Advanced Characterization of Surface Acoustic Wave Fields at High Temperature

The application of wireless surface acoustic wave (SAW) sensors is state of the art for several years. These sensors are capable of measuring physical quantities in harsh environments. Beside electrical characterization, the SAW wave field, i.e. the lateral distribution of surface normal displacement, gives significant information on the operation of SAW devices, so on loss evolution and the generation of parasitic modes. Knowledge of wave fields can also support custom design of SAW devices with special sensor functionality under extreme conditions. Here, we present for the first time results of in-situ wave field measurements in a SAW resonator device operated at high temperature.