CN110455423A - A kind of overlength distance low-power consumption temperature monitoring sensor - Google Patents
A kind of overlength distance low-power consumption temperature monitoring sensor Download PDFInfo
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- CN110455423A CN110455423A CN201910767384.2A CN201910767384A CN110455423A CN 110455423 A CN110455423 A CN 110455423A CN 201910767384 A CN201910767384 A CN 201910767384A CN 110455423 A CN110455423 A CN 110455423A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K1/00—Details of thermometers not specially adapted for particular types of thermometer
- G01K1/02—Means for indicating or recording specially adapted for thermometers
- G01K1/024—Means for indicating or recording specially adapted for thermometers for remote indication
Abstract
The present invention provides a kind of overlength distance low-power consumption temperature monitoring sensors, comprising: unidirectional interdigital transducer, frequency orthogonal reflecting grating chip set；The frequency orthogonal reflecting grating chip set, comprising: the n chips being arranged successively；The n chip constitutes a kind of sensor coding；Each chip is made of a kind of electrode in period, forms the reflection to a positive jiao zi frequency；The sub- frequency formed between the multiple chip is mutually orthogonal；The time domain length of each chip reflection signal is consistent, and meets orthogonality condition.The present invention also provides corresponding systems.Remote, Mulit-point Connection provided by the invention and jamproof surface acoustic wave sensor method solve " near-far interference " of the sensing system of code division multiplexing coding, can satisfy requirement of the smart grid to power equipment temperature monitoring while reducing power consumption.
Description
Technical field
The present invention relates to the temperature monitoring fields of power equipment, and in particular, to overlength distance low-power consumption temperature monitoring
Sensor and its system.
Background technique
In the numerous monitoring quantities of power equipment state monitoring, temperature is the most key one of detection limit.It is supervised by temperature
It surveys, can timely and accurately understand the operating status and fault message of power equipment.Monitor the running temperature of power equipment, such as transformation
The conductor temperature of the oil temperature of device, transmission line of electricity (overhead line and power cable) can calculate its load limit capacity and ageing equipment journey
Degree provides foundation to update for power equipment dynamic compatibilization or maintenance.Monitor rotor, the high-tension switch cabinet, mother of generator
The temperature of wire terminal, outdoor chopper switch, contact of breaker, capacitor, reactor, high-tension cable, transformer etc., can be in time
It was found that the adjoint overheat or Temperature Distribution relative anomalies partly or wholly when it abnormal conditions or failure occurs, it can also
Historical summary is provided for accident analysis.
It is existing mainly to have infrared measurement of temperature, wired thermometric and distributed optical fiber temperature measurement for power equipment temperature monitoring
Etc. technical solutions.Infrared measurement of temperature is affected by environmental condition factor, and scheme cost is also high；Wired thermometric scheme, now
It powers after generally battery or current transformer (CT) being taken to take electricity for thermometric chip, distance sensing is very remote.But in high temperature, surpass
Under the adverse circumstances such as low temperature, strong-electromagnetic field, the service life of battery and electronic component is problematic in that.Take the active of CT way to take power
Sensor can not also power under line fault conditions because CT takes the coil of electricity to have installation site requirement, and application equally has
Significant limitation.Optical fiber temperature-measurement belongs to wired thermometric mode, and the optical fiber or its sheath for measuring high voltage primary side exist over the ground
Insulating properties problem.Optical fiber has characteristic easy to break, easily broken simultaneously.In addition fibre optical sensor equipment manufacturing cost is higher.
Radio temperature sensor based on surface acoustic wave (surface acoustic wave, be abbreviated as SAW) technology utilizes
Be piezoelectric material, have pure passive, radio characteristics, regardless of sensor power supply, High-Voltage Insulation, equipment rotate etc. ask
Topic；Tolerable high temperature and low temperature (~-200~1000 DEG C)；Its transition process for not involving electronics in semiconductor material, service life
The interference performances such as long, anti-discharge impact and anti-electric field, magnetic field are strong；Size sensor is small (Centimeter Level), light-weight, is easy to structure and sets
Meter and installation.It can be seen that SAW wireless sensor technology provides one with before wide application for the temperature monitoring of power equipment
The desirable technique platform of scape.
