can also be transmitted by the NFC antenna 301 and the second NFC antenna 306 together, thereby further improving the signal transmission efficiency, improving the probability of waking up the user terminal equipment from the LPCD mode, and further improving the near field communication success rate.

[0087] Similarly to the improvement of the embodiment shown in Fig. 2 described in the foregoing embodiments, similar improvements can be made to the embodiments shown in Figs. 4 and 5.

[0088] Specifically, for the circuit unit 310 shown in Fig. 4, a second NFC antenna 306 can be further provided, so that the excitation signal can be transmitted by the second NFC antenna 306, or the excitation signal can be transmitted by the NFC antenna 301 and the second NFC antenna 306 together.

[0089] Similarly, for the circuit unit 320 shown in Fig. 5, a second NFC antenna 306 can be further provided, so that the excitation signal can be transmitted by the second NFC antenna 306, or the excitation signal can be transmitted by the NFC antenna 301 and the second NFC antenna 306 together.

[0090] According to the above description, an actual application scenario of the circuit unit for implementing near field communication provided by the embodiment of the present application and a scenario diagram of near field communication with the user terminal equipment working in the active mode are shown in Fig. 7.

[0091] As shown in FIG. 7, the circuit unit can include an NFC antenna 301, an NFC chip 302, and an excitation circuit 303, wherein the excitation circuit 303 can specifically include a controller 3031 and a signal generator 3032. When a user terminal device working in an active mode approaches the NFC antenna 301, the NFC antenna 301 senses the approach of a radio frequency field, and the NFC chip 302 connected with the NFC antenna 301 can output part of the energy recovered from the NFC antenna 301 to the excitation circuit 303, and can generate an interrupt signal according to the change of the field signal sensed by the NFC antenna 301 and send it to the excitation circuit 303, so that the excitation circuit 303 sends an excitation signal and radiates through the NFC antenna 301 to wake up the user terminal device from the LPCD mode when it is determined that the preset condition is met based on the interrupt signal. Specifically, the excitation signal can be radiated through the NFC antenna 301, or the excitation signal can be radiated through a second NFC antenna 306 additionally arranged.

[0092] Optionally, in order to improve the energy recovery rate of the radio frequency field emitted by the user terminal device working in the active mode, a regulation circuit 304 connected between the NFC antenna 301 and the excitation circuit 303 can be arranged. The regulation circuit 304 is used to collect the energy of the radio frequency field and output it to the excitation circuit 303 when the NFC antenna 301 senses the radio frequency field.

[0093] In actual application, when the NFC chip 302 and the regulation circuit 304 are used to recover energy at the same time, the energy recovery rate can be greatly improved. For example, about 30 mW-50 mW (1.8 V, 16 mA-28 mA) of energy can be recovered in the process of approaching a radio frequency field once, which is used to provide for the excitation circuit 303 in the rear stage.

[0094] Further, the controller 3031 can include a low-power microcontroller unit (MCU). Generally, a low-power MCU has a sleep power consumption of uA level and a working capacity of dozens of uA@1 MHz (such as the N32L40 series of the National and the related MCU of ST, etc.); generally, a low-power MCU works at about 40 MHz and can control the working current at about 3.6 mW-7.2 mW (1.8 V, 2-4 mA).

[0095] In actual application, when the NFC chip 302 cannot directly wake up the peer device through passive load change of the NFC antenna 301, leading to communication obstruction, the energy recovered by the NFC chip 302 and the rectifier circuit 304 can be used to supply the low-power MCU to work. Specifically, when the field signal is close to the NFC antenna 301, the NFC chip 302 and the rectifier circuit 310 can start to recover energy to supply the low-power MCU to work in a low-power state. Then, when the NFC chip 302 detects the field interruption signal, the low-power MCU is woken up from the low-power state, and the low-power MCU can further determine the working state of the peer device according to the pulse width, time period, pulse amplitude, and other comprehensive information of the interruption signal. If it is determined that the peer device is in the LPCD state, the low-power MCU can control the signal transmitter to transmit a 13.56M active field to wake up the peer device and then complete the next step of communication, thereby improving the communication success rate.

