CN101655925A - Close coupling radio frequency identification devices (RFID) tag and control method thereof - Google Patents
Close coupling radio frequency identification devices (RFID) tag and control method thereof Download PDFInfo
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- CN101655925A CN101655925A CN200910108379A CN200910108379A CN101655925A CN 101655925 A CN101655925 A CN 101655925A CN 200910108379 A CN200910108379 A CN 200910108379A CN 200910108379 A CN200910108379 A CN 200910108379A CN 101655925 A CN101655925 A CN 101655925A
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Abstract
The invention discloses a close coupling radio frequency identification devices (RFID) tag and a control method thereof. The close coupling RFID tag comprises a master control module, a signal receiving circuit, an amplifying circuit, antennas, a power supply and a gain control circuit, and the signal receiving circuit comprises a controllable amplifying circuit. The power supply supplies power for each part of the RFID tag; the master control module sends carrier detection signals to antennas after being connected with the power supply, acquires sampling signals from the signal receiving circuit as the basis for the master control module to determine the amplification factor of the controllable amplifying circuit, and adjusts the amplification factor of the controllable amplifying circuitthrough the gain control circuit. The invention can ensure that the close coupling RFID tag can receive data both in different environments and in a certain range. Therefore, the invention is a closecoupling RFID tag which can detect the self-located electromagnetic environment, adapts to influence from different electromagnetic environments automatically, and can keep the reading distance and range unchangeable.
Description
[technical field]
The present invention relates to radio RF recognition technology, especially relate to a kind of close coupling radio frequency identification devices (RFID) tag and control method thereof.
[background technology]
In close coupling radio frequency identification devices (RFID) tag design in the past, because market does not have special application requirements, in receiving circuit, adopted direct inductance near field coupling technique, in signal receiving circuit, the signal that receives is directly handled through detection.At first, when label receiving antenna Card Reader distance under small size very near; Secondly, under the environment that has shielding, label can not be identified.And, because traditional electronic tag can not be found out self residing electromagnetic environment, on the Card Reader distance, can only be implemented under the different electromagnetic environments, different decipherment distances appears.Yet under application scenarios such as stored value card, ecommerce, electronic accounting business, the decipherment distance of electronic tag needs strictness to be limited within the in-plant certain limit.The electronic tag of the 2.4G hertz frequency of widespread use on the market does not have controllability because of it reads distance, and fixedly the application scenario of Card Reader distance can not normal use at some.
Under the situation that the current phone user popularizes very much, use mobile phone and realize that the requirement pendulum of paying consumption fast is in face of mobile phone manufacturer and Virtual network operator.This just needs a kind of electronic tag that can be integrated on the SIM card, and all cellphone subscribers are as long as change the consumption pattern that SIM card just can have this tool potentiality.But what more need for Virtual network operator is the security of consumption, and this just requires air interface to encrypt, and the Card Reader distance must be controlled within the specific limits.Because its structure design of different mobile phones is different with material, its influence for radiofrequency signal also has nothing in common with each other, and the electronic tag on the SIM card can't can both satisfy the fixedly requirement of Card Reader distance in the mobile phone of different structure mobile phone at present.In order to realize the constant this purpose of Card Reader distance, it is irrational requiring to change mobile phone in the mobile phone users, and this just needs electronic tag on the SIM card can adapt to the variation of different mobile phone electromagnetic environments automatically, realizes the constant effect of Card Reader distance range.
[summary of the invention]
The technical problem to be solved in the present invention provides a kind of self residing electromagnetic environment of enough finding out, and can adapt to the influence of different electromagnetic environments automatically, realizes the constant close coupling radio frequency identification devices (RFID) tag of Card Reader distance range.
Another technical matters that will solve of the present invention provides a kind of self residing electromagnetic environment of enough finding out, and can adapt to the influence of different electromagnetic environments automatically, realizes the control method of the close coupling radio frequency identification devices (RFID) tag that the Card Reader distance range is constant.
In order to solve the problems of the technologies described above, the technical solution used in the present invention is that a kind of close coupling radio frequency identification devices (RFID) tag comprises main control module, signal receiving circuit, amplifying circuit and antenna, also comprise power supply and gain control circuit, described signal receiving circuit comprises controlled amplifying circuit; Described power supply is to the each several part power supply of electronic tag, described main control module sends carrier sense signal at the energized rearward-facing antenna, described main control module obtains sampled signal from signal receiving circuit and determines the foundation of controlled amplifying circuit enlargement factor as main control module, and described main control module is regulated the enlargement factor of controlled amplifying circuit by gain control circuit.