But the SAW wireless sensing array developed at present can't be fully met in smart grid and extra-high voltage application to temperature
The demand of monitoring, the problem of showing, specifically include that
Problem 1: operating distance is inadequate.By taking the temperature monitoring of overhead transmission line dynamic compatibilization as an example, if being read with the SAW of installation
Device is the centre of sphere to consider, operating radius is at least at 30 meters or so.What Sengenuity company, the U.S. developed is used for switch cabinet temperature
The SAW wireless sensor thermometric operating distance of monitoring is only within 2 meters.German Brunsb ü ttel, Preussen Elektra is public
Department and Darmstadt polytechnical university the end of the nineties in last century develops be used for power transmission line, conductor oxidate arrester
And whether disconnecting switch combined floodgate waits the SAW wireless temperature measuring system operating distance of applications up to 10 meters in place, but will be in electricity
It is promoted and applied in power equipment monitoring, operating distance still needs to further increase.
Problem 2: while the temperature spot quantity of detection is inadequate.In transmission line of electricity monitoring, a backcrossing on same shaft tower is considered
The three-phase for flowing ultra-high-tension power transmission line considers multi circuit transmission lines with bar situation and conducting wire if installed on the connect power transmission line in tower two sides
Temperature model calculates situations such as needing carried out environment temperature monitoring, and the quantity of sensor is then at least at 7 or more.Transformer
The temperature monitoring of oil temperature, switch cabinet temperature and other power equipments requires to require number of sensors similar.The U.S.
Number of sensors (is adopted up to 6 in the SAW wireless sensing array for switch cabinet temperature monitor that Sengenuity company develops
It is 18 reachable after implementation space division multiplexing with 3 antennas), but 20MHz bandwidth is occupied, allow considerably beyond 433MHz frequency range
1.87MHz bandwidth requirement.The units such as the domestic Central China University of Science and Technology, Shanghai Communications University, University Of Chongqing and acoustics institute, the Chinese Academy of Sciences
The SAW wireless sensor of the electric power thermometric of development also belongs to the working method.
Problem 3: sensor interference free performance is to be improved.With the extensive use of wireless sensor in " smart grid ",
Sensor array is greatly increased by a possibility that sudden, in-band on-channel interference effect；In the various applications of " smart grid "
Under, the influences such as frequency selective fading, multipath effect, climatic environment of different scenes are also different, may cause passive biography
Sensor Radio Link interrupts, and measurement outlier is lost or caused since signal-to-noise ratio is very poor to echo data.These factors are all seriously
The reliability for influencing sensor array may cause false alarm even protective relaying maloperation and make.
In recent years, scholar proposes the SAW RF tag sensing technology scheme using orthogonal frequency coding (OFC).The program
The thought of orthogonal frequency division multiplexing in wireless telecommunications (OFDM) has been used for reference, can have been had efficiently against the frequency selective fading of channel
Conducive to the reliability for improving SAW sensor.Meanwhile every reflecting grating of SAW wireless sensor of OFC is all narrowband, substantially not
Reflect other orthogonal frequencies.Relative to reflection delay line style SAW sensor, the reflectivity of every reflecting grating is no longer only 10% left
Right (otherwise subsequent reflection grid will not receive inquiry pulse energy), but can achieve 40~50%.Only reflecting grating reflection damage
Consumption one, can reduce Insertion Loss 12-13dB using the SAW sensor of OFC.Orthogonal frequency coding is a kind of spread spectrum coding, similar
Radar is modulated in intrapulse information, sensor can increase 20log according to the number of chips N for including in every in demodulation10N's
Signal-to-noise ratio is conducive to the raising of operating distance.According to the literature, SAW RF tag (RFID) reading distance of OFC coding is reachable
60 meters.But there is also several difficult needs to overcome when the coding mode is used for temperature sensor:
Difficulty 1: because wanting temperature sensitive, therefore the piezoelectric material that low-temperature coefficient cannot be chosen as OFC-RFID is made
For substrate material.But due to temperature change, it is similar to OFDM in communication system and generates Doppler frequency shift, originally mutually orthogonal frequency
Condition be destroyed.When reader demodulates sensor information, relevant peaks performance varies with temperature range and increases and sharply decline.Text
The temperature-measuring range for offering report only has 55 degree.
