CN106019181B - The superconducting quantum interference device Magnetic Sensor and detection method of high speed wide range - Google Patents
The superconducting quantum interference device Magnetic Sensor and detection method of high speed wide range Download PDFInfo
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- CN106019181B CN106019181B CN201610319580.XA CN201610319580A CN106019181B CN 106019181 B CN106019181 B CN 106019181B CN 201610319580 A CN201610319580 A CN 201610319580A CN 106019181 B CN106019181 B CN 106019181B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
- G01R33/035—Measuring direction or magnitude of magnetic fields or magnetic flux using superconductive devices
- G01R33/0354—SQUIDS
- G01R33/0358—SQUIDS coupling the flux to the SQUID
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Abstract
The present invention provides a kind of the superconducting quantum interference device Magnetic Sensor and detection method of high speed wide range, including generates the magnetic flux lock-in circuit of loop output voltage；The voltage detecting circuit of detection loop output voltage；The control bias potential circuit of bias voltage is adjusted according to loop output voltage；And the counter circuit of the counting to flux quantum.The loop output voltage proportional to tested magnetic flux is exported based on magnetic flux lock-in circuit；According to the state bias voltage of loop output voltage, operating point is relocked after so that magnetic flux lock-in circuit is zeroed；The transitional states of bias voltage are counted, realize the counting to flux quantum；Final synthesis loop output voltage and count value realize the detection of wide range.The present invention only changes bias voltage value, does not destroy the transmission characteristic of original sensor；Bias voltage value is adjusted flexibly according to the response characteristic of loop, and the speed of circuit output zero reaches most fast；Zero control is completed by state switching circuit, eliminates miscount.
Description
Technical field
The present invention relates to Weak magentic-field detection fields, more particularly to a kind of superconducting quantum interference device magnetic of high speed wide range
Sensor and detection method.
Background technology
Using superconducting quantum interference device (Superconducting Quantum Interference Device, below
Abbreviation SQUID) sensor be the most sensitive Magnetic Sensor being currently known.It is widely used in heart magnetic, brain magnetic, extremely low field nuclear-magnetism
In the atomic weak magnetic signal detection such as resonance and scientific research.Since it uses microelectronic technique, in multichannel, high-resolution, collection
At changing there is irreplaceable role in high-end applications system.
SQUID device is the superconducting ring being made of two Josephson junction parallel connections, and the both ends of knot are drawn to form one
The passive device of a two-terminal.After injecting certain bias current to SQUID, SQUID both end voltages will be with its induction
Magnetic flux is in mechanical periodicity, and the period is just a flux quantum Φ0(0=2.07 × 10 Φ-15Weber), as shown in Figure 1.SQUID
Magnetic Sensor is to realize the linear transformation of field voltage based on flux locked loop road (Flux-Locked Loop, abbreviation FLL),
As shown in Figure 2.FLL circuits select the point conduct of magnetic flux voltage conversion maximum slope in SQUID magnetic flux voltage transfer curves
Label is in operating point, such as Fig. 1, w1, w2 are operating point, these operating point period profiles, therefore is spaced between operating point
One flux quantum Φ0。
The transfer curve such as Fig. 3 for the input magnetic flux and output voltage that above-mentioned FLL circuits work under different operating point
It is shown, a transfer curve is corresponded under each operating point, and the magnetic of a flux quantum is just differed between every curve
Logical and corresponding voltage.FLL circuits under some fixation operating point, since its output voltage limits (being usually ± 10V), because
This measurable magnetic flux range is limited (dash area in such as Fig. 3).And the magnetic flux that SQUID can actually incude is much larger than the survey
Measure range.
For SQUID device performance, expands SQUID Magnetic Sensor performances, switched at present using operating point, coordinate magnetic flux
The method of sub-count realizes the measurement of wide range.That is, under some operating point, measures magnetic flux and be right up to N number of Φ0, wherein
The integer that N is ± 1, ± 2 ....By FLL circuit output zero setting, and restart to lock, FLL circuits at this time will be switched to therewith
Preceding difference N Φ0Operating point on start from scratch locking output.Pass through above-mentioned switching, the correspondence Φ of record operating point jump0Change
Change amount and the output normally locked in FLL circuits, you can learn the size of current tested magnetic flux.
By the above method, the magnetic-flux measurement range of SQUID Magnetic Sensors the magnetic flux that SQUID can incude has been expanded to
Range, therefore measurement capability greatly promotes.Realize the SQUID Magnetic Sensors of wide range.
But existed in practical applications using the wide range SQUID Magnetic Sensors that above-mentioned work point switching method is realized
Following problem：
1, using the handoff procedure relocked again after zero is resetted, the moment is locked in zero and again, there is overshoot and shakes
Phenomenon is swung, as shown in Figures 4 and 5, Fig. 5 is the partial enlarged view in Fig. 4 dotted line frames.
It, will be in integrator capacitance when resetting in the circuit for using integrator especially in flux locked loop FLL
Charge repid discharge is zeroed, thus generates prodigious electric current, causes prodigious impact to reset switch and operation discharger, Yi Zao
It is damaged at circuit.If controlling discharge current, discharge time extends, and switch speed is not fast enough.
2, working sensor point switch speed is not fast enough, and the reset curves of conventional reset circuit are index decreasing functions, because
It is longer that later time is more arrived in this reset, so that there is the case where counting loss or miscount.