[0096] Further, the signal generator 3032 can include an active crystal or an RC oscillation circuit, which is mainly used to generate a signal field of about 12-14MHz, and the power consumption is about 3.6mW-5.4mW (1.8V, 2-3mA). Specifically, the signal field generated by the signal generator 3032 can be conducted to the antenna to radiate outward under the control of the controller 3031. Alternatively, it can be conducted to the NFC antenna 301 to radiate outward (NFC antenna 301 time division multiplexing), as shown in FIGS. 2-5. Alternatively, it can be conducted to the second NFC antenna 306 to radiate outward, as shown in FIG. 6.

[0097] In one or more embodiments of the present specification, the frequency of the active field radiated outward based on the excitation signal provided by the signal generator 3032 can be tuned to be consistent with the frequency of the radio frequency field of the user terminal device, i.e., to achieve resonance multipoint. Specifically, it can be set to 12-14MHz. More specifically, it can be set to about 13.56M.

[0098] In one or more embodiments of the present specification, the NFC antenna 301 in the circuit unit (including the circuit units 300, 310, 320, or 330) can be further optimized.

[0099] FIG. 8 shows a structural schematic diagram of a metal sheet for an NFC antenna according to an embodiment of the present specification.

[0100] In a circuit unit for implementing near field communication, the NFC antenna 301 can include a metal sheet 401 as shown in FIG. 8. The metal sheet 401 can be bent in the plane where the metal sheet 401 is located, so that the two ends of the metal sheet 401 along the length direction are close to each other and form a gap space.

[0101] Fig. 9 shows another structure of a metal sheet for an NFC antenna according to an embodiment of the present specification.

[0102] In a circuit unit for implementing near field communication, the NFC antenna 301 can include a metal sheet 402 as shown in Fig. 9. Similarly to Fig. 8, the metal sheet 402 can be bent in a plane in which the metal sheet 402 is located, so that both ends of the metal sheet 402 in the length direction are close to each other and form a gap space.

[0103] Specifically, in the metal sheet as shown in Figs. 8 and 9, a metal sheet bent into a ring in a plane can be used instead of the conventional metal coil structure for the NFC antenna 301. In actual application, the middle region surrounded by the metal sheet 401 or 402 can be used to place the NFC chip 302. The relative position of the NFC chip 302 to the metal sheet 401 or 402 can not be limited to this.

[0104] It can be understood that Figs. 8 and 9 only give two specific examples of the metal sheet, and in actual application, the shape of the metal sheet can not be limited to being circular or rectangular, but can also be polygonal or irregular, and the bending form of the metal sheet can be set according to actual needs. For example, it can be adapted to the spatial position of the NFC chip.

[0105] Further, the material of the metal sheet can use conventional metals used as communication antennas. For example, copper can be used.

[0106] Optionally, in actual application, a metal sheet can be used instead of a metal coil as an NFC antenna. Specifically, both ends of the metal sheet in the length direction can be used as the feed point of the NFC antenna 301. In actual application, the NFC antenna 301 can be connected to the NFC chip 302 through the feed point.

[0107] Optionally, in actual application, a metal sheet and a metal coil can be used in combination in the NFC antenna 301. Specifically, the metal coil can include a feed point connected to the NFC chip 302, and the metal sheet can not include a feed point.

[0108] Unlike the conventional linear metal coil, in the embodiments of the present specification, the NFC antenna can be set as a sheet-shaped metal ring having a large area in the plane in which the antenna body is located. Thus, the equivalent inductance value of the antenna can be improved, for example, to 500nHˉ2uH, and under such an inductance value, a resonant circuit can be formed by matching with a capacitor to have a resonant point at about 13.56MHz, so that the radiated energy is large, and a suitable capacitor can be found to match with it.

