High Temperature SAW wireless sensors based on YCOB and Langasite

Abstract

High temperature SAW resonators were fabricated on YCa 4 O(BO 3 ) 3 substrates with cutting type of X-90° and Z-90° and langasite substrates with Euler angle of (0°, 138.5°, 117°) and (0°, 138.5°, 27°). The temperature characteristics of these resonators have been studied in this paper. The results show that resonators on all four substrates have high temperature stability up to 600 °C. The resonance frequency of the SAW resonators based on YCa 4 O(BO 3 ) 3 substrates decrease more linearly with temperature than those on langasite substrates. The temperature sensitivity of SAW resonator with Z-90° YCOB substrates and X-90° YCOB substrates are 21.22 kHz/°C and 13.44 kHz/°C, respectively. It suggests that YCa 4 O(BO 3 ) 3 with cutting type of Z-90° is suitable candidate for piezoelectric substrate used for sensors working in high temperature environment.