Invention content
In view of the foregoing deficiencies of prior art, the purpose of the present invention is to provide a kind of superconduction amounts of high speed wide range
Sub- interferometer Magnetic Sensor and detection method, the magnetic-flux measurement range for solving SQUID Magnetic Sensors in the prior art increase
Afterwards the problems such as existing overshoot, oscillation and miscount.
In order to achieve the above objects and other related objects, the present invention provides a kind of superconducting quantum interference device of high speed wide range
The superconducting quantum interference device Magnetic Sensor of Magnetic Sensor, the high speed wide range includes at least：
Magnetic flux lock-in circuit, voltage detecting circuit, control bias potential circuit and counter circuit；
The magnetic flux lock-in circuit is detected tested magnetic flux, and it is defeated to export the loop proportional to the tested magnetic flux
Go out voltage；The magnetic flux lock-in circuit includes SQUID superconducting rings, is connected to the operation amplifier of the SQUID superconducting rings output end
Device, the feedback resistance and feedback coil for being sequentially connected to the operational amplifier output terminal；
The voltage detecting circuit is connected to the output end of the magnetic flux lock-in circuit, to the number of the loop output voltage
Value is detected；
The control bias potential circuit is connected to the voltage detecting circuit, is adjusted according to the loop output voltage inclined
Voltage is set, operating point is relocked after so that the magnetic flux lock-in circuit is zeroed；
The counter circuit is connected to the control bias potential circuit, according to the jump of the control bias potential circuit
Change state carries out plus-minus counting, realizes the counting to flux quantum.
Preferably, the voltage detecting circuit is respectively by the loop output voltage and the first reference voltage, the second reference
Voltage and reference no-voltage are compared；Wherein, the first reference voltage is input magnetic flux when being the first n flux quantum of quantity pair
The voltage answered, the second reference voltage are the negative of first reference voltage, and the first quantity n is natural number.
It is highly preferred that the voltage detecting circuit includes four comparators, the normal phase input end of first comparator connects institute
State the first reference voltage, inverting input connects the loop output voltage, described in the normal phase input end connection of the second comparator
Loop output voltage, reverse inter-input-ing ending grounding, the normal phase input end connection loop output voltage of third comparator, reverse phase are defeated
Enter end and connect second reference voltage, positive input end grounding, the inverting input connection loop of the 4th comparator are defeated
Go out voltage.
It is highly preferred that the control bias potential circuit includes state trigger module and potential-divider network module；Wherein, described
State trigger module connects the output end of the voltage detecting circuit, when the loop output voltage is more than described first with reference to electricity
Saltus step is to the first working condition when pressure, and when the loop output voltage is less than second reference voltage, saltus step is to the second work
State, saltus step is to third working condition after the loop output voltage is zeroed；The potential-divider network module connects the state
Trigger module is controlled by the state trigger module, the first bias voltage is exported in first working condition, described
The second bias voltage is exported when the second working condition, the output third bias voltage in the third working condition, described first
The value of bias voltage is more than the maximum output voltage of the SQUID superconducting rings, and the value of second bias voltage is less than described
The minimum output voltage of SQUID superconducting rings, the third bias voltage are the biased electrical at SQUID superconducting rings operating point
Pressure.
It is highly preferred that the state trigger module includes the first trigger and the second trigger, first trigger
Set end connects the output end of the first comparator, and reset terminal connects the output end of second comparator；Described second touches
The set end of hair device connects the output end of the third comparator, and reset terminal connects the output end of the 4th comparator.
It is highly preferred that the potential-divider network module includes connecting the first~tetra- resistance of the opamp input terminal,
The other end of the first resistor connects the first bias supply by first switch, and the other end of the second resistance passes through second
Switch the second bias supply of connection, the other end of the 3rd resistor connect third bias supply, the 4th resistance it is another
End ground connection.
In order to achieve the above objects and other related objects, the present invention also provides a kind of superconductive quantum interferences of high speed wide range
The superconducting quantum interference device detection method of device detection method, the high speed wide range includes at least：
Tested magnetic flux is detected based on a magnetic flux lock-in circuit, and exports the loop proportional to the tested magnetic flux
Output voltage；
The loop output voltage is detected, adjusting the magnetic flux according to the state of the loop output voltage locks
The bias voltage of circuit relocks operating point after so that the magnetic flux lock-in circuit is zeroed；
The transitional states of the bias voltage are counted, realize the counting to flux quantum；
Eventually by the detection for synthesizing the loop output voltage and count value realization wide range.
Preferably, by by the loop output voltage and the first reference voltage, the second reference voltage and with reference to no-voltage
It is compared to determine the output valve of the bias voltage, wherein first reference voltage is that input magnetic flux is the first quantity n
Corresponding voltage when a flux quantum, second reference voltage are the negative of first reference voltage, the first quantity n
For natural number.
It is highly preferred that when the loop output voltage is more than first reference voltage, saltus step to the first working condition,
Then the bias voltage is more than the maximum output voltage of SQUID superconducting rings, and the loop output voltage is gradually reduced zero；Work as institute
When stating loop output voltage less than second reference voltage, saltus step to the second working condition, then the bias voltage is less than institute
The minimum output voltage of SQUID superconducting rings is stated, the loop output voltage is gradually increasing zero；When the loop output voltage is returned
After zero, saltus step to third working condition, then the bias voltage is the bias voltage at SQUID superconducting rings operating point.
It is highly preferred that carrying out plus counting when the loop output voltage is more than first reference voltage, when the ring
Road output voltage carries out subtracting counting when being less than second reference voltage.
