CN115801062B - Near field communication circuit and electronic equipment - Google Patents
Near field communication circuit and electronic equipment Download PDFInfo
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- CN115801062B CN115801062B CN202211206288.9A CN202211206288A CN115801062B CN 115801062 B CN115801062 B CN 115801062B CN 202211206288 A CN202211206288 A CN 202211206288A CN 115801062 B CN115801062 B CN 115801062B
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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Abstract
The application discloses a near field communication circuit and electronic equipment, and belongs to the technical field of communication. The circuit comprises: an NFC antenna module; a control module; the first end of the driving module is connected with the output end of the control module, and the second end of the driving module is connected with the NFC antenna module; the first end of the voltage detection module is connected with the NFC antenna module; the first end of the vibration detection module is connected with the second end of the voltage detection module, and the second end of the vibration detection module is connected with the input end of the control module; the voltage detection module is used for collecting voltage signals of the NFC antenna module under the condition that the NFC antenna module is in a resonance state; the vibration detection module is used for determining the vibration times of the NFC antenna module according to the voltage signals; the control module is used for determining the resonance frequency of the NFC antenna module according to the vibration times and the vibration time of the NFC antenna module so as to determine whether the object is close to the electronic equipment according to the resonance frequency.
Description
Technical Field
The application belongs to the technical field of communication, and particularly relates to a near field communication circuit and electronic equipment.
Background
Currently, in order to provide a mobile terminal with a better communication effect, a plurality of antennas are generally arranged within the mobile terminal. However, when the user approaches the antenna transmitting the signal during the use of the mobile terminal, the specific absorption rate (Specific Absorption Ratio, SAR) value of the corresponding portion of the user exceeds the standard, which causes injury to the user.
For this reason, in the related art, whether a human body approaches a mobile terminal may be detected by setting a SAR sensor to adjust the output power of an antenna when the human body approaches. On the one hand, however, this approach requires separate configuration of the SAR sensor IC and the multiple SAR inductive antennas, requires a large space occupation within the mobile terminal, and increases costs; on the other hand, the SAR sensor is easily interfered by an electromagnetic field generated by an NFC antenna in a Near Field Communication (NFC) circuit in the mobile terminal, which affects the accuracy of detection.
Disclosure of Invention
The embodiment of the application aims to provide a near field communication circuit and electronic equipment, which can solve the problems that a large space in a mobile terminal is occupied and the cost is increased when human body approach detection is performed through an SAR sensor and an SAR sensing antenna.
In a first aspect, an embodiment of the present application provides a near field communication circuit, including:
An NFC antenna module;
The control module comprises an output end and an input end;
The first end of the driving module is connected with the output end of the control module, and the second end of the driving module is connected with the NFC antenna module;
The first end of the voltage detection module is connected with the NFC antenna module;
The first end of the vibration detection module is connected with the second end of the voltage detection module, and the second end of the vibration detection module is connected with the input end of the control module;
The NFC antenna module is used for receiving a voltage signal of the NFC antenna module and outputting the voltage signal to the vibration detection module when the NFC antenna module is in a resonance state; the vibration detection module is used for determining the vibration times of the NFC antenna module according to the voltage signal; the control module is used for determining the resonance frequency of the NFC antenna module according to the vibration times and the vibration time of the NFC antenna module so as to determine whether an object is close to the electronic equipment according to the resonance frequency.
In a second aspect, an embodiment of the application provides an electronic device comprising a near field communication circuit as described in the first aspect.
In the embodiment of the application, the vibration detection module is arranged in the near field communication circuit, so that the resonance oscillation condition of the NFC antenna module can be quantified to determine the vibration times and the vibration times of the resonance oscillation of the NFC antenna module, and the resonance frequency of the NFC antenna module is determined according to the vibration times and the vibration times of the resonance oscillation of the NFC antenna module, and whether an object is close to the electronic equipment or not can be determined according to the resonance frequency of the NFC antenna module. Therefore, by utilizing the near field communication circuit and the NFC antenna module, the NFC communication function and the SAR human body approach detection function can be realized simultaneously, multiplexing of the near field communication circuit and the NFC antenna module of the electronic equipment is realized, and the problem of mutual interference between the NFC chip and the SAR sensor is solved. In addition, the SAR sensor and the SAR sensing antennas are not required to be arranged, so that the requirement of layout area can be reduced, and the design of miniaturization and light weight of the electronic equipment is facilitated. In addition, the circuit of the embodiment has simple structure, does not relate to a new process and is convenient for large-scale application.