Difficult 2:OFC itself does not have multiple access capability.SAW device be again it is pure passive, can only passively reflect inquiry letter
Number, and cannot actively control and when send or stop to send information.Reader is to inquire and reading simultaneously multiple OFC-SAW
When sensor, currently existing scheme is to be combined using time division multiplexing with OFC coding.But due to being limited to applicable wireless bandwidth
It (has been the limit, then long SAW propagation loss and diffraction loss will on 10 millimeters of long piezoelectric substrates with SAW substrate material length
It is so big that can not to receive) 8 kinds or more of sensor type difficult to realize.
Summary of the invention
For the defects in the prior art, the object of the present invention is to provide a kind of biographies of overlength distance low-power consumption temperature monitoring
Sensor and its system.
The sensor of the overlength distance low-power consumption temperature monitoring provided according to the present invention, comprising: unidirectional interdigital transducer, frequency
The orthogonal reflecting grating chip set of rate；
The frequency orthogonal reflecting grating chip set, comprising: the n chips being arranged successively；
The n chip constitutes a kind of sensor coding；
Each chip is made of a kind of electrode in period, forms the reflection to a positive jiao zi frequency；
The sub- frequency formed between the multiple chip is mutually orthogonal；
The time domain length of each chip reflection signal is consistent, and meets orthogonality condition.
Preferably, in each frequency orthogonal reflecting grating chip set, be respectively provided between adjacent chip one it is equal
Fixed delay τDIt fills as protection, to the superposition of different frequency signals and to influence each other to form partition in time domain space, presses down
Make the interference between each sub- frequency.
Preferably, the sensor is the sensor after optimizing as follows:
By Green's function combination finite element tool, optimize SAW sensor energy converter and reflection grid structure, reduces insertion damage
Consumption, specifically: according to lithium niobate base on piece different orientation, energy converter and open circuit, short circuit, floating finger formula reflecting grating in fundamental frequency and
Under secondary harmonics: finger number, metallization thickness, degree of metalization and floating finger topological weighting, position weighting and reflection, transmission are
Several amplitudes and Phase Changing calculates the anti-of reflecting grating under the conditions such as different finger numbers, metallization thickness, degree of metalization
Penetrate coefficient and transmission coefficient.Using its regularity, the identical SAW sensor of each quadrature frequency components reflection coefficient is designed.Benefit
With the temperature coefficient under Lagrangian description, Green's function is brought into, optimization becomes the temperature of each orthogonal frequency reflection characteristic
Change the minimum reflecting grating topological structure of slope, reduce influence of the temperature to reflectivity, guarantees sensor reading distance not with temperature
Degree is increased and is remarkably decreased.
The sensing system of the overlength distance low-power consumption temperature monitoring provided according to the present invention, including multiple claims 1
The sensor, wherein each not phase of sensor coding that frequency orthogonal reflecting grating chip set contained by different sensors is constituted
Together.
Preferably, in the sensor array that multiple sensors are constituted, each sensor encodes corresponding first chip institute
The sub- frequency formed is different, and the arrangement for the sub- frequency that the n-1 chip in back is formed uses random code, is based on carrier-in-interference
It is encoded than maximum precoding or Turbo code.