[0109] Thus, on one hand, the ability to wake up a user terminal device from an LPCD state by affecting the inductive load of the user terminal device at the other end can be improved; on the other hand, the efficiency of energy recovery can be improved; on yet another hand, the strength and efficiency of radiating the excitation signal via the NFC antenna 301 can be improved. In general, the success rate of communication when the NFC slave device communicates with the user terminal device in near field can be improved.

[0110] Fig. 10 is a schematic diagram of an NFC antenna including a metal sheet and a metal coil according to an embodiment of the present specification.

[0111] Specifically, in a circuit unit for implementing near field communication, the NFC antenna 301 includes a metal sheet (for example, the metal sheet 401 as shown in Fig. 8 or the metal sheet 402 as shown in Fig. 9), and further, the NFC antenna 301 can further include a metal coil, which can be arranged in the same plane as the metal sheet, and the metal coil can be arranged in the area surrounded by the metal sheet after being bent.

[0112] As shown in Fig. 10, the metal coil 501 can be arranged in the area surrounded by the metal sheet 401 after being bent. In actual application, the NFC chip 302 can be further arranged in the area surrounded by the metal coil 501.

[0113] Fig. 11 is a schematic diagram of another NFC antenna including a metal sheet and a metal coil according to an embodiment of the present specification.

[0114] Specifically, in a circuit unit for implementing near field communication, the NFC antenna 301 includes a metal sheet (for example, the metal sheet 401 as shown in Fig. 8 or the metal sheet 402 as shown in Fig. 9), and further, the NFC antenna 301 can further include a metal coil, which can be arranged in the same plane as the metal sheet, and the metal coil can be arranged in the area surrounded by the metal sheet after being bent.

[0115] As shown in Fig. 11, the metal sheet 401 can be arranged closer to the scanned side of the device including the circuit unit than the metal coil 501.

[0116] In actual application, by arranging the metal sheet and the metal coil in a sleeve or overlapping manner in the NFC antenna module, the annular metal sheet can function as an amplifier, thereby improving the emission efficiency and strength of the signal, and further improving the success rate of waking up the user terminal device from the LPCD mode, and further improving the success rate of near field communication.

[0117] In addition, in the embodiments of the present application, in order to enable the NFC antenna to better couple with the antenna of the user terminal device at the opposite end, the NFC antenna can be tuned to the transmission frequency band of 13.56 MHz (12-14 MHz) by setting a matching circuit (for example, by connecting a certain capacitance in parallel), so as to achieve better coupling with the antenna of the user terminal device at the opposite end and enhance the energy conversion efficiency.

[0118] In one or more embodiments of the present application, similar to the NFC antenna 301, when the second NFC antenna 306 is used in the circuit module, a metal sheet can also be used in the second NFC antenna 306.

[0119] Specifically, in a circuit unit for implementing near field communication, the second NFC antenna 306 contained therein can include a metal sheet, the metal sheet being bent in a plane in which the metal sheet is located, so that the two ends of the metal sheet in the length direction are close to each other and form a gap space. For example, the metal sheet can be a metal sheet 401 as shown in FIG. 8 or a metal sheet 402 as shown in FIG. 9, and the shape of the metal sheet is not limited thereto.

[0120] Optionally, in actual application, a metal sheet can be used instead of a metal coil as an NFC antenna. Specifically, the two ends of the metal sheet in the length direction can serve as the feed points of the second NFC antenna 306. In actual application, the second NFC antenna 306 can be connected to the NFC chip 302 through the feed points.

[0121] Optionally, in actual application, a metal sheet and a metal coil can be used in combination in the second NFC antenna 306. Specifically, the metal coil can include feed points connected to the NFC chip 302, and the metal sheet can not include feed points.

[0122] Further optionally, in a circuit unit for implementing near field communication, the NFC antenna 306 is based on a metal sheet (for example, a metal sheet 401 as shown in FIG. 8 or a metal sheet 402 as shown in FIG. 9), and further, the second NFC antenna 306 can further include a metal coil, the metal coil can be located in the same plane as the metal sheet, and the metal coil can be located in the area surrounded by the metal sheet after being bent.