As described above, the present invention high speed wide range superconducting quantum interference device Magnetic Sensor and detection method, have with
Lower advantageous effect：
1, the superconducting quantum interference device Magnetic Sensor of high speed wide range of the invention and detection method only change bias voltage
Value, does not change the feedback parameter of original sensor circuit, will not destroy the transmission characteristic of original sensor circuit.
2, bias voltage value can in the superconducting quantum interference device Magnetic Sensor and detection method of high speed wide range of the invention
It is adjusted flexibly according to the response characteristic of loop, zero process is linear function type, and return-to-zero-time is short, passes through parameter tune
Section may make the speed that circuit output is zeroed to reach most fast, and traditional reset circuit is deposited and limited by charge and discharge time parameter,
Property is decaying exponential function type, and it is long to be output to the zero-time, therefore the handoff procedure time is long, simultaneously because discharge impact, holds
Easily occurs overshooting and vibrate.
3, the zero of the superconducting quantum interference device Magnetic Sensor of high speed wide range of the invention and detection method is controlled by shape
State switching circuit is completed, and state control ensures that circuit triggering operating point jumps to saltus step completion, and real-time tracking locks magnetic flux
The state of locked loop realizes that flux locked loop road completely resets and exit flow, it is ensured that be not in miscount.
Description of the drawings
Fig. 1 is shown as SQUID magnetic fluxs-voltage-transfer characteristic curve schematic diagram in the prior art.
Fig. 2 is shown as flux locked loop road in the prior art schematic diagram.
Fig. 3 is shown as the magnetic flux-voltage-transfer characteristic curve schematic diagram on flux locked loop road in the prior art.
Fig. 4 is shown as in the prior art using overshoot and oscillatory occurences in the handoff procedure relocked again after reset zero
Schematic diagram.
Fig. 5 is shown as overshooting the close-up schematic view with oscillatory occurences in the prior art.
Fig. 6 is shown as the principle schematic of the superconducting quantum interference device Magnetic Sensor of the high speed wide range of the present invention.
Fig. 7 is shown as the structural schematic diagram of the superconducting quantum interference device Magnetic Sensor of the high speed wide range of the present invention.
Fig. 8 is shown as the state machine principle schematic of the present invention.
Component label instructions
The superconducting quantum interference device Magnetic Sensor of 1 high speed wide range
11 magnetic flux lock-in circuits
111 operational amplifiers
12 voltage detecting circuits
13 control bias potential circuits
131 state trigger modules
132 potential-divider network modules
14 counter circuits
S1~S4 steps
Specific implementation mode
Illustrate that embodiments of the present invention, those skilled in the art can be by this specification below by way of specific specific example
Disclosed content understands other advantages and effect of the present invention easily.The present invention can also pass through in addition different specific realities
The mode of applying is embodied or practiced, the various details in this specification can also be based on different viewpoints with application, without departing from
Various modifications or alterations are carried out under the spirit of the present invention.
Please refer to Fig. 6~Fig. 8.It should be noted that the diagram provided in the present embodiment only illustrates this in a schematic way
The basic conception of invention, package count when only display is with related component in the present invention rather than according to actual implementation in schema then
Mesh, shape and size are drawn, when actual implementation kenel, quantity and the ratio of each component can be a kind of random change, and its
Assembly layout kenel may also be increasingly complex.
As shown in Fig. 6~Fig. 7, the present invention provides a kind of superconducting quantum interference device Magnetic Sensor 1 of high speed wide range, described
The superconducting quantum interference device Magnetic Sensor 1 of high speed wide range includes at least：
Magnetic flux lock-in circuit 11, voltage detecting circuit 12, control bias potential circuit 13 and counter circuit 14.
As shown in Fig. 6~Fig. 7, the magnetic flux lock-in circuit 11 is detected tested magnetic flux Φ e, and exports and the quilt
Survey the proportional loop output voltage V of magnetic flux Φ ef。
Specifically, the magnetic flux lock-in circuit 11 includes SQUID superconducting rings SQ1, operational amplifier 111, feedback resistance Rf
And feedback coil L1.The SQUID superconducting rings SQ1 and feedback coil L1 constitutes four terminal SQUID devices.The SQUID
One end ground connection of superconducting ring SQ1, the other end connect the first input end of the operational amplifier 111, as shown in fig. 7, in this reality
It applies in example, the SQUID superconducting rings SQ1 connects the normal phase input end of the operational amplifier 111.The operational amplifier 111
The second input terminal connect the control bias potential circuit 13, as shown in fig. 7, in the present embodiment, the control bias electricity
Volt circuit 13 connects the inverting input of the operational amplifier 111.The feedback resistance RfOne end connect the operation and put
Output end, the other end of big device 111 connect the feedback coil L1.The other end of the feedback coil L1 is grounded.Such as Fig. 7 institutes
Show, in the present embodiment, the output end of the SQUID superconducting rings SQ1 is also connected with a SQUID biasing circuits, including one end ground connection
Bias voltage Vb1, the other end passes through biasing resistor Rb1It is connected to the output end of the SQUID superconducting rings SQ1, and it is described
SQUID superconducting rings SQ1 constitutes bias loop, and bias current I is provided to the SQUID superconducting rings SQ1bSo that the SQUID is super
The magnetic flux that lead ring SQ1 puts up the best performance-voltage transfer characteristic.
As shown in Fig. 6~Fig. 7, the voltage detecting circuit 12 is connected to the output end of the magnetic flux lock-in circuit 11, right
The loop output voltage VfNumerical value be detected.