Above-described close coupling radio frequency identification devices (RFID) tag, described main control module comprises control module, carrier wave output circuit, analog to digital conversion circuit and D/A converting circuit, described main control module is controlled the carrier wave output circuit to the antenna transmission carrier sense signal after energized, described sampled signal is determined the foundation of controlled amplifying circuit enlargement factor through the analog to digital conversion circuit Input Control Element as control module; Described control module control D/A converting circuit is exported the DC current of different numerical value, and the DC current that described gain control circuit is exported different numerical value with D/A converting circuit converts different DC voltage to.
Above-described close coupling radio frequency identification devices (RFID) tag, described gain control circuit comprises first triode, boost resistor and pull-up resistor, described boost resistor is connected between the base stage and ground of first triode, described pull-up resistor is connected between the emitter and ground of first triode, and the collector of first triode connects positive source; The base stage of first triode connects the output terminal of described D/A converting circuit, and the emitter of first triode connects the power input of described controlled amplifying circuit.
Above-described close coupling radio frequency identification devices (RFID) tag, described controlled amplifying circuit comprises second triode, the second triode pull-up resistor, the second transistor collector resistance, the collector of described second triode connects the gain control circuit dc voltage output end through the second transistor collector resistance, the described second triode pull-up resistor is connected between the gain control circuit dc voltage output end and second transistor base, the base stage of second triode connects antenna through antenna matching electric capacity, the collector of second triode is as the output terminal of controlled amplifying circuit, the grounded emitter of second triode.
Above-described close coupling radio frequency identification devices (RFID) tag, described signal receiving circuit comprises second amplifying circuit, detecting circuit and filtering circuit, described second amplifying circuit comprises the 3rd triode, the 3rd triode pull-up resistor, the 3rd transistor collector resistance, the collector of described the 3rd triode connects positive source through the 3rd transistor collector resistance, described the 3rd triode pull-up resistor is connected between positive source and the 3rd transistor base, the base stage of the 3rd triode connects the collector of second triode through first coupling capacitance, the grounded emitter of the 3rd triode, the collector of the 3rd triode connects detecting circuit through second coupling capacitance, the signal of second amplifying circuit output is input amplifying circuit after detecting circuit and filtering circuit processing in turn, and described sampled signal is exported through the analog to digital conversion circuit Input Control Element by detecting circuit.
Above-described close coupling radio frequency identification devices (RFID) tag, described detecting circuit comprises detector diode, charging capacitor and discharge resistance, the anode of detector diode connects the collector of the 3rd triode through second coupling capacitance, charging capacitor and discharge resistance also connect the negative electrode of a termination detector diode afterwards, other end ground connection; Described filtering circuit comprises filter resistance and filter capacitor, the negative electrode of described filter resistance one termination detector diode, the input end of another termination amplifying circuit, the input end of described filter capacitor one termination amplifying circuit, other end ground connection; The negative electrode of described detector diode connects the analog to digital conversion circuit of main control module.
Above-described close coupling radio frequency identification devices (RFID) tag comprises match circuit, and described match circuit comprises transmission resistance, first matching capacitance, second matching capacitance and coupling inductance, and described transmission resistance, first matching capacitance and coupling inductance are connected in series successively; The output terminal of the carrier wave output circuit of the resistance termination main control module of sequential circuit, the inductance termination antenna of sequential circuit; The inductance end of one termination sequential circuit of second matching capacitance, other end ground connection.
A kind of technical scheme of control method of close coupling radio frequency identification devices (RFID) tag is may further comprise the steps:
801) main control module sends carrier sense signal at electronic tag energized rearward-facing antenna;
802) main control module obtains sampled signal and sampled signal is carried out digitizing from signal receiving circuit;
803) digital value with sampled signal compares with the preset value that is kept in the main control module; More than or equal to preset value, just carry out step 805 as the digital value of sampled signal, then carry out step 804 less than preset value as the digital value of sampled signal;
804) main control module increases the enlargement factor of controlled amplifying circuit by gain control circuit, returns step 802 then;
805) main control module is preserved the controlled variable to gain control circuit, and the follow-up enlargement factor of fixing controlled amplifying circuit is constant;
806) main control module stops to the antenna transmission carrier sense signal;
807) electronic tag enters normal operating conditions.
