Wideband Acoustic Data Transmission Through Staircase Piezoelectric Transducers

Ultrasounds have been investigated for data communication to transmit data across enclosed