Specifically, the voltage detecting circuit 12 is respectively by the loop output voltage VfWith the first reference voltage Vref,
Two reference voltage-VrefAnd it is compared with reference to no-voltage.Wherein, the first reference voltage VrefIt is the first quantity n for input magnetic flux
Corresponding voltage when a flux quantum, that is,N is the natural number of a setting, Φ0For a flux quantum, Rf
For the feedback resistance RfResistance value, MfFor the mutual inductance of the feedback coil L1 and the SQUID superconducting rings SQ1；Second with reference to electricity
Pressure-VrefFor the first reference voltage VrefNegative.In the present embodiment, using model LM311, positive and negative two voltage is defeated
Enter, export the logical signal being compatible with for Transistor-Transistor Logic level, when positive terminal voltage is more than negative terminal voltage, comparator output is high level；Instead
When the positive terminal voltage of comparator be less than negative terminal input voltage when, comparator output be low level.As shown in fig. 7, the voltage inspection
Slowdown monitoring circuit 12 includes four comparators, and the normal phase input end of first comparator IC1 connects the first reference voltage Vref, reverse phase
Input terminal connects the loop output voltage Vf, the normal phase input end connection loop output voltage V of the second comparator IC2f、
The normal phase input end of reverse inter-input-ing ending grounding, third comparator IC3 connects the loop output voltage Vf, inverting input connection
Second reference voltage-the Vref, positive input end grounding, the inverting input of the 4th comparator IC4 connect the loop output
Voltage Vf.The first comparator IC1 realizes the loop output voltage VfWith the first reference voltage VrefComparison, work as institute
It states loop output voltage Vf voltages and is more than the first reference voltage VrefWhen, the first comparator IC1 exports low level, instead
Output high level.The second comparator IC2 realizes the loop output voltage VfWith with reference to no-voltage comparison, when described
Loop output voltage VfWhen voltage is less than 0, the second comparator IC2 exports low level, otherwise exports high level.The third
Comparator IC3 realizes the loop output voltage VfWith the second reference voltage-VrefComparison, when the loop export electricity
Press VfLess than the second reference voltage-VrefWhen, the third comparator IC3 exports low level, otherwise exports high level.Institute
It states the 4th comparator IC4 and realizes the loop output voltage VfWith with reference to no-voltage comparison, as the loop output voltage VfElectricity
When pressure is more than 0, the 4th comparator IC4 exports low level, otherwise exports high level.
As shown in Fig. 6~Fig. 7, the control bias potential circuit 13 is connected to the voltage detecting circuit 12, according to institute
State loop output voltage VfBias voltage is adjusted, operating point is relocked after so that the magnetic flux lock-in circuit 11 is zeroed.
Specifically, as shown in fig. 7, the control bias potential circuit 13 includes state trigger module 131 and potential-divider network
Module 132.
More specifically, as shown in fig. 7, the state trigger module 131 connects the output end of the voltage detecting circuit 12,
Including the set end of the first trigger IC5-1 and the second trigger IC5-2, the first trigger IC5-1 connection described first
The output end of comparator IC1, reset terminal connect the output end of the second comparator IC2；The second trigger IC5-2's sets
Position end connects the output end of the third comparator IC3, and reset terminal connects the output end of the 4th comparator IC4；Described
The clock end CLK and data input pin D of one trigger IC5-1 and the second trigger IC5-2 are grounded.In the present embodiment
In, the first trigger IC5-1 and the second trigger IC5-2 are D flip-flop 71ls74, arbitrary that the present invention can be achieved
State transition trigger or circuit structure be suitable for the present invention, be not limited to this embodiment.D flip-flop 71ls74's
Truth table is as follows：
Work as set endFor low level when, output end Q is set to 1；Work as reset terminalFor low level when, output end
Q is 0 clearly,；Work as set endAnd reset terminalWhen being high level, output end Q keeps previous state constant.Thus structure
At state machine：
1) when the loop output voltage Vf is more than first reference voltage Vref, the first trigger IC5-1
Output will be set 1.
2) when the loop output voltage Vf is less than 0, the output of the first trigger IC5-1 will be by clear 0.
3) when the loop output voltage Vf is less than the second reference voltage-Vref, the second trigger IC5-2
Output will be set 1.
4) when the loop output voltage Vf is more than 0, the output of the second trigger IC5-2 will be by clear 0.
The output combination table of the first trigger IC5-1 and the second trigger IC5-2 levy the state of state machine：
First working condition S1：Corresponding two triggers combination output is 10；Second working condition S2：Corresponding two triggerings
Device combination output is 01；Third working condition S0：Corresponding two triggers combination output 00.That is, working as the loop output voltage
VfMore than the first reference voltage VrefWhen saltus step to the first working condition S1, as the loop output voltage VfLess than described
Two reference voltage-VrefWhen saltus step to the second working condition S2, saltus step to third works after the loop output voltage Vf is zeroed
State S0.
More specifically, the potential-divider network module 132 connects the state trigger module 131, in the first work shape
When state S1, the potential-divider network module 132 exports the value of the first bias voltage V1, the first bias voltage V1 more than described
The maximum output voltage of SQUID superconducting rings SQ1 can do specific setting according to actual conditions；In the second working condition S2,
The value that the potential-divider network module 132 exports the second bias voltage V2, the second bias voltage V2 is less than the SQUID superconductions
The minimum output voltage of ring SQ1；In the third working condition S0, the potential-divider network module 132 exports third biased electrical
It is the bias voltage at the operating points SQUID superconducting rings SQ1 to press V0, the third bias voltage V0.The state trigger mode
Block 131 controls the switch in the potential-divider network module 132, to realize different bias voltages under different working condition
Output arbitrarily can be achieved the output phase under working condition and the circuit of bias voltage answered to be suitable for the present invention, is not with the present embodiment
Limit.As shown in fig. 7, in the present embodiment, include the first~tetra- resistance of connection 111 inverting input of operational amplifier,
The first resistor RO1The other end pass through first switch SW1 the first bias supplies of connection VOS, the second resistance RO2It is another
End passes through second switch SW2 the second bias supplies of connection-VOS, the 3rd resistor RO3The other end connect third bias supply
VO0, the 4th resistance RO4The other end ground connection.Bias voltage comes from the 4th resistance RO4On voltage, it is described 4th electricity
Hinder RO4Resistance value it is suitable with D.C. resistances of the SQUID superconducting rings SQ1 at operating point, choose 1~10 ohm.The first~tri-
Resistance RO1、RO2、RO3Value be more than the 4th resistance RO4.Load is in the 4th resistance RO4Upper voltage comes from three tunnels：
The third bias supply VO0Drive the 3rd resistor RO3It generates electric current and flows into the 4th resistance RO4, generate
Bias voltage is denoted as V0：
When the output of the first trigger IC5-1 is high level 1, which controls the first switch SW1 and is closed,
The first bias supply V is connectedOS, the first bias supply VOSDrive the first resistor RO1It generates described in electric current inflow
4th resistance RO4And the third bias supply VO0In the 4th resistance RO4The voltage integrated of upper generation is denoted as V1：
Similarly, when the output of the second trigger IC5-2 is high level 1, which controls the second switch SW2
It is closed, the second bias supply-V is connectedOS, the second bias supply-VOSDrive the second resistance RO2Generate electric current stream
Enter the 4th resistance RO4And the third bias supply VO0The voltage integrated generated on the 4th resistance RO4 is denoted as
V2：
(RO1、RO2Value is positive back bias voltage amplitude phase that is identical, generating in this way
Together)
Therefore according to the loop output voltage VfState machine is formed, the state according to state machine can realize different biased electricals
Pressure value exports.
As the loop output voltage VfOutput reaches the first reference voltage V for justrefWhen, described first compares
Device IC1 triggers the set end of the first trigger IC5-1, and the output of the first trigger IC5-1 is 1, and described first opens
It closes SW1 to be closed, the voltage that the control bias potential circuit 13 is input to 111 inverting input of the operational amplifier is first
Bias voltage V1, the loop output voltage VfStart reverse phase zero.During exporting zero, when the loop output voltage
VfWhen less than 0, the reset terminal of the first trigger IC5-1 is triggered by the second comparator IC2, first trigger
The output of IC5-1 is 0, and the first switch SW1 is disconnected, and the control bias potential circuit 13 restores output third bias voltage
V0, the magnetic flux lock-in circuit 11 relock work, complete the switching of one action point.
Similarly, as the loop output voltage VfOutput is negative, and reaches the second reference voltage-VrefWhen, described
Three comparator IC3 trigger the set end of the second trigger IC5-2, and the output of the second trigger IC5-2 is 1, described
Second switch SW2 is closed, and the control bias potential circuit 13 is input to the voltage of 111 inverting input of the operational amplifier
For the second bias voltage V2, the loop output voltage VfStart reverse phase zero.During exporting zero, when the loop is defeated
Go out voltage VfWhen more than 0, the reset terminal of the second trigger IC5-2 is triggered by the 4th comparator IC4, and described second touches
The output for sending out device IC5-2 is 0, and the second switch SW2 is disconnected, and the control bias potential circuit 13 restores output third biasing
Voltage V0, the magnetic flux lock-in circuit 11 relock work, complete the switching of one action point.
As shown in Fig. 6~Fig. 7, the counter circuit 14 is connected to the control bias potential circuit 13, according to described
The transitional states of control bias potential circuit 13 carry out plus-minus counting, realize the counting to flux quantum.
Specifically, as shown in fig. 7, the output end of the first trigger IC5-1 connects the of the counter circuit 14
One clock end CLK1, the counting pulse signal as the positive operating point switching of the magnetic flux lock-in circuit 11；Similarly, described second
The output end of trigger IC5-2 connects the second clock end CLK2 of the counter circuit 14, as the magnetic flux lock-in circuit
The counting pulse signal of 11 negative sense operating points switching.The two pulse signals input respectively can forward-backward counter adduction subtract when
Clock inputs, and the count results of counter are that total operating point switches corresponding magnetic flux subnumber.
The output valve D of the counter circuit 14outWith the loop output voltage Vf, last total tested magnetic can be synthesized
Output, since the range that magnetic flux counts can be very big, the Magnetic Sensor that the present invention realizes have traditional Magnetic Sensor without
The wide range that method is realized.
As shown in Figure 6 to 8, the present invention also provides a kind of superconducting quantum interference device detection method of high speed wide range,
The superconducting quantum interference device Magnetic Sensor 1 based on the high speed wide range is realized in the present embodiment, and the detection method at least wraps
It includes：
Step S1：Tested magnetic flux is detected based on a magnetic flux lock-in circuit, and export with the tested magnetic flux at than
The loop output voltage of example.