Above-described control method, described main control module comprises control module and D/A converting circuit, in step 804, described control module control D/A converting circuit strengthens the DC current values of output, and described gain control circuit converts the DC current of D/A converting circuit output to DC voltage in proportion; In step 805, the magnitude of voltage of the current value of fixed die change-over circuit output and gain control circuit output.
Promptly launching carrier sense signal after the main control module of close coupling radio frequency identification devices (RFID) tag of the present invention powers on, and then is exactly the environmental testing process, and antenna is equivalent to an inductance in this process, and when metal was close, the parameter of inductance was put and changed.Antenna and coupling capacitance are formed a resonant circuit, antenna and coupling capacitance have an initial resonance frequency when powering on, the carrier signal that this moment, main control module sent self is sampled by the signal of the feedback of signal receiving circuit, main control module just can detect the intensity of carrier wave feedback signal like this, when metal object is close, the energy of carrier sense signal changes, and sampled signal weakens, and so just knows to have entered a metalloid shielding environment.Gain control circuit increases the enlargement factor appropriateness of the controlled amplifying circuit of signal receiving circuit under the control of main control module.Even metallic shield is arranged, because signal energy is exaggerated, signal still might be identified.If sampled signal does not change, illustrate that close coupling radio frequency identification devices (RFID) tag does not enter the shielding environment, controlled amplifying circuit is with regard to the original smaller enlargement factor of setting of employing system.So both guaranteed that close coupling radio frequency identification devices (RFID) tag can receive data under different environment, and guaranteed again and can only in certain scope, receive data.So the present invention is a kind of self residing electromagnetic environment of enough finding out, and can adapt to the influence of different electromagnetic environments automatically, realize the constant close coupling radio frequency identification devices (RFID) tag of Card Reader distance range.
[description of drawings]
The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments.
Fig. 1 is the theory diagram of close coupling radio frequency identification devices (RFID) tag embodiment of the present invention.
Fig. 2 is the wiring diagram of close coupling radio frequency identification devices (RFID) tag embodiment of the present invention as the single-chip microcomputer C8051F330 of main control module.
Fig. 3 is the circuit diagram of close coupling radio frequency identification devices (RFID) tag embodiment gain control circuit of the present invention.
Fig. 4 is the circuit diagram of the controlled amplifying circuit of close coupling radio frequency identification devices (RFID) tag embodiment of the present invention and second amplifying circuit.
Fig. 5 is the circuit diagram of close coupling radio frequency identification devices (RFID) tag embodiment detecting circuit of the present invention and filtering circuit.
Fig. 6 is the circuit diagram of close coupling radio frequency identification devices (RFID) tag embodiment match circuit of the present invention.
Fig. 7 is the circuit diagram of close coupling radio frequency identification devices (RFID) tag embodiment amplifying circuit of the present invention.
Fig. 8 is the process flow diagram of close coupling radio frequency identification devices (RFID) tag control method of the present invention.
[embodiment]
The principle of close coupling radio frequency identification devices (RFID) tag embodiment of the present invention as shown in Figure 1.Close coupling radio frequency identification devices (RFID) tag comprises that main control module, gain control circuit, signal receiving circuit, amplifying circuit, antenna and power supply (power supply is not shown) signal receiving circuit comprises controlled amplifying circuit, detecting circuit and filtering circuit.Power supply is to the each several part power supply of electronic tag, the employed single-chip microcomputer of main control module comprises control module, carrier wave output circuit, analog to digital conversion circuit and D/A converting circuit among the present invention, main control module is controlled the carrier wave output circuit to the antenna transmission carrier sense signal after energized, simultaneously, main control module obtains sampled signal from signal receiving circuit, sampled signal is determined the foundation of controlled amplifying circuit enlargement factor through the analog to digital conversion circuit Input Control Element as control module; Control module control D/A converting circuit is exported the DC current of different numerical value, and the DC current that gain control circuit is exported different numerical value with D/A converting circuit converts different DC voltage to regulate the enlargement factor of controlled amplifying circuit.
