SAW parameters for langasite at high temperatures

For three cuts of langasite with Euler angles (0°,138.5°,27°), (0°,22°,31°), and (0°,22°,90°) the temperature dependencies of SAW parameters - velocities, reflection coefficients and propagation loss were determined experimentally up to 800°C. For this, the test structures - delay lines and resonators, operating in the frequency range from 200 MHz up to 600 MHz, were designed and fabricated using Pt metallization. The influence of a passivation layer of Al
₂
O
₃
was investigated. The perspective for the use of the STW cut is discussed.