Compared with prior art, the present invention have it is following the utility model has the advantages that
The present invention proposes remote, Mulit-point Connection and jamproof surface acoustic wave wireless sensor side based on orthogonal frequency
Method is innovation, because the technology path can be by means of orthogonal frequency technology, the preferably nothing of solution code division multiplexing coding
" near-far interference " of source sensing system can read the farthest system of multiple passive SAW sensor operating distances simultaneously, meet
The requirement that smart grid monitors power equipment temperature wireless.In terms of specific technology path, there are study characteristics at two.One
It is that can lead to the problem of non-orthogonal after being affected by temperature for orthogonal frequency coding, the invention proposes increase between reflecting grating
The protection is filled not will form the reflection of each sub- frequency signal between each chip on certifiable SAW sensor and be interfered with each other,
Even each chip is influenced by temperature, and reflection frequency shifts, this section of time slot can also believe different frequency in time domain space
Number superposition and influence each other to form partition, the interference between each sub- frequency of inhibition.The second is utilizing the anti-of SAW device
When penetrating grid indicates orthogonal frequency coding, the present invention utilizes generalized green function combination finite element theory, Accurate Analysis sparse electrode
The physical problems such as reflection, transmission and scattering of the Rayleigh wave of the reflecting grating of composition under fundamental frequency and harmonics, solve the world
The disadvantages such as calculating speed is slow, bulk wave scattering computational accuracy is low in upper utilization fourier transform method.
Detailed description of the invention
Upon reading the detailed description of non-limiting embodiments with reference to the following drawings, other feature of the invention,
Objects and advantages will become more apparent upon:
Fig. 1 is to utilize the power equipment temperature monitoring scheme general frame of the invention based on OFC surface acoustic wave sensor；
Fig. 2 be multisensor code division multiplexing coding when-frequency characteristic；
Fig. 3 is the adaptive matched filter schematic diagram based on CDMA；
Fig. 4 is transmission line-oriented temperature monitoring sensor structure.
In figure:
101 be counterpart bolt；102 be the core of power transmission line；103 be screw；104 be microstrip antenna；105 be surface acoustic wave
Sensor；106 be the metal shell of power transmission line.
Specific embodiment
The present invention is described in detail combined with specific embodiments below.Following embodiment will be helpful to the technology of this field
Personnel further understand the present invention, but the invention is not limited in any way.It should be pointed out that the ordinary skill of this field
For personnel, without departing from the inventive concept of the premise, various modifications and improvements can be made.These belong to the present invention
Protection scope.
The present invention provides a kind of CDMAs (CDMA) to encode SAW (passive and wireless) the sensor skill combined with OFC
Art.CDMA is the good method for solving multiple access in mobile communication.But passive SAW sensor cannot be as communication equipment
Power equalization is initiatively carried out, i.e., when multiple sensors and reader have " near-far interference ", echo amplitude differs greatly, nothing
Method isolates the information of each sensor by related operation, therefore individually using the SAW sensor array of CDMA coding and not firm
With.If but orthogonal frequency is encoded and is combined with CDMA, it can be real first by estimating the frequency spectrum size of each orthogonal frequency
Then existing power equalization may be implemented multi-sensor information and separate one by one to solve.Due to this mode SAW sensor it is all
Reflection echo signal permission overlaps in time-domain, but when-frequency two-dimensional space can be very good to separate, in addition, designing
Sensor echo-signal the associated processing gain of code division multiplexing may be implemented again, can easily realize 8 kinds or more differences
Sensor.
The SAW sensor that orthogonal frequency combines coding with CDMA can be using different from current OFC- when carrying out thermometric
The demodulation method of SAW temperature sensor.On the one hand, SAW reflecting grating can be accurately calculated to each orthogonal frequency reflection characteristic with temperature
Variation relation is spent, therefrom the optimization reflecting grating topological structure minimum to temperature change slope to each orthogonal frequency reflection characteristic,
Influence of the temperature to reflectivity is reduced, guarantees sensor reading distance not as temperature increases and is remarkably decreased；On the other hand,
It can be using a kind of demodulation method according to the search of measurement temperature self-adaptation, matched filtering, while obtaining matching output
Obtain measured angle value.
