Investigation of langasite surface acoustic wave pressure sensors with a structure of reinforcing its pressure sensitivity

Langasite (LGS) surface acoustic wave (SAW) pressure sensor utilizing a structure of reinforcing the pressure sensitivity was analyzed in theory and experiments. The structure made pressure force applied to the substrate at one point to enlarge the deformation. Theoretical analysis combined the finite element method and the perturbation theory was adopted to analyze its pressure sensitivity. Experiments of SAW pressure sensor utilizing the reinforced structure based on Z-cut LGS cuts with propagation angles of 80° were done. The theoretical and experimental pressure sensitivity were about 0.046MHz/MPa and 0.040MHz/MPa respectively. Experimental results agree well with theoretical results, which demonstrate the accuracy of theoretical analysis of the reinforced LGS SAW pressure sensors.