CN206451204U - A kind of carrier cancellation circuit and RFID reader - Google Patents
A kind of carrier cancellation circuit and RFID reader Download PDFInfo
- Publication number
- CN206451204U CN206451204U CN201621030517.6U CN201621030517U CN206451204U CN 206451204 U CN206451204 U CN 206451204U CN 201621030517 U CN201621030517 U CN 201621030517U CN 206451204 U CN206451204 U CN 206451204U
- Authority
- CN
- China
- Prior art keywords
- input
- output end
- balun
- double
- phase shift
- 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
- Transmitters (AREA)
Abstract
The utility model provides a kind of carrier cancellation circuit and RFID reader, carrier cancellation circuit is coupled out a road carrier signal from the first end of transceiver insulation circuit U 3 by coupler U2 and introduces the first phase shift attenuation module M1 first input end, the adjust instruction that first phase shift attenuation module M1 is then generated according to micro-control unit, the carrier signal being coupled out to coupler U2 carries out phase shift and amplitude attenuation generation offseting signal, synthesized by the signal of the first synthesizer U5 carrier signals received to the second end of transceiver insulation circuit U 3 and the first phase shift attenuation module M1 outputs, obtain composite signal, realize the counteracting of the carrier signal of leakage, complete filtering out for interference signal, ensure only to retain the tag reflection weak signal received in read write line receiving channel, improve the read-write sensitivity of read write line.
Description
Technical field
The application is related to field of radio frequency communication, more particularly to a kind of carrier cancellation circuit and RFID reader.
Background technology
At present, RFID system is mainly made up of read write line and label, and read write line is by launching radiofrequency signal by energy sum
According to being sent to label；And the data returned to label are handled, the identification to label and read-write operation are completed.Label, which is received, to be read
The radiofrequency signal of device transmitting is write, the order of reader is responded, and returns to corresponding radiofrequency signal to read write line.
Wherein, circulator or directional coupler are used in read write line, strong carrier signal that read write line is launched and is received
Tag reflection weak signal separate.But, circulator or directional coupler can be revealed in the strong carrier signal of read write line transmitting
The strong carrier signal in part is to read write line receiving channel, and due to the strong carrier signal launched in RFID system and the label that receives
Weak signal is reflected completely with frequency, therefore wave filter can not filter out the strong carrier signal in read write line receiving channel, cause read write line
There is interference signal in receiving channel, read write line can not be clearly identified tag reflection weak signal, reduce read write line
Read and write poor sensitivity.
Utility model content
In order to solve the above technical problems, the embodiment of the present application provides a kind of carrier cancellation circuit, leakage is realized to reach
The counteracting of carrier signal, it is ensured that only retain the tag reflection weak signal received in read write line receiving channel, improves read write line
The purpose of sensitivity is read and write, technical scheme is as follows：
A kind of carrier cancellation circuit, including：First phase shift attenuation module M1, coupler U2, transceiver insulation circuit U 3, first
Digital analog converter U4, the first synthesizer U5, micro-control unit and the first power detector U6；
The coupler U2 is used to be coupled out a road carrier signal from the first end of the transceiver insulation circuit U 3 and introduced
The first input end of the first phase shift attenuation module M1；
3rd end of the transceiver insulation circuit U 3 is connected with the first input end of the first synthesizer U5, and described first
Synthesizer U5 the second input is connected with the output end of the first phase shift attenuation module M1, the first phase shift attenuation module
M1 the second input is connected with the micro-control unit；
The output end of the first synthesizer U5 is connected with the input of the first power detector U6, first work(
Rate detector U6 output end is connected with the input of the first digital analog converter U4, and the first digital analog converter U4's is defeated
Go out end with the micro-control unit to be connected；
The first phase shift attenuation module M1, for the adjust instruction generated according to the micro-control unit, to the coupling
The carrier signal that clutch U2 is coupled out carries out phase shift and amplitude attenuation generation offseting signal；
The first synthesizer U5, for the carrier signal to the reception of the second end of the transceiver insulation circuit U 3 and described
The signal of first phase shift attenuation module M1 outputs is synthesized, and composite signal is obtained, wherein the first phase shift attenuation module M1
The offseting signal of output, which is used to offsetting the first end of transceiver insulation circuit U 3, leaks to the transceiver insulation circuit U 3 the
The carrier signal at three ends；
The first power detector U6, the power of the composite signal for monitoring the first synthesizer U5 outputs, and
The power of the first synthesizer U5 composite signals exported is sent to the micro-control by the first digital analog converter U4
Unit processed, by power of the micro-control unit according to the first synthesizer U5 composite signals exported, to generate described adjust
Whole instruction.
It is preferred that, in addition to：Power splitter U7, the second phase shift attenuation module M2, the first limiter U8, low noise amplifier U9,
Second digital analog converter U10, the second power detector U11, the second synthesizer U12 and the second limiter U13；
The input SUM of the power splitter U7 is connected with the coupling port CP of the coupler U2, the power splitter U7's
First output end P1 is connected with the first input end of the first phase shift attenuation module M1, the second output end of the power splitter U7
P2 is connected with the first input end of the second phase shift attenuation module M2；
The second input of the second phase shift attenuation module M2 is connected with the micro-control unit, and second phase shift declines
The output end for subtracting module M2 is connected with the first input end P1 of the second synthesizer U12；
The input of the first limiter U8 is connected with the output end SUM of the first synthesizer U5, first limit
Width device U8 output end is connected with the input of the low noise amplifier U9, the output end of the low noise amplifier U9 and described the
Two synthesizer U12 the second input P2 is connected, the output end SUM of the second synthesizer U12 respectively with second amplitude limit
Device U13 input and the second power detector U11 input is connected, the output end of the second power detector U11 with
The input of the second digital analog converter U10 is connected, output end and the microcontroller list of the second digital analog converter U10
Member is connected.
It is preferred that, the transceiver insulation circuit U 3 is circulator.
