CN205847256U - Radio-frequency carrier offsets process circuit - Google Patents
Radio-frequency carrier offsets process circuit Download PDFInfo
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- CN205847256U CN205847256U CN201620829653.5U CN201620829653U CN205847256U CN 205847256 U CN205847256 U CN 205847256U CN 201620829653 U CN201620829653 U CN 201620829653U CN 205847256 U CN205847256 U CN 205847256U
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Abstract
This utility model provides a kind of radio-frequency carrier to offset process circuit, including: control module；Modulation module, this control module connects the first control end of this modulation module, the second control end；Offseting module, this modulation module receives carrier signal and offsets, by I road input voltage, the control output of Q road input voltage, the first input end that signal offsets module to this, and this second input offseting module receives leakage radio-frequency carrier；Connect this quadrature demodulator offseting module outfan, this quadrature demodulator receives to offset signal and leak radio-frequency carrier and offsets Hou He road signal, and according to local oscillation signal quadrature demodulation output I road output voltage, Q road output voltage, it is supplied to this control module by the first outfan of this quadrature demodulator, the second outfan；This control module adjusts I road input voltage, Q road input voltage according to I road output voltage, Q road output voltage.This utility model can improve speed and the effect that carrier wave offsets, it is achieved mode is simple.
Description
Technical field
This utility model relates to technical field of RFID, particularly relates to a kind of radio-frequency carrier and offsets process circuit.
Background technology
It is one of the key technology of super high frequency radio frequency identification that carrier wave offsets, and its purpose is to remove the radio-frequency carrier of leakage
The influence of noise of signal, its principle is to extract portion of carriers energy to modulate a phase bit and amplitude through special modulating device
Offseting signal, offset with the radio-frequency carrier signal revealed, the amplitude of the radio-frequency carrier signal that will leak out is down to minimum.For
From the point of view of using the super high frequency radio frequency recognition read-write machine of zero-intermediate-frequency architecture, since it is desired that transmitting-receiving is simultaneously, carrier wave cancellation techniques can have
Effect ground promotes its sensitivity received, it is achieved RF identification effect at a distance.
The processing method that existing carrier wave offsets mainly has following several: 1. hard wired feed back loop, hard wired feed back loop
Mode realizes automatic carrier wave and offsets, it is achieved the circuit structure of this mode is complicated, higher to circuit coherence request；2. fuzzy calculation
Method, carrys out the signal amplitude after detected carrier offsets to judge the result that carrier wave offsets by cymoscope, and this mode cannot be learnt
The phase information of the radio-frequency carrier signal revealed, its carrier wave cancellation process typically uses fuzzy algorithmic approach to realize, and carrier wave offsets
Cycle is longer；3. approach algorithm, by driving carrier wave cancellation circuit so that the signal that offsets collected levels off to a certain setting
Threshold value, this mode is extremely difficult to optimal carrier wave and offsets effect.
Utility model content
The purpose of this utility model is to provide a kind of radio-frequency carrier to offset process circuit, solves carrier wave in prior art
Offset speed slow, the technical problem of poor effect.
In order to solve above-mentioned technical problem, a kind of radio-frequency carrier of the present utility model offsets process circuit, including:
Control module；
Modulation module, described modulation module includes that the first control end and second controls end, and described control module connects described
First control end, to provide I road input voltage, connects described second and controls end to provide Q road input voltage；
Offseting module, described modulation module receives carrier signal and controls output by I road input voltage, Q road input voltage
Offset signal to described in offset the first input end of module, described in offset the second input of module and receive leakage radio-frequency carrier；
Offseting the quadrature demodulator of module outfan described in connection, the reception of described quadrature demodulator offsets signal and penetrates with leakage
Frequently carrier wave offsets Hou He road signal, and according to local oscillation signal quadrature demodulation output I road output voltage, Q road output voltage, logical
Cross the first outfan of described quadrature demodulator, the second outfan is supplied to described control module；
Described control module adjusts I road input voltage, Q road input voltage according to I road output voltage, Q road output voltage.