Specifically, as shown in Fig. 6~Fig. 7, the SQUID superconducting rings SQ1 is detected tested magnetic flux Φ e, and generates
Corresponding voltage signal, SQUID biasing circuits provide bias current Ib to the SQUID superconducting rings SQ1 so that the SQUID
The magnetic flux that superconducting ring SQ1 puts up the best performance-voltage transfer characteristic.The output of the SQUID superconducting rings SQ1 and the biasing circuit 13
Signal is sent into the operational amplifier 111, and the operational amplifier 111 is defeated by the voltage difference progress open loop amplification output loop
Go out voltage Vf.The loop output voltage Vf drives the feedback resistance Rf to generate feedback current, by the feedback coil with
Feedback current is converted into magnetic flux and is coupled in the SQUID superconducting rings SQ1 by the mutual inductance Mf of the SQUID superconducting rings SQ1, is formed
Complete loop makes the loop output voltage V by the locking of operating pointfIt is proportional to the tested magnetic flux Φ e.
Step S2：The loop output voltage is detected, according to the adjustment of the state of the loop output voltage
The bias voltage of magnetic flux lock-in circuit relocks operating point after so that the magnetic flux lock-in circuit is zeroed.
Specifically, pass through the loop output voltage VfWith the first reference voltage Vref, the second reference voltage-VrefAnd reference
No-voltage is compared to determine the output valve of the bias voltage, wherein first reference voltage is that input magnetic flux is the
Corresponding voltage when one n flux quantum of quantity, that is,N is the natural number of a setting, Φ0For a magnetic flux
Quantum, RfFor the feedback resistance RfResistance value, MfFor the mutual inductance of the feedback coil L1 and the SQUID superconducting rings SQ1；Institute
State the second reference voltage-VrefFor the first reference voltage VrefNegative.As shown in figure 8, passing through the loop output voltage
VfValue state of a control machine, then bias voltage is controlled by state machine.The operation of the state machine and state switching are according to
Loop output voltage VfOutput valve determine, i.e.,：
1) under normal circumstances, the control bias potential circuit 13 is operated in third working condition S0, and bias voltage is defeated
Go out for third bias voltage V0, the range of the loop output voltage Vf is in the second reference voltage-VrefWith first ginseng
Examine voltage VrefBetween, i.e.-Vref<Vf<Vref.The value of the third bias voltage V0 and the operating points SQUID superconducting rings SQ1
The voltage V at placebIt is identical.
2) the control bias potential circuit 13 is operated under third working condition S0, as the loop output voltage VfGreatly
In the first reference voltage VrefWhen, the control bias potential circuit 13 enters the first work by third working condition S0
State S1, bias voltage output are the first bias voltage V1.The first bias voltage V1 is more than the SQUID superconducting rings
The maximum output voltage of SQ1.The input of the operational amplifier 111 is defeated higher than the SQUID superconducting rings SQ1 because of bias voltage
Go out voltage and reverse phase variation occurs, the loop output voltage VfDrop to zero.
3) the control bias potential circuit 13 is operated under the first working condition S1, as the loop output voltage VfUnder
When drop is less than zero, the control bias potential circuit 13 is switched to the third working condition S0, and bias voltage restores output and is
V0。
4) the control bias potential circuit 13 is operated under third working condition S0, as the loop output voltage VfIt is small
In the second reference voltage-VrefWhen, the control bias potential circuit 13 is switched to the second work by third working condition S0
State S2, bias voltage output are the second bias voltage V2.The second bias voltage V2 is less than the SQUID superconducting rings
The minimum output voltage of SQ1.Therefore, the input of the operational amplifier 111 is because bias voltage is less than the SQUID superconducting rings
The output voltage of SQ1 and occur reverse phase variation, the loop output voltage VfRise to zero.
5) the control bias potential circuit 13 is operated under the second working condition S2, as the loop output voltage VfIt returns
When being raised to zero, the control bias potential circuit 13 is switched to the third working condition S0, and it is V0 that bias voltage, which restores output,.
As shown in Figure 6 to 8, in the present embodiment, loop output voltage V is determined by the voltage detecting circuit 12f
Voltage status, the operation of state of a control machine, at third working condition S0, the output of the control bias potential circuit 13 electricity
It is the quiescent potential of the SQUID superconducting rings SQ1 to press V0 just, and the magnetic flux lock-in circuit 11 keeps normally locking operation,
At the first working condition S1, the output voltage V1 of the control bias potential circuit 13 will drive the operational amplifier 111
Make the loop output voltage VfIt is quickly zeroed by positive voltage.At the second working condition S2, the control bias potential circuit
13 output voltage V2 will drive the operational amplifier 111 to make the loop output voltage VfIt is quickly zeroed by negative voltage.
When the loop output voltage Vf reaches the first reference voltage VrefOr the second reference voltage-VrefWhen,
It is just driven by the output voltage of control bias potential circuit 13 so that the output of the operational amplifier 111 is quickly zeroed, voltage
After zero, circuit just restores normal locking output on new operating point.Therefore the present invention accurately quick can must carry out operating point
Switching.
Step S3：The transitional states of the bias voltage are counted, realize the counting to flux quantum.