Promptly launching carrier sense signal by the carrier wave output circuit after main control module powers on, and then is exactly the environmental testing process, and antenna is equivalent to an inductance in this process, and when metal was close, the parameter of inductance was put and changed.Antenna and coupling capacitance are formed a resonant circuit, antenna and coupling capacitance have an initial resonance frequency when powering on, the carrier signal that this moment, main control module sent self is sampled by the signal of the feedback of signal receiving circuit, main control module just can detect the intensity of carrier wave feedback signal like this, when metal object is close, the energy of carrier sense signal changes, and sampled signal weakens, and so just knows to have entered a metalloid shielding environment.Gain control circuit increases the enlargement factor appropriateness of the controlled amplifying circuit of signal receiving circuit under the control of main control module.Even metallic shield is arranged, because signal energy is exaggerated, signal still might be identified.If sampled signal does not change, illustrate that close coupling radio frequency identification devices (RFID) tag does not enter the shielding environment, controlled amplifying circuit is with regard to the original smaller enlargement factor of setting of employing system.So both guaranteed that close coupling radio frequency identification devices (RFID) tag can receive data under different environment, and guaranteed again and can only in certain scope, receive data.
As shown in Figure 2, the employed single-chip microcomputer C8051F 330 of main control module has 1 DAC pin, and this port can be exported a controllable current IDC who is similar to current source.The ADC pin can carry out sampled digitalization to voltage analog as the input end of analog to digital conversion circuit.
Gain control circuit as shown in Figure 3.Comprise triode Q1, boost resistor R4 and pull-up resistor R5, boost resistor R4 is connected between the base stage and ground of triode Q1, and pull-up resistor is connected between the emitter and ground of triode Q1, and the collector of triode Q1 meets positive source VCC; The base stage of triode Q1 meets the output terminal IDC of D/A converting circuit, and the emitter of triode Q1 meets the power input CONT of controlled amplifying circuit.
The controlled amplifying circuit and second amplifying circuit are as shown in Figure 4.Controlled amplifying circuit comprises triode Q2, pull-up resistor R6, collector resistance R7, the collector of triode Q2 meets the dc voltage output end CONT of gain control circuit through collector resistance R7, pull-up resistor R6 is connected between gain control circuit dc voltage output end CONT and the triode Q2 base stage, the base stage of triode Q2 meets antenna ANT through antenna matching capacitor C 4, the collector of triode Q2 is as output termination second amplifying circuit of controlled amplifying circuit, the grounded emitter of triode Q2.
The IDC electric current is because the boosting of boost resistor R4 can produce a voltage, because IDC is that single-chip microcomputer C8051F330 changes by D/A, therefore this voltage on boost resistor R4 is controllable, this voltage has just produced a controlled voltage CONT through the amplification of triode Q1, this controllable voltage is used for controlling the enlargement factor of controlled amplifying circuit as the voltage of the amplifying triode Q2 collector of controlled amplifying circuit.
Second amplifying circuit comprises pull-up resistor R8, the triode Q3 collector resistance R15 of triode Q3, triode Q3, the collector of triode Q3 meets positive source VCC through collector resistance R15, pull-up resistor R8 is connected between positive source VCC and triode Q 3 base stages, the base stage of triode Q3 connects the collector of triode Q2 through the first coupling capacitance C5, the grounded emitter of triode Q3, the collector of triode Q3 connects detecting circuit through the second coupling capacitance C6.Second amplifying circuit can make signal be amplified to as fixing enlargement factor amplifier to help analog-to-digital signal energy.