Offset the further improvement processing circuit as the above-mentioned radio-frequency carrier of this utility model, described modulation module is multiplication
One in device, vector modulator, amplitude phase modulation circuit.
Offset the further improvement processing circuit as the above-mentioned radio-frequency carrier of this utility model, described in offset module for closing road
One in device, bonder, electric bridge.
Offset the further improvement processing circuit as the above-mentioned radio-frequency carrier of this utility model, described quadrature demodulator includes
Multiplier that two-way is orthogonal and connect the integrator of described multiplier.
Offset the further improvement processing circuit as the above-mentioned radio-frequency carrier of this utility model, described quadrature demodulator is just
Hand over and demodulate integrated chip.
Offset the further improvement processing circuit as the above-mentioned radio-frequency carrier of this utility model, described quadrature demodulator connects
Internal phaselocked loop is to obtain local oscillation signal.
Offset the further improvement processing circuit as the above-mentioned radio-frequency carrier of this utility model, described control module includes two
Road amplifilter, connects the first outfan of described quadrature demodulator, the second outfan respectively, and described control module is to amplification
Filtered I road output voltage, Q road output voltage process.
Offset the further improvement processing circuit as the above-mentioned radio-frequency carrier of this utility model, described control module includes place
Reason device and connect the analog-digital converter of described processor, described processor by described analog-digital converter obtain I road output voltage,
The value of Q road output voltage.
Offset the further improvement processing circuit as the above-mentioned radio-frequency carrier of this utility model, described control module also includes
Connecting the digital to analog converter of described processor, described processor is by defeated with output I road to digital to analog converter output digit signals
Enter voltage, Q road input voltage.
Offset the further improvement processing circuit as the above-mentioned radio-frequency carrier of this utility model, described control module is according to I
Road output voltage change changes and the change of Q road input voltage with corresponding relation or the Q road output voltage of the change of I road input voltage
Between corresponding relation determine and adjust the I road input voltage of described modulation module, Q road input voltage.
Compared with prior art, this utility model analysis principle based on vector planisphere, by circuit design to offseting
Hou He road signal carries out quadrature demodulation and obtains I road output voltage, Q road output voltage, according to output voltage and input voltage it
Between relation, control adjusting module output.This utility model can improve speed and the effect that carrier wave offsets, it is achieved mode letter
Single.
After reading in conjunction with the accompanying the detailed description of this utility model embodiment, other features of the present utility model and advantage
Will become clearer from.
Accompanying drawing explanation
In order to be illustrated more clearly that the technical scheme of this utility model embodiment or prior art, below will be to embodiment party
In formula or description of the prior art, the required accompanying drawing used is briefly described, it is therefore apparent that the accompanying drawing in describing below is only
It is some embodiments described in this utility model, for those of ordinary skill in the art, is not paying creative labor
On the premise of Dong, it is also possible to obtain other accompanying drawing according to these accompanying drawings.
Fig. 1 is that in this utility model one embodiment, radio-frequency carrier offsets process circuit diagram.
Fig. 2 is the planisphere leaking radio-frequency carrier S1 in this utility model one embodiment.
Fig. 3 is the planisphere that in this utility model one embodiment, leakage radio-frequency carrier S1 and ideal offset signal S1 '.
Fig. 4 is the planisphere offseting signal S0 in this utility model one embodiment.
Fig. 5 is the planisphere of this utility model one embodiment Zhong He road signal Sf.
Detailed description of the invention
Below with reference to each embodiment shown in the drawings, this utility model is described in detail.But these embodiments
It is not limiting as this utility model, structure, method or the merit that those of ordinary skill in the art is made according to these embodiments
Conversion on energy is all contained in protection domain of the present utility model.
It should be noted that in various embodiments, identical label or labelling may be used, but these not generations
List structure or the relation that definitely contacts functionally.Further, " first ", " second " that be previously mentioned in each embodiment does not the most represent
Structure or relation of definitely distinguishing functionally, these are merely for convenience of description.