Specifically, counting pulse is exported simultaneously when 13 state of the control bias potential circuit switching, drives the counting
Device circuit 14 is counted, as the loop output voltage VfMore than the first reference voltage VrefWhen produced by trigger circuit
Raw pulse is carried out plus is counted, as the loop output voltage VfLess than the second reference voltage-VrefWhen by accordingly triggering
Circuit generates pulse, subtract countings, plus-minus counting obtained after operating must count value be exactly that operating point switches total offset
Number, switching offset numbers by operating point can show that the magnetic flux subnumber of corresponding variation, i.e., the magnetic flux that operating point variation generates are inclined
Shifting amount.
Step S4：Finally, the real-time output of the magnetic flux offset of operating point variation and flux locked loop road is integrated, just
Obtain the size of actual external input magnetic flux.The spy of wide range is realized by synthesizing the loop output voltage and count value
It surveys.
Specifically, the flux quantum for recording operating point switching counts, and is normally locked in conjunction with the magnetic flux lock-in circuit 11
Fixed loop output voltage Vf, so that it may to record the signal for being tested magnetic field super large variation range, without being bound by the fixed work of tradition
The measurement method of the limited range of SQUID flux locked loops of point realizes the SQUID Magnetic Sensors of super large range.
As described above, the present invention high speed wide range superconducting quantum interference device Magnetic Sensor and detection method, have with
Lower advantageous effect：
1, the superconducting quantum interference device Magnetic Sensor of high speed wide range of the invention and detection method only change bias voltage
Value, does not change the feedback parameter of original sensor circuit, will not destroy the transmission characteristic of original sensor circuit.
2, bias voltage value can in the superconducting quantum interference device Magnetic Sensor and detection method of high speed wide range of the invention
It is adjusted flexibly according to the response characteristic of loop, zero process is linear function type, and return-to-zero-time is short, passes through parameter tune
Section may make the speed that circuit output is zeroed to reach most fast, and traditional reset circuit is deposited and limited by charge and discharge time parameter,
Property is decaying exponential function type, and it is long to be output to the zero-time, therefore the handoff procedure time is long, simultaneously because discharge impact, holds
Easily occurs overshooting and vibrate.
3, the zero of the superconducting quantum interference device Magnetic Sensor of high speed wide range of the invention and detection method is controlled by shape
State switching circuit is completed, and state control ensures that circuit triggering operating point jumps to saltus step completion, and real-time tracking locks magnetic flux
The state of locked loop realizes that flux locked loop road completely resets and exit flow, it is ensured that be not in miscount.
In conclusion the present invention provides a kind of superconducting quantum interference device Magnetic Sensor of high speed wide range, including：To tested
Magnetic flux is detected, and exports the magnetic flux lock-in circuit of loop output voltage；The numerical value of the loop output voltage is examined
The voltage detecting circuit of survey；Bias voltage is adjusted according to the loop output voltage, weight after making the magnetic flux lock-in circuit be zeroed
The control bias potential circuit of new locking operating point；And it is added and subtracted according to the transitional states of the control bias potential circuit
It counts, realizes the counter circuit of the counting to flux quantum.It is dry that the present invention also provides a kind of Superconducting Quantums of high speed wide range
Device detection method is related to, including：Tested magnetic flux is detected based on a magnetic flux lock-in circuit, and export with the tested magnetic flux at
The loop output voltage of ratio；The loop output voltage is detected, is adjusted according to the state of the loop output voltage
The bias voltage of the magnetic flux lock-in circuit relocks operating point after so that the magnetic flux lock-in circuit is zeroed；To the biasing
The transitional states of voltage are counted, and realize the counting to flux quantum；Eventually by the synthesis loop output voltage and meter
The detection of Numerical Implementation wide range.The superconducting quantum interference device Magnetic Sensor and detection method of the high speed wide range of the present invention only change
Become bias voltage value, does not change the feedback parameter of original sensor circuit, the transmission characteristic of original sensor circuit will not be destroyed；
Bias voltage value can be adjusted flexibly according to the response characteristic of loop so that and the speed of circuit output zero reaches most fast, and
Traditional reset circuit is deposited to be limited by charge and discharge time parameter, and the handoff procedure time is long, is susceptible to overshoot and oscillation；Zero control
System is completed by state switching circuit, and state control ensures that circuit triggering operating point jumps to saltus step completion, eliminates error count
Number.So the present invention effectively overcomes various shortcoming in the prior art and has high industrial utilization.
The above-described embodiments merely illustrate the principles and effects of the present invention, and is not intended to limit the present invention.It is any ripe
The personage for knowing this technology can all carry out modifications and changes to above-described embodiment without violating the spirit and scope of the present invention.Cause
This, institute is complete without departing from the spirit and technical ideas disclosed in the present invention by those of ordinary skill in the art such as
At all equivalent modifications or change, should by the present invention claim be covered.
Claims (10)
1. a kind of superconducting quantum interference device Magnetic Sensor of high speed wide range, which is characterized in that the superconduction of the high speed wide range
Quantum interfering device Magnetic Sensor includes at least：
Magnetic flux lock-in circuit, voltage detecting circuit, control bias potential circuit and counter circuit；
The magnetic flux lock-in circuit is detected tested magnetic flux, and exports the loop output electricity proportional to the tested magnetic flux
Pressure；The magnetic flux lock-in circuit includes SQUID superconducting rings, be connected to the operational amplifier of the SQUID superconducting rings output end, according to
The secondary feedback resistance and feedback coil for being connected to the operational amplifier output terminal；
The voltage detecting circuit is connected to the output end of the magnetic flux lock-in circuit, to the numerical value of the loop output voltage into
Row detection；
The control bias potential circuit is connected to the voltage detecting circuit, and biased electrical is adjusted according to the loop output voltage
Pressure relocks operating point after so that the magnetic flux lock-in circuit is zeroed；
The counter circuit is connected to the control bias potential circuit, according to the saltus step shape of the control bias potential circuit
State carries out plus-minus counting, realizes the counting to flux quantum.
