New Design for Stable and Robust Resonators, and Wireless Temperature SAW Sensors Based on the Use of a Single SAW Resonator Taking Advantage of New Design Criteria

Surface acoustic wave (SAW) devices are often used to monitor environmental parameters such as temperature, pressure or stress for instance. In order to ensure the continuity of the frequency response versus these parameters - namely, to remove the effects of directivity, transducers working out of the Bragg conditions are studied. In other words, the electrical excitation of the transducer is no more the usual alternating of one electrode set at a given potential with another one connected to the ground. This solution can be used either to preserve the spectral purity of the device or, on the contrary to enhance the multimodal nature of the acoustic cavity. Actually this paper shows that it can be exploited to design monolithic temperature SAW sensors