It is preferred that, the first phase shift attenuation module M1 includes：3rd digital analog converter m1, the 4th digital analog converter m2 and
First IQ vector modulators m3；
The input of the 3rd digital analog converter m1 is connected with the micro-control unit, the 3rd digital analog converter m1
Output end be connected with the first control port of the first IQ vector modulators m3, the input of the 4th digital analog converter m2
End is connected with the micro-control unit, and the output end of the 4th digital analog converter m2 is with the first IQ vector modulators m3's
Second control port is connected；
The input of the first IQ vector modulators m3 as the first phase shift attenuation module M1 first input end,
The output end of the first IQ vector modulators m3 is closed as the output end of the first phase shift attenuation module M1 with described first
Grow up to be a useful person U5 the second input P2 be connected.
It is preferred that, the first IQ vector modulators m3 includes：First electric bridge m31, the first balun m32, the second balun
M33, the 3rd balun m34, the 4th balun m35, the first double-point double-throw switch m36, the second double-point double-throw switch m37, the first numerical control
Attenuator m38, the second numerical-control attenuator m39 and the 3rd synthesizer m310；
The input of the first electric bridge m31 is used as the input of the first IQ vector modulators m3, first electricity
Bridge m31 the first output end is connected with the input of the first balun m32, the second output end of the first electric bridge m31 with
The input of the 3rd balun m34 is connected；
The first output end of the first balun m32 is connected with the first switch end of the first double-point double-throw switch m36,
The second output end of the first balun m32 is connected with the second switch end of the first double-point double-throw switch m36, and described first
Double-point double-throw switch m36 the 3rd switch terminals are connected with the first input end of the second balun m33, first DPDT
Switch m36 the 4th switch terminals are connected with the second input of the second balun m33, the first double-point double-throw switch m36
Control end be connected with the micro-control unit；
The output end of the second balun m33 is connected with the first input end of the first numerical-control attenuator m38, and described
One numerical-control attenuator m38 the second input is connected with the micro-control unit, the output of the first numerical-control attenuator m38
End is connected with the first input end P1 of the 3rd synthesizer m310；
The first output end of the 3rd balun m34 is connected with the first switch end of the second double-point double-throw switch m37,
The second output end of the 3rd balun m34 is connected with the second switch end of the second double-point double-throw switch m37, and described second
Double-point double-throw switch m37 the 3rd switch terminals are connected with the first input end of the 4th balun m35, second DPDT
Switch m37 the 4th switch terminals are connected with the second input of the 4th balun m35, the second double-point double-throw switch m37
Control end be connected with the micro-control unit；
The output end of the 4th balun m35 is connected with the first input end of the second numerical-control attenuator m39, and described
Two numerical-control attenuator m39 the second input is connected with the micro-control unit, the output end of the second numerical-control attenuator m39
It is connected with the second input P2 of the 3rd synthesizer m310, the output end of the 3rd synthesizer m310 is used as described first
IQ vector modulators m3 output end.
It is preferred that, the second phase shift attenuation module M2 includes：5th digital analog converter m4, the 6th digital analog converter m5 and
2nd IQ vector modulators m6；
The input of the 5th digital analog converter m4 is connected with the micro-control unit, the 5th digital analog converter m4
Output end be connected with the first control port of the 2nd IQ vector modulators m6, the input of the 6th digital analog converter m5
End is connected with the micro-control unit, and the output end of the 6th digital analog converter m5 is with the 2nd IQ vector modulators m6's
Second control port is connected；
The input of the 2nd IQ vector modulators m6 as the second phase shift attenuation module M2 first input end,
The output end of the 2nd IQ vector modulators m6 is closed as the output end of the second phase shift attenuation module M2 with described second
Grow up to be a useful person U12 the second input P2 be connected.
It is preferred that, the 2nd IQ vector modulators m6 includes：Second electric bridge m61, the 5th balun m62, the 6th balun
M63, the 7th balun m64, the 8th balun m65, the 3rd double-point double-throw switch m66, the 4th double-point double-throw switch m67, the 3rd numerical control
Attenuator m68, the 4th numerical-control attenuator m69 and the 4th synthesizer m610；
The input of the second electric bridge m61 is used as the input of the 2nd IQ vector modulators m6, second electricity
Bridge m61 the first output end is connected with the input of the 5th balun m62, the second output end of the second electric bridge m61 with
The input of the 7th balun m64 is connected；
The first output end of the 5th balun m62 is connected with the first switch end of the 3rd double-point double-throw switch m66,
The second output end of the 5th balun m62 is connected with the second switch end of the 3rd double-point double-throw switch m66, and the described 3rd
Double-point double-throw switch m66 the 3rd switch terminals are connected with the first input end of the 6th balun m63, the 3rd DPDT
Switch m66 the 4th switch terminals are connected with the second input of the 6th balun m63, the 3rd double-point double-throw switch m66
Control end be connected with the micro-control unit；
The output end of the 6th balun m63 is connected with the first input end of the 3rd numerical-control attenuator m68, and described
Three numerical-control attenuator m68 the second input is connected with the micro-control unit, the output end of the 3rd numerical-control attenuator m68
It is connected with the first input end P1 of the 4th synthesizer m610；
The first output end of the 7th balun m64 is connected with the first switch end of the 4th double-point double-throw switch m67,
The second output end of the 7th balun m64 is connected with the second switch end of the 4th double-point double-throw switch m67, and the described 4th
Double-point double-throw switch m67 the 3rd switch terminals are connected with the first input end of the 8th balun m65, the 4th DPDT
Switch m67 the 4th switch terminals are connected with the second input of the 8th balun m65, the 4th double-point double-throw switch m67
Control end be connected with the micro-control unit；
The output end of the 8th balun m65 is connected with the first input end of the 4th numerical-control attenuator m69, and described
Four numerical-control attenuator m69 the second input is connected with the micro-control unit, the output end of the 4th numerical-control attenuator m69
It is connected with the second input P2 of the 4th synthesizer m610, the output end of the 4th synthesizer m610 is used as described second
IQ vector modulators m6 output end.
A kind of RFID reader, including the carrier cancellation circuit as described in above-mentioned any one.
It is preferred that, the RFID reader is operated in 900M frequency ranges.
