High-linearity surface acoustic wave delay line sensors: A comprehensive strategy for triple transition echo elimination.

Abstract

Triple transition echo (TTE) in surface acoustic wave (SAW) delay line sensors arises from multiple reflections within the device, generating spurious signals that interfere with the primary sensor response. We present a comprehensive approach to eliminate the TTE effect through simultaneous optimization of interdigital transducer configuration, input excitation signal characteristics, and output time window selection. The methodology is verified with an electronic implementation of the delay line sensor. Experimental results demonstrate that this strategy achieves complete temporal separation between the primary signal and TTE echoes. Implementation through a dedicated electronic system significantly improved the sensor linearity from 0.916 to 0.999 for temperature sensing applications and from 0.946 to 0.995 for mass loading measurements. The enhanced signal quality and measurement reliability make this method particularly valuable for high-precision SAW sensing applications.