Research On SAW-RFID Tag In High-Temperature Environment

Surface Acoustic Wave（SAW）RFID is a kind of passive and wirelesstag. It has been used in a wide range of applications for showing theadvantages of long reading distance and better performance in harshenvironments. In some special field such as industry Internet of Things,Smart Grid, aerospace and military, RFID tag tends to operate in hightemperature environment.Compared to the commonly used IC tag, which could not be readeffectively when the temperature is higher than85℃, SAW tag showsapplication potential in high-temperature(250℃). Therefore, this papermainly research on the design and realization of SAW tag inhigh-temperature environment.First, the existing main problem on high-temperature applications ofSAW tag is analyzed, and the work in this paper centered on solving suchproblems. Based on the theoretical model, the frequency response of SAWtag is calculated. The calculation results provided the theoreticalfoundation for the impedance matching between tag and its antenna in hightemperature.Then, focused on the design of high-temperature SAW-RFID tag withnew packaging technology, some key issues existing in implementationprocess, such as high-temperature material, impedance matching betweenantenna and SAW tag etc. is researched. In addition, the identificationaccuracy in high temperature is improved by designing the reflectors totemperature compensate the SAW tag. The relationship of temperaturerange whichcould be compensated and maximum error of phasemeasurement by reader is calculated. After that, the experimental platform is built and the high-temperatureperformance of tag is experimented. The design was improved in theprocess of experiment. Then, the heat resistance of SAW tag is verified byanalyzing the results of the experiments that the tag can reach the targettemperature of250℃.