Properties of radio frequency Rayleigh waves on langasite at elevated temperatures

The properties of Rayleigh waves operating both at radio frequency (RF) and at high temperatures (HT) on langasite crystal cuts with Euler angles of (0/spl deg/, 138.5/spl deg/, 26.6/spl deg/) and (0/spl deg/, 30.1/spl deg/, 26.6/spl deg/) are investigated. By evaluating the frequency response of surface acoustic wave (SAW) test devices the SAW velocity, the coupling factor, and the propagation attenuation have been determined experimentally in a temperature range from 20/spl deg/C to 500/spl deg/C. The SAW devices could be operated up to frequencies of 3 GHz. However, considering a future sensor application a limiting factor is a strong increase of the acoustic losses in conjunction with frequency and temperature.