Radio-frequency identification reader/writer operationally, ideally launched by antenna by the radio-frequency carrier signal of transmitting terminal
Go, but the radio-frequency carrier signal that actually can there is certain power leaks into receiving terminal, relative to penetrating that receiving terminal receives
Frequency identifies the signal of electronic tag feedback, and the power of the radio-frequency carrier signal of leakage is much bigger, thus can be RF identification
The signal of electronic tag feedback is flooded, and causes the sensitivity decrease of radio-frequency identification reader/writer, and recognition efficiency receives the biggest
Impact.Therefore, in order to reduce above-mentioned impact, need the radio-frequency carrier signal that will leak out to fall as noise remove, attainable
Mode can by generate one with leak the frequency of radio-frequency carrier signal, amplitude identical, the signal of opposite in phase supports therewith
Disappearing, so because positive and negative addition of waveforms just reduces to zero the amplitude of the radio-frequency carrier signal of leakage, this signal generated just claims
For offseting signal.But, in actual application, the offseting signal and often can not comply fully with and leak radio frequency and carry of generation
Wave amplitude is identical, opposite in phase, causes offseting result undesirable, and the design of closed loop therefore can be used to carry out soon offseting signal
Adjust fastly, offset effect reaching splendid carrier wave.
As it is shown in figure 1, radio-frequency carrier offsets process circuit diagram in this utility model one embodiment.Radio-frequency carrier offsets place
Reason circuit includes modulation module 10, offsets module 20, quadrature demodulator 30 and control module 40.Modulation module 10 receives carrier wave letter
Number, the carrier signal that i.e. transmitting terminal of radio-frequency identification reader/writer exports away, in a preferred embodiment, modulation module connects
The coupled end of directional coupler, is believed by the carrier wave of the radio-frequency identification reader/writer transmitting terminal of directional coupler coupling part energy
Number.Modulation module can be modulated entering the amplitude of carrier signal, phase place according to I road input voltage, Q road input voltage
Row sum-equal matrix, output offsets signal.In a particular embodiment, modulation module can be multiplier, vector modulator, amplitude phase
Position modulation circuit etc..Modulation module 10 includes the first control end, the second control end, respectively link control module 40, control module
40 send control voltage by the first control end, the second control end to modulation module 10, and first controls end is used for receiving the input of I road
Voltage Vii, second controls end is used for receiving Q road input voltage Vqi.
Offseting module 20 and include first input end, the second input, first input end connects the outfan of modulation module 10,
Signal is offseted for receive modulation module 10.Second input is used for receiving leakage signal, i.e. radio-frequency identification reader/writer send out
Penetrate the radio-frequency carrier signal that end leaks into the receiving terminal of radio-frequency identification reader/writer.By offseting module 20, signal will be offseted and let out
Leakage radio-frequency carrier signal carries out offseting generation and closes road signal, as mentioned previously, because the signal that offsets produced at the beginning is often paid no attention to
Thinking, so closing the amplitude of road signal and being not zero, the conjunction road signal therefore exported by offseting the outfan of module 20 also has one
Fixed amplitude.Offseting module 20 can be combiner, bonder, electric bridge etc..
The outfan offseting module 20 connects the input of quadrature demodulator 30.The quadrature demodulator 30 conjunction road to receiving
Signal carries out quadrature demodulation.Quadrature demodulator 30 receives the local oscillation signal waveform as quadrature demodulator 30 built-in multiplication computing,
Local oscillation signal can obtain by connecting the phaselocked loop within radio-frequency identification reader/writer, and the frequency of local oscillation signal is read with RF identification
The frequency of carrier signal writing device transmitting is consistent.Signal demodulation in conjunction road is become the output of I road according to local oscillation signal by quadrature demodulator 30
Voltage Vio, Q road output voltage Vqo.First outfan link control module 40 of quadrature demodulator 30 is to provide I road output electricity
Pressure Vio, the second outfan link control module 40 of quadrature demodulator 30 is to provide Q road output voltage Vqo.In enforcement below
Mode would indicate that, the first outfan of quadrature demodulator 30, the second outfan can be filtered by the amplification in control module 40
Device provides output voltage Vio, Q road, I road output voltage Vqo indirectly.Specifically, quadrature demodulator includes the multiplication that two-way is orthogonal
Device and the integrator of connection multiplier, obtain I road component and Q road component by multiplier, obtain DC voltage by integrator.
Quadrature demodulator is preferably by the integrated chip of quadrature demodulation.
Control module 40 includes processor 41, is used for processing digital signal, owing to the voltage of quadrature demodulator 30 output is
Analogue signal, it is possible to by analog-digital converter 43(ADC, Analog-to-Digital Converter) by analogue signal
Being converted into digital signal, processor 41 obtains I road output voltage, the value of Q road output voltage by analog-digital converter 43.It addition,
Control module 40 is by processor 41 and digital to analog converter 44(DAC, Digital-to the control voltage that modulation module 10 sends
To-Analog Converter) coordinated, processor 41 by the digital signal specified to digital to analog converter 44 output with
Output I road input voltage, Q road input voltage.
Preferably, the output voltage of quadrature demodulator is owing to amplitude is less and there is certain noise, it is possible to control mould
Analog-digital converter in block 40 can not accurately recognize, in order to ensure higher acquisition precision, analog-digital converter 43 with just
Hand over and between demodulator 30, be provided with the amplifilter 421 of correspondence, amplifilter 422, amplifilter 421 and quadrature demodulation
First outfan of device 30 connects to provide I road output voltage Vio, and amplifilter 422 is defeated with the second of quadrature demodulator 30
Go out end to connect to provide Q road output voltage Vqo.
Assuming that leakage radio-frequency carrier S1=asin (ω t+ θ 1), middle coordinate-I1, Q1 represent leakage radio frequency respectively as shown in Figure 2
The I component of carrier wave S1, Q component, therefore in planisphere, the distance of the point that S1 represents to initial point O is leakage radio-frequency carrier S1
The radius of circle in amplitude, namely figure, the line of the point that S1 represents to initial point O and the θ 1 jiao folded by abscissa are leakage radio-frequency carrier
The phase place of S1.The position on planisphere I axle and Q axle can also be determined by amplitude and phase place simultaneously.Generate offsets signal
If able to eliminate with leakage radio-frequency carrier, the most preferably offseting signal must, phase identical with the amplitude of leakage radio-frequency carrier
Position is contrary, is reflected in planisphere, it is simply that the point offseting point corresponding to signal corresponding with leakage radio-frequency carrier is centrosymmetric, as
Shown in Fig. 3, point corresponding for S1 ' represents and preferably offsets signal, offsets the I component of signal S1 ', Q component is respectively I1 ,-Q1, just
Good positive and negative contrary with leak radio-frequency carrier S1.
But, the most initial to offset signal unsatisfactory, it is assumed that offsets signal S0=bsin (ω t+ θ 2), now with let out
The amplitude of leakage radio-frequency carrier S1 is different, and phase place is the most contrary.As shown in Figure 4, offset signal S0 and be mapped in planisphere, I0, Q0
Respectively offseting the I component of signal S0, Q component, θ 2 jiaos is to offset the phase place of signal S0.Carry with leakage radio frequency when offseting signal S0
Ripple S1 produces after offseting and closes road signal Sf=S1+SO=asin (ω t+ θ 1)+bsin (ω t+ θ 2), closes road signal Sf and is mapped in
As it is shown in figure 5, close the point corresponding for the road signal Sf amplitude that distance is conjunction road signal to initial point O on planisphere, close road signal Sf
Corresponding point is the phase place closing road signal Sf to the line of initial point O and the angle of I axle.From planisphere it is found that close road signal
The I component of Sf, Q component are respectively-I1+I0, Q1+Q0, are to leak radio-frequency carrier S1 and offset the I component of signal S0, Q respectively
The algebraical sum of component, therefore from above-mentioned planisphere it can be seen that when know leakage radio-frequency carrier, offset signal and offset after conjunction
The I component of any two in the signal of road, Q component, it is possible to know surplus Next I component, Q component.
