Advanced Piezoelectric Transduction for Acoustic Sensing and Data Transmission

Abstract

The work developed in this thesis targets two applications relative to piezoelectric transduction for sensing and data transmission purposes. The first project is based on a Surface Acoustic Wave device measuring strains in two directions along a plane. Such a device has been manufactured using microfabrication methods and tested on a loaded beam to determine its accuracy, while comparing the experimental output with the expected theoretical results. The second project involves data transmission across a metallic barrier through piezoelectric transduction. A theoretical model has been derived to describe the electric and mechanical behaviors of the channels before comparing it with numerical and experimental results. Different approaches modifying the mechanical structure and the connected electric circuits have been pursued with the objective of reducing the amplitude variations down to 2 dB over large bandwidths for low carrier frequencies (below 10MHz). Transducer designs in the shape of staircases have been proposed for channels with high carrier frequencies (above 100 MHz) in order to communicate over bandwidths larger than 100 MHz within which the amplitude variations are limited to 3 dB.