A kind of SAW Temperature Sensors based on multiple coupled device
Technical field
The present invention relates to a kind of temperature sensor, especially relate to a kind of SAW Temperature Sensors based on multiple coupled device.
Background technology
The development trend of current sensor technology mainly is:
1, from contact to contactless development, (band signal treatment circuit) future development from passive type to active formula.
2, realize multifunction, integrated and intelligent.Multifunction refers to that a sensor can detect a plurality of parameters, and integrated is to utilize the MEMS technology that sensitive element, processor are integrated on the chip; Intellectuality is that sensor is combined with ECU, has self-detection, memory and rated capacity.
3, in order to realize the information sharing of sensor, the Novel digital type sensor must have Embedded microprocessor, and what have requires digital output, is fit to the bus requests such as CAN Bus, LINBus.
And the SAW sensor is the pottery that continues; Always up-and-coming youngster after the semiconductor, the sensors such as optical fiber.The sensor that general pottery or semiconductor material are made adopts resistance-type or condenser type mostly.With mini signal output, need through mould/number conversion ability and computer interface; And the sensor that the SAW technology is made, during work, signal output do not need through A/D (mould/number) change just can with computer interface, thereby precision is high.SAW Temperature Sensors based on multiple coupled device can repeatedly be coupled by fiber coupler, can obtain simultaneously different temperature values, measures simultaneously.
Summary of the invention
Purpose of the present invention be exactly provide a kind of high precision, high sensitivity in order to overcome the defective that above-mentioned prior art exists, be convenient to produce in enormous quantities, volume is little, lightweight, low in energy consumption, processability of product structure the is good SAW Temperature Sensors based on multiple coupled device.
Purpose of the present invention can be achieved through the following technical solutions:
A kind of SAW Temperature Sensors based on multiple coupled device, it is characterized in that, comprise surface acoustic wave input end, electrical to optical converter, fiber coupler, photoelectric commutator, surface acoustic wave output terminal, described photoelectric commutator, surface acoustic wave output terminal are equipped with two, described surface acoustic wave input end, electrical to optical converter, fiber coupler connect successively, described fiber coupler is connected with two photoelectric commutators respectively, and described two photoelectric commutators connect with corresponding surface acoustic wave output terminal respectively; One of them of two surface acoustic wave output terminals is provided with the responsive to temperature film.
Described surface acoustic wave input end comprises first input end power supply, the first input interdigital transducer, first input end wire, the first output interdigital transducer and the first output terminal, described first input end power supply is connected with the first input interdigital transducer by the first input end wire, and described the first output interdigital transducer is connected with the first output terminal.
Described the first input interdigital transducer upper end is connected with the positive pole of first input end power supply, and described the first input interdigital transducer lower end is connected with the negative pole of first input end power supply.
Described electrical to optical converter comprises resistance R 211, resistance R 212, resistance R 213, capacitor C 22, slide rheostat R23, photodiode D24 and transistor Q25;
Described transistor Q25 comprises base stage, collector and emitter, described base stage is connected with capacitor C 22 1 ends, resistance R 213 1 ends, slide rheostat R23 one end respectively, described collector is connected with the negative pole of photodiode D24, and described emitter is by resistance R 212 ground connection;
Described capacitor C 22 other ends are by resistance R 211 ground connection, and described resistance R 213 other ends are connected with the positive pole of photodiode D24, described slide rheostat R23 other end ground connection.
Described fiber coupler comprises optical fiber and polygon prism.
Described photoelectric commutator comprises capacitor C 411, capacitor C 412, resistance R 42, amplifier and photodiode D44, described photodiode D44 plus earth, the electrode input end of described photodiode D44 negative pole and amplifier, the negative input ground connection of described amplifier, described capacitor C 412, resistance R 42 all are connected in parallel on amplifier anode input end and the amplifier out, and described amplifier out is connected with capacitor C 411.
Described surface acoustic wave output terminal comprises the second input end power supply, the second input interdigital transducer and the second output interdigital transducer, and described the second input end power supply is connected with the second input interdigital transducer.
Compared with prior art, the present invention has the following advantages:
1) high precision, high sensitivity: sensor of the present invention is the always up-and-coming youngster after the sensors such as pottery, semiconductor, optical fiber, and the sensor that general pottery or semiconductor material are made adopts resistance-type or condenser type mostly.With mini signal output, need through mould/number conversion ability and computer interface; And the sensor that the technology of the present invention is made, during work, signal output do not need through A/D (mould/number) change just can with computer interface, thereby precision is high.
2) be convenient to produce in enormous quantities: the critical component that sensor of the present invention is red---SAW resonator or lag line, adopt the semiconductor planar manufacture craft, very easily integrated, integrated, various functional circuits are combination and simplification easily, sound construction, steady quality, repeatability and good reliability.Being easy to produce in enormous quantities, is the electronic technology development, for installing and package technique all provides easily condition on the surface.
3) volume is little, lightweight, low in energy consumption: from theoretical analysis as can be known, the concentration of energy of product of the present invention more than 90% is in the degree of depth apart from about the wavelength in surface, thereby loss is low; Add that the SAW sensor circuit is simple, so the power consumption of whole sensor is very little.
4) processability of product structure is good: sensor of the present invention is planar structure, flexible design; The sheet profile is easy to combination; Can realize more easily monolithic multifunction, intellectuality; Install easily, and can obtain good thermal behavior and mechanical property.
5) can repeatedly be coupled, can obtain simultaneously different temperature values, measure simultaneously.
Description of drawings
Fig. 1 is structural representation of the present invention;
Fig. 2 is the structural representation of surface acoustic wave input end of the present invention;
Fig. 3 is the electrical block diagram of invention electrical to optical converter;
Fig. 4 is the structural representation of invention fiber coupler;
Fig. 5 is the electrical block diagram of photoelectric commutator of the present invention;
Fig. 6 is the structural representation of surface acoustic wave output terminal of the present invention.
Embodiment
The present invention is described in detail below in conjunction with the drawings and specific embodiments.
Embodiment
As shown in Figure 1, a kind of SAW Temperature Sensors based on multiple coupled device, comprise surface acoustic wave input end 1, electrical to optical converter 2, fiber coupler 3, photoelectric commutator 4, surface acoustic wave output terminal 5, described photoelectric commutator 4, surface acoustic wave output terminal 5 are equipped with two, and connect one to one; One of them of two surface acoustic wave output terminals 5 is provided with responsive to temperature film 6.Electric signal obtains different output waveforms after containing responsive to temperature film and the output terminal that does not contain the responsive to temperature film, by waveform is weighted, thereby finally judge size and the temperature difference of temperature.
As shown in Figure 2, described surface acoustic wave input end 1 comprises first input end power supply 11, the first input interdigital transducer, first input end wire 14, the first output interdigital transducer 15, the first output terminal 16, described first input end power supply 11 is connected with the first input interdigital transducer by first input end wire 14, and described the first output interdigital transducer 15 is connected with the first output terminal 16.
Described the first input interdigital transducer upper end 12 is connected with the positive pole of first input end power supply 11, and described first inputs interdigital transducer lower end 13 is connected with the negative pole of first input end power supply 11.
As shown in Figure 3, described electrical to optical converter 2 comprises resistance R 211, resistance R 212, resistance R 213, capacitor C 22, slide rheostat R23, photodiode D24, transistor Q25; Described transistor Q25 comprises base stage, collector, emitter, described base stage is connected with capacitor C 22 1 ends, resistance R 213 1 ends, slide rheostat R23 one end respectively, described collector is connected with the negative pole of photodiode D24, and described emitter is by resistance R 212 ground connection; Described capacitor C 22 other ends are by resistance R 211 ground connection, and described resistance R 213 other ends are connected with the positive pole of photodiode D24, described slide rheostat R23 other end ground connection.
As shown in Figure 3, described fiber coupler 3 comprises optical fiber 31, polygon prism 32, and described polygon prism 32 is located in the optical fiber 31.
As shown in Figure 4, described photoelectric commutator 4 comprises capacitor C 411, capacitor C 412, resistance R 42, amplifier 43, photodiode D44, described photodiode D44 plus earth, the electrode input end of described photodiode D44 negative pole and amplifier 43, the negative input ground connection of described amplifier 43, described capacitor C 412, resistance R 42 all are connected in parallel on amplifier 43 electrode input ends and amplifier 43 output terminals, and described amplifier 43 output terminals are connected with capacitor C 411.
As shown in Figure 5, described surface acoustic wave output terminal 5 comprises the second input end power supply 51, the 52, second input interdigital transducer lower end 53, the second input interdigital transducer upper end, the 54, second output interdigital transducer lower end 55, the second output interdigital transducer upper end, and described the second input end power supply 51 is connected with the second input interdigital transducer.