For solution " smart grid " power equipment, especially demand of the extra-high voltage electric power equipment to temperature monitoring, the present invention
It proposes to encode the passive wireless acoustic surface wave method for sensing combined with CDMA based on orthogonal frequency, remote with realization,
The temperature monitoring of Mulit-point Connection measurement and high reliability.
The general frame for the monitoring system that can be realized using the present invention is illustrated below.
As shown in Figure 1, in the constructed power equipment temperature monitoring model space, comprising: reader, broad-band antenna, more
A surface acoustic wave sensor.Wherein, surface acoustic wave sensor includes: unidirectional interdigital transducer, frequency orthogonal reflecting grating chip set；
1~N of surface acoustic wave sensor Arbitrary distribution (monitors actual demand according to power equipment, N value can meet between 8 to 10 to be wanted
It asks).
Temperature monitoring signal processing flow is as follows:
Step 1: reader emits upper linear frequency modulation (upchirp) by broad-band antenna and inquires signal, and upper linear frequency modulation is looked into
It askes signal and propagates to surface acoustic wave sensor in strong electromagnetic channel A；
Step 2: surface acoustic wave sensor inquires signal according to upper linear frequency modulation by unidirectional interdigital transducer and receives OFC letter
Number and be converted into surface acoustic wave signal；
Step 3: surface acoustic wave signal being enabled to reflect by frequency orthogonal reflecting grating chip set and pass through unidirectional interdigital transducer
Form echo-signal；
Step 4: echo-signal propagates to reader in strong electromagnetic channel A, and reader is received by broad-band antenna
Echo-signal simultaneously carries out lower linear frequency modulation (downchirp)；
Step 5: reader carries out the echo-signal after lower linear frequency modulation the signal processing such as to demodulate, and carries out pass more
Sensor identification is extracted with temperature information.
Wherein, upper and lower linear frequency modulation can increase by 20~50 or so processing gain, be conducive to improve surface acoustic wave sensing
Device operating distance.
The technology path of OFC combination CDMA coding is illustrated below.
As shown in the lower right corner Fig. 1, surface acoustic wave sensor contains f0~f78 chip s simultaneously constitute a kind of coding, wherein code
Piece refers to chip.Wherein each chip is made of a kind of electrode in period again, forms the reflection to a positive jiao zi frequency；It is multiple
The sub- frequency formed between chip is mutually orthogonal.The number of electrode in each chip should be designed according to orthogonal frequency coding theory
Amount, to ensure that the time domain length of each chip reflection signal is consistent the (delay, τ on time response in corresponding diagram 1C), it is full
Sufficient orthogonality condition.The difference that puts in order of each chip, forms other codings.Such as: f in Fig. 16、f4、f0、f7、f1、f2、f5、f3's
It puts in order and constitutes a kind of coding；If pressing f4、f7、f6、f0、f1、f2、f3、f5Put in order, constitute another sensor.
There can be very high relevant peaks (theoretically to there are N when response device carries out auto-correlation computation according to orthogonal coding theory
The surface acoustic wave sensor of orthogonal frequency coding, handles echo-signal by way of compressing pulse, can form N2It handles again
Gain, in conjunction with upper and lower chirped processing gain 50, therefore can under transmission power and receiving sensitivity same case,
Greatly improve sensor wireless operating distance).And the device of two kinds of different codings is when carrying out computing cross-correlation, but has very low mutual
Relevant peaks.Present invention research emulation selects those, and the very low coding in cross-correlation peak forms a sensor array two-by-two, even if this
A little sensors respond the inquiry signal of reader simultaneously, and all aliasing together, still can be by code division multiplexing side in the time domain for echo
Method distinguishes.
An equal fixed delay τ is increased between each chip also can see that in Fig. 1D(protection filling).Increasing should
Protection is filled not will form the reflection of each sub- frequency signal between each chip on certifiable SAW sensor and be interfered with each other, i.e.,
It is that each chip is influenced by temperature, reflection frequency shifts, this section of time slot also can be in time domain space to different frequency signals
Superposition and influence each other to form partition, the interference between each sub- frequency of inhibition.
FUSION WITH MULTISENSOR DETECTION is identified below, offset estimation and the temperature detection based on adaptive matched filter are said
It is bright.
In order to realize the identification of multiple surface acoustic wave sensors, the discrimination of coding is improved in complex electromagnetic environment, it is right
For taking related operation to improve signal processing gain and personal identification method in echo signal processing, need to reduce each volume
Cross correlation between code signal, it is necessary to the spatial classification of the corresponding each sub- frequency chip of optimization.Possible aligning method can be borrowed
Mirror random code can reduce intersymbol interference based on the maximum precoding of Carrier interference ratio or Turbo code coding, guarantee at signal
Manage the raising of gain.The above method is also the multiple access principle of code division multiplexing.But the distance between multisensor and reader
In the case where not equal, the power and noise level of each sensor echo-signal are differed, only between elimination reader and sensor
" near-far interference ", the response of each sensor could be efficiently separated out under multisensor time domain response each other aliasing situation.
The sub- frequency of the first chip that the present invention encodes each sensor in array of saw sensors is different, then
The arrangement of n-1, face frequency is encoded using random code, based on the maximum precoding of Carrier interference ratio or Turbo code.It is solving
The increased time slot of institute equally works to sensor identification when intersymbol interference on sensor substrate.If delay, τDBelieve greater than modulation
Number and its echo-signal the sum of propagation time in the channel after sensor response, the ball domain if radius is 30 meters it is empty
Between, which is less than 200ns, then the time delay can guarantee reader when receiving multisensor echo-signal, and any sensor is returned
Second encoded signal of wave will not enter the first encoded signal time slot in time domain space.As shown in figure 3, f (t) is all
The superposition of sensor time domain response signal, g [(f- Δ fi), (t- τi), si] it is adaptive matched filter function, it is frequency shift (FS),
Time delay, the function of power match coefficient, best match coefficient (Δ fM, τM, sM) corresponding matching factor when being relevant peaks maximum
Value.Echo-signal first segment (τ after demodulationc+τD) in time slot, the signal of contained different frequency ingredient corresponds to different sensors.
It can tentatively identify in aliasing signal according to the signal of the first coding containing several sensor informations and these sensings in this way
The coding of device.The assessment that the present invention is composed according to each echo signal power carries out power equalization to different coding sensor.It is every at this time
The size accuracy of a sub- frequency frequency deviation is not high, it is impossible to be used in temperature detection, but can greatly reduce subsequent match filtering
Temperature search range, improve search efficiency.
It can then proceed in method shown in Fig. 3, gradually carry out adaptive matched filter, when a certain specific coding of generation
When the auto-correlation computation relevant peaks of the multiple sensor signals f (t) of matched signal g (f, s, t) and Time-domain aliasing reach maximum value, i.e.,
It can determine that the corresponding temperature value of the code sensor.Then another coding weight present in array echo signal is replaced again
Newly scanned for by Fig. 3.It should be noted that the matched signal g (f, s, t) generated appears to be a 2D signal, but wherein
Two independents variable all be temperature function respective value can determine that according to the temperature of search.Therefore plain speed is entirely searched
Degree can guarantee.
The optimization response of sensor is illustrated below.
To guarantee low-loss characterization of the orthogonal frequency coding on SAW sensor, primary study interdigital transducer of the present invention
The reflection characteristic and Frequency Response of Frequency Response, conversion efficiency and reflecting grating, and its parameter is optimized.Because of orthogonal frequency
The reflecting grating metallization thickness of rate coding is identical, but reflecting grating periodicity, reflecting electrode radical differ greatly, can be according to niobic acid
Different orientation, energy converter and open circuit, short circuit, floating finger formula reflecting grating are under fundamental frequency and secondary harmonics on lithium substrate: finger number,
Metallization thickness, degree of metalization and floating finger topological weighting, position weight amplitude and phase change with reflection, transmission coefficient
Rule calculates the reflection coefficient and transmission coefficient of reflecting grating under the conditions of different finger numbers, metallization thickness, degree of metalization etc..
To its regularity, to ensure to design the identical SAW sensor of each quadrature frequency components reflection coefficient.It is retouched using Lagrangian
Temperature coefficient under stating, brings Green's function into, anti-minimum to the temperature change slope of each orthogonal frequency reflection characteristic of optimization
Grid topological structure is penetrated, influence of the temperature to reflectivity is reduced, guarantees sensor reading distance not as temperature increases and significant
Decline.
In terms of sensor structure, sensor installation, sensor accuracy and dynamic should be comprehensively considered and eliminated and installed
The problems such as disturbing factors such as stress, reader drift of crystal oscillator temperature.Fig. 4 is the transmission line-oriented temperature detection sensing that the present invention takes
Device structure.The position of sensor installation as shown in Figure 4, can be contacted very well by metal with core, while passing through partiting thermal insulation material
Material is separated with outer cover metal, guarantees that temperature can follow the variation of core wire temperature well, while again will not be because of outer cover metal
Heat dissipation influences the precision of measurement.It is separated between microstrip antenna and Shell Plate with insulating materials, is fixed by screw.Utilize finite element
The thermal capacity and conductive structure of the tools such as software optimization sensor structure size and encapsulation.Improve sensor dynamic index.It passes
An important factor for encapsulation of sensor and lead are influence sensor stabilities, since SAW is very sensitive to quality load, dust,
The factors such as grease stain, humidity may make sensor entirely ineffective.How to pass through rationally to encapsulate and had both guaranteed that substrate surface was complete with the external world
Full isolation, and guarantee to be measured after sensor is installed and can efficiently be loaded on substrate, reach mechanically securely, anti-vibration resists
Impact, while thermal stress and package parasitics are avoided to the influence of sensing element and high frequency surface wave, it is surface wave sensor
It has to consider the problems of and solve when encapsulation.
In terms of Antenna Design, using micro-strip antenna form.It is built using full-wave simulation software Ansoft HFSS
Mould, the parameters such as reflection coefficient, gain, directional diagram and the impedance curve of simulation calculation antenna.Feed system it is correct design for
Aerial radiation is improved, receiving efficiency is highly important.The impedance of SAW device itself and the impedance of transmitting antenna can lead to
Microstrip feed network structure is crossed to realize matching.According to the impedance characteristic of antenna, microstrip balun feeder line is designed, antenna is made to exist
The gradual change of frequency band internal impedance is designed to 50 Ω.The frequency band of antenna is preliminary according to the characteristic of electric apparatus monitoring on-site electromagnetic interference signal
Select the 890MHz-940MHz in centre frequency for 915MHz.
That realizes according to the present invention realizes the noiseless synchronous read in 8-10 30 meters of sensor, temperature detection range-
50 DEG C~+150 DEG C, within detection error ± 1 DEG C.The operating distance of 915MHz wireless SAW sensor therein is up to 5 meters.
By reducing sensor reflection loss 12-13dB, upper and lower linear frequency modulation brings processing gain 50 multiplied by code division multiplexing demodulation process
Gain 64, two convert into 30dB altogether, and therefore, the operating distance of sensor, which is increased to 30 meters, to be achieved.
Specific embodiments of the present invention are described above.It is to be appreciated that the invention is not limited to above-mentioned
Particular implementation, those skilled in the art can make various deformations or amendments within the scope of the claims, this not shadow
Ring substantive content of the invention.
Claims (3)
1. a kind of overlength distance low-power consumption temperature monitoring sensor characterized by comprising unidirectional interdigital transducer, frequency are just
Hand over reflecting grating chip set；
The frequency orthogonal reflecting grating chip set, comprising: the n chips being arranged successively；The n chip constitutes a kind of sensor
Coding；
Each chip is made of a kind of electrode in period, forms the reflection to a positive jiao zi frequency；Shape between the n chip
At sub- frequency it is mutually orthogonal；
The time domain length of each chip reflection signal is consistent, and meets orthogonality condition；
In each frequency orthogonal reflecting grating chip set, an equal fixed delay τ is respectively provided between adjacent chipDMake
It is filled for protection, to the superposition of different frequency signals and to influence each other to form partition in time domain space, between each sub- frequency of inhibition
Interference；
The sensor is the sensor after optimizing as follows:
By Green's function combination finite element tool, optimization SAW sensor energy converter and reflection grid structure reduce insertion loss,
Specifically: according to lithium niobate base on piece different orientation, energy converter and open circuit, short circuit, floating finger formula reflecting grating in fundamental frequency and two
Under secondary harmonics: finger number, metallization thickness, degree of metalization and floating finger topological weighting, position weighting and reflection, transmission coefficient
Amplitude and Phase Changing, calculate the reflection coefficient of reflecting grating under the conditions of different finger numbers, metallization thickness, degree of metalization
And transmission coefficient；Using its regularity, the identical SAW sensor of each quadrature frequency components reflection coefficient is designed；It utilizes
Temperature coefficient under Lagrangian description, brings Green's function, temperature change of the optimization to each orthogonal frequency reflection characteristic into
The minimum reflecting grating topological structure of slope reduces influence of the temperature to reflectivity, guarantees sensor reading distance not with temperature
It increases and is remarkably decreased.
2. a kind of overlength distance low-power consumption temperature monitoring sensor system, which is characterized in that including multiple described in claim 1
Sensor, wherein the sensor coding that frequency orthogonal reflecting grating chip set contained by different sensors is constituted is different.
3. the sensing system of remote low-power consumption temperature monitoring according to claim 2, which is characterized in that in multiple biographies
In the sensor array that sensor is constituted, each sensor encodes corresponding first chip, and to be formed by sub- frequency different, and
The arrangement for the sub- frequency that n-1 chip is formed below using random code, based on the maximum precoding of Carrier interference ratio or
Turbo code coding.
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| CN116681023A (en) * | 2023-06-08 | 2023-09-01 | 合芯科技有限公司 | Waveform screening method and device based on green function |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8596862B1 (en) * | 2010-08-30 | 2013-12-03 | Sandia Corporation | Wireless passive radiation sensor |
| CN103868620A (en) * | 2014-03-03 | 2014-06-18 | 上海交通大学 | Sensor for use in long-distance passive wireless temperature monitoring of power equipment and system thereof |
| CN103868618A (en) * | 2014-03-03 | 2014-06-18 | 上海交通大学 | Multi-sensor recognition-based temperature detection system |
| CN103884447A (en) * | 2014-03-03 | 2014-06-25 | 上海交通大学 | SAW sensing method based on combination of code division multiple access and OFC coding |
| CN206517617U (en) * | 2016-09-22 | 2017-09-22 | 北京三清互联科技有限公司 | A kind of wireless sensor system for intelligent grid |
-
2019
- 2019-08-20 CN CN201910767384.2A patent/CN110455423A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8596862B1 (en) * | 2010-08-30 | 2013-12-03 | Sandia Corporation | Wireless passive radiation sensor |
| CN103868620A (en) * | 2014-03-03 | 2014-06-18 | 上海交通大学 | Sensor for use in long-distance passive wireless temperature monitoring of power equipment and system thereof |
| CN103868618A (en) * | 2014-03-03 | 2014-06-18 | 上海交通大学 | Multi-sensor recognition-based temperature detection system |
| CN103884447A (en) * | 2014-03-03 | 2014-06-25 | 上海交通大学 | SAW sensing method based on combination of code division multiple access and OFC coding |
| CN206517617U (en) * | 2016-09-22 | 2017-09-22 | 北京三清互联科技有限公司 | A kind of wireless sensor system for intelligent grid |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116681023A (en) * | 2023-06-08 | 2023-09-01 | 合芯科技有限公司 | Waveform screening method and device based on green function |
| CN116681023B (en) * | 2023-06-08 | 2024-04-09 | 合芯科技有限公司 | Waveform screening method and device based on green function |
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