Circuit unit and NFC device for realizing short-range wireless communication

Abstract

To provide a circuit unit and a near field communication (NFC) device for achieving near field communication.SOLUTION: The circuit unit 300 includes an NFC antenna 301, an NFC chip 302, and an exciting circuit 303, where the NFC antenna 301 is connected to the NFC chip 302, and the NFC302 chip is connected to the exciting circuit 303. The NFC chip 302 is configured to obtain first energy when the NFC antenna 301 senses a radio frequency field of a user terminal device, and provide a part of the first energy to the excitation circuit 303, the excitation circuit 303 is configured to generate and emit an excitation signal by using the energy obtained from the NFC chip 302, and the excitation signal is configured to excite the user terminal device to communicate with a device including the circuit unit 300.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] This application relates to the field of short - range wireless communication technology, especially to a circuit unit and an NFC device for realizing short - range wireless communication.

Background Art

[0002] Near - field communication (NFC) technology, as a short - range wireless communication protocol, has been widely applied in multiple fields such as mobile payment, information interaction, smart home control, access control, identity authentication and identification, electronic tickets, and anti - counterfeiting. Devices involved in NFC may include an NFC initiating device and an NFC target device. Here, the NFC initiating device (also called the master device) requires a power - supplying device. The master device uses the energy of the power - supplying device to provide a radio - frequency field, transmits data to the NFC target device (also called the slave device), and needs to select one of the transmission rates of 106 kbps, 212 kbps, or 424 kbps. The slave device does not generate a radio - frequency field and does not require a power - supplying device. It uses the radio - frequency field generated by the master device to convert it into electrical energy to supply power to the circuit of the slave device, receives the data transmitted by the master device, and can transmit the data of the slave device to the master device at the same transmission rate by using the load modulation technology.

[0003] In practical applications, when using mobile devices such as smartphones as NFC master devices, NFC master devices incorporate many low-power design features, such as reduced transmission power for their card readers, to control power consumption. This means that a good communication success rate can only be achieved by the target device using an active power supply approach to interact with the mobile device. However, this approach consumes a lot of power and is costly. Conversely, using a low-cost passive approach often results in a low communication success rate. This hinders the widespread adoption of short-range wireless communication using mobile devices like smartphones as NFC master devices.

[0004] In light of this, there is a need to provide a short-range wireless communication solution that consumes little power and has a high success rate. [Overview of the project] [Problems that the invention aims to solve]

[0005] In view of this, the embodiments of this application provide a circuit unit and an NFC device for realizing short-range wireless communication in order to improve the success rate of short-range wireless communication under low power consumption conditions. [Means for solving the problem]

[0006] According to a first embodiment of the present invention, a circuit unit for realizing short-range wireless communication is provided, comprising an NFC antenna, an NFC chip, and an excitation circuit, wherein the NFC antenna is connected to the NFC chip, and the NFC chip is connected to the excitation circuit, wherein the NFC chip is used to obtain first energy when the NFC antenna senses the radio frequency field of a user terminal device and to provide a portion of the first energy to the excitation circuit, the excitation circuit is used to generate and emit an excitation signal using the energy obtained from the NFC chip, and the excitation signal is used to excite the user terminal device to communicate with a device including the circuit unit.

[0007] According to a second embodiment of the present application, an NFC device is provided, which includes a circuit unit for realizing short-range wireless communication, the circuit unit including an NFC antenna, an NFC chip, and an excitation circuit, wherein the NFC antenna is connected to the NFC chip, and the NFC chip is connected to the excitation circuit, the NFC chip is used to obtain first energy when the NFC antenna senses the radio frequency field of a user terminal device and to provide a portion of the first energy to the excitation circuit, the excitation circuit is used to generate and emit an excitation signal using the energy obtained from the NFC chip, and the excitation signal is used to excite the user terminal device to communicate with the device including the circuit unit. [Effects of the Invention]

[0008] One embodiment of this specification can achieve at least the following beneficial effects: by installing an excitation circuit and using an NFC chip, when the NFC antenna senses the radio frequency field of a user terminal device, it obtains energy and provides it to the excitation circuit, thereby switching to standard card detection mode, and further causing the excitation circuit to emit an excitation signal to excite the user terminal device to perform short-range wireless communication, thereby improving the success rate of short-range wireless communication in a low-power manner. [Brief explanation of the drawing]

[0009] To more clearly illustrate the examples of this specification or the technical concepts in the prior art, the following briefly introduces the drawings that may be used in the descriptions of the examples or the prior art. Obviously, the drawings in the following descriptions are only a few examples of the examples described in this application, and those skilled in the art can obtain other drawings based on these without any creative effort.

[0010] [Figure 1] This is a schematic diagram illustrating an application scenario of the circuit unit for realizing short-range wireless communication according to the embodiments described herein. [Figure 2] This is a schematic diagram of a circuit unit for realizing short-range wireless communication according to the embodiments described herein. [Figure 3] This is a detailed schematic diagram of a circuit unit for realizing short-range wireless communication according to the embodiments described herein. [Figure 4] This is a schematic diagram of a circuit unit for realizing another short-range wireless communication according to the embodiments described herein. [Figure 5] This is a schematic diagram of a circuit unit for realizing yet another short-range wireless communication according to the embodiments described herein. [Figure 6] This is a schematic diagram of a circuit unit for realizing further short-range wireless communication according to the embodiments described herein. [Figure 7] This is a schematic diagram illustrating a scenario in which a circuit unit for realizing short-range wireless communication in an actual application scenario according to the embodiments of this specification and a user terminal device operating in active mode perform short-range wireless communication. [Figure 8] This is a schematic diagram of the structure of a metal piece used in an NFC antenna according to the embodiments described herein. [Figure 9] This is a schematic diagram of the structure of a metal piece used in another NFC antenna according to the embodiments described herein. [Figure 10] This is a schematic diagram of an NFC antenna including a metal piece and a metal coil according to an embodiment of this specification. [Figure 11] This is a schematic diagram of another NFC antenna, comprising a metal piece and a metal coil, according to the embodiments of this specification. [Modes for carrying out the invention]

[0011] The following description contains many specific details necessary for a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and a person skilled in the art can disseminate similar applications without contradicting the content of this application; therefore, this application is not limited to the specific limitations on implementation disclosed below.

[0012] The terms used in one or more embodiments of this application are for the sole purpose of describing a particular embodiment and are not intended to limit one or more embodiments of this application. The singular forms “one kind,” “the said,” and “this” used in one or more embodiments of this application and in the appended claims are intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, the terms “and / or” used in one or more embodiments of this application refer to and include any or all possible combinations of one or more related items listed.

[0013] It should be understood that, in one or more embodiments of this application, terms such as "first," "second," etc., may be used to describe various pieces of information, but this information is not limited to these terms. These terms are used solely to distinguish information of the same type from one another. For example, without departing from the scope of one or more embodiments of this application, "first" may be called "second," and similarly, "second" may be called "first." Depending on the context, the vocabulary used herein, for example, may be interpreted as "when," "in the case of," or "in response to a decision."

[0014] It should be explained that the user information (including, but not limited to, user device information and user personal information) and data (including, but not limited to, data used for analysis, data used for storage, and data used for presentation) related to this application are all information and data for which user permission has been obtained or sufficient permission has been obtained from each party, and the collection, use and processing of the relevant data must comply with the relevant laws, regulations and standards of the relevant region, and the appropriate entry points for the user to choose to permit or refuse are provided.

[0015] First, we will interpret the noun terms relating to one or more embodiments of this application.

[0016] NFC, or Near Field Communication, is a short-range, high-frequency radio communication technology.

[0017] NFC Active Mode: Also called Card Reader Mode. In Active Mode, the NFC device can act as a single card reader, emit a radio frequency field, and identify and read / write the information of passive NFC devices. The NFC device in Active Mode may be called an Active NFC device or an NFC Master device.

[0018] NFC Passive Mode: Also called Card Simulation Mode. In Passive Mode, the NFC device is simulated as a single card, responds passively in the radio frequency field emitted by other devices, and information can be read / written. The NFC device in Passive Mode may be called a Passive NFC device or an NFC Slave device.

[0019] LPCD mode: That is, the Low Power Card Detection mode or the Low Power Card Search mode, where LPCD stands for Low Power Card Detection. In NFC technology, LPCD is a technology for efficiently detecting adjacent contactless smart cards or tags, mainly used to reduce the power consumption while the NFC card reader is waiting for the smart card or tag to approach. An NFC card reader in the LPCD mode can periodically transmit low-power pulses. When the NFC card reader detects a change in the signal amplitude on the antenna and exceeds a preset threshold, it determines that an NFC device is in proximity and can initiate a further interaction process. Specifically, when a card enters the radio frequency field, the presence of the card causes changes in the amplitude and phase of the signal. The LPCD mode utilizes a software-based card detection mechanism and the LPCD algorithm to detect these changes, analyzes the in-phase (I) and quadrature (Q) components of the received signal to determine whether a card is in proximity, and can further trigger further NFC communication. In portable devices such as mobile phones, the LPCD mode is particularly important, and its main advantage is the low power consumption characteristic. Mobile phones generally require long-term standby, but frequent activation of the NFC function may significantly consume the battery. The LPCD mode allows the mobile phone to continuously detect NFC signals in the background while maintaining a relatively low energy consumption level. Once a card is detected, the mobile phone can quickly switch from the low-power state to the full-function state and perform NFC transactions or data exchanges.

[0020] Standard Card Detection Mode: Also called normal card detection mode or normal card search mode. To increase the rate and success rate of NFC communication, NFC card readers are generally in a fully functional state, i.e., standard card detection mode, when performing NFC communication. In practical applications, both LPCD mode and standard card detection mode NFC card readers (e.g., mobile devices such as cell phones) emit a 13.56MHz sine wave. The difference lies in the transmission time and amplitude of the sine wave in LPCD mode and standard card detection mode. For example, in LPCD mode, the pulse width is generally at the microsecond level, while in standard card detection mode, the pulse width is generally at the tens of millisecond level.

[0021] NFC tag: The full name is Near Field Communication tag. It is a small device based on short-range wireless communication technology that enables data exchange between devices within a short distance. An NFC tag typically contains one microchip and one antenna. The chip stores information (e.g., ID, URL, etc.), while the antenna is responsible for sending and receiving data. NFC tags are passive devices and can operate without an external power source. In practical applications, when an NFC card reader (e.g., a smart mobile device that supports NFC functionality) comes close to an NFC tag, the magnetic field generated by the NFC card reader is sensed by the tag's antenna, which generates enough power to activate the chip within the tag, allowing the tag to transmit the information stored on it.

[0022] NFC technology is already widely applied in several fields, such as mobile payments, information interaction, smart home control, access control, identity authentication and identification, electronic tickets, and anti-counterfeiting. For example, in the field of mobile payments, payment methods based on NFC technology are currently developing rapidly both domestically and internationally.

[0023] In mobile payment scenarios, the currently dominant NFC-based payment method involves the deposit-side register (POS) operating as an active-mode card reader, reading information passively simulated on the mobile device (payer) to complete the transaction. However, since electronic wallets used by consumers are all provided by mobile device manufacturers, users must enable various wallets according to the manufacturer's requirements in order to use the NFC payment function of their mobile device. This makes management difficult and poses information security risks. Furthermore, not all mobile device models currently support passive card simulation functions such as financial settlements, limiting the widespread adoption and application of NFC payment methods where mobile devices operate in passive mode. In light of this, it is necessary to operate mobile devices in active mode.

[0024] However, NFC payment methods that operate in active mode on mobile devices currently have several problems in practice. Specifically, mobile devices are generally powered by batteries and are very sensitive to power consumption. To control power consumption, they are generally designed to be low power, such as by setting the emission power of their card reader to LPCD mode. For example, when a mobile phone screen is turned off, the card reading function is generally turned off, and many mobile phones automatically enter LPCD mode after a short time has passed since the screen was turned on. When a mobile device in LPCD mode comes close to an NFC target device, it can switch to standard card detection mode. In actual application, the mobile device will only wake up from LPCD mode and enter standard card detection mode if it detects that the intensity change caused by the detection of its emitted radio frequency signal by the nearby NFC target device exceeds a preset threshold. However, in LPCD mode, the signal strength emitted from the mobile device is weak, and the amplitude of the emitted radio frequency signal is lower compared to standard card detection mode. As a result, the influence of the other NFC target device on this signal is also reduced accordingly. Consequently, the mobile device cannot determine whether an NFC target device is present in the vicinity based on the amplitude of this signal change, and therefore cannot obtain a correct judgment result. Furthermore, the mobile device cannot switch to standard card detection mode, and this significantly reduces the success rate of the mobile device detecting an NFC target device, further affecting the success rate of short-range wireless communication and impacting the user experience.

[0025] Taking the example of a smartphone acting as an NFC master device for short-range wireless communication with a cash register, in related technologies, a good communication success rate can only be achieved if the other party interacts with the mobile phone using an active device. However, active cash registers not only consume a lot of power, but also have a high level of design complexity and cost, as well as high offline installation costs, making widespread adoption difficult. On the other hand, low-cost, passive payment solutions often have low communication success rates (for example, currently the communication success rate for payment solutions based on passive solutions is less than 70%, and for some mobile device models, it is even less than 50%), and this relatively low success rate also hinders the widespread adoption of this payment mode.

[0026] In view of this, embodiments of this specification provide a passive, low-power, short-range wireless communication solution for use in NFC slave devices. By installing an excitation circuit and providing a portion of the energy obtained by the NFC chip to the excitation circuit when the NFC antenna senses the radio frequency field of the user terminal device, the excitation circuit further emits an excitation signal to excite the user terminal device and communicate with the NFC slave device. This improves the success rate of short-range wireless communication with low power consumption and low cost, and further promotes the production and widespread application of convenient NFC payment products as NFC slave devices.

[0027] Figure 1 is a schematic diagram illustrating an application scenario of the circuit unit for realizing short-range wireless communication according to the embodiments described herein.

[0028] As shown in Figure 1, when a mobile terminal device 100 with NFC functionality comes into close proximity to an NFC tag 201 or a deposit terminal device 202 with NFC functionality, short-range wireless communication can occur between the NFC tag 201 or the deposit terminal device 202, thereby allowing the mobile terminal device 100 to obtain information provided by the NFC tag 201 or the deposit terminal device 202. In this process, the mobile terminal device 100 operates in active mode, and the NFC tag 201 or the deposit terminal device 202 operates in passive mode.

[0029] Figure 1 shows a mobile terminal device 100 in which the NFC master device that initiates NFC communication is a smartphone type. However, when actually applying the scheme described herein, the NFC master device may further include, but is not limited to, smart wearable devices such as smartwatches and smart glasses. Figure 1 shows that the NFC slave device is an NFC tag 201 or a deposit terminal device 202. However, when actually applying the scheme described herein, the NFC slave device may further include, but is not limited to, electronic door locks, payment code cards, entrance / exit gates, etc.

[0030] In actual application, an NFC master device, such as a mobile terminal device 100, can emit a radio frequency field, and an NFC slave device, such as an NFC tag 201 or a deposit terminal device 202, can respond when it senses a short-range wireless communication signal emitted from the NFC master device and transmit service information to the mobile terminal device 100. Here, the service information may vary depending on the application. For example, in a payment scenario, the service information may include payment order information; for example, in a meal ordering scenario, the service information may include a unified resource locator for opening the meal ordering page; and for example, under product traceability, the service information may include product description information.

[0031] The circuit unit for realizing short-range wireless communication provided from the embodiments of this specification may be attached to an NFC slave device such as the NFC tag 201 or deposit terminal device 202 shown in Figure 1. The NFC device provided from the embodiments of this specification may be used, for example, as the NFC tag 201 or deposit terminal device 202 shown in Figure 1.

[0032] In the embodiment described herein, a circuit unit for realizing short-range wireless communication utilizes the NFC chip's ability to recover energy from the radio frequency field of a nearby user terminal device, provides the recovered energy to an excitation module, and the excitation module excites the user terminal device, thereby enabling the user terminal device to sense the presence of an NFC slave device (which includes the circuit unit according to the embodiment described herein) and to perform normal short-range wireless communication with this NFC slave device.

[0033] One or more embodiments of this specification provide a circuit unit for realizing short-range wireless communication.

[0034] Figure 2 shows a schematic diagram of the circuit unit 300 for realizing short-range wireless communication according to the embodiment described herein.

[0035] As shown in Figure 2, specifically, the circuit unit 300 for realizing short-range wireless communication may include an NFC antenna 301, an NFC chip 302, and an excitation circuit 303, wherein the NFC chip 302 may be connected to the NFC antenna 301, or the NFC chip 302 may be connected to the excitation circuit 303.

[0036] Here, the NFC chip 302 and the NFC antenna 301 connected thereto can have the capability to transmit and receive signals, as well as to modulate and demodulate signals. Specifically, the NFC chip 302 and the NFC antenna 301 connected thereto can operate in passive mode and communicate directly with a user terminal device (e.g., a smartphone) operating in active mode.

[0037] The communication carrier frequency for NFC (Near Field Communication) technology is 13.56 MHz. This frequency is standardized globally, enabling interoperability between NFC devices from different manufacturers. The 13.56 MHz frequency is chosen to ensure efficient and secure data exchange over short distances (typically 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, and the radio frequency field emitted from an NFC master device operating in active mode can generally provide energy to an NFC slave device, while an NFC slave device operating in passive mode can operate directly on the energy provided from the NFC master device lock to complete communication with the NFC master device. In the embodiments herein, the NFC chip 302 and the NFC antenna 301 connected thereto may be, but are not limited to, commercially available chips, such as the NXP NTAG5LINK chip, the FUDAN MICRO FM11NT082C chip, and related chips from manufacturers such as ST.

[0038] In the embodiments of this specification, considering that the user terminal device may be in LPCD mode, making communication difficult and difficult to wake up, the success rate of communication can be increased by providing energy recovered from the NFC chip 302 operating in passive mode to the excitation circuit 303, which in turn emits an active radio frequency field to excite the user terminal device, switching it to standard card detection mode and performing short-range wireless communication data interaction.

[0039] As shown in Figure 2, the circuit unit 300 for realizing short-range wireless communication is equipped with an excitation circuit 303. Specifically, the NFC chip 302 may be electrically connected to the excitation circuit 303, thereby allowing the NFC chip 302 to provide the excitation circuit 303 with a portion of the energy recovered by the NFC antenna 301 based on the nearby radio frequency field, thereby activating the excitation circuit 303. In actual application, the NFC chip 302 can, for example, output the recovered energy to the excitation circuit 303 via the VOUT pin.

[0040] Furthermore, the NFC chip 302 may be used to obtain a first energy when the NFC antenna 301 senses the radio frequency field of a user terminal device and to provide a portion of the first energy to the excitation circuit 303. The excitation circuit 303 may 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 including the circuit unit 300.

[0041] Furthermore, in the circuit unit 300, the NFC antenna 301 may be connected to the excitation circuit 303, and the excitation circuit 303 may be used to radiate the excitation signal to the user terminal device via the NFC antenna.

[0042] In one or more embodiments of this specification, a communication connection is possible between the NFC chip 302 and the excitation circuit 303. Specifically, the NFC chip 302 may sense the field strength state of a user terminal device via the NFC antenna 301 and output a signal (e.g., an interrupt signal) related to the excitation circuit 303.

[0043] More specifically, the NFC chip 302 may also be used to send an interrupt signal to the excitation circuit 303 when the NFC antenna 301 senses the proximity of the radio frequency field of the user terminal device, and accordingly, the excitation circuit 303 may be used to generate and emit an excitation signal when it is determined, based on the signal characteristics of the interrupt signal, that the user terminal device is in low-power card detection mode, and the excitation signal is used to switch the user terminal device from low-power card detection mode to standard card detection mode.

[0044] Figure 3 shows a detailed schematic diagram of the circuit unit 300 for realizing short-range wireless communication according to the embodiment of this specification.

[0045] As shown in Figure 3, the circuit unit 300 for realizing short-range wireless communication may include an NFC antenna 301, an NFC chip 302, and an excitation circuit 303, and the excitation circuit 303 may further include a controller 3031 and a signal generator 3032. The controller 3031 can detect relevant interrupt signals and, when necessary, control the signal generator 3032 to turn on field-radiated excitation with a hardware enable signal, and further wake up the other party's user terminal device.

[0046] Selectively, the controller 3031 may control the signal generator 3032 to turn on field radiation excitation when it determines, based on the interrupt signal, that the other user terminal device is in an LPCD state.

[0047] Specifically, the controller 3031 may use the energy obtained from the NFC chip 302 to determine whether the user terminal device is in low-power card detection mode based on the signal characteristics of the interrupt signal, and if the user terminal device is in low-power card detection mode, it may be used to emit a hardware enable signal to the signal generator 3032. Accordingly, the signal generator 3032 may use the energy obtained from the NFC chip 302 to generate and emit the excitation signal in response to the hardware enable signal.

[0048] In actual application, the NFC chip 302 may be electrically connected to the excitation circuit 303 in order to provide energy to the excitation circuit 303. Specifically, the NFC chip 302 may be electrically connected to the controller 3031 and the signal generator 3032, respectively, in order to provide energy to the controller 3031 and the signal generator 3032.

[0049] The NFC chip 302 may be connected to the excitation circuit 303 via communication in order to output an interrupt signal to the excitation circuit 303. Specifically, the NFC chip 302 may be connected to the controller 3031 via communication and output an interrupt signal to the controller 3031. Furthermore, the controller 3031 may execute a pre-set decision flow and, if it determines that it is necessary to emit an excitation signal, output a hardware enable signal to the signal generator 3032, causing the signal generator 3032 to emit an excitation signal.

[0050] In actual application, the NFC chip 302 and the controller 3031 may communicate via a communication interface such as I2C or SPI. Specifically, in implementation, a software program may be injected into the NFC chip 302 so that when the NFC chip 302 acquires a signal from a nearby radio frequency field based on the sensing of the NFC antenna 301, it outputs an interrupt signal to the controller 3031, enabling the controller 3031 to understand the characteristics of the radio frequency field.

[0051] Taking the FUDAN MICRO FM11NT082C chip as an example, when the NFC chip 302 detects a change in field strength, it outputs a high-level interrupt to the controller 3031 via the Interrupt Request (IRQ) pin, thereby establishing communication between the NFC chip 302 and the controller 3031.

[0052] Specifically, the characteristics of the field strength signal of the radio frequency field emitted from the user terminal device may be superimposed on the interrupt signal.

[0053] In actual application, the signal characteristics of the interrupt signal may include, but are not limited to, at least one of the pulse width, time period, or pulse amplitude. In actual application, determining whether the user terminal device is in low-power card detection mode may specifically include determining whether the user terminal device is in low-power card detection mode based on at least one of the pulse width, time period, or pulse amplitude of the interrupt signal.

[0054] Specifically, the signal characteristics of the terminal request information transmitted by the NFC chip 302 may be used to reflect the characteristics of the radio frequency field of the user terminal device. When the user terminal device is in a different card detection state, the characteristics of the emitted radio frequency field will differ, and consequently, the characteristics of the interrupt signal generated by the NFC chip and transmitted to the controller 3031 will differ.

[0055] For example, compared to the standard card detection mode, when the user terminal device is in LPCD mode, the pulse width of the emitted radio frequency field signal is shorter, and accordingly, the pulse width of the interrupt signal is shorter. Also, for example, compared to the standard card detection mode, when the user terminal device is in LPCD mode, the time period of the emitted radio frequency field signal is longer, and accordingly, the time period of the interrupt signal is longer. Also, for example, compared to the standard card detection mode, when the user terminal device is in LPCD mode, the pulse amplitude of the emitted radio frequency field signal is weaker, and accordingly, the pulse amplitude of the interrupt signal is weaker.

[0056] Furthermore, to conserve energy, the controller 3031 may control the signal generator 3032 to turn on field emission excitation when it determines that no information has been read from the NFC chip 302.

[0057] In actual application, if communication between the NFC chip and the user terminal device is successful and the information in the NFC chip 302 is read by the user terminal device, the NFC chip outputs the corresponding flag bit information according to the NFC chip's program settings. In actual application, after the controller 3031 receives an interrupt signal, it can read this flag bit information from the NFC chip via a communication interface (e.g., I2C, SPI, etc.) and determine whether communication was successful based on this flag bit information.

[0058] Specifically, the controller 3031 may further use the energy obtained from the NFC chip 302 to determine whether communication between the user terminal device and the NFC chip 302 has been successful, based on the flag bit information obtained from the NFC chip 302, and if the user terminal device is in low-power card detection mode and communication between the user terminal device and the NFC chip 302 has not been successful, it may be used to emit a hardware enable signal to the signal generator 3032. Accordingly, the signal generator 3032 may use the energy obtained from the NFC chip 302 to generate and emit the excitation signal in response to the hardware enable signal.

[0059] In other words, the excitation circuit 303 may be used specifically to generate and emit an excitation signal when it is determined, based on the signal characteristics of the interrupt signal, that the user terminal device is in low-power card detection mode and that communication between the NFC chip and the user terminal device has not been successful.

[0060] In one or more embodiments of this specification, an energy recovery circuit may be further installed to further enhance the efficiency of recovering energy from the radio frequency field provided by an NFC master device operating in active mode.

[0061] Figure 4 shows a schematic diagram of a circuit unit 310 for realizing another short-range wireless communication according to the embodiments of this specification.

[0062] As shown in Figure 4, a circuit unit 310 for realizing short-range wireless communication may include an NFC antenna 301, an NFC chip 302, and an excitation circuit 303, and the circuit unit 310 may further include a sorting circuit 304, the sorting circuit 304 may be connected to the NFC antenna 301, and the sorting circuit 304 may be connected to the excitation circuit 33. Specifically, the sorting circuit 304 may be used to obtain a second energy when the NFC antenna 301 senses the radio frequency field of a user terminal device, and to provide at least a portion of the second energy to the excitation circuit 303.

[0063] Specifically, the 13.56 MHz sine wave detected by the NFC antenna may be output to the subsequent excitation circuit 303 by the processing circuit 304 and used for that purpose. The processing circuit 304 may be electrically connected to the excitation circuit 303, and more specifically, it may be electrically connected to the controller 3031 and the signal generator 3032 to provide energy to the controller 3031 and the signal generator 3032.

[0064] In one or more embodiments of this specification, given that the field period of the LPCD is particularly short, an energy supply module may be selectively added to the excitation circuit 303 as a supplement to emergency power supply to ensure the completion of one communication cycle.

[0065] Figure 5 shows a schematic diagram of a circuit unit 320 for realizing yet another short-range wireless communication according to the embodiments of this specification.

[0066] As shown in Figure 5, the circuit unit 320 for realizing short-range wireless communication may include an NFC antenna 301, an NFC chip 302, an excitation circuit 303, and a sorting circuit 304, and the circuit unit 320 may further include an energy supply module 305, the energy supply module 305 is connected to the excitation circuit 303 and is used to provide a third energy to the excitation circuit 303.

[0067] Selectively, the energy supply module 305 may be configured as a rechargeable module. When a rechargeable energy supply module 305 is installed, the energy recovered from the NFC chip 302 and the sorting circuit 304 is supplied to this rechargeable energy supply module 305 to improve energy utilization efficiency, and may also be supplied to the excitation circuit 303 as needed. The rechargeable energy supply module 305 may also have an external charging interface to obtain additional energy.

[0068] In actual application, the energy supply module 305 may be specifically configured as a button cell, a lithium battery, or the like.

[0069] It should be explained that in the embodiments described herein, the arrangement of installing an energy supply module 305 to provide additional energy to the excitation circuit 303 differs from the arrangement of active NFC chips in related technologies. In active NFC chips of related technologies, generally, instead of installing an excitation circuit 303 and then installing a supplementary power supply to power the excitation circuit 303, a power supply is installed to directly power the NFC chip. In the embodiments described herein, the energy supply module 305 plays the role of a supplementary power supply and is used as the final arrangement. In other words, even without using this energy supply module 305, it is still possible to drive the excitation circuit 303 by recovering the energy sensed by the NFC antenna, further enabling the wake-up of the other device and increasing the success rate of short-range wireless communication.

[0070] In one or more embodiments of this specification, a separate antenna may be installed to radiate the excitation signal generated by the excitation circuit 303.

[0071] Figure 6 shows a schematic diagram of a circuit unit 330 for realizing further short-range wireless communication according to the embodiments of this specification.

[0072] As shown in Figure 6, the circuit unit 330 for realizing short-range wireless communication may include an NFC antenna 301, an NFC chip 302, and an excitation circuit 303, and the circuit unit 330 may further include a second NFC antenna 306, the second NFC antenna 306 being connected to the excitation circuit 303, and the excitation circuit 303 being used to radiate the excitation signal to the user terminal device via the second NFC antenna 306.

[0073] Unlike the embodiment shown in Figure 2, in the embodiment shown in Figure 6, the excitation signal may be radiated by a separately established NFC antenna. By installing a second NFC antenna 306 to radiate the excitation signal, it is not necessary to perform a complex time-division multiplexing design, the design is simpler, and the signal emission efficiency is higher. Furthermore, because the antenna is installed separately, the shape and position of the second NFC antenna can be set more flexibly compared to multiplexing the original existing antenna, thereby greatly increasing the emission intensity of the excitation signal, achieving better inductance coupling with the user terminal equipment on the other side, further increasing the probability of waking up the user terminal equipment from LPCD mode, and further increasing the success rate of short-range wireless communication.

[0074] As shown in Figure 6, the embodiment shown in Figure 2 is optimized by changing the emission of the excitation signal via the NFC antenna 301 to the emission of the excitation signal via the second NFC antenna 306. Selectively, the NFC antenna 301 and the second NFC antenna 306 may jointly emit the excitation signal, thereby further increasing the signal emission efficiency, increasing the probability of waking up the user terminal device from LPCD mode, and further increasing the success rate of short-range wireless communication.

[0075] Similar improvements may be made to the embodiments shown in Figures 4 and 5, similar to the improvements made to the embodiment shown in Figure 2 described in the above-mentioned embodiments.

[0076] Specifically, the circuit unit 310 shown in Figure 4 may be further improved by installing a second NFC antenna 306, thereby allowing the excitation signal to be emitted via the second NFC antenna 306, or allowing the excitation signal to be emitted jointly via the NFC antenna 301 and the second NFC antenna 306.

[0077] Similarly, the circuit unit 320 shown in Figure 5 may be further improved by installing a second NFC antenna 306, thereby allowing the excitation signal to be emitted via the second NFC antenna 306, or allowing the excitation signal to be emitted jointly via the NFC antenna 301 and the second NFC antenna 306.

[0078] Based on the above description, Figure 7 shows a schematic diagram illustrating a scenario in which a circuit unit for realizing short-range wireless communication in an actual application scenario according to the embodiments of this specification and a user terminal device operating in active mode perform short-range wireless communication.

