Sensitivity improvement of SAW pressure sensors based on finite element analysis

This paper evaluates the influence of the geometry design on the sensitivity of SAW (surface acoustic wave) pressure sensors. The SAW propagation characteristics on the pressurized ST-x quartz diaphragm are simulated through the finite element analysis. The pressure sensitivities for different sensor configurations are obtained by studying the resonance frequency over a wide range of the operating pressure. It is found that the estimated sensitivity is almost linear with the frequency and accordingly the pressure sensitivity can be improved effectively by increasing the resonance frequency of the SAW resonators. Meanwhile, the simulation results show that a higher sensitivity can be achieved by the proper design of the number of IDT fingers, and the selection of the resonator location.