[0123] As shown in FIG. 10, the metal coil 501 can be located in the area surrounded by the metal sheet 401 after being bent. In actual application, the NFC chip 302 can be further placed in the area surrounded by the metal coil 501.

[0124] Further additionally optionally, in a circuit unit for implementing near field communication, the NFC antenna 301 is in a case comprising a metal sheet (for example, the metal sheet 401 as shown in FIG. 8 or the metal sheet 402 as shown in FIG. 9), further, the second NFC antenna 306 can further comprise a metal coil, the metal coil can be arranged in overlapping with the metal sheet; the metal sheet can be closer to the scanned side of the device containing the circuit unit than the metal coil.

[0125] As shown in FIG. 11, the metal sheet 401 can be arranged to be closer to the scanned side of the device containing the circuit unit than the metal coil 501.

[0126] In actual application, by arranging the metal sheet and the metal coil in the NFC antenna module (for example, the NFC antenna 301 or the second NFC antenna 306), the annular metal sheet can play the role of an amplifier, thereby improving the transmission efficiency and strength of the signal, and further improving the success rate of waking up the user terminal device from the LPCD mode, and further improving the success rate of near field communication.

[0127] The various technical features in the above embodiments can be combined in any manner as long as there is no conflict or contradiction between the features, but for the sake of brevity, they are not described one by one, and therefore any combination of the various technical features in the above embodiments also belongs to the scope disclosed by the present specification.

[0128] In one or more embodiments of the present specification, an NFC device corresponding to the circuit unit for implementing near field communication is also provided. The NFC device can comprise any one of the circuit units provided by the embodiments of the present specification as described above.

[0129] Specifically, the NFC device can comprise a circuit unit for implementing near field communication, the circuit unit can comprise: an NFC antenna 301, an NFC chip 302 and an excitation circuit 303, the NFC chip 302 is connected with the NFC antenna 302, and the NFC chip 302 is connected with the excitation circuit 303.

[0130] The NFC chip 302 can be configured to obtain a first energy in a case where the NFC antenna 301 senses a radio frequency field of a user terminal device, and provide part of the first energy to the excitation circuit.

[0131] The excitation circuit 303 can be configured to generate and emit an excitation signal using the energy obtained from the NFC chip 302, the excitation signal being used to excite the user terminal device to communicate with the NFC device.

[0132] In the embodiments of the present application, the NFC device works in a passive mode, and the user terminal device communicating with the NFC device works in an active mode.

[0133] It should be noted that the technical solution of the NFC device belongs to the same concept as the technical solution of the circuit unit described above, and the details of the technical solution of the NFC device that are not described in detail can be seen from the description of the technical solution of the circuit unit.

[0134] Each of the embodiments in the present application is described in a progressive manner, and the same or similar parts of each of the embodiments can be referred to each other. Each of the embodiments focuses on the difference from other embodiments. The device provided in the embodiments of the present application includes the embodiments of the circuit unit for implementing near field communication, and therefore the device also has the beneficial technical effects similar to the embodiments of the circuit unit for implementing near field communication. Since the beneficial technical effects of the embodiments of the circuit unit for implementing near field communication have been described in detail above, the beneficial technical effects of the corresponding device will not be described here.

[0135] The above describes specific embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than the order in which they are recited and still achieve desirable results. In addition, the processes depicted in the figures do not necessarily require the particular order shown, or sequential order, to achieve the desired results.

[0136] It should also be noted that the terms "comprising", "including", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods or devices including a series of elements not only include those elements, but also include other elements not explicitly listed, or inherent to such processes, methods or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, product or device including the element.

[0137] The above only describes the embodiments of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A circuit unit for implementing near field communication, comprising an NFC antenna, an NFC chip and an excitation circuit, the NFC antenna being connected with the NFC chip, the NFC chip being connected with the excitation circuit, wherein the NFC chip is configured to obtain a first energy in a case that the NFC antenna senses a radio frequency field of a user terminal device, and provide part of the first energy to the excitation circuit; the excitation circuit is configured to generate and emit an excitation signal by using the energy obtained from the NFC chip, the excitation signal being used to excite the user terminal device to communicate with a device containing the circuit unit. The NFC antenna is connected with the excitation circuit; the excitation circuit is configured to radiate the excitation signal to the user terminal device through the NFC antenna.

3. The circuit unit of claim 1, further comprising a second NFC antenna, the second NFC antenna being connected with the excitation circuit; the excitation circuit is configured to radiate the excitation signal to the user terminal device through the second NFC antenna.

2. The circuit unit of claim 1, wherein, 4. The circuit unit of claim 1, wherein the NFC chip is further configured to send an interrupt signal to the excitation circuit in a case that the NFC antenna senses the radio frequency field of the user terminal device; the excitation circuit is specifically configured to generate and emit the excitation signal based on a signal feature of the interrupt signal in a case that it is determined that the user terminal device is in a low-power card detection mode; the excitation signal is used to switch the user terminal device in the low-power card detection mode to a standard card detection mode. The excitation circuit comprises a controller and a signal generator; The controller is configured to determine whether the user terminal device is in the low-power card detection mode according to the signal feature of the interrupt signal by using the energy obtained from the NFC chip, and emit a hardware enable signal to the signal generator in a case that the user terminal device is in the low-power card detection mode; The signal generator is configured to generate and emit the excitation signal in response to the hardware enable signal by using the energy obtained from the NFC chip.

6. The circuit unit of claim 5, wherein the controller is further configured to determine whether the user terminal device successfully communicates with the NFC chip based on flag information obtained from the NFC chip by using the energy obtained from the NFC chip, and emit the hardware enable signal to the signal generator in a case that the user terminal device is in the low-power card detection mode and the user terminal device does not successfully communicate with the NFC chip.

5. The circuit unit of claim 4, wherein, 7. The circuit unit of claim 1, further comprising a trimming circuit, the trimming circuit being connected with the NFC antenna and the excitation circuit; the trimming circuit is configured to obtain a second energy in a case that the NFC antenna senses the radio frequency field of the user terminal device, and provide at least part of the second energy to the excitation circuit. ​ ​ ​ ​ ​ ​ 8. The circuit unit of claim 1, further comprising an energy supply module connected to the excitation circuit, for providing a third energy to the excitation circuit.

9. The circuit unit of claim 1, wherein the NFC antenna comprises a metal sheet, the metal sheet being bent in a plane in which the metal sheet lies, so that two ends of the metal sheet in a length direction are close to each other and form a gap space.

10. The circuit unit of claim 9, wherein the two ends of the metal sheet in the length direction are used as feed points of the NFC antenna.

11. The circuit unit of claim 9, wherein the NFC antenna further comprises a metal coil, the metal coil being in the same plane as the metal sheet, and the metal coil being located in an area surrounded by the metal sheet after the metal sheet is bent.

12. The circuit unit of claim 9, wherein the NFC antenna further comprises a metal coil, the metal coil being overlapped with the metal sheet; and the metal sheet is closer to a scanned side of a device containing the circuit unit than the metal coil.

13. The circuit unit of claim 3, wherein the second NFC antenna comprises a metal sheet, the metal sheet being bent in a plane in which the metal sheet lies, so that two ends of the metal sheet in a length direction are close to each other and form a gap space.

14. The circuit unit of claim 13, wherein the two ends of the metal sheet in the length direction are used as feed points of the second NFC antenna.

15. The circuit unit of claim 13, wherein the second NFC antenna further comprises a metal coil, the metal coil being in the same plane as the metal sheet, and the metal coil being located in an area surrounded by the metal sheet after the metal sheet is bent.

16. The circuit unit of claim 13, wherein the second NFC antenna further comprises a metal coil, the metal coil being overlapped with the metal sheet; and the metal sheet is closer to a scanned side of a device containing the circuit unit than the metal coil.

17. An NFC device, comprising the circuit unit of any one of claims 1 to 16.

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