As shown in Figure 5, signal receiving circuit also comprises detecting circuit and filtering circuit detecting circuit, the signal of second amplifying circuit output is input amplifying circuit after detecting circuit and filtering circuit processing in turn, and sampled signal is exported through the analog to digital conversion circuit Input Control Element by detecting circuit.The mode that present embodiment adopts envelope detection to add low-pass filtering is carried out detection.Detecting circuit comprises detector diode D1, charging capacitor C8 and discharge resistance R13, the anode of detector diode D1 connects the collector of triode Q3 through the second coupling capacitance C6, charging capacitor C8 and discharge resistance R13 also connect the negative electrode of a termination detector diode D1 afterwards, other end ground connection.Filtering circuit comprises filter resistance R14 and filter capacitor C9, the negative electrode of the termination detector diode D1 of filter resistance R14, the input end FILTER of another termination amplifying circuit, the input end FILTER of the termination amplifying circuit of filter capacitor C9, other end ground connection; The negative electrode of detector diode meets the interface ADC of single-chip microcomputer analog to digital conversion circuit, the output sampled signal.The envelope detection circuit of forming by detector diode D1 and charging capacitor C8, discharge resistance R13 can become the frenulum signal to the high-frequency signal detection, and baseband signal at this moment just can the sampled digital change
Match circuit as shown in Figure 6, match circuit comprises transmission resistance R 9, the first matching capacitance C11, second matching capacitance C12 and coupling inductance L 1.Transmission resistance R 9, the first matching capacitance C11 and coupling inductance L 1 are connected in series successively.The resistance terminal of above-mentioned sequential circuit meets the output terminal CD of the carrier wave output circuit of single-chip microcomputer, the inductance termination antenna ANT of sequential circuit; The inductance end of the termination sequential circuit of the second matching capacitance C12, other end ground connection.
Antenna ANT and antenna matching electric capacity capacitor C 4 couplings are formed resonant tank, the capacitor C 4 of antenna ANT and coupling does not have an intrinsic resonance frequency when having metal object close, the carrier signal of sending for single-chip microcomputer has an intrinsic decay, when metallics is close, will break original tuning-points, the carrier wave that sends for single-chip microcomputer has changed damping capacity, so carrier wave can change by the sampled value behind the receiving circuit.Antenna ANT goes up the signal demand that receives and amplifies through triode Q2, and control signal CONT can controllably adjust the enlargement factor of aerial signal, therefore can reach the purpose of dynamic adjustment signal amplification factor.Triode Q3 forms second amplifying circuit, and the purpose of this circuit is that signal is amplified to the degree that can be digitized.Signal after amplifying will become baseband signal through detection.The effect of amplifying circuit shown in Figure 7 is to be amplified to the digital signal level that can be handled by single-chip microcomputer for the signal that makes detection.Signal DATA is the digital signal mutual with read write line.
Workflow of the present invention is as shown in Figure 8:
1) single-chip microcomputer sends carrier sense signal at electronic tag energized rearward-facing antenna;
2) single-chip microcomputer obtains sampled signal and sampled signal is carried out digitizing from the signal of signal receiving circuit feedback;
3) digital value with sampled signal compares with the default standard value that is kept in the single-chip microcomputer; More than or equal to default standard value, just carry out step 5 as the digital value of sampled signal, then carry out step 4 less than preset value as the digital value of sampled signal;
4) Single-chip Controlling unit controls D/A converting circuit is by the DC current values of certain differential increasing output, gain control circuit converts the DC current of D/A converting circuit output to DC voltage in proportion, thereby increase the enlargement factor of controlled amplifying circuit, return step 2 then; If the DC current of output has reached default maximal value, just enter next step;
5) single-chip microcomputer is preserved the controlled variable to gain control circuit, and it is constant that the magnitude of voltage of the current value of analog conversion circuit output and gain control circuit output is fixed up, thereby the enlargement factor of having fixed controlled amplifying circuit follow-up work is constant;
6) single-chip microcomputer stops to the antenna transmission carrier sense signal;
7) electronic tag enters normal operating conditions.
After single-chip microcomputer powered on, its carrier wave output circuit clock shook and promptly begins concussion, and at this moment the control module of single-chip microcomputer makes clock shake output pin for the state of opening, and the clock signal that shakes just can directly be gone out from the pin of CD signal like this.The matching network that this signal is formed by the first matching capacitance C11, coupling inductance L 1, the second matching capacitance C12 by transmission resistance R 9 is to antenna transmission, and the matching network that matching capacitance C11, coupling inductance L 1, matching capacitance C12 form can make the energy of signal obtain substantially carrying.
Capacitor C 4 in receiving end antenna and coupling is formed a matching network, and antenna can equivalence become an inductance L, and the inductance and matching capacitance are formed series resonant circuit, and its matched impedance reaches minimum when at carrier frequency resonance.Circuit reaches resonance when the capacitive reactance conjugation of the induction reactance of inductance L and capacitor C 4, this moment matching network the impedance minimum.Under the normal condition, the electric capacity of antenna and coupling is in the matching status of impedance minimum, and the signal energy that receives is maximum.The object that metalloid is arranged when the external world near the time, can influence electromagnetic wave and be received by antenna, can increase or reduce the inductance value of antenna, must increase for the impedance of signal, signal certainty energy reduces, the voltage of ADC sampled signal will reduce like this.Single-chip Controlling unit controls D/A converting circuit to strengthen the voltage of controlled amplifying circuit triode Q2 collector, has changed the quiescent point of triode Q2 by the DC current values of certain differential increasing output, has just changed the enlargement factor of triode Q2.Sample once more through said process, regulate once more, reach the value intensity of pre-value,, just regulate electric current and arrive maximal value if do not reach pre-value intensity up to the intensity of signal.Through overtesting, the standard value of test sample signal can be arranged on 1.22V, and this value is the magnitude of voltage in resonant circuit situation down-sampled signal.
Claims (9)
1. a close coupling radio frequency identification devices (RFID) tag comprises main control module, signal receiving circuit, amplifying circuit and antenna, it is characterized in that, comprises power supply and gain control circuit, and described signal receiving circuit comprises controlled amplifying circuit; Described power supply is to the each several part power supply of electronic tag, described main control module sends carrier sense signal at the energized rearward-facing antenna, described main control module obtains sampled signal from signal receiving circuit and determines the foundation of controlled amplifying circuit enlargement factor as main control module, and described main control module is regulated the enlargement factor of controlled amplifying circuit by gain control circuit.
2. close coupling radio frequency identification devices (RFID) tag according to claim 1, it is characterized in that, described main control module comprises control module, carrier wave output circuit, analog to digital conversion circuit and D/A converting circuit, described main control module is controlled the carrier wave output circuit to the antenna transmission carrier sense signal after energized, described sampled signal is determined the foundation of controlled amplifying circuit enlargement factor through the analog to digital conversion circuit Input Control Element as control module; Described control module control D/A converting circuit is exported the DC current of different numerical value, and the DC current that described gain control circuit is exported different numerical value with D/A converting circuit converts different DC voltage to.
3. close coupling radio frequency identification devices (RFID) tag according to claim 2, it is characterized in that, described gain control circuit comprises first triode, boost resistor and pull-up resistor, described boost resistor is connected between the base stage and ground of first triode, described pull-up resistor is connected between the emitter and ground of first triode, and the collector of first triode connects positive source; The base stage of first triode connects the output terminal of described D/A converting circuit, and the emitter of first triode connects the power input of described controlled amplifying circuit.
4. according to claim 2 or 3 described close coupling radio frequency identification devices (RFID) tags, it is characterized in that, described controlled amplifying circuit comprises second triode, the second triode pull-up resistor, the second transistor collector resistance, the collector of described second triode connects the gain control circuit dc voltage output end through the second transistor collector resistance, the described second triode pull-up resistor is connected between the gain control circuit dc voltage output end and second transistor base, the base stage of second triode connects antenna through antenna matching electric capacity, the collector of second triode is as the output terminal of controlled amplifying circuit, the grounded emitter of second triode.
5. close coupling radio frequency identification devices (RFID) tag according to claim 4, it is characterized in that, described signal receiving circuit comprises second amplifying circuit, detecting circuit and filtering circuit, described second amplifying circuit comprises the 3rd triode, the 3rd triode pull-up resistor, the 3rd transistor collector resistance, the collector of described the 3rd triode connects positive source through the 3rd transistor collector resistance, described the 3rd triode pull-up resistor is connected between positive source and the 3rd transistor base, the base stage of the 3rd triode connects the collector of second triode through first coupling capacitance, the grounded emitter of the 3rd triode, the collector of the 3rd triode connects detecting circuit through second coupling capacitance, the signal of second amplifying circuit output is input amplifying circuit after detecting circuit and filtering circuit processing in turn, and described sampled signal is exported through the analog to digital conversion circuit Input Control Element by detecting circuit.
6. close coupling radio frequency identification devices (RFID) tag according to claim 4, it is characterized in that, described detecting circuit comprises detector diode, charging capacitor and discharge resistance, the anode of detector diode connects the collector of the 3rd triode through second coupling capacitance, charging capacitor and discharge resistance also connect the negative electrode of a termination detector diode afterwards, other end ground connection; Described filtering circuit comprises filter resistance and filter capacitor, the negative electrode of described filter resistance one termination detector diode, the input end of another termination amplifying circuit, the input end of described filter capacitor one termination amplifying circuit, other end ground connection; The negative electrode of described detector diode connects the analog to digital conversion circuit of main control module.