In the circuit shown in Fig. 1, the superposition value of the I component of I road input voltage and leakage radio-frequency carrier is through offseting module
20, the decay of quadrature demodulator 30, amplifilter 421 etc. obtains I road output voltage, leaks radio-frequency carrier and offsets signal institute
Completely the same through path, and circuit is changeless, therefore amplitude fading and the phase situation of two paths of signals are the most complete
Unanimously, i.e. carry-over factor K is invariable, carry-over factor K for offset module loss factor, quadrature demodulator attenuation quotient and
Amplifilter gain coefficient sum.Therefore carry-over factor K can be by between independent input Vi and independent output Vo
Relation obtains, i.e. K=Vo/Vi, the most just can be by leakage radio-frequency carrier I component, Q component with carry-over factor K is counter releases I road
Input voltage, Q road input voltage.
Calculate for convenience, I road output voltage, Q road output voltage can be mapped directly to planisphere, straight by these two groups
Stream voltage also combines planisphere and can reflect amplitude and the phase condition of signal intuitively.
Control module 40 adjusts I road input voltage, Q road input voltage according to I road output voltage, Q road output voltage.As above
Described, carry-over factor K is determined by offseting module, quadrature demodulator and amplifilter etc., because I road input voltage, Q road
Defeated input voltage also by offseting the output such as module, quadrature demodulator and amplifilter, in addition combined with planisphere point
Analysis principle, so having only to deduction leakage radio-frequency carrier to I road output voltage, the impact of Q road output voltage, it is possible to calculate
The occurrence of carry-over factor K.Leakage radio-frequency carrier impact can by close modulation module input by the way of it is known that.
In a particular embodiment, control module is corresponding with the change of I road input voltage according to the change of I road output voltage
Corresponding relation between relation or the change of Q road output voltage and the change of Q road input voltage determines the I adjusting described modulation module
Road input voltage, Q road input voltage.Above-mentioned embodiment determines the pass between independent input and independent output by variable quantity
System, i.e. carry-over factor K, because what leakage radio-frequency carrier was no variation in, so variable quantity not including leak radio-frequency carrier
Impact, it is relatively independent for inputting the impact on output.On the basis of carry-over factor K is known, it is possible to know how to lead to
Cross change I road input voltage, Q road input voltage to adjust the signal that offsets of generation, and then can be defeated by I road output voltage, Q road
The amplitude going out voltage adjusts to minimum, i.e. radio-frequency leakage carrier wave is eliminated substantially.
In sum, this utility model analysis principle based on vector planisphere, by circuit design to the conjunction after offseting
Road signal carries out quadrature demodulation and obtains I road output voltage, Q road output voltage, according to the pass between output voltage and input voltage
System, controls the output of adjusting module.This utility model can improve speed and the effect that carrier wave offsets, it is achieved mode is simple.
It is to be understood that, although this specification is been described by according to embodiment, but the most each embodiment only comprises one
Individual independent technical scheme, this narrating mode of description is only that for clarity sake those skilled in the art should will say
Bright book is as an entirety, and the technical scheme in each embodiment can also be through appropriately combined, and forming those skilled in the art can
With other embodiments understood.
The a series of detailed description of those listed above is only for the tool of feasibility embodiment of the present utility model
Body illustrates, they are also not used to limit protection domain of the present utility model, all is made without departing from this utility model skill spirit
Within equivalent implementations or change should be included in protection domain of the present utility model.
Claims (10)
1. a radio-frequency carrier offsets process circuit, it is characterised in that including:
Control module；
Modulation module, described modulation module includes that the first control end and second controls end, and described control module connects described first
Control end, to provide I road input voltage, connects described second and controls end to provide Q road input voltage；
Offseting module, described modulation module is received carrier signal and is offseted by I road input voltage, the control output of Q road input voltage
Signal offsets the first input end of module described in giving, described in offset the second input of module and receive leakage radio-frequency carrier；
Offseting the quadrature demodulator of module outfan described in connection, described quadrature demodulator receives and offsets signal and leakage radio frequency load
Ripple offsets Hou He road signal, and according to local oscillation signal quadrature demodulation output I road output voltage, Q road output voltage, by institute
State the first outfan of quadrature demodulator, the second outfan is supplied to described control module；
Described control module adjusts I road input voltage, Q road input voltage according to I road output voltage, Q road output voltage.
Radio-frequency carrier the most according to claim 1 offsets process circuit, it is characterised in that described modulation module is multiplication
One in device, vector modulator, amplitude phase modulation circuit.
Radio-frequency carrier the most according to claim 1 offsets process circuit, it is characterised in that described in offset module for close road
One in device, bonder, electric bridge.
Radio-frequency carrier the most according to claim 1 offsets process circuit, it is characterised in that described quadrature demodulator includes two
Multiplier that road is orthogonal and connect the integrator of described multiplier.
Radio-frequency carrier the most according to claim 4 offsets process circuit, it is characterised in that described quadrature demodulator is orthogonal
Demodulate integrated chip.
Radio-frequency carrier the most according to claim 1 offsets process circuit, it is characterised in that in described quadrature demodulator connects
Portion's phaselocked loop is to obtain local oscillation signal.
Radio-frequency carrier the most according to claim 1 offsets process circuit, it is characterised in that described control module includes two-way
Amplifilter, connects the first outfan of described quadrature demodulator, the second outfan respectively, and described control module is to amplifying filter
I road output voltage, Q road output voltage after ripple process.
Radio-frequency carrier the most according to claim 1 offsets process circuit, it is characterised in that described control module includes processing
Device and connect the analog-digital converter of described processor, described processor obtains I road output voltage, Q by described analog-digital converter
The value of road output voltage.
Radio-frequency carrier the most according to claim 8 offsets process circuit, it is characterised in that described control module also includes even
Connecing the digital to analog converter of described processor, described processor is by inputting with output I road to digital to analog converter output digit signals
Voltage, Q road input voltage.
Radio-frequency carrier the most according to claim 1 offsets process circuit, it is characterised in that described control module is according to I road
Output voltage change changes it with corresponding relation or the change of Q road output voltage of the change of I road input voltage with Q road input voltage
Between corresponding relation determine and adjust the I road input voltage of described modulation module, Q road input voltage.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201620829653.5U CN205847256U (en) | 2016-08-03 | 2016-08-03 | Radio-frequency carrier offsets process circuit |
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| CN201620829653.5U CN205847256U (en) | 2016-08-03 | 2016-08-03 | Radio-frequency carrier offsets process circuit |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107749769A (en) * | 2017-10-30 | 2018-03-02 | 武汉万集信息技术有限公司 | A kind of Fast carrier offsets method and device |
| CN108734043A (en) * | 2018-07-27 | 2018-11-02 | 天津中兴智联科技有限公司 | A kind of adaptive feed-through nulling system and method |
| CN109802704A (en) * | 2018-12-27 | 2019-05-24 | 航天信息股份有限公司 | A kind of carrier wave leakage signal eliminating apparatus and method based on reader |
-
2016
- 2016-08-03 CN CN201620829653.5U patent/CN205847256U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107749769A (en) * | 2017-10-30 | 2018-03-02 | 武汉万集信息技术有限公司 | A kind of Fast carrier offsets method and device |
| CN108734043A (en) * | 2018-07-27 | 2018-11-02 | 天津中兴智联科技有限公司 | A kind of adaptive feed-through nulling system and method |
| CN108734043B (en) * | 2018-07-27 | 2024-03-22 | 高新兴智联科技股份有限公司 | Self-adaptive leakage cancellation system and method |
| CN109802704A (en) * | 2018-12-27 | 2019-05-24 | 航天信息股份有限公司 | A kind of carrier wave leakage signal eliminating apparatus and method based on reader |
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