2. the superconducting quantum interference device Magnetic Sensor of high speed wide range according to claim 1, it is characterised in that：The electricity
Pressure detection circuit compares by the loop output voltage with the first reference voltage, the second reference voltage and with reference to no-voltage respectively
Compared with；Wherein, the first reference voltage is to input corresponding voltage, the second reference voltage when magnetic flux is the first n flux quantum of quantity
For the negative of first reference voltage, the first quantity n is natural number.
3. the superconducting quantum interference device Magnetic Sensor of high speed wide range according to claim 2, it is characterised in that：The electricity
It includes four comparators to press detection circuit, and the normal phase input end of first comparator connects first reference voltage, anti-phase input
End connects the loop output voltage, and the normal phase input end of the second comparator connects the loop output voltage, inverting input
The normal phase input end of ground connection, third comparator connects the loop output voltage, inverting input connection described second with reference to electricity
Pressure, positive input end grounding, the inverting input of the 4th comparator connect the loop output voltage.
4. the superconducting quantum interference device Magnetic Sensor of high speed wide range according to claim 3, it is characterised in that：It is described can
It includes state trigger module and potential-divider network module to control bias voltage circuit；Wherein, the state trigger module connects the electricity
Press detection circuit output end, when the loop output voltage be more than first reference voltage when saltus step to first work shape
State, when the loop output voltage is less than second reference voltage, saltus step is to the second working condition, when the loop exports
Saltus step is to third working condition after voltage zero；The potential-divider network module connects the state trigger module, by the state
The control of trigger module exports the first bias voltage in first working condition, is exported in second working condition
Second bias voltage, third bias voltage is exported in the third working condition, and the value of first bias voltage is more than institute
The maximum output voltage of SQUID superconducting rings is stated, the value of second bias voltage is less than the minimum output of the SQUID superconducting rings
Voltage, the third bias voltage are the bias voltage at SQUID superconducting rings operating point.
5. the superconducting quantum interference device Magnetic Sensor of high speed wide range according to claim 4, it is characterised in that：The shape
State trigger module includes the first trigger and the second trigger, and the set end of first trigger connects the first comparator
Output end, reset terminal connects the output end of second comparator；The set end of second trigger connects the third
The output end of comparator, reset terminal connect the output end of the 4th comparator.
6. the superconducting quantum interference device Magnetic Sensor of high speed wide range according to claim 4, it is characterised in that：Described point
It includes the first~tetra- resistance for connecting the opamp input terminal to press network module, and the other end of the first resistor passes through
First switch connects the first bias supply, and the other end of the second resistance connects the second bias supply, institute by second switch
State the other end connection third bias supply of 3rd resistor, the other end ground connection of the 4th resistance.
7. a kind of superconducting quantum interference device detection method of high speed wide range, which is characterized in that the superconduction of the high speed wide range
Quantum interfering device detection method includes at least：
Tested magnetic flux is detected based on a magnetic flux lock-in circuit, and exports the loop output proportional to the tested magnetic flux
Voltage；
The loop output voltage is detected, the magnetic flux lock-in circuit is adjusted according to the state of the loop output voltage
Bias voltage, relock operating point after so that the magnetic flux lock-in circuit is zeroed；
The transitional states of the bias voltage are counted, realize the counting to flux quantum；
Eventually by the detection for synthesizing the loop output voltage and count value realization wide range.
8. the superconducting quantum interference device detection method of high speed wide range according to claim 7, it is characterised in that：Passing through will
The loop output voltage and the first reference voltage, the second reference voltage and reference no-voltage are compared to determine the biasing
The output valve of voltage, wherein first reference voltage is to input corresponding electricity when magnetic flux is the first n flux quantum of quantity
Pressure, second reference voltage are the negative of first reference voltage, and the first quantity n is natural number.
9. the superconducting quantum interference device detection method of high speed wide range according to claim 8, it is characterised in that：When described
When loop output voltage is more than first reference voltage, saltus step to the first working condition, then the bias voltage is more than SQUID
The maximum output voltage of superconducting ring, the loop output voltage are gradually reduced zero；Described in being less than when the loop output voltage
When the second reference voltage, saltus step to the second working condition, then minimum output of the bias voltage less than the SQUID superconducting rings
Voltage, the loop output voltage are gradually increasing zero；After the loop output voltage is zeroed, saltus step to third work shape
State, then the bias voltage is the bias voltage at SQUID superconducting rings operating point.
10. the superconducting quantum interference device detection method of high speed wide range according to claim 8, it is characterised in that：Work as institute
It carries out plus counts when stating loop output voltage more than first reference voltage, when the loop output voltage is less than described second
It carries out subtracting counting when reference voltage.
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| US10488469B2 (en) * | 2017-06-05 | 2019-11-26 | The Regents Of The University Of California | Magnetic flux control in superconducting devices |
| CN110109314B (en) * | 2019-04-29 | 2020-12-08 | 清华大学 | Time division multiplexing SQUID amplifier for superconducting transition edge detector array reading and preparation process thereof |
| CN111049503B (en) * | 2019-12-19 | 2021-10-22 | 中国科学院计算技术研究所 | Superconducting trigger and operation method thereof |
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