7. according to claim 2 or 3 described close coupling radio frequency identification devices (RFID) tags, it is characterized in that, comprise match circuit, described match circuit comprises transmission resistance, first matching capacitance, second matching capacitance and coupling inductance, and described transmission resistance, first matching capacitance and coupling inductance are connected in series successively; The output terminal of the carrier wave output circuit of the resistance termination main control module of sequential circuit, the inductance termination antenna of sequential circuit; The inductance end of one termination sequential circuit of second matching capacitance, other end ground connection.
8. the control method of a close coupling radio frequency identification devices (RFID) tag according to claim 1 is characterized in that, may further comprise the steps:
801) main control module sends carrier sense signal at electronic tag energized rearward-facing antenna;
802) main control module obtains sampled signal and sampled signal is carried out digitizing from signal receiving circuit;
803) digital value with sampled signal compares with the preset value that is kept in the main control module; More than or equal to preset value, just carry out step 805 as the digital value of sampled signal, then carry out step 804 less than preset value as the digital value of sampled signal;
804) main control module increases the enlargement factor of controlled amplifying circuit by gain control circuit, returns step 802 then;
805) main control module is preserved the controlled variable to gain control circuit, and the follow-up enlargement factor of fixing controlled amplifying circuit is constant;
806) main control module stops to the antenna transmission carrier sense signal;
807) electronic tag enters normal operating conditions.
9. control method according to claim 8, it is characterized in that, described main control module comprises control module and D/A converting circuit, in step 804, described control module control D/A converting circuit strengthens the DC current values of output, and described gain control circuit converts the DC current of D/A converting circuit output to DC voltage in proportion; In step 805, the magnitude of voltage of the current value of fixed die change-over circuit output and gain control circuit output.
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| CN2009101083797A CN101655925B (en) | 2009-06-23 | 2009-06-23 | Close coupling radio frequency identification devices (RFID) tag and control method thereof |
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| Application Number | Priority Date | Filing Date | Title |
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| CN2009101083797A CN101655925B (en) | 2009-06-23 | 2009-06-23 | Close coupling radio frequency identification devices (RFID) tag and control method thereof |
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| CN101655925A true CN101655925A (en) | 2010-02-24 |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103310267A (en) * | 2012-03-16 | 2013-09-18 | 晶隼科技股份有限公司 | Amplitude shift keying modulator and transmitter comprising same |
| CN107865661A (en) * | 2016-09-28 | 2018-04-03 | 深圳市理邦精密仪器股份有限公司 | Respiration measurement device and method |
| CN113703355A (en) * | 2021-08-05 | 2021-11-26 | 百富计算机技术（深圳）有限公司 | Antenna magnetic field intensity control circuit and electronic equipment |
| CN114552992A (en) * | 2022-03-22 | 2022-05-27 | 青岛汉泰智能科技有限公司 | Direct-current power supply system and control method |
-
2009
- 2009-06-23 CN CN2009101083797A patent/CN101655925B/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103310267A (en) * | 2012-03-16 | 2013-09-18 | 晶隼科技股份有限公司 | Amplitude shift keying modulator and transmitter comprising same |
| CN103310267B (en) * | 2012-03-16 | 2016-03-30 | 晶隼科技股份有限公司 | Amplitude shift keying modulator and transmitter comprising same |
| CN107865661A (en) * | 2016-09-28 | 2018-04-03 | 深圳市理邦精密仪器股份有限公司 | Respiration measurement device and method |
| CN113703355A (en) * | 2021-08-05 | 2021-11-26 | 百富计算机技术（深圳）有限公司 | Antenna magnetic field intensity control circuit and electronic equipment |
| CN114552992A (en) * | 2022-03-22 | 2022-05-27 | 青岛汉泰智能科技有限公司 | Direct-current power supply system and control method |
| CN114552992B (en) * | 2022-03-22 | 2024-01-26 | 青岛汉泰智能科技有限公司 | Direct-current power supply system and control method |
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| Publication number | Publication date |
|---|---|
| CN101655925B (en) | 2011-09-28 |
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