Moreover, compared with the detection mode in the driving emission state in the prior art, the embodiment can detect the object approaching when the NFC antenna module is in the resonance state, further reduce the power consumption of the electronic equipment and prolong the service time of the electronic equipment.
Drawings
Fig. 1 is a schematic diagram of a structure of a near field communication circuit in the prior art;
fig. 2 is a schematic diagram of a structure of another near field communication circuit in the prior art;
Fig. 3 is a schematic structural diagram of a near field communication circuit according to an embodiment of the present application;
Fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present application;
fig. 5 is a schematic diagram of a resonance state of an NFC antenna module provided in an embodiment of the present application;
Fig. 6 is a schematic structural diagram of another near field communication circuit according to an embodiment of the present application;
fig. 7 is a relationship curve between a reference resonant frequency of an NFC antenna module and a distance between an object and an electronic device according to an embodiment of the present application;
fig. 8 is a schematic circuit diagram of an electronic device according to an embodiment of the present application.
Detailed Description
The technical solutions of the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which are obtained by a person skilled in the art based on the embodiments of the present application, fall within the scope of protection of the present application.
The terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged, as appropriate, such that embodiments of the present application may be implemented in sequences other than those illustrated or described herein, and that the objects identified by "first," "second," etc. are generally of a type, and are not limited to the number of objects, such as the first object may be one or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/", generally means that the associated object is an "or" relationship.
Currently, on the one hand, as the application of near field Communication (NEAR FIELD Communication) is gradually expanded, more and more electronic devices support NFC technology. The NFC technology is a short-distance high-frequency wireless communication technology, and an antenna in an NFC circuit can realize information transmission in an electromagnetic induction coupling mode, so that short-distance wireless communication can be performed among mobile equipment, consumer electronic products, computers and intelligent control tools. Along with the popularization of NFC functions in electronic devices, NFC has also been increasingly used in applications, such as swiping bus cards, bank cards, access cards, etc. by using the NFC function of a mobile phone.
On the other hand, in order for a mobile terminal to have a better communication effect, a plurality of antennas are generally arranged within the mobile terminal. In the use process of the mobile terminal, when a user approaches an antenna transmitting signals, SAR values of corresponding parts of the user are out of standard, and the user is injured. For this, whether the human body approaches the mobile terminal may be detected by setting the SAR sensor to adjust the output power of the antenna when the human body approaches.
Referring to fig. 1 and 2, an electronic device with NFC and SAR approach detection functions is shown in the prior art. As shown in fig. 1, the electronic device includes an NFC integrated circuit (INTEGRATED CIRCUIT, IC) 11, an NFC antenna 12, a SAR IC 13, a SAR antenna 14. The NFC IC 11 and the NFC antenna 12 are used for implementing an NFC function, and the SAR IC 13 and the SAR antenna 14 are used for performing human body approach detection. Where the NFC antenna 12 is provided on top of the electronic device, the NFC antenna may be the same antenna that is multiplexed with the main antenna of the electronic device. The SAR antenna 14 is typically disposed at a bottom case of the electronic device, and the SAR antenna 14 may be disposed one or more. As shown in fig. 2, the electronic device further comprises an application processor 15, a modem 16, a main antenna matching circuit 17, an NFC antenna matching circuit, etc.
However, in the prior art, the electronic device needs to configure the SAR sensor IC and the multiple SAR sensing antennas separately, and needs to occupy a larger space in the mobile terminal, and increase the production cost; in addition, the SAR sensor is easily interfered by an electromagnetic field generated by an NFC antenna in an NFC circuit in the mobile terminal, and the accuracy of detection is affected.
In order to solve the problems, the embodiment of the application provides a near field communication circuit, which can simultaneously realize an NFC function and an SAR human body approach detection function by utilizing the near field communication circuit and an NFC antenna module, realize multiplexing of the near field communication circuit and the NFC antenna module of electronic equipment, and solve the problem of mutual interference between an NFC chip and an SAR sensor. In addition, the SAR sensor and the SAR sensing antennas are not required to be arranged, so that the requirement of layout area can be reduced, and the design of miniaturization and light weight of the electronic equipment is facilitated. In addition, the circuit of the embodiment has simple structure, does not relate to a new process and is convenient for large-scale application.
The near field communication circuit provided by the embodiment of the application is described in detail below through specific embodiments and application scenes thereof with reference to the accompanying drawings.
Fig. 3 and fig. 4 are schematic structural diagrams of a near field communication circuit according to an embodiment of the present application. The near field communication circuit comprises a control module 31, a driving module 32, a voltage detection module 33, a vibration detection module 34 and an NFC antenna module 35, wherein the control module 31 comprises an output end and an input end, a first end of the driving module 32 is connected with the output end of the control module 31, and a second end of the driving module 32 is connected with the NFC antenna module 35; the first end of the voltage detection module 33 is connected with the NFC antenna module 35; the first end of the vibration detection module 34 is connected to the second end of the voltage detection module 33, and the second end of the vibration detection module 34 is connected to the input end of the control module 31.
The voltage detection module 33 is configured to collect a voltage signal of the NFC antenna module 35 and output the voltage signal to the vibration detection module 34 when the NFC antenna module 35 is in a resonant state; the vibration detection module 34 is configured to determine the vibration frequency of the NFC antenna module 35 according to the voltage signal; the control module 31 is configured to determine a resonant frequency of the NFC antenna module 35 according to the number of vibrations and the vibration time of the NFC antenna module 35, so as to determine whether the object is close to the electronic device according to the resonant frequency.
In this embodiment, when a metal equivalent (e.g., a human body, an NFC card, a metal) approaches the NFC antenna module 35, the NFC antenna module 35 may generate a detuning phenomenon, based on which human body approach detection can be implemented according to a near field communication circuit of the electronic device.
Furthermore, referring to fig. 5, since the NFC antenna module 35 itself has a certain parasitic capacitance, a matching capacitance, a parasitic inductance, a matching inductance, and an equivalent dc resistance of a loop, the NFC antenna module 35 is driven by the driving module 32 to generate forced oscillation, and at this time, the forced oscillation frequency of the NFC antenna module 35 is consistent with the driving frequency (such as the waveform of the forced oscillation shown in the left side of fig. 5). After the driving module 32 drives the NFC antenna module 35 to vibrate for a certain period of time, the driving module 32 stops driving the NFC antenna module 35 to vibrate, at this time, the NFC antenna module 35 does not immediately stop vibrating, the NFC antenna module 35 is converted from forced vibration into resonant vibration, and as the resonant vibration occurs, the resonant amplitude gradually decreases, and finally the wireless approaches zero (as shown in the waveform of the resonant vibration on the right side of fig. 6). In addition, the resonance frequency at which the NFC antenna module 35 resonates is determined by its own parasitic capacitance, parasitic inductance, and the like. The parasitic capacitance and parasitic inductance of the NFC antenna module 35 may be affected by the external environment, for example, when the metal equivalent approaches the NFC antenna module 35, the capacitance value of the parasitic capacitance of the NFC antenna module 35 changes. Based on this, by utilizing the characteristic that the NFC antenna module 35 can perform resonance oscillation at the resonance frequency after the driving module 32 stops driving, it is possible to detect whether the metal equivalent is close to the NFC antenna module 35, that is, whether the object is close to the electronic device by detecting the resonance frequency at which the NFC antenna module 35 performs resonance oscillation.
In the embodiment of the application, the vibration detection module is arranged in the near field communication circuit, so that the resonance oscillation condition of the NFC antenna module can be quantified to determine the vibration times and the vibration times of the resonance oscillation of the NFC antenna module, and the resonance frequency of the NFC antenna module is determined according to the vibration times and the vibration times of the resonance oscillation of the NFC antenna module, and whether an object is close to the electronic equipment or not can be determined according to the resonance frequency of the NFC antenna module. Therefore, by utilizing the near field communication circuit and the NFC antenna module, the NFC communication function and the SAR human body approach detection function can be realized simultaneously, multiplexing of the near field communication circuit and the NFC antenna module of the electronic equipment is realized, and the problem of mutual interference between the NFC chip and the SAR sensor is solved. In addition, the SAR sensor and the SAR sensing antennas are not required to be arranged, so that the requirement of layout area can be reduced, and the design of miniaturization and light weight of the electronic equipment is facilitated. In addition, the circuit of the embodiment has simple structure, does not relate to a new process and is convenient for large-scale application.
Moreover, compared with the detection mode in the driving emission state in the prior art, the embodiment can detect the object approaching when the NFC antenna module is in the resonance state, further reduce the power consumption of the electronic equipment and prolong the service time of the electronic equipment.
Each module in the near field communication circuit is described in detail below.
In this embodiment, the driving module 32 is configured to drive the NFC antenna module 35 to oscillate at a set driving frequency, and the oscillation frequency of the NFC antenna module 35 is the same as the driving frequency.
Illustratively, as shown in fig. 6, the driving module 32 may include a TX driving controller 321, a first switch 322, a second switch 323, a first inductor 324, a first capacitor 325, a third switch 326, a fourth switch 327, a second inductor 328, and a second capacitor 329. A first end of the TX driving controller 321 is connected with the output end of the control module 31, a grid electrode of the first switch 322 is connected with the TX driving controller 321, a source electrode of the first switch 322 is connected with the battery voltage VBAT, a grid electrode of the second switch 323 is connected with the TX driving controller 321, a drain electrode of the second switch 323 is connected with a drain electrode of the first switch 322, and a source electrode of the second switch 323 is grounded; a first end of the first inductor 324 is connected between the drain of the first switch 322 and the drain of the second switch 323, a second end of the first inductor 324 is connected to a first end of the first capacitor 325, and a second end of the first capacitor 325 is grounded. The grid of the third switch 326 is connected with the TX driving controller 321, the source electrode of the third switch 326 is connected with the power supply VDDPA, the grid of the fourth switch 327 is connected with the TX driving controller 321, the drain electrode of the fourth switch 327 is connected with the drain electrode of the third switch 326, and the source electrode of the fourth switch 327 is grounded; the first end of the second inductor 328 is connected between the drain of the third switch 326 and the drain of the fourth switch 327, the second end of the second inductor 328 is connected to the first end of the second capacitor 329, and the second end of the second capacitor 329 is grounded. The first end of the NFC antenna module 35 is connected between the first inductance 324 and the first capacitance 325, and the second end of the NFC antenna module 35 is connected between the second inductance 328 and the second capacitance 329. In addition, the driving module 32 may further include a voltage converter 3210 and a voltage regulator 3211, and the voltage converter 3210 and the voltage regulator 3211 are connected between the battery voltage VBAT and the first switch 322. It is understood that the first switch 322 and the third switch 326 may be PMOS switch transistors, the second switch 323 and the fourth switch 327 may be NMOS switch transistors, and the regulator 3211 may be a low-power regulator.
In the present embodiment, the voltage detection module 33 is configured to detect a voltage signal on the NFC antenna module 35, that is, detect an oscillating voltage of the NFC antenna module 35.
Illustratively, as shown in fig. 6, the voltage detection module 33 includes a third capacitor 331, a first resistor 332, a first variable resistor 333, a fourth capacitor 334, a second resistor 335, a second variable resistor 336, an automatic gain controller 337, a first amplifier 338, and a second amplifier 339. The first end of the third capacitor 331 is connected to the first end of the NFC antenna module 35, the second end of the third capacitor 331 is connected to the first end of the first resistor 332, the first resistor 332 is connected to the first end of the first variable resistor 333, and the second end of the first variable resistor 333 is connected to the bias voltage Vbias. The first end of the fourth capacitor 334 is connected to the second end of the NFC antenna module 35, the second end of the fourth capacitor 334 is connected to the first end of the second resistor 335, the second resistor 335 is connected to the first end of the second variable resistor 336, and the second end of the second variable resistor 336 is connected to the bias voltage Vbias. A first input end of the automatic gain controller 337 is connected with a control end of the first variable resistor 333, a second input end of the automatic gain controller 337 is connected with a control end of the second variable resistor 336, a first output end and a second output end of the automatic gain controller 337 are combined and input into the first amplifier 338, an output end of the first amplifier 338 is connected with an input end of the control module 31, a first output end and a second output end of the automatic gain controller 337 are also combined and input into the second amplifier 339, and an output end of the second amplifier 339 is connected with an input end of the control module 31.
In this embodiment, the vibration detection module 34 is configured to receive the voltage signal of the NFC antenna module, and determine the number of vibration times of the NFC antenna module 35 that resonates according to the voltage signal of the NFC antenna module.
In this embodiment, when a metal equivalent (e.g., a human body, an NFC card, a metal) approaches the electronic device, the parasitic capacitance of the NFC antenna module may change, which may further cause the resonant frequency of the NFC antenna module to change. Based on this, through detecting the voltage signal of NFC antenna module, can confirm the vibration number of times that NFC antenna module takes place resonant oscillation to confirm the resonant frequency of NFC antenna module, and then whether can survey the object and be close to electronic equipment according to the resonant frequency of NFC antenna module.
The number of times the NFC antenna module oscillates in resonance is determined according to the number of times the signal value of the voltage signal satisfies the preset condition. The signal value of the voltage signal meets the preset condition that the signal value of the voltage signal is larger than or equal to the preset voltage threshold, so that noise interference can be avoided, and the detection accuracy is improved.
In some embodiments of the present application, as shown in fig. 3, the vibration detection module includes a trigger unit 341 and a counting unit 342. The first end of the trigger unit 341 is connected with the second end of the voltage detection module 33; a first end of the counting unit 342 is connected with a second end of the triggering unit 341, and a second end of the counting unit 342 is connected with an input end of the control module 31; the trigger unit 341 is configured to output a count signal to the count unit 342 when the signal value of the voltage signal is greater than or equal to a preset voltage threshold; the counting unit 342 determines the number of vibrations of the NFC antenna module 35 according to the count signal.
Alternatively, the trigger unit 341 may be a smith trigger.
In this embodiment, in order to eliminate noise interference, the signal value of the voltage signal of the NFC antenna module may be compared with a preset voltage threshold, and when the signal value of the voltage signal of the NFC antenna module is greater than or equal to the preset voltage threshold, the NFC antenna module is considered to generate a resonant oscillation. At this time, the triggering unit outputs a count signal to the counting unit once, so that the counting unit records the number of times of resonant oscillation of the NFC antenna module according to the count signal. Therefore, the triggering unit and the counting unit can be used for quantifying the resonance oscillation condition of the NFC antenna module, so that the resonance frequency of the NFC antenna module can be accurately detected. In addition, the circuit structure is simple.
In this embodiment, the control module 31 is configured to determine the resonant frequency of the NFC antenna module 35 according to the number of vibration times and the vibration time of the NFC antenna module 35, so as to determine whether the object is close to the electronic device according to the resonant frequency.
The number of vibrations may be the number of oscillations of the NFC antenna module when the NFC antenna module is in a resonant state.
The vibration time may be a time length corresponding to the oscillation of the NFC antenna module, in which the number of vibrations occurs. By way of example, the vibration time may be a preset time, for example, 100ms. In specific implementation, the number of vibration times of the NFC antenna module during which the NFC antenna module resonates within a preset vibration time (100 ms) may be determined, so as to determine the resonant frequency of the NFC antenna module according to the number of vibration times and the preset vibration time. Here, it should be noted that the preset vibration time may be set according to the simulation test result, which is not limited in the embodiment of the present application.
For example, the vibration time may be calculated. In a specific implementation, after the driving module 32 stops driving the NFC antenna module, the voltage detection module 33 collects a voltage signal on the NFC antenna module, determines the number of times the voltage signal meets a preset condition, that is, determines the number of times the NFC antenna module oscillates in resonance, and the control module 31 determines the time corresponding to the resonant oscillation of the number of times the NFC antenna module oscillates, that is, the oscillation time, and determines the resonant frequency of the NFC antenna module according to the number of oscillations and the preset oscillation time.
In some embodiments of the present application, the control module 31 is further configured to control the driving module 32 to drive the NFC antenna module 35 to operate at a driving frequency; the control module 31 is further configured to control the driving module 32 to stop driving the NFC antenna module 35 to operate so that the NFC antenna module 35 is in a resonant state when the NFC antenna module 35 operates at the driving frequency.
In this embodiment, the control module 31 is configured to send a control signal to the driving module to control the driving module to drive the NFC antenna module 35 to work. The control module 31 is an NFC chip, which is an integrated circuit, and a micro control unit (Microcontroller Unit, MCU) and a radio frequency modem are provided inside the NFC chip. The NFC chip may be an integrated circuit mainly used for implementing a near field communication function of the electronic device. The NFC chip has an NFC communication function, for example, a card reading function, a card simulation function, and the like. In addition, the NFC chip has a low-power consumption card detecting (Low power card detection, LPCD) function, and whether an object is close to the electronic equipment can be detected by utilizing the detuning phenomenon which occurs when a metal equivalent (for example, a human body, an NFC card and metal) is close to the NFC antenna module.
In some embodiments of the present application, the control module 31 is specifically configured to determine, according to a resonant frequency of the NFC antenna module and preset first mapping data, a reference distance corresponding to the resonant frequency, and determine that an object is close to the electronic device if the reference distance is less than a preset distance threshold; the first mapping data is data reflecting a mapping relation between a reference resonant frequency of the NFC antenna module and a distance between the object and the electronic device.
In this embodiment, the first mapping data may include data reflecting a mapping relationship between the reference resonant frequency of the NFC antenna module and the distance between the object and the electronic device. The reference resonant frequency may be a resonant frequency of the NFC antenna module at a distance between the object and the electronic device measured in advance.
For example, as shown in fig. 7, the first mapping data may be a relationship curve of a reference resonant frequency of the NFC antenna module and a distance between the object and the electronic device. More specifically, when the electronic device leaves the factory, different distances of the object near the electronic device can be simulated, and reference resonant frequencies of the NFC antenna module under different distances can be obtained, and a relation curve of the reference resonant frequencies of the NFC antenna module and the distances between the object and the electronic device can be obtained. And then, in the use process of the electronic equipment, when the resonant frequency of the NFC antenna module is obtained, a relation curve between the resonant frequency and the reference resonant frequency of the NFC antenna module and the distance between the object and the electronic equipment can be fitted, and the reference distance corresponding to the resonant frequency is determined, so that whether the object is close to the electronic equipment or not is determined, the interference of environmental factors can be eliminated, and the detection accuracy is further improved.
In some embodiments of the present application, the control module 31 is further configured to perform a corresponding operation according to an operation mode of the electronic device in a case where the resonant frequency of the NFC antenna module indicates that the object is close to the electronic device.
In this embodiment, the working modules of the electronic device may include a first working module and a second working module. The first operation mode may be a SAR detection mode, i.e. a human body approach detection module. The second mode of operation may be an NFC mode.
In some embodiments of the present application, the control module 31 is specifically configured to control the transmission power of the radio frequency signal of the electronic device to be reduced to the target power when the electronic device is in the first operation mode.
In this embodiment, when the electronic device is under the first working module, that is, the near field communication circuit is used for SAR detection, and the resonant frequency of the NFC antenna module indicates that the object is close to the electronic device, the human body is considered to be close to the electronic device, and at this time, the control module 31 is used for controlling the transmitting power of the radio frequency signal of the electronic device to be reduced to the target power, which can reduce the injury of electromagnetic radiation to the human body.
In some embodiments of the present application, the control module 31 is specifically configured to control the electronic device to send the card checking instruction when the electronic device is in the second operation mode.
In this embodiment, when the electronic device is under the second working module, that is, the near field communication circuit is used for NFC communication, and the NFC antenna module indicates that the object is close to the electronic device, the NFC card is considered to be close to the electronic device, and at this time, the control module 31 is used for controlling the electronic device to send a card checking instruction to enter a card reading and checking program, so that power consumption of the electronic device can be reduced.
In some embodiments of the present application, the control module 31 is further configured to control the electronic device to switch between the first operation mode and the second operation mode according to a preset policy.
The electronic device is illustratively controlled to switch between the first mode of operation and the second mode of operation in a time-sharing manner. For example, at time T1, the control module 31 is configured to control the near field communication circuit of the electronic device to be in the first operation module, at time T2, the control module 31 is configured to control the near field communication circuit of the electronic device to be in the second operation module, at time T3, the control module 31 is configured to control the near field communication circuit of the electronic device to be in the first operation module, and at time T4, the control module 31 is configured to control the near field communication circuit of the electronic device to be in the second operation module. In this way, the NFC functionality and the SAR detection functionality may be implemented with the near field communication circuitry of the electronic device.
In this embodiment, as shown in fig. 4, the NFC antenna module 35 may be an antenna disposed on the top of the electronic device, and the NFC antenna module 35 may be multiplexed with a main antenna of the electronic device. Therefore, a plurality of NFC antennas are not required to be arranged, and human body approaching detection of the front side and the rear side of the electronic equipment can be realized.
In some embodiments of the application, the NFC antenna module comprises a plurality of NFC antenna elements connected in series.
In this embodiment, the NFC circuit may be provided with a plurality of NFC antenna units, and the arrangement mode of the NFC coil is more flexible, so that the sensing area of the NFC function may be increased, and the use is more convenient. In addition, the polling control of the operation of the plurality of NFC antenna units can further reduce the power consumption of the electronic device.
In some embodiments of the application, as shown in fig. 6, the near field communication circuit further comprises an antenna matching module 36, which antenna matching module 36 is connected between the driving module 32 and the NFC antenna module 35.
As shown in fig. 6, the antenna matching module 36 includes a fifth capacitor 361, a sixth capacitor 362, a seventh capacitor 363, and an eighth capacitor 364, wherein a first end of the fifth capacitor 361 is connected between the first inductor 324 and the first capacitor 325, a second end of the fifth capacitor 361 is connected to the first end of the NFC antenna module 35, the sixth capacitor 362 is connected between the second inductor 328 and the second capacitor 329, a second end of the sixth capacitor 362 is connected to the second end of the NFC antenna module 35, a first end of the seventh capacitor 363 is connected to the second end of the fifth capacitor 361 and the first end of the NFC antenna module 35, a second end of the seventh capacitor 363 is grounded, a first end of the eighth capacitor 364 is connected to the second end of the sixth capacitor 361 and the second end of the NFC antenna module 35, and a second end of the eighth capacitor 364 is grounded.
In this embodiment, when the NFC antenna module 35 is driven to oscillate by the driving module 32, the antenna matching module 36 may make the forced vibration frequency of the NFC antenna module 35 consistent with the driving frequency of the driving module 32, so as to improve the emission efficiency of the NFC antenna module.
The embodiment of the application also provides electronic equipment, which comprises the near field communication circuit of the embodiment. The electronic device can be a mobile phone, a tablet computer, a notebook computer, a wearable device and the like.
Illustratively, as shown in fig. 8, the electronic device may include an application processor 81, a near field communication circuit 82, a modem 83, a main antenna matching circuit 84, and a matching switch 85.
Wherein the application processor 81 is the control hub of the overall electronic device control system. The application processor 81 is used for software system operation, implementation of functions of the electronic device, control of peripheral devices, and the like. For example, the application processor 81 may control peripheral devices, such as NFC IC and SAR IC. The modem 83 is used to modulate the baseband signal into a radio frequency signal for transmission, and to receive the radio frequency signal. The near field communication circuit 82 may be a near field communication circuit as described in the above embodiments, and may implement an NFC function and a human body proximity detection function. For a complex architecture, a transmitting system corresponding to different frequencies, there will also typically be different ground matches, which can be selected by the matching switch 85 to achieve different resonant frequencies.
In the embodiment of the application, the vibration detection module is arranged in the near field communication circuit, so that the resonance oscillation condition of the NFC antenna module can be quantified to determine the vibration times and the vibration times of the resonance oscillation of the NFC antenna module, and the resonance frequency of the NFC antenna module is determined according to the vibration times and the vibration times of the resonance oscillation of the NFC antenna module, and whether an object is close to the electronic equipment or not can be determined according to the resonance frequency of the NFC antenna module. Therefore, by utilizing the near field communication circuit and the NFC antenna module, the NFC communication function and the SAR human body approach detection function can be realized simultaneously, multiplexing of the near field communication circuit and the NFC antenna module of the electronic equipment is realized, and the problem of mutual interference between the NFC chip and the SAR sensor is solved. In addition, the SAR sensor and the SAR sensing antennas are not required to be arranged, so that the requirement of layout area can be reduced, and the design of miniaturization and light weight of the electronic equipment is facilitated. In addition, the circuit of the embodiment has simple structure, does not relate to a new process and is convenient for large-scale application.
Moreover, compared with the detection mode in the driving emission state in the prior art, the embodiment can detect the object approaching when the NFC antenna module is in the resonance state, further reduce the power consumption of the electronic equipment and prolong the service time of the electronic equipment.
The embodiments of the present application have been described above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and many forms may be made by those having ordinary skill in the art without departing from the spirit of the present application and the scope of the claims, which are to be protected by the present application.
Claims (11)
1. A near field communication circuit, comprising:
An NFC antenna module;
The control module comprises an output end and an input end;
The first end of the driving module is connected with the output end of the control module, and the second end of the driving module is connected with the NFC antenna module;
The first end of the voltage detection module is connected with the NFC antenna module;
The first end of the vibration detection module is connected with the second end of the voltage detection module, and the second end of the vibration detection module is connected with the input end of the control module;
The NFC antenna module is used for receiving a voltage signal of the NFC antenna module and outputting the voltage signal to the vibration detection module when the NFC antenna module is in a resonance state; the vibration detection module is used for determining the vibration times of the NFC antenna module according to the voltage signal, wherein the vibration times are times when the signal value of the voltage signal meets a preset condition, and the preset condition is that the signal value of the voltage signal is larger than or equal to a preset voltage threshold value; the control module is used for determining the resonance frequency of the NFC antenna module according to the vibration times and the vibration time of the NFC antenna module so as to determine whether an object is close to the electronic equipment according to the resonance frequency.
2. The near field communication circuit of claim 1, wherein the vibration detection module comprises:
the first end of the triggering unit is connected with the second end of the voltage detection module;
The first end of the counting unit is connected with the second end of the triggering unit, and the second end of the counting unit is connected with the input end of the control module;
the trigger unit is used for outputting a counting signal to the counting unit under the condition that the signal value of the voltage signal is larger than or equal to a preset voltage threshold value; and the counting unit determines the vibration times of the NFC antenna module according to the counting signal.
3. The near field communication circuit of claim 1, wherein the control module is further configured to control the driving module to drive the NFC antenna module to operate at a driving frequency;
the control module is further configured to control the driving module to stop driving the NFC antenna module to work under the condition that the NFC antenna module works at a driving frequency, so that the NFC antenna module is in a resonance state.
4. The near field communication circuit of claim 1, wherein the control module is specifically configured to determine a reference distance corresponding to the resonant frequency according to the resonant frequency of the NFC antenna module and preset first mapping data, and determine that an object is close to the electronic device if the reference distance is less than a preset distance threshold;
the first mapping data is data reflecting a mapping relation between a reference resonant frequency of the NFC antenna module and a distance between an object and the electronic equipment.
5. The near field communication circuit of claim 1, wherein the control module is further configured to perform a corresponding operation according to an operation mode of the electronic device if the resonant frequency of the NFC antenna module indicates that an object is near the electronic device.
6. The near field communication circuit of claim 5, wherein the control module is configured to control the transmit power of the radio frequency signal of the electronic device to be reduced to the target power, in particular, when the electronic device is in the first mode of operation.
7. The near field communication circuit of claim 5, wherein the control module is specifically configured to control the electronic device to send the card check instruction if the electronic device is in the second operation mode.
8. The near field communication circuit of claim 1, wherein the control module is further configured to control the electronic device to switch between the first mode of operation and the second mode of operation according to a preset policy.
9. The near field communication circuit of claim 1, wherein the NFC antenna module comprises a plurality of NFC antenna elements connected in series.
10. The near field communication circuit of claim 1, further comprising:
and the antenna matching module is connected between the driving module and the NFC antenna module.
11. An electronic device, characterized in that the electronic device comprises a near field communication circuit as claimed in any of claims 1 to 10.
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| CN113049879A (en) * | 2019-12-26 | 2021-06-29 | 三星电子株式会社 | Near field communication device and method for detecting resonant frequency thereof |
| CN114879262A (en) * | 2022-04-28 | 2022-08-09 | 深圳市汇顶科技股份有限公司 | NFCC and electronic device |
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| US9411993B2 (en) * | 2012-06-18 | 2016-08-09 | Master Lock Company Llc | RFID detection system |
| US10511347B2 (en) * | 2017-11-14 | 2019-12-17 | Nxp B.V. | Device detection in contactless communication systems |
| FR3085088B1 (en) * | 2018-08-20 | 2020-07-17 | Continental Automotive France | DEVICE FOR DETECTION OF ELECTRONIC EQUIPMENT AND COMMUNICATION WITH TWO NEAR-FIELD COMMUNICATION ANTENNAS |
| JP7261474B2 (en) * | 2019-07-24 | 2023-04-20 | 株式会社ユニバーサルエンターテインメント | Electronic circuit device detection device and detection method |
| CN215420286U (en) * | 2021-07-29 | 2022-01-04 | Oppo广东移动通信有限公司 | NFC communication circuit, shell assembly and NFC communication system |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113049879A (en) * | 2019-12-26 | 2021-06-29 | 三星电子株式会社 | Near field communication device and method for detecting resonant frequency thereof |
| CN114879262A (en) * | 2022-04-28 | 2022-08-09 | 深圳市汇顶科技股份有限公司 | NFCC and electronic device |
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