CN103544521B - A kind of non-contact card modulation circuit - Google Patents
A kind of non-contact card modulation circuit Download PDFInfo
- Publication number
- CN103544521B CN103544521B CN201210235192.5A CN201210235192A CN103544521B CN 103544521 B CN103544521 B CN 103544521B CN 201210235192 A CN201210235192 A CN 201210235192A CN 103544521 B CN103544521 B CN 103544521B
- Authority
- CN
- China
- Prior art keywords
- pull
- current
- contact card
- down current
- modulation circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Near-Field Transmission Systems (AREA)
Abstract
The invention discloses a kind of non-contact card modulation circuit.Including：Modulating unit and control unit, wherein, modulating unit is modulated for the data-signal to be sent to the non-contact card；Control unit is used to be adjusted the modulate intensity of the modulation circuit.The non-contact card modulation circuit can provide modulation capability higher.The non-contact card modulation circuit can be appropriate non-contact card modulate intensity is adjusted, improve the radio communication quality of non-contact card and card reader.
Description
Technical field
The present invention relates to wireless communication field, more particularly to a kind of non-contact card modulation circuit.
Background technology
With the development of radio-frequency technique, the application of contact type intelligent card is also more and more extensive.It is most common in the market
Non-contact IC card be contactless logic encryption card, this kind of IC-card is obtained by its good performance and cost performance higher
The favor of users, and it has been widely used in the fields such as public transport, medical treatment, all-in-one campus card, gate inhibition.Non-contact IC card
Communication operation is completed by radio wave between card reader.Generally therebetween communication frequency is 13.56MHZ.It is non-to connect
It is in itself passive card to touch property IC-card, and when read write line carries out read-write operation to card, the signal that read write line sends is superimposed by two parts
Composition:A part is carrier signal, the power supply by being converted into chip operation after rectification；Another part then be instruction sum it is believed that
Number, the circuit of card chip internal will be stored in the data of therein according to instruction, be carried in what card reader sent by modulation
On carrier wave, card reader is returned to, complete a communication operation.The modulation depth of the non-contact communication for chip of current 13.56M
Require, i.e., modulation capability is required.The modulation capability of existing contactless card circuit is more logical in difference than being relatively inaccessible to people
Requirement under letter environment to non-contact card and the communication quality of card reader, and existing non-contact card is not to modulate intensity
The circuit being adjusted.
The content of the invention
The main technical problem to be solved in the present invention is to provide a kind of non-contact card modulation circuit, can be appropriate to non-
Contact card modulate intensity is adjusted, and improves the radio communication quality of non-contact card and card reader.
In order to solve the above technical problems, the present invention provides a kind of non-contact card modulation circuit, its concrete technical scheme is as follows：
A kind of non-contact card modulation circuit, it is characterised in that including：Modulating unit and control unit, wherein,
Modulating unit is modulated for the data-signal to be sent to the non-contact card；
Control unit is used to be adjusted the modulate intensity of the modulating unit.
Further, the non-contact card modulation circuit also includes first antenna circuit；The first antenna circuit is used for
The magnetic field that sensing reader device sends produces the first pull-down current, and it is single that first pull-down current is transferred into the modulation
Unit；The modulating unit is used to control first pull-down current to realize being modulated the data-signal；Control unit is used
The modulate intensity of the modulating unit is adjusted in by adjusting first pull-down current.
Further, the modulating unit is used to control the break-make of first pull-down current to realize to the data-signal
It is modulated, and when first pull-down current is turned on, modulating unit is according to first pull-down current to the data
Signal is modulated.
Further, described control unit is used to, according to first pull-down current, produce control electric current, and by described
Control electric current adjusts first pull-down current.
Further, described control unit includes synchronizing current subelement and current control subelement；The synchronizing current
Subelement is used for according to first time electric current, produces the second pull-down current in synchronous change with first pull-down current；
The current control subelement is used to, according to second pull-down current, produce control electric current, and adjust by the control electric current
Whole first pull-down current.
Further, the current control subelement be used for by make first pull-down current and the control electric current into
The mode of direct ratio change adjusts first pull-down current.
Further, described control unit also includes adjustment subelement；The adjustment subelement is used for single to the control
The adjustment amplitude of unit is limited.
Further, the adjustment subelement is used to increase to predetermined current threshold range when the second pull-down current value
When interior, reduce the control electric current.
Further, the adjustment subelement includes the first PMOS；The grid of first PMOS connects reference voltage
VC, source electrode is connected with described control unit, and drain electrode is connected with the synchronizing current subelement.
Further, the modulation circuit is the first NMOS tube；The drain electrode of first NMOS tube and the first antenna
Circuit is connected, and the source ground of first NMOS tube, grid is connected with described control unit.
Further, the current control subelement includes：Second PMOS, the second NMOS tube, the 3rd NMOS tube；It is described
The source electrode of the second PMOS is connected with the drain electrode of first PMOS, the grid of second PMOS and the 2nd NMOS
The grid of pipe is connected, the drain electrode of second PMOS drain electrode respectively with second NMOS tube, first NMOS tube
Grid is connected；The grid of the source ground of second NMOS tube, second PMOS and the second NMOS tube receives described non-
Contact blocks data-signal to be sent；The grid of the 3rd NMOS tube and drain electrode are connected with the grid of first NMOS tube,
The source ground of the 3rd NMOS tube.
The beneficial effects of the invention are as follows：
Non-contact card modulation circuit of the invention, sets the intensity that control unit adjusts modulating unit so that modulating unit
Modulation capability be adapted to radio communication；The present invention also produces the first pull-down current by setting first antenna circuit, makes modulation list
Unit's the first pull-down current of control realizes the modulation of non-data signal, and control unit the first pull-down current of adjustment is adjusted indirectly
The modulation capability of whole modulating unit, by such setting, it is possible to increase modulation accuracy, enables non-contact card modulation circuit root
According to different environment, the modulation capability of circuit is fast and accurately adjusted；The present invention also by set synchronizing current subelement according to
First pull-down current, produces the second pull-down current in synchronous change with the first pull-down current, can indirectly to modulating unit
It is adjusted, it is not necessary to its direct adjustment on modulating unit, does not interfere with modulating unit performance in itself, more meets reality
Situation；Adjustment subelement is set in a control unit, prevents non-contact card modulation capability excessive, cause electricity under power supply.
Brief description of the drawings
Fig. 1 is the first structural representation of embodiment of the present invention non-contact card modulation circuit；
Fig. 2 is second structural representation of embodiment of the present invention non-contact card modulation circuit；
Fig. 3 is the third structural representation of embodiment of the present invention non-contact card modulation circuit；
Fig. 4 is the 4th kind of structural representation of embodiment of the present invention non-contact card modulation circuit；
Fig. 5 is the 5th kind of structural representation of embodiment of the present invention non-contact card modulation circuit；
Fig. 6 is the 6th kind of structural representation of embodiment of the present invention non-contact card modulation circuit；
Fig. 7 is the 7th kind of structural representation of embodiment of the present invention non-contact card modulation circuit；
Fig. 8 is the 8th kind of structural representation of embodiment of the present invention non-contact card modulation circuit；
Fig. 9 is the 9th kind of structural representation of embodiment of the present invention non-contact card modulation circuit.
Specific embodiment
The present invention is described in further detail below by specific embodiment combination accompanying drawing.
Idea of the invention is that being adjusted to the modulate intensity of modulation circuit by setting control unit, can expire
To the requirement of modulation capability under various field intensity, such as high field intensity needs to need to close under high modulation ability, low field intensity sufficient non-contact card
Suitable modulation capability；And then meet modulation requirement of the people for non-contact card modulation circuit.As shown in figure 1, for the present invention is non-
Contact the schematic diagram of card modulation circuit.
The present invention is described in further detail below by specific embodiment combination accompanying drawing.
Fig. 2 is refer to, is the structural representation of this implementation non-contact card modulation circuit.The non-contact card of present embodiment is adjusted
Circuit processed includes：Modulating unit, control unit and first antenna circuit；First antenna circuit sends for sensing reader device
Magnetic field produce the first pull-down current, and the first pull-down current is transferred to modulating unit；The modulating unit is used to control the
One pull-down current is realized being modulated the data-signal；Control unit is used for by adjusting first pull-down current to institute
The modulate intensity for stating modulating unit is adjusted.The modulation circuit of the present embodiment is to realize logarithm by controlling the first pull-down current
According to signal modulation.Modulating unit such as this implementation can be realized to data-signal by controlling the break-make of the first pull-down current
Modulation, and when the first pull-down current is turned on, modulating unit is carried out according to first pull-down current to the data-signal
Modulation.When being modulated to radiofrequency signal, modulating unit treats the data-signal for sending to non-contact card in short-range communication
Modulation be usually when data-signal be located at high level when, modulating unit is finely adjusted system to data-signal, and is now not
Needs are modulated according to pull-down current, and when data-signal is in low level, modulating unit will turn on the first pull-down current,
And modulating unit will be modulated according to the first pull-down current, usually when the first pull-down current is big, modulation is single
The modulation capability of unit is just strong, and when the first pull-down current is small, the modulation capability of modulating unit is just weak.In a practical situation when
When modulating unit includes a modulating tube NMOS tube, it is modulated to sent data-signal using NMOS tube, when data letter
Number in high level when, NMOS tube be in switch cutoff state, now NMOS tube can not be formed with the branch road of first antenna circuit
Effective loop, the first pull-down current can not be transmitted to NMOS tube；When data-signal processes low level, NMOS tube is in switch
Closure state, now the first pull-down current can transmit to modulating tube；Modulating tube NMOS is according to the first pull-down current to be sent
Data be modulated.
Control unit in the present embodiment non-contact card modulation circuit can adjust institute by way of output control electric current
State the first pull-down current.Such as at the data-signal to be sent by non-contact card during low level, the first pull-down current can be increased,
Making the modulation capability of modulating unit gradually strengthens, and meets modulation requirement high.
From above-mentioned non-contact card modulation circuit, when the first pull-down current is to conducting, the size of its modulation capability
It is relevant with the first pull-down current, so the adjustment to non-contact card modulating circuit modulates ability, can be by control first
Pull-down current is adjusted.Control unit can produce control signal, and adjust by the control signal according to the first pull-down current
The first pull-down current is made, so as to adjust the modulation capability of modulating unit.If necessary to the modulation capability of enhanced modulation unit, can be with
When the first pull-down current is turned on, control signal is produced according to the first pull-down current, increase the first pull-down current, on the contrary needs subtract
The modulation capability of small modulating unit produces control signal to reduce the first pull-down current.Control unit is obtained under first in the present embodiment
The change of sourcing current can have directly or indirectly mode.Direct mode can make branch road directly from where the first pull-down current
The first pull-down current of upper acquisition；Indirectly mode can set one with the first pull-down current in the electric current of synchronous change, control
Unit processed can control the modulation capability of modulating unit according to the electric current of synchronization change.As shown in figure 3, the present embodiment is non-
Contact card modulation circuit can include synchronizing current subelement and current control subelement；Synchronizing current subelement is used for according to the
Once electric current, produces the second pull-down current in synchronous change with first pull-down current；Current control subelement is used for root
According to second pull-down current, control electric current is produced, and first pull-down current is adjusted by the control electric current.This implementation
The synchronizing current subelement that example is set, can share day with first antenna circuit identical circuit by with first antenna circuit
Line is realized.As shown in figure 4, setting and first antenna circuit the second antenna circuit of identical, first antenna circuit and second day
The same antenna of line sharing, first antenna circuit is constituted by with by antenna, two NMOS tubes, as shown in figure 4, first antenna is electric
The drain electrode of NM21, grid are connected with one end of antenna in road, and the source electrode of NM21 pipes, the source electrode of NM22 pipes are respectively at modulating tube NMOS
The drain electrode of pipe is connected, and the drain electrode of NM22 pipes, grid are connected with the other end of antenna, the drain electrode of same second antenna circuit NM23,
Grid is connected with one end of antenna, and the source electrode difference current control subelement of NM23, NM24 pipe is connected, the drain electrode of NM24 pipes, grid
Pole is connected with the other end of antenna.When the first pull-down current changes, just change aerial voltage, due to first antenna circuit and
Second antenna circuit is identical, and shares an antenna so the second pull-down current I1 of the second antenna circuit also can be with first
In synchronous change, the first pull-down current I0 becomes big to sourcing current I0, and the second pull-down current I1 also becomes big, on the contrary the first pull-down current
I0 diminishes, and the second pull-down current I1 also diminishes.So current control subelement need to only control to modulate according to the second pull-down current I1
Unit also may be used.So directly operated not necessarily in original module in practical application, can by module outside second
Antenna circuit, obtains the change of the first pull-down current, convenient actual application indirectly.
Above-mentioned current control subelement can be used for according to second pull-down current, adjust output control electric current, and
First pull-down current is set to be directly proportional to the control electric current change.The non-contact card modulation circuit can be in different field intensity
It is middle that modulation capability higher is provided, when the non-contact card with above-mentioned modulation circuit is placed in high field intensity, when data to be sent are believed
During number in low level, the branch road where modulating unit and first antenna circuit forms effective loop, and on the branch road first
Pull-down current has jumped to current value from zero, and when modulating unit is just started working, the first pull-down current is smaller, to first antenna electricity
The voltage on road is drop-down less, and similarly the second pull-down current is also smaller, and the voltage to the second antenna circuit is drop-down also less, electric current control
Subunit then keeps voltage higher, and the control electric current inside the regulation of current control subelement makes its lasting increase, and
Because control electric current is directly proportional to the first pull-down current, so the first pull-down current also continues to increase, the modulation energy of modulation circuit
Power is consequently increased, and meets the high modulation ability under high field intensity.
Equally when being placed in low field intensity with above-mentioned non-contact card modulation circuit, the modulation capability of its modulation circuit
Continue to increase, but in order to prevent under low field intensity, modulation capability is excessive, causes electricity, the noncontact of the present embodiment under power supply
It is also provided with adjusting subelement in card modulation circuit control unit, adjustment unit is used to limit the adjustment amplitude of control unit
System.The modulation capability for making modulation circuit with control unit increases in certain limit, reduces modulation capability.
The present embodiment non-contact card adjustment subelement can limit the adjustment width of control unit by way of adjusting electric current
Degree.Such as, above-mentioned when the first pull-down current increases to very big certain value, adjustment subelement can reduce first by control unit
The increase of pull-down current, so as to reduce the modulation capability of modulation circuit.
Certain the present embodiment non-contact card adjustment unit can indirectly reduce the first pull-down current, and such as adjustment subelement can
For when the second pull-down current value increases in predetermined current threshold range, reducing in the current control subelement
The control electric current in portion, as shown in Figure 5.When data-signal to be sent is in low level, because the second pull-down current is and first
Pull-down current is in identical change, so the situation that adjustment unit can change according to the second pull-down current, judges that first is drop-down
The change of electric current, when the second pull-down current value increases in predetermined current threshold range, by reducing current control subelement
Internal control electric current, reduces the first pull-down current.Because the first pull-down current and control electric current make proportional relation, so
When control electric current reduces, the first pull-down current also reduces, and the modulation capability of modulation circuit reduces, and prevents because modulation capability is excessive,
Cause electricity under power supply.The non-contact card modulation circuit can avoid lower electricity on the premise of modulation depth is ensured.
As shown in fig. 6, in actual applications, such as adjustment subelement can include PMOS, the grid of PMOS connects reference
Voltage VC, source electrode is connected with current control subelement, and drain electrode is connected with synchronizing current subelement.The cut-in voltage of the PMOS
Von=VC+Vth, Vth are the unlatching threshold voltage of PMOS.When the second pull-down current increases to predetermined current in said process
When in threshold range, the total voltage of current control subelement and PMOS drops to below Von=VC+Vth, then PMOS is cut
Only, the control electric current inside control unit reduces rapidly, and due to proportional relation, the first pull-down current also reduces rapidly, modulation electricity
The modulation capability on road reduces.The present embodiment can change opening for PMOS according to actual concrete condition by changing the value of VC
Voltage Von is opened, modulation depth is flexibly controlled.
As shown in fig. 6, in actual applications, the modulation circuit in above-mentioned the present embodiment non-contact card modulation circuit can be
One NMOS tube, the NMOS tube is modulating tube, and its drain electrode is connected with first antenna circuit, source ground, grid and control unit
It is connected.On the basis of modulation circuit is NMOS tube, in order to the control electric current inside control unit and the first pull-down current into
Direct ratio, metal-oxide-semiconductor in control unit and NMOS tube in above-mentioned non-contact card modulation circuit may be constructed current mirror circuit.
As shown in fig. 7, current control subelement can include：PMOS PM0, NMOS tube NM0 and NMOS tube NM2；It is described
The source electrode of PM0 is connected with the drain electrode of PMOS PM1 in adjustment subelement, and grid is connected with the grid of NM0, the drain electrode difference of PM0
Drain electrode, the grid of modulation circuit NMOS tube NM1 with NM0 pipes are connected；The source ground of NMOS tube NM0, PMOS PM0 and NMOS
The grid of pipe NM0 receives the data-signal that modulation is needed inside the non-contact card；The drain electrode of NMOS tube NM2, grid are connected, and
Grid with modulating tube NMOS tube NM1 is connected, the source ground of NM2.Its internal control electric current I1=K*I0 (K is coefficient),
When the total voltage of adjustment unit PMOS drops to below Von=VC+Vth, then PMOS cut-off, I1 reduces rapidly.
Above-mentioned control unit can replace the grid of NMOS tube NM2, resistance one end and NMOS tube NM1 with suitable resistance
Extremely it is connected, other end ground connection.
Of course for the level that can improve data-signal, can be set before needing modulated signal to enter control unit
One level translator, it is specific to set as shown in Figure 8.
In above-mentioned non-contact card modulation circuit control can also be provided in as the PMOS in adjustment unit
Inside unit, as shown in Figure 9.
Above content is to combine specific embodiment further description made for the present invention, it is impossible to assert this hair
Bright specific implementation is confined to these explanations.For general technical staff of the technical field of the invention, do not taking off
On the premise of present inventive concept, some simple deduction or replace can also be made, should all be considered as belonging to protection of the invention
Scope.
Claims (10)
1. a kind of non-contact card modulation circuit, it is characterised in that including：Modulating unit and control unit, wherein,
Modulating unit is modulated for the data-signal to be sent to the non-contact card；
Control unit is used to be adjusted the modulate intensity of the modulating unit；
The non-contact card modulation circuit also includes first antenna circuit, and the first antenna circuit is used to sense reader device
The magnetic field for sending produces the first pull-down current, and first pull-down current is transferred into the modulating unit；The modulation is single
Unit realizes being modulated the data-signal for controlling first pull-down current；Control unit is used for described by adjustment
First pull-down current is adjusted to the modulate intensity of the modulating unit.
2. non-contact card modulation circuit as claimed in claim 1, it is characterised in that the modulating unit is used to controlling described the
The break-make of one pull-down current is realized being modulated the data-signal, and when first pull-down current is turned on, modulation
Unit is modulated according to first pull-down current to the data-signal.
3. non-contact card modulation circuit as claimed in claim 2, it is characterised in that described control unit is used for according to described the
One pull-down current, produces control electric current, and adjust first pull-down current by the control electric current.
4. non-contact card modulation circuit as claimed in claim 3, it is characterised in that described control unit includes synchronizing current
Unit and current control subelement；The synchronizing current subelement is used to, according to first time electric current, produce and described first
Pull-down current is in synchronous the second pull-down current for changing；The current control subelement is used for according to second pull-down current,
Control electric current is produced, and first pull-down current is adjusted by the control electric current.
5. non-contact card modulation circuit as claimed in claim 4, it is characterised in that the current control subelement is used to pass through
Be directly proportional to the control electric current mode of change of first pull-down current is set to adjust first pull-down current.
6. the non-contact card modulation circuit as described in claim any one of 4-5, it is characterised in that described control unit also includes
Adjustment subelement；The adjustment subelement is used to limit the adjustment amplitude of described control unit.
7. non-contact card modulation circuit as claimed in claim 6, it is characterised in that the adjustment subelement is used for when described the
Two pull-down current values increase to when in predetermined current threshold range, reduce the control electric current.
8. non-contact card modulation circuit as claimed in claim 7, it is characterised in that the adjustment subelement includes a PMOS
Pipe；The grid of first PMOS meets reference voltage VC, and drain electrode is connected with the synchronizing current subelement, source electrode and the electricity
Flow control subelement is connected.
9. non-contact card modulation circuit as claimed in claim 8, it is characterised in that the modulating unit includes a NMOS
Pipe；The drain electrode of first NMOS tube is connected with the first antenna circuit, the source ground of first NMOS tube, grid with
Described control unit is connected.
10. non-contact card modulation circuit as claimed in claim 9, it is characterised in that the current control subelement includes：The
Two PMOSs, the second NMOS tube, the 3rd NMOS tube；The drain electrode phase of the source electrode of second PMOS and first PMOS
Even, the grid of second PMOS is connected with the grid of second NMOS tube, the drain electrode of second PMOS respectively with
The drain electrode of second NMOS tube, the grid of first NMOS tube are connected；The source ground of second NMOS tube, described
The grid of two PMOSs and the second NMOS tube receives non-contact card data-signal to be sent；The grid of the 3rd NMOS tube
Pole and drain electrode are connected with the grid of first NMOS tube, the source ground of the 3rd NMOS tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210235192.5A CN103544521B (en) | 2012-07-09 | 2012-07-09 | A kind of non-contact card modulation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210235192.5A CN103544521B (en) | 2012-07-09 | 2012-07-09 | A kind of non-contact card modulation circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103544521A CN103544521A (en) | 2014-01-29 |
| CN103544521B true CN103544521B (en) | 2017-06-06 |
Family
ID=49967955
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210235192.5A Active CN103544521B (en) | 2012-07-09 | 2012-07-09 | A kind of non-contact card modulation circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103544521B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2783429Y (en) * | 2005-03-01 | 2006-05-24 | 北京清华同方微电子有限公司 | Modulation circuit for contactless IC card read apparatus |
| CN101197003A (en) * | 2006-12-06 | 2008-06-11 | 北京中电华大电子设计有限责任公司 | Reference card used for calibrating reception sensitivity of non-contact read-write machine |
| CN101373524A (en) * | 2007-08-20 | 2009-02-25 | 天津南大强芯半导体芯片设计有限公司 | Radio frequency identification label circuit system structure and working method and application thereof |
-
2012
- 2012-07-09 CN CN201210235192.5A patent/CN103544521B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2783429Y (en) * | 2005-03-01 | 2006-05-24 | 北京清华同方微电子有限公司 | Modulation circuit for contactless IC card read apparatus |
| CN101197003A (en) * | 2006-12-06 | 2008-06-11 | 北京中电华大电子设计有限责任公司 | Reference card used for calibrating reception sensitivity of non-contact read-write machine |
| CN101373524A (en) * | 2007-08-20 | 2009-02-25 | 天津南大强芯半导体芯片设计有限公司 | Radio frequency identification label circuit system structure and working method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103544521A (en) | 2014-01-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103117775B (en) | Varying duty modulation in the device of the support NFC in a series of field intensity | |
| CN104283324B (en) | Power receiving system and contactless power supply system | |
| CN104718700B (en) | Power path switching in the electronic equipment including multiple charging ports | |
| CN104573649A (en) | Fingerprint recognition sensor and terminal equipment | |
| CN103778673B (en) | Electronic communication device, electronic tag and electronic charging system without parking | |
| CN105099527A (en) | Passive Near Field Communication (NFC) communication interface having independent energy receiving antenna | |
| Correia et al. | Design of high order modulation backscatter wireless sensor for passive IoT solutions | |
| WO2015103960A1 (en) | Rectification and amplitude limiting circuit having a variety of time constants, and passive radio-frequency tag | |
| CN103413168A (en) | Rectification amplitude limiting circuit of RFID | |
| CN102831448B (en) | A kind of rfid device | |
| US9641364B2 (en) | Communication circuit and approach with modulation | |
| CN106203543A (en) | A kind of switching device | |
| CN105811947B (en) | RF switch and demultiplexer | |
| CN103544521B (en) | A kind of non-contact card modulation circuit | |
| US20160119033A1 (en) | Method for Operating Object Capable via Contactless Communication | |
| CN103606003B (en) | The automatic off resonance mu balanced circuit of radio frequency identification label chip | |
| CN203366368U (en) | Controlled NFC (Near Field Communication) tag | |
| CN104808738B (en) | Amplitude modulation circuit, signal emission circuit and card reader | |
| TW200840137A (en) | Switching frequency band apparatus of wideband antenna and method thereof | |
| CN206819380U (en) | A kind of near-field communication modulation-demodulation circuit, safety chip and dynamic token | |
| CN107094037B (en) | The front end hardware circuit of dynamic token and its method for awarding seed or production configuration | |
| CN106200852B (en) | Wake-up switch circuit and terminal | |
| CN104463311A (en) | Circuit for improving contactless card strong field modulation waveform and modulation length | |
| CN202632345U (en) | Antenna amplitude-limit circuit for electronic tags in radio frequency system | |
| CN102752075A (en) | Radio frequency identifiable communication link rate adjusting method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |