Design And Application Solution Of Passive Wireless SAW Temperature Sensor

With the emergencing of the concept of IOT(internet of things), and the developmentof the Smart Grid, more and more attention is paid on the research of Sensors and sensortechnology day by day. SAW(surface acoustic wave) technology is an emerging diciplinewhich is mixed of acoustics and electricity. SAW sensors that based on SAW principleadvances in passive and wireless, strongly anti-interfere ability and miniaturization. Thereis almost nothing can replace the SAW sensor using in high temperature and high pressure,flammability and explosibility, strongly electropositive and strong magnetic,and high speedmovement environment.IDT(interdigital transducer) is the core of SAW device, thus the visual angle of theresearch working of passive wireless SAW sensor concentrates in improving theperformance of the IDT, such as increasing the Q factor to increase the energy storagecapacity of the transducer and increasing the side-lobe rejection to improve the reliabilityof the sensor.Aiming at this problems, the main work was done as follows.(1) The history and the current situation of SAW technology and the SAW temperaturesensor, the principle of SAW sensing, and the applications in diferent fields have beenstudied and analysised.(2) As the core of the SAW temperature sensor, the effect of geometrical structure to theworking performance of the IDT was reseached by theoretical and simulation analysis.Theremore, the diferent performances of diferent weighting functions to the side-loberejection of IDT were studied by simulation.(3) The effect of the property parameters of thepiezoelectric materials to the propagationproperty of the SAW was studied,and a kind of Y-cut quartz crystal was selected for theSAWtemperature sensor at last.(4) With the electode proceeding by apodised weighting based on Hamming function, ASAW temperature sensor was designed based on theoretical analysis and simulation. The performance of the SAW temperature sensor was tested, the test result was shownat last.(5) The working features of the SAW sensor was tested by building hardware and softwareplatform, and the application feasibility of the SAW temperature to the temperaturestatus of the Smart Grid.(6) Amming to the application in high voltage switchgear, the application resolution wasproposed at last.