[0079] As shown in Figure 7, this circuit unit may include an NFC antenna 301, an NFC chip 302, and an excitation circuit 303, where the excitation circuit 303 may specifically include a controller 3031 and a signal generator 3032. When a user terminal device operating in active mode approaches the NFC antenna 301, the NFC antenna 301 senses the proximity of the radio frequency field, and the NFC chip 302 connected to the NFC antenna 301 can output a portion of the energy recovered from the NFC antenna 301 to the excitation circuit 303. At the same time, it can generate an interrupt signal based on the change in the field signal sensed by the NFC antenna 301 and transmit it to the excitation circuit 303. This makes it easier for the excitation circuit 303 to emit an excitation signal when it determines that it meets a preset condition based on the interrupt signal, and radiate it through the NFC antenna 301 to wake up the user terminal device from LPCD mode. Specifically, the excitation signal may be radiated through the NFC antenna 301, or it may be radiated through a second NFC antenna 306 that is installed separately.

[0080] A sorting circuit 304 may be installed between the NFC antenna 301 and the excitation circuit 303 to selectively improve the recovery rate of the radio frequency field energy emitted from a user terminal device operating in active mode. The sorting circuit 304 is used to collect the energy of the radio frequency field and output it to the excitation circuit 303 during the process in which the NFC antenna 301 senses the radio frequency field.

[0081] When actually applying this technology, the energy recovery rate can be significantly increased by using the NFC chip 302 and the processing circuit 304 simultaneously to recover energy. For example, in processes where the primary radio frequency field is close, it can be used to recover approximately 30mW to 50mW (1.8V, 16mA to 28mA) of energy and provide it to the subsequent excitation circuit 303 for use.

[0082] Furthermore, the controller 3031 may include a low-power microcontroller unit (MCU). Generally, low-power MCUs have sleep power consumption at the uA level and operating capability of tens of uA at 1MHz (e.g., Nintendo's N32L40 series, ST's related MCUs, etc.), and generally operate at around 40MHz and can be controlled to an operating current of about 3.6mW to 7.2mW (1.8V, 2 to 4mA).

[0083] In actual application, if the NFC chip 302 cannot directly wake up the other device due to passive load changes of the NFC antenna 301, and communication is hindered, the energy recovered from the NFC chip 302 and the sorting circuit 304 can be provided to the operation of the low-power MCU. Specifically, when a field signal approaches the NFC antenna 301, the NFC chip 302 and the sorting circuit 310 start energy recovery and supply it to the operation of the low-power MCU, allowing it to operate in a low-power state. Subsequently, after the NFC chip 302 detects that an interrupt signal has been transmitted from the field, it wakes up the low-power MCU from the low-power state. The low-power MCU can then determine the operating state of the other device from comprehensive information such as the pulse width, time period, and pulse amplitude of the interrupt signal. If it determines that the other device is in an LPCD state, the low-power MCU controls the signal emitter to emit a 13.56M active field, wake up the other device, complete the next communication, and further improve the success rate of communication.

[0084] Furthermore, the signal generator 3032 may include an active crystal or an RC oscillator circuit, and is mainly used to generate a signal field of about 12 to 14 MHz, with a power consumption of basically 3.6 mW to 5.4 mW (1.8 V, 2 to 3 mA). Specifically, under the control of the controller 3031, the signal generator 3032 may conduct the generated signal field to an antenna via a link and radiate it outwards. Selectively, as shown in Figures 2 to 5, it may be conducted to the NFC antenna 301 and radiated outwards (NFC antenna 301 time division multiplexing). Alternatively, as shown in Figure 6, it may be conducted to the second NFC antenna 306 and radiated outwards.

[0085] In one or more embodiments of this specification, the frequency of the active field radiated outward based on the excitation signal provided by the signal generator 3032 may be tuned to match the frequency of the radio frequency field of the user terminal equipment, i.e., to be resonant multi-point. Specifically, it may be set to 12 to 14 MHz. More specifically, it may be set to about 13.56 MHz.

[0086] In one or more embodiments of this specification, the NFC antenna 301 in the circuit unit (including circuit units 300, 310, 320, or 330) may be further optimized.

[0087] Figure 8 shows a schematic diagram of the structure of a metal piece used in an NFC antenna according to the embodiments described herein.

[0088] In a circuit unit for realizing short-range wireless communication, the NFC antenna 301 may include a metal piece 401 as shown in Figure 8. The metal piece 401 may be curved in the plane in which it is located such that both ends along the longitudinal direction of the metal piece 401 are close to each other and form a gap space.

[0089] Figure 9 shows a schematic diagram of the structure of a metal piece used in another NFC antenna according to the embodiments described herein.

[0090] In a circuit unit for realizing short-range wireless communication, the NFC antenna 301 may include a metal piece 402 as shown in Figure 9. Similar to Figure 8, the metal piece 402 may be curved in the plane in which it is located such that both ends along the longitudinal direction of the metal piece 402 are close to each other and form a gap space.

[0091] Specifically, the metal pieces shown in Figures 8 and 9 may differ from the conventional metal wire winding structure used in NFC antennas 301 by using metal pieces that are curved in a loop shape within a plane. In actual application, the intermediate region surrounded by the metal pieces 401 or 402 may be used to place the NFC chip 302. The relative positions of the NFC chip 302 and the metal pieces 401 or 402 are not limited to these positions.

[0092] To ensure clarity, Figures 8 and 9 show only two specific examples of metal pieces. In actual application, the shape of the metal piece is not limited to circular or rectangular shapes; it may be polygonal or irregular, and the curvature of the metal piece may be set according to actual needs. For example, it may be adaptively adjusted for the spatial position in which the NFC chip is mounted.

[0093] Furthermore, the material of the metal piece may be a common metal used for communication antennas. For example, copper may be used.

[0094] In an actual application, a metal piece may be used as the NFC antenna instead of a metal coil. Specifically, both ends of the metal piece along its longitudinal direction may serve as the feed points for the NFC antenna 301. In an actual application, the NFC antenna 301 may connect to the NFC chip 302 via the feed points.

[0095] Selectively, when actually applying the technology, the NFC antenna 301 may be used in combination with a metal piece and a metal coil. Specifically, the metal coil may include a feed point connected to the NFC chip 302, while the metal piece may not include a feed point.

[0096] To distinguish it from conventional linear metal coils, in the embodiments of this specification, the NFC antenna may be configured as a sheet-like metal ring having a relatively large area in the plane in which the antenna body is located. This allows the equivalent inductance value of the antenna to be increased, for example, to reach 500 nH to 2 uH. With such an inductance value, when matched with capacitance to form a resonant circuit with a resonance point of approximately 13.56 MHz, relatively high energy radiation can be achieved, and an appropriate capacitance to match it can be found.

[0097] This enhances the ability to wake up the user terminal device from the LPCD state by influencing the sensing load of the other party's user terminal device, while also increasing the efficiency of energy recovery, and further improving the intensity and efficiency of the excitation signal radiated via the NFC antenna 301. Overall, this increases the success rate of communication when NFC devices and user terminal devices perform short-range wireless communication.

[0098] Figure 10 is a schematic diagram of an NFC antenna including a metal piece and a metal coil provided in the embodiments of this specification.

[0099] Specifically, in a circuit unit for realizing short-range wireless communication, the NFC antenna 301 includes a metal piece (for example, the metal piece 401 shown in Figure 8 or the metal piece 402 shown in Figure 9), and furthermore, the NFC antenna 301 may include a metal coil, the metal coil may be located in the same plane as the metal piece, and the metal coil may be located in the region surrounded after the metal piece has curved.

[0100] As shown in Figure 10, the metal coil 501 may be located in the region enclosed after the metal piece 401 has bent. In actual application, the NFC chip 302 may be placed in the region further enclosed by the metal coil 501.

[0101] Figure 11 is a schematic diagram of an NFC antenna including another metal piece and a metal coil provided in the embodiments of this specification.

[0102] Specifically, in a circuit unit for realizing short-range wireless communication, if the NFC antenna 301 includes a metal piece (for example, the metal piece 401 shown in Figure 8 or the metal piece 402 shown in Figure 9), the NFC antenna 301 may further include a metal coil, the metal coil may be installed overlapping with the metal piece, and the metal piece may be closer to the scanned side of the device including the circuit unit than the metal coil.

[0103] As shown in Figure 11, the metal piece 401 may be set to be closer to the scanned side of the device including the circuit unit than the metal coil 501.

[0104] In practical applications, by arranging the metal piece and metal coil in a ferrule configuration or overlapping them in the NFC antenna module, the ring-shaped metal piece can function as an amplifier, thereby increasing the signal transmission efficiency and strength, further improving the success rate of user terminal devices waking up from LPCD mode, and further increasing the success rate of short-range wireless communication.

[0105] Furthermore, in the embodiments of this specification, by installing a matching circuit (for example, by connecting a certain capacitance value in parallel) to enable better coupling of the NFC antenna to the antenna of the other user terminal device, the NFC antenna can be tuned to the 13.56 MHz (12-14 MHz) transmission frequency band, thereby achieving better coupling with the antenna of the other user terminal device and enhancing the energy conversion efficiency.

[0106] In one or more embodiments of this specification, when a second NFC antenna 306 is employed in the circuit module, similar to the NFC antenna 301, a metal piece may be used for the second NFC antenna 306.

[0107] Specifically, the second NFC antenna 306 included in the circuit unit for realizing short-range wireless communication may include a metal piece, which is curved in the plane in which it is located such that both ends along the longitudinal direction of the metal piece are close to each other and form a gap space. For example, the metal piece may be the metal piece 401 shown in Figure 8 or the metal piece 402 shown in Figure 9, and the shape of the metal piece is not limited thereto.

[0108] In an optional application, a metal piece may be used as the NFC antenna instead of a metal coil. Specifically, both ends of the metal piece along its longitudinal direction may serve as the feed points for the second NFC antenna 306. In an actual application, the second NFC antenna 306 may connect to the NFC chip 302 via the feed points.

[0109] Selectively, when actually applying the technology, the second NFC antenna 306 may be used in combination with a metal piece and a metal coil. Specifically, the metal coil may include a feed point connected to the NFC chip 302, while the metal piece may not include a feed point.

[0110] More selectively, in a circuit unit for realizing short-range wireless communication, the NFC antenna 306 includes a metal piece (for example, the metal piece 401 shown in Figure 8 or the metal piece 402 shown in Figure 9), and further, the second NFC antenna 306 may include a metal coil, the metal coil may be located in the same plane as the metal piece, or the metal coil may be located in the region surrounded after the metal piece has curved.

[0111] As shown in Figure 10, the metal coil 501 may be located in the region surrounded by the metal piece 401 after it has been bent. In actual application, the NFC chip 302 may be placed in the region further surrounded by the metal coil 501.

[0112] Furthermore, selectively in a circuit unit for realizing short-range wireless communication, if the NFC antenna 301 includes a metal piece (for example, the metal piece 401 shown in Figure 8 or the metal piece 402 shown in Figure 9), the second NFC antenna 306 may further include a metal coil, the metal coil may be installed overlapping the metal piece, and the metal piece may be closer to the scanned side of the device including the circuit unit than the metal coil.

[0113] As shown in Figure 11, the metal piece 401 may be set to be closer to the scanned side of the device including the circuit unit than the metal coil 501.

[0114] In actual application, by arranging the metal piece and metal coil in a ferrule configuration or overlapping the NFC antenna module (for example, the NFC antenna 301 or the second NFC antenna 306), the ring-shaped metal piece can function as an amplifier, thereby increasing the signal transmission efficiency and strength, further increasing the success rate of user terminal devices waking up from LPCD mode, and further increasing the success rate of short-range wireless communication.

[0115] The various technical features in the above embodiments can be combined in any way, as long as there are no conflicts or contradictions between the combinations of features. Although not described individually due to space limitations, any combination of the various technical features in the above embodiments also falls within the scope of disclosure of this specification.

[0116] One or more embodiments of this specification further provide an NFC device corresponding to a circuit unit for realizing the short-range wireless communication. The NFC device may include any circuit unit according to the embodiments of this specification described above.

[0117] Specifically, the NFC device may include a circuit unit for realizing short-range wireless communication, and the circuit unit may include an NFC antenna 301, an NFC chip 302, and an excitation circuit 303, wherein the NFC chip 302 is connected to the NFC antenna 302 and the NFC chip 302 is connected to the excitation circuit 303.

[0118] Here, the NFC chip 302 may be used to obtain first energy when the NFC antenna 301 senses the radio frequency field of a user terminal device and to provide a portion of the first energy to the excitation circuit.

[0119] The excitation circuit 303 may be used to generate and emit an excitation signal using energy obtained from the NFC chip 302, and the excitation signal is used to excite the user terminal device and communicate with the NFC device.

[0120] In the embodiments of this specification, the NFC device operates in passive mode, and the user terminal device that communicates with the NFC device operates in active mode.

[0121] It should be explained that the technical proposal for this NFC device and the technical proposal for the circuit unit described above belong to the same concept, and for any detailed information not described in the technical proposal for the NFC device, please refer to the description of the technical proposal for the circuit unit described above.

[0122] Each embodiment in this specification is described using a step-by-step approach, and similar or identical parts between embodiments can be referred to from one another. The emphasis of each embodiment is on explaining the differences from other embodiments. Since the devices according to the embodiments of this specification include embodiments of circuit units for realizing short-range wireless communication, the devices also have beneficial technical effects similar to those of the embodiments of circuit units for realizing short-range wireless communication. As the beneficial technical effects of the embodiments of circuit units for realizing short-range wireless communication have already been described in detail above, the beneficial technical effects of the corresponding devices will not be described further here.

[0123] The above describes specific embodiments of this application. Other embodiments are within the scope of the appended claims. In some cases, the operations or steps described in the claims may be performed in a different order than those in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the drawings do not necessarily require that the desired results be achieved only in the specific order or sequence shown.

[0124] It should be further explained that the terms “include,” “incorporate,” or any other variation thereof are intended to cover the non-exclusive “include,” thereby meaning that a process, method, or apparatus containing a set of elements includes not only those elements but also other elements not explicitly listed, or further elements specific to such a process, method, or apparatus. Unless otherwise specified, an element limited by the phrase “including one…” does not preclude the existence of another identical element in a process, method, product, or apparatus containing such element.

[0125] As stated above, this is merely an embodiment of the present application and is not intended to limit it. To those skilled in the art, this application is subject to various modifications and changes. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A circuit unit for realizing short-range wireless communication, The system includes an NFC antenna, an NFC chip, and an excitation circuit, wherein the NFC antenna is connected to the NFC chip, and the NFC chip is connected to the excitation circuit. The NFC chip is used to obtain a first energy when the NFC antenna senses the radio frequency field of a user terminal device and to provide a portion of the first energy to the excitation circuit. The circuit unit further includes a sorting circuit, which is connected to the NFC antenna and the excitation circuit. The sorting circuit is used to obtain a second energy when the NFC antenna senses the radio frequency field of a user terminal device, and to provide at least a portion of the second energy to the excitation circuit. The excitation circuit is used to generate and emit an excitation signal using energy obtained from the NFC chip and energy obtained from the sorting circuit, and the excitation signal is used to excite the user terminal device to communicate with the device including the circuit unit.

2. The circuit unit according to claim 1, wherein the NFC antenna is connected to the excitation circuit, and the excitation circuit is used to radiate the excitation signal to the user terminal device via the NFC antenna.

3. The circuit unit according to claim 1, further comprising a second NFC antenna, the second NFC antenna being connected to the excitation circuit, the excitation circuit being used to radiate the excitation signal to the user terminal device via the second NFC antenna.

4. The NFC chip is further used to transmit an interrupt signal to the excitation circuit when the NFC antenna detects the radio frequency field of the user terminal device. The circuit unit according to claim 1, wherein the excitation circuit is specifically used to generate and emit an excitation signal when it is determined that the user terminal device is in low-power card detection mode based on the signal characteristics of the interrupt signal, and the excitation signal is used to switch the user terminal device, which is in low-power card detection mode, to standard card detection mode.

5. The excitation circuit includes a controller and a signal generator. The controller is used to determine whether the user terminal device is in low-power card detection mode based on the signal characteristics of the interrupt signal, using the energy obtained from the NFC chip, and to emit a hardware enable signal to the signal generator if the user terminal device is in low-power card detection mode. The circuit unit according to claim 4, wherein the signal generator is used to generate and emit the excitation signal in response to the hardware enable signal, utilizing the energy obtained from the NFC chip.

6. The circuit unit according to claim 5, further comprising: the controller using energy obtained from the NFC chip to determine whether communication between the user terminal device and the NFC chip has been successful based on flag bit information obtained from the NFC chip; and, if the user terminal device is in low-power card detection mode and communication between the user terminal device and the NFC chip has not been successful, the controller is used to emit a hardware enable signal to the signal generator.

7. The circuit unit according to claim 1, further comprising an energy supply module, the energy supply module being connected to the excitation circuit and used to provide a third energy to the excitation circuit.

8. The circuit unit according to claim 1, wherein the NFC antenna includes a metal piece, and the metal piece is curved in the plane in which it is located such that both ends along the longitudinal direction of the metal piece are close to each other and form a gap space.

9. The circuit unit according to claim 8, wherein both ends of the metal piece along its longitudinal direction serve as feed points for the NFC antenna.

10. The circuit unit according to claim 8, wherein the NFC antenna further includes a metal coil, the metal coil is located in the same plane as the metal piece, and the metal coil is located in the region enclosed after the metal piece is curved.

11. The circuit unit according to claim 8, wherein the NFC antenna further includes a metal coil, the metal coil is installed overlapping with the metal piece, and the metal piece is closer to the scanned side of the device including the circuit unit than the metal coil.

12. The circuit unit according to claim 3, wherein the second NFC antenna includes a metal piece, and the metal piece is curved in the plane in which it is located such that both ends along the longitudinal direction of the metal piece are close to each other and form a gap space.

13. The circuit unit according to claim 12, wherein both ends of the metal piece along its longitudinal direction serve as feed points for the second NFC antenna.

14. The circuit unit according to claim 12, wherein the second NFC antenna further includes a metal coil, the metal coil is located in the same plane as the metal piece, and the metal coil is located in the region enclosed after the metal piece is curved.

15. The circuit unit according to claim 12, wherein the second NFC antenna further includes a metal coil, the metal coil is installed overlapping with the metal piece, and the metal piece is closer to the scanned side of the device including the circuit unit than the metal coil.

16. An NFC device comprising the circuit unit described in any one of claims 1 to 15.

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