Compared with prior art, the application has the beneficial effect that：
In this application, a road carrier signal is coupled out from the first end of transceiver insulation circuit U 3 by coupler U2 and drawn
Enter the first phase shift attenuation module M1 first input end, what the first phase shift attenuation module M1 was then generated according to the micro-control unit
Adjust instruction, the carrier signal being coupled out to the coupler U2 carries out phase shift and amplitude attenuation generation offseting signal, by first
Carrier signal and the signal of the first phase shift attenuation module M1 outputs that synthesizer U5 is received to the second end of transceiver insulation circuit U 3
Synthesized, obtain composite signal, wherein the offseting signal of the first phase shift attenuation module M1 outputs is used to offset transceiver insulation electricity
Road U3 first ends leak to the carrier signal at the end of transceiver insulation circuit U 3 the 3rd, realize the counteracting of the carrier signal of leakage, complete
Interference signal is filtered out, it is ensured that is only retained the tag reflection weak signal received in read write line receiving channel, is improved read write line
Read-write sensitivity.
Brief description of the drawings
In order to illustrate more clearly of the technical scheme in the embodiment of the present application, make required in being described below to embodiment
Accompanying drawing is briefly described, it should be apparent that, drawings in the following description are only some embodiments of the present application, for
For those of ordinary skill in the art, without having to pay creative labor, it can also be obtained according to these accompanying drawings
His accompanying drawing.
Fig. 1 is a kind of electronic schematic diagram for the carrier cancellation circuit that the application is provided；
Fig. 2 is another electronic schematic diagram for the carrier cancellation circuit that the application is provided；
Fig. 3 is a kind of structural representation for the first phase shift attenuation module M1 that the application is provided；
Fig. 4 is a kind of structural representation for the first IQ vector modulators m3 that the application is provided；
Fig. 5 is a kind of structural representation for the second phase shift attenuation module M2 that the application is provided；
Fig. 6 is a kind of structural representation for the 2nd IQ vector modulators m6 that the application is provided.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present application, the technical scheme in the embodiment of the present application is carried out clear, complete
Site preparation is described, it is clear that described embodiment is only some embodiments of the present application, rather than whole embodiments.It is based on
Embodiment in the application, it is every other that those of ordinary skill in the art are obtained under the premise of creative work is not made
Embodiment, belongs to the scope of the application protection.
Embodiment one
In the present embodiment there is provided a kind of carrier cancellation circuit, Fig. 1 is referred to, carrier cancellation circuit includes：First moves
Phase attenuation module M1, coupler U2, transceiver insulation circuit U 3, the first digital analog converter U4, the first synthesizer U5, micro-control unit
With the first power detector U6.
The coupler U2 is used to be coupled out a road carrier signal from the first end of the transceiver insulation circuit U 3 and introduced
The first input end of the first phase shift attenuation module M1.
Wherein, a road carrier signal is coupled out from the first end of the transceiver insulation circuit U 3 to refer to from RFID reader
Transmitting terminal be coupled out a road carrier signal into the signal stream of the first end of transceiver insulation circuit U 3.
Wherein coupler U2 can be directional coupler, and coupler U2 input port IN is used to receive the carrier wave that need to launch
Signal, coupler U2 the first output port OUT is connected with isolating transmission circuit U3 first end, coupler U2 coupling port
CP is connected with the first phase shift attenuation module M1 first input end, and the first of coupler U2 the second output port ISO and resistance R
End is connected, resistance R the second end ground connection.
Wherein, resistance R resistance value is specially 50 Ω.
3rd end of transceiver insulation circuit U 3 is connected with the first synthesizer U5 first input end P1, the first synthesizer U5's
Second input P2 is connected with the first phase shift attenuation module M1 output end, the first phase shift attenuation module M1 the second input with
Micro-control unit is connected.
First power detector U6 input is connected with the first synthesizer U5 output end SUM, the first power detector
U6 output end is connected with the first digital analog converter U4 input, the first digital analog converter U4 output end and micro-control unit
It is connected.
In the present embodiment, the principle now to the carrier cancellation circuit shown in Fig. 1 is illustrated, specific as follows：
First phase shift attenuation module M1, for the adjust instruction generated according to the micro-control unit, to coupler U2 couplings
The carrier signal closed out carries out phase shift and amplitude attenuation generation offseting signal.
The first synthesizer U5, the carrier signal received to the second end of the transceiver insulation circuit U 3 and the first phase shift
The signal of attenuation module M1 outputs is synthesized, and obtains composite signal, wherein the institute of the first phase shift attenuation module M1 outputs
Stating offseting signal is used to offset the load that the first end of transceiver insulation circuit U 3 leaks to the end of transceiver insulation circuit U 3 the 3rd
Ripple signal.
First power detector U6, the power of the composite signal for monitoring the first synthesizer U5 outputs, and pass through
The first digital analog converter U4 sends the power of the first synthesizer U5 composite signals exported to the microcontroller list
Member, is referred to by power of the micro-control unit according to the first synthesizer U5 composite signals exported, generating the adjustment
Order.
Wherein, the first power detector U6 can specifically monitor the composite signal of the first synthesizer U5 outputs in real time
Power.
In the present embodiment, transceiver insulation circuit U 3 is specifically as follows circulator.
In the present embodiment, the principle now to the carrier cancellation circuit shown in Fig. 1 is illustrated, specific as follows：
The carrier signal that need to launch of first end input of transceiver insulation circuit U 3, coupler U2 is from the transceiver insulation circuit
U3 first end is coupled out a road carrier signal and introduces the first input end of the first phase shift attenuation module M1.And, receive
The carrier signal that hair isolation circuit U3 inputs first end is launched by the antenna ANT at the second end, and passes through the second end
Antenna ANT receives carrier signal (the tag reflection weak signal of the label transmitting matched with above-mentioned read write line), transceiver insulation electricity
Road U3 the 3rd end can export the carrier signal received, and the first end of transceiver insulation circuit U 3 can reveal portion of carriers letter
Number to the end of transceiver insulation circuit U 3 the 3rd.The synthesis letter of first power detector U6 the first synthesizer U5 of monitoring outputs in real time
Number power, and the power of the first synthesizer U5 composite signals exported is sent by the first digital analog converter U4
To the micro-control unit, with by power of the micro-control unit according to the first synthesizer U5 composite signals exported,
Adjust instruction is generated, corresponding adjustment order is sent to the first phase shift attenuation module M1, until the first phase shift attenuation module M1 lifes
Untill the anti-phase offseting signal of the carrier signal constant amplitude of the second end leakage with isolating transmission circuit U3.
In this application, a road carrier signal is coupled out from the first end of transceiver insulation circuit U 3 by coupler U2 and drawn
Enter the first phase shift attenuation module M1 first input end, what the first phase shift attenuation module M1 was then generated according to the micro-control unit
Adjust instruction, the carrier signal being coupled out to the coupler U2 carries out phase shift and amplitude attenuation generation offseting signal, by first
Carrier signal and the signal of the first phase shift attenuation module M1 outputs that synthesizer U5 is received to the second end of transceiver insulation circuit U 3
Synthesized, obtain composite signal, wherein the first phase shift attenuation module M1 output the offseting signal be used for offset transmitting-receiving every
From the second end of the carrier signal, wherein transceiver insulation circuit U 3 that the first end of circuit U 3 leaks to the end of transceiver insulation circuit U 3 the 3rd
The carrier wave letter that the first end of transceiver insulation circuit U 3 leaks to the end of transceiver insulation circuit U 3 the 3rd is contaminated with the carrier signal of reception
Number, it is thus achieved that the counteracting of the carrier signal of leakage, completes filtering out for interference signal, it is ensured that only protected in read write line receiving channel
The tag reflection weak signal received is stayed, the read-write sensitivity of read write line is improved.
But, it is to ensure RFID reader in the farthest carrier signal of suppression receiving channel in the present embodiment
While only retaining the tag reflection weak signal received in receiving channel, RFID reader receiving channel midsole, which is made an uproar also, certain
Raise, therefore the signal to noise ratio of RFID reader receiving channel also has improved space.
Embodiment two
In the present embodiment, another carrier cancellation electricity is expanded on the basis of the carrier cancellation circuit shown in Fig. 1
Road, refers to Fig. 2, also includes on the basis of the carrier cancellation circuit shown in Fig. 1：Power splitter U7, the second phase shift attenuation module
M2, the first limiter U8, low noise amplifier U9, the second digital analog converter U10, the second power detector U11, the second synthesizer
U12 and the second limiter U13.
The input SUM of the power splitter U7 is connected with the coupling port CP of the coupler U2, the power splitter U7's
First output end P1 is connected with the first input end of the first phase shift attenuation module M1, the second output end of the power splitter U7
P2 is connected with the first input end of the second phase shift attenuation module M2.
The second input of the second phase shift attenuation module M2 is connected with the micro-control unit, and second phase shift declines
The output end for subtracting module M2 is connected with the first input end P1 of the second synthesizer U12.
The input of the first limiter U8 is connected with the output end SUM of the first synthesizer U5, first limit
Width device U8 output end is connected with the input of the low noise amplifier U9, the output end of the low noise amplifier U9 and described the
Two synthesizer U12 the second input P2 is connected, the output end SUM of the second synthesizer U12 respectively with second amplitude limit
Device U13 input and the second power detector U11 input is connected, the output end of the second power detector U11 with
The input of the second digital analog converter U10 is connected, output end and the microcontroller list of the second digital analog converter U10
Member is connected.
Now the operation principle to the carrier cancellation circuit shown in the present embodiment is illustrated, specific as follows：
The first end of transceiver insulation circuit U 3 receives the carrier signal that need to launch, and coupler U2 is from the transceiver insulation circuit
U3 first end is coupled out a road carrier signal and introduces power splitter U7, and the carrier signal that coupler U2 is coupled out passes through individual work(
Divide device U7 production two paths of signals, be separately input in the first phase shift attenuation module M1 and the second phase shift attenuation module M2, first moves
The offseting signal that phase attenuation module M1 and the second phase shift attenuation module M2 is produced is respectively used to first time carrier cancellation and second
Carrier cancellation.During the first phase shift attenuation module M1 adjustment, the first synthesizer U5 power output is possible to very high, because
A limiter U8 is with the addition of after this first time carrier cancellation, to prevent low noise amplifier U9 from burning out.Low noise amplifier U9 is to mark
While label reflection weak signal is amplified, the carrier wave after first time carrier cancellation is also exaggerated.In order to improve noise
Than in low noise amplifier U9 followed by second of carrier cancellation.Its operation principle is similar with first time carrier cancellation, passes through
Two power detector U11 monitor the watt level of the second synthesizer U12 output ends, constantly the second phase shift attenuation module M2's of adjustment
State, until the second synthesizer U12 power output is minimum.After second of carrier cancellation, one second limit equally with the addition of
Width device U13, to its protective effect of follow-up radio frequency chip.
Compared with the carrier cancellation circuit shown in embodiment one, the LNA pair of the carrier cancellation circuit shown in the present embodiment
While tag reflection weak signal is exaggerated, pass through the second phase shift attenuation module M2, the second synthesizer U12, the second power
Detector U11, the second digital analog converter U10 carry out second of carrier cancellation, make the carrier signal of leakage still be able to keep relatively low
Power, further improves the read-write sensitivity of read write line.In terms of the stability of RFID reader, in first time carrier cancellation
In the case that effect has deteriorated due to environmental change, second of carrier cancellation branch road still is able to be automatically adjusted, and makes to let out
The carrier power of leakage is stable in some relatively low level, is held essentially constant the performance of product.
In the above-described embodiments, the first phase shift attenuation module M1 concrete structure refers to Fig. 3, the first phase shift attenuation module
M1 includes：3rd digital analog converter m1, the 4th digital analog converter m2 and the first IQ vector modulators m3.
The input of the 3rd digital analog converter m1 is connected with the micro-control unit, the 3rd digital analog converter m1
Output end be connected with the first control port of the first IQ vector modulators m3, the input of the 4th digital analog converter m2
End is connected with the micro-control unit, and the output end of the 4th digital analog converter m2 is with the first IQ vector modulators m3's
Second control port is connected.
The input of the first IQ vector modulators m3 as the first phase shift attenuation module M1 first input end,
The output end of the first IQ vector modulators m3 is closed as the output end of the first phase shift attenuation module M1 with described first
Grow up to be a useful person U5 the second input P2 be connected.
Now the operation principle to the first phase shift attenuation module M1 shown in Fig. 3 is illustrated, specific as follows：
Micro-control unit is defeated by the 4th digital analog converter m2 by the 3rd digital analog converter m1 output simulations controlled quentity controlled variable I
Go out to simulate controlled quentity controlled variable Q, the first IQ vector modulators m3 of control enters to the coupler U2 coupling port CP carrier signals being coupled out
Amplitude attenuation in the range of 0 °~360 ° phase shifts of row and 30dB.Wherein, micro-control unit is by suitably adjusting, and output is corresponding
Controlled quentity controlled variable I and simulation controlled quentity controlled variable Q are simulated, the first IQ vector modulators m3 generations and the second end of transceiver insulation circuit U 3 can be made
The anti-phase offseting signal of the carrier signal constant amplitude of leakage.
In the present embodiment, the concrete structure of the first IQ vector modulators m3 shown in Fig. 3 may refer to Fig. 4, the first IQ
Vector modulator m3 includes：First electric bridge m31, the first balun m32, the second balun m33, the 3rd balun m34, the 4th balun m35,
First double-point double-throw switch m36, the second double-point double-throw switch m37, the first numerical-control attenuator m38, the second numerical-control attenuator m39 and
3rd synthesizer m310.
The input of the first electric bridge m31 is used as the input of the first IQ vector modulators m3, first electricity
Bridge m31 the first output end is connected with the input of the first balun m32, the second output end of the first electric bridge m31 with
The input of the 3rd balun m34 is connected.
The first output end of the first balun m32 is connected with the first switch end of the first double-point double-throw switch m36,
The second output end of the first balun m32 is connected with the second switch end of the first double-point double-throw switch m36, and described first
Double-point double-throw switch m36 the 3rd switch terminals are connected with the first input end of the second balun m33, first DPDT
Switch m36 the 4th switch terminals are connected with the second input of the second balun m33, the first double-point double-throw switch m36
Control end be connected with the micro-control unit.
The output end of the second balun m33 is connected with the first input end of the first numerical-control attenuator m38, and described
One numerical-control attenuator m38 the second input is connected with the micro-control unit, the output end of the first numerical-control attenuator m38
It is connected with the first input end P1 of the 3rd synthesizer m310.
The first output end of the 3rd balun m34 is connected with the first switch end of the second double-point double-throw switch m37,
The second output end of the 3rd balun m34 is connected with the second switch end of the second double-point double-throw switch m37, and described second
Double-point double-throw switch m37 the 3rd switch terminals are connected with the first input end of the 4th balun m35, and second double-pole is double
Throw switch m37 the 4th switch terminals are connected with the second input of the 4th balun m35, second double-point double-throw switch
M37 control end is connected with the micro-control unit.
The output end of the 4th balun m35 is connected with the first input end of the second numerical-control attenuator m39, and described
Two numerical-control attenuator m39 the second input is connected with the micro-control unit, the output end of the second numerical-control attenuator m39
It is connected with the second input P2 of the 3rd synthesizer m310, the output end of the 3rd synthesizer m310 is used as described first
IQ vector modulators m3 output end.
Wherein, the first electric bridge m31 is specifically as follows the first 3dB electric bridges.
Now the operation principle to the first IQ vector modulators m3 shown in Fig. 4 is illustrated, specific as follows：First electric bridge
M31 the first output end output I roads signal, the first electric bridge m31 the second output end output Q roads signal, and I roads signal and Q roads
Signal differs 90 °.When the device in dashed rectangle in Fig. 4 is not present, the two-way of the first electric bridge m31 outputs differs 90 ° of I roads
Signal and Q roads signal, carry out power combing after two numerical-control attenuators respectively.According to vector superposed principle, when two-way just
Hand over the amplitude of signal in 0~30dB ranges, its composite signal phase can realize 0 °~90 ° of phase shift, and amplitude can realize 0
~30dB change.
First balun m32, the second balun m33 and the first double-point double-throw switch m36 can realize whether input signal is reverse
Function (0 ° or 180 ° of phase shift), and the 3rd balun m34, the 4th balun m35 and the second double-point double-throw switch m37 can be real
The whether reverse function (0 ° or 180 ° of phase shift) of existing input signal.If being synthesized again with Q roads signal after 180 ° of I roads signal phase shift,
90 °~180 ° of phase shift can be achieved, amplitude can also realize 0~30dB change.Similarly, can if 180 ° of the phase shift simultaneously of I, Q two-way
Realize 180 °~270 ° of phase shift；If the signal not phase shift of I roads, 270 °~360 ° of phase shift can be achieved in 180 ° of Q roads signal phase shift.
To sum up, by micro-control unit switch I, Q two paths of signals whether 180 ° of phase shift, and adjust the first numerical-control attenuator m38 and the
Change in the range of two numerical-control attenuator m39, the phase shift of achievable 0 °~360 ° of output signal and amplitude 30dB.
In above-mentioned carrier cancellation circuit, the second phase shift attenuation module M2 concrete structure refers to Fig. 5, and the second phase shift declines
Subtracting module M2 includes：5th digital analog converter m4, the 6th digital analog converter m5 and the 2nd IQ vector modulators m6.
The input of the 5th digital analog converter m4 is connected with the micro-control unit, the 5th digital analog converter m4
Output end be connected with the first control port of the 2nd IQ vector modulators m6, the input of the 6th digital analog converter m5
End is connected with the micro-control unit, and the output end of the 6th digital analog converter m5 is with the 2nd IQ vector modulators m6's
Second control port is connected.
The input of the 2nd IQ vector modulators m6 as the second phase shift attenuation module M2 first input end,
The output end of the 2nd IQ vector modulators m6 is closed as the output end of the second phase shift attenuation module M2 with described second
Grow up to be a useful person U12 the second input P2 be connected.
The operation principle of the second phase shift attenuation module M2 shown in Fig. 5 is with the first phase shift attenuation module M1's shown in Fig. 3
Operation principle is identical, will not be repeated here.
Wherein, the 2nd IQ vector modulators m6 concrete structure refers to Fig. 6, and the 2nd IQ vector modulators m6 includes：The
Two electric bridge m61, the 5th balun m62, the 6th balun m63, the 7th balun m64, the 8th balun m65, the 3rd double-point double-throw switch
M66, the 4th double-point double-throw switch m67, the 3rd numerical-control attenuator m68, the 4th numerical-control attenuator m69 and the 4th synthesizer m610.
The input of the second electric bridge m61 is used as the input of the 2nd IQ vector modulators m6, second electricity
Bridge m61 the first output end is connected with the input of the 5th balun m62, the second output end of the second electric bridge m61 with
The input of the 7th balun m64 is connected.
The first output end of the 5th balun m62 is connected with the first switch end of the 3rd double-point double-throw switch m66,
The second output end of the 5th balun m62 is connected with the second switch end of the 3rd double-point double-throw switch m66, and the described 3rd
Double-point double-throw switch m66 the 3rd switch terminals are connected with the first input end of the 6th balun m63, the 3rd DPDT
Switch m66 the 4th switch terminals are connected with the second input of the 6th balun m63, the 3rd double-point double-throw switch m66
Control end be connected with the micro-control unit.
The output end of the 6th balun m63 is connected with the first input end of the 3rd numerical-control attenuator m68, and described
Three numerical-control attenuator m68 the second input is connected with the micro-control unit, the output end of the 3rd numerical-control attenuator m68
It is connected with the first input end P1 of the 4th synthesizer m610.
The first output end of the 7th balun m64 is connected with the first switch end of the 4th double-point double-throw switch m67,
The second output end of the 7th balun m64 is connected with the second switch end of the 4th double-point double-throw switch m67, and described
Four double-point double-throw switch m67 the 3rd switch terminals are connected with the first input end of the 8th balun m65, and the 4th double-pole is double
Throw switch m67 the 4th switch terminals are connected with the second input of the 8th balun m65, the 4th double-point double-throw switch
M67 control end is connected with the micro-control unit.
The output end of the 8th balun m65 is connected with the first input end of the 4th numerical-control attenuator m69, and described
Four numerical-control attenuator m69 the second input is connected with the micro-control unit, the output end of the 4th numerical-control attenuator m69
It is connected with the second input P2 of the 4th synthesizer m610, the output end of the 4th synthesizer m610 is used as described second
IQ vector modulators m6 output end.
Wherein, the second electric bridge m61 is specifically as follows the 2nd 3dB electric bridges.
The operation principle of the 2nd IQ vector modulators m6 shown in Fig. 6 is with the first IQ vector modulators m3's shown in Fig. 4
Operation principle is identical, will not be repeated here.
Embodiment three
The utility model additionally provides a kind of RFID reader, and the RFID reader includes above-described carrier cancellation electricity
Road.
Wherein, RFID reader is operated in 900M frequency ranges, for being interacted with 900M electronic tags.
It should be noted that herein, term " comprising ", "comprising" or its any other variant are intended to non-row
His property is included, so that process, method, article or equipment including a series of key elements not only include those key elements, and
And also including other key elements being not expressly set out, or also include for this process, method, article or equipment institute inherently
Key element.In the absence of more restrictions, the key element limited by sentence "including a ...", it is not excluded that including institute
Also there is other identical element in process, method, article or the equipment of stating key element.
The foregoing description of the disclosed embodiments, enables professional and technical personnel in the field to realize or new using this practicality
Type.A variety of modifications to these embodiments are it will be apparent that defined herein for those skilled in the art
General Principle can in other embodiments be realized in the case where not departing from spirit or scope of the present utility model.Therefore,
The utility model is not intended to be limited to the embodiments shown herein, and is to fit to and principles disclosed herein and new
The consistent widest range of clever feature.
Claims (9)
1. a kind of carrier cancellation circuit, it is characterised in that including：First phase shift attenuation module M1, coupler U2, transceiver insulation electricity
Road U3, the first digital analog converter U4, the first synthesizer U5, micro-control unit and the first power detector U6；
The coupler U2 is used to be coupled out a road carrier signal from the first end of the transceiver insulation circuit U 3 and introduces described
First phase shift attenuation module M1 first input end；
3rd end of the transceiver insulation circuit U 3 is connected with the first input end of the first synthesizer U5, first synthesis
Device U5 the second input is connected with the output end of the first phase shift attenuation module M1, the first phase shift attenuation module M1's
Second input is connected with the micro-control unit；
The output end of the first synthesizer U5 is connected with the input of the first power detector U6, the first power inspection
The output end for surveying device U6 is connected with the input of the first digital analog converter U4, the output end of the first digital analog converter U4
It is connected with the micro-control unit,
The first phase shift attenuation module M1, for the adjust instruction generated according to the micro-control unit, to the coupler
The carrier signal that U2 is coupled out carries out phase shift and amplitude attenuation generation offseting signal；
The first synthesizer U5, the carrier signal and described first for the second end reception to the transceiver insulation circuit U 3
The signal of phase shift attenuation module M1 outputs is synthesized, and obtains composite signal, wherein the first phase shift attenuation module M1 is exported
The offseting signal be used to offset the first end of transceiver insulation circuit U 3 and leak to the end of transceiver insulation circuit U 3 the 3rd
Carrier signal；
The first power detector U6, the power of the composite signal for monitoring the first synthesizer U5 outputs, and pass through
The first digital analog converter U4 sends the power of the first synthesizer U5 composite signals exported to the microcontroller list
Member, is referred to by power of the micro-control unit according to the first synthesizer U5 composite signals exported, generating the adjustment
Order.
2. carrier cancellation circuit according to claim 1, it is characterised in that also include：Power splitter U7, the second phase shift decay
Module M2, the first limiter U8, low noise amplifier U9, the second digital analog converter U10, the second power detector U11, the second synthesis
Device U12 and the second limiter U13；
The input SUM of the power splitter U7 is connected with the coupling port CP of the coupler U2, and the first of the power splitter U7
Output end P1 is connected with the first input end of the first phase shift attenuation module M1, the second output end P2 of the power splitter U7 with
The first input end of the second phase shift attenuation module M2 is connected；
The second input of the second phase shift attenuation module M2 is connected with the micro-control unit, the second phase shift decay
Module M2 output end is connected with the first input end P1 of the second synthesizer U12；
The input of the first limiter U8 is connected with the output end SUM of the first synthesizer U5, first limiter
U8 output end is connected with the input of the low noise amplifier U9, and the output end of the low noise amplifier U9 is closed with described second
U12 the second input P2 of growing up to be a useful person is connected, the output end SUM of the second synthesizer U12 respectively with the second limiter U13
Input and the second power detector U11 input be connected, the output end of the second power detector U11 and described the
Two digital analog converter U10 input is connected, output end and the micro-control unit phase of the second digital analog converter U10
Even.
3. carrier cancellation circuit according to claim 1, it is characterised in that the transceiver insulation circuit U 3 is circulator.
4. the carrier cancellation circuit according to claim any one of 1-3, it is characterised in that the first phase shift attenuation module
M1 includes：3rd digital analog converter m1, the 4th digital analog converter m2 and the first IQ vector modulators m3；
The input of the 3rd digital analog converter m1 is connected with the micro-control unit, and the 3rd digital analog converter m1's is defeated
Go out end be connected with the first control port of the first IQ vector modulators m3, the input of the 4th digital analog converter m2 and
The micro-control unit is connected, the output end of the 4th digital analog converter m2 and the second of the first IQ vector modulators m3
Control port is connected；
The input of the first IQ vector modulators m3 as the first phase shift attenuation module M1 first input end, it is described
First IQ vector modulators m3 output end as the first phase shift attenuation module M1 output end, with first synthesizer
U5 the second input P2 is connected.
5. carrier cancellation circuit according to claim 4, it is characterised in that the first IQ vector modulators m3 includes：
First electric bridge m31, the first balun m32, the second balun m33, the 3rd balun m34, the 4th balun m35, the first double-point double-throw switch
M36, the second double-point double-throw switch m37, the first numerical-control attenuator m38, the second numerical-control attenuator m39 and the 3rd synthesizer m310；
The input of the first electric bridge m31 is used as the input of the first IQ vector modulators m3, the first electric bridge m31
The first output end be connected with the input of the first balun m32, the second output end of the first electric bridge m31 and described the
Three balun m34 input is connected；
The first output end of the first balun m32 is connected with the first switch end of the first double-point double-throw switch m36, institute
The second output end for stating the first balun m32 is connected with the second switch end of the first double-point double-throw switch m36, described first pair
Double-pole double throw switch m36 the 3rd switch terminals are connected with the first input end of the second balun m33, and first DPDT is opened
The 4th switch terminals for closing m36 are connected with the second input of the second balun m33, the first double-point double-throw switch m36's
Control end is connected with the micro-control unit；
The output end of the second balun m33 is connected with the first input end of the first numerical-control attenuator m38, first number
Control attenuator m38 the second input is connected with the micro-control unit, the output end of the first numerical-control attenuator m38 and institute
The first input end P1 for stating the 3rd synthesizer m310 is connected；
The first output end of the 3rd balun m34 is connected with the first switch end of the second double-point double-throw switch m37, described
3rd balun m34 the second output end is connected with the second switch end of the second double-point double-throw switch m37, second double-pole
Commutator m37 the 3rd switch terminals are connected with the first input end of the 4th balun m35, second double-point double-throw switch
M37 the 4th switch terminals are connected with the second input of the 4th balun m35, the control of the second double-point double-throw switch m37
End processed is connected with the micro-control unit；
The output end of the 4th balun m35 is connected with the first input end of the second numerical-control attenuator m39, second number
Control attenuator m39 the second input is connected with the micro-control unit, the output end of the second numerical-control attenuator m39 and institute
The the second input P2 for stating the 3rd synthesizer m310 is connected, and the output end of the 3rd synthesizer m310 is sweared as the first IQ
Measure modulator m3 output end.
6. carrier cancellation circuit according to claim 2, it is characterised in that the second phase shift attenuation module M2 includes：
5th digital analog converter m4, the 6th digital analog converter m5 and the 2nd IQ vector modulators m6；
The input of the 5th digital analog converter m4 is connected with the micro-control unit, and the 5th digital analog converter m4's is defeated
Go out end be connected with the first control port of the 2nd IQ vector modulators m6, the input of the 6th digital analog converter m5 and
The micro-control unit is connected, the output end of the 6th digital analog converter m5 and the second of the 2nd IQ vector modulators m6
Control port is connected；
The input of the 2nd IQ vector modulators m6 as the second phase shift attenuation module M2 first input end, it is described
2nd IQ vector modulators m6 output end is synthesized as the output end of the second phase shift attenuation module M2 with described second
Device U12 the second input P2 is connected.
7. carrier cancellation circuit according to claim 6, it is characterised in that the 2nd IQ vector modulators m6 includes：
Second electric bridge m61, the 5th balun m62, the 6th balun m63, the 7th balun m64, the 8th balun m65, the 3rd double-point double-throw switch
M66, the 4th double-point double-throw switch m67, the 3rd numerical-control attenuator m68, the 4th numerical-control attenuator m69 and the 4th synthesizer m610；
The input of the second electric bridge m61 is used as the input of the 2nd IQ vector modulators m6, the second electric bridge m61
The first output end be connected with the input of the 5th balun m62, the second output end of the second electric bridge m61 and described the
Seven balun m64 input is connected；
The first output end of the 5th balun m62 is connected with the first switch end of the 3rd double-point double-throw switch m66, described
5th balun m62 the second output end is connected with the second switch end of the 3rd double-point double-throw switch m66, the 3rd double-pole
Commutator m66 the 3rd switch terminals are connected with the first input end of the 6th balun m63, the 3rd double-point double-throw switch
M66 the 4th switch terminals are connected with the second input of the 6th balun m63, the control of the 3rd double-point double-throw switch m66
End processed is connected with the micro-control unit；
The output end of the 6th balun m63 is connected with the first input end of the 3rd numerical-control attenuator m68, the 3rd number
Control attenuator m68 the second input is connected with the micro-control unit, the output end of the 3rd numerical-control attenuator m68 and institute
The first input end P1 for stating the 4th synthesizer m610 is connected；
The first output end of the 7th balun m64 is connected with the first switch end of the 4th double-point double-throw switch m67, described
7th balun m64 the second output end is connected with the second switch end of the 4th double-point double-throw switch m67, the 4th double-pole
Commutator m67 the 3rd switch terminals are connected with the first input end of the 8th balun m65, the 4th double-point double-throw switch
M67 the 4th switch terminals are connected with the second input of the 8th balun m65, the control of the 4th double-point double-throw switch m67
End processed is connected with the micro-control unit；
The output end of the 8th balun m65 is connected with the first input end of the 4th numerical-control attenuator m69, the 4th number
Control attenuator m69 the second input is connected with the micro-control unit, the output end of the 4th numerical-control attenuator m69 and institute
The the second input P2 for stating the 4th synthesizer m610 is connected, and the output end of the 4th synthesizer m610 is sweared as the 2nd IQ
Measure modulator m6 output end.
8. a kind of RFID reader, it is characterised in that including the carrier cancellation circuit as described in claim 1-7 any one.
9. RFID reader according to claim 8, it is characterised in that the RFID reader is operated in 900M frequency ranges.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621030517.6U CN206451204U (en) | 2016-08-31 | 2016-08-31 | A kind of carrier cancellation circuit and RFID reader |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201621030517.6U CN206451204U (en) | 2016-08-31 | 2016-08-31 | A kind of carrier cancellation circuit and RFID reader |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN206451204U true CN206451204U (en) | 2017-08-29 |
Family
ID=59661690
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201621030517.6U Active CN206451204U (en) | 2016-08-31 | 2016-08-31 | A kind of carrier cancellation circuit and RFID reader |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN206451204U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107529623A (en) * | 2017-09-29 | 2018-01-02 | 北京微度芯创科技有限责任公司 | A kind of antenna feeding network system for improving receive-transmit isolation |
| CN108418601A (en) * | 2018-01-26 | 2018-08-17 | 苏州安迪卡普科技有限公司 | A kind of carrier wave cancellation system |
| CN109547382A (en) * | 2017-09-22 | 2019-03-29 | 刘伟 | Width phase control circuit and multichannel width phase control matrix |
-
2016
- 2016-08-31 CN CN201621030517.6U patent/CN206451204U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109547382A (en) * | 2017-09-22 | 2019-03-29 | 刘伟 | Width phase control circuit and multichannel width phase control matrix |
| CN107529623A (en) * | 2017-09-29 | 2018-01-02 | 北京微度芯创科技有限责任公司 | A kind of antenna feeding network system for improving receive-transmit isolation |
| CN108418601A (en) * | 2018-01-26 | 2018-08-17 | 苏州安迪卡普科技有限公司 | A kind of carrier wave cancellation system |
| CN108418601B (en) * | 2018-01-26 | 2020-07-10 | 苏州安迪卡普科技有限公司 | Carrier cancellation system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN206451204U (en) | A kind of carrier cancellation circuit and RFID reader | |
| CN102006102B (en) | Coupling apparatus for dividing receiving and transmitting signals and control method thereof | |
| CN101304259B (en) | Leakage power reducing apparatus | |
| CN101951241B (en) | Device and method for realizing radio frequency RF leakage compensation and radio frequency identification RFID reader | |
| CN103746713B (en) | The device and method launching carrier wave is suppressed in RFID integral type read write line | |
| CN103997352A (en) | Active antenna associated equipment, system and transmitting and receiving calibration method | |
| WO2008105742A1 (en) | A leakage suppressing circuit | |
| CN103954956B (en) | Self-adaptation four-port cancellation network structure and self-adaptation cancellation method | |
| CN208938118U (en) | A kind of passive self-interference cancellation circuit of RFID reader | |
| CN206147647U (en) | Echo is offset system for remote UHF RFID read write line | |
| CN205232221U (en) | Radio frequency front end device based on general radio frequency transceiving chip | |
| CN107634299A (en) | A kind of compact Wilkinson power divider | |
| CN107094032A (en) | A kind of RF front-end module and frequency signal processing method | |
| CN103927413B (en) | A kind of airborne shortwave receives and dispatches interstation antenna coupled interference Pre-Evaluation method with ultrashort wave | |
| CN204967832U (en) | Jointly disturb system based on frequency spectrum perception and modulation recognition | |
| CN107359944A (en) | Bluetooth equipment radio frequency test system | |
| CN103974271B (en) | Communication shielding harness and method based on the control of indoor distribution link | |
| CN207517041U (en) | For the carrier wave cancellation circuit of passive ultra-high frequency RFID reader | |
| Koller et al. | Adaptive carrier supression for UHF RFID using digitally tunable capacitors | |
| CN103684646B (en) | A kind of time division multiplex system and the method for common-use tunnel | |
| CN109120290B (en) | RFID receiving circuit, storage medium, and electronic device | |
| Zhonghua et al. | Carrier extraction cancellation circuit in RFID reader for improving the Tx‐to‐Rx isolation | |
| CN104123571A (en) | Carrier wave offset circuit based on RFID reader-writer, and RFID reader-writer | |
| CN107070492A (en) | A kind of signal transmitting and receiving control structure, method and electronic equipment | |
| CN203895591U (en) | Wireless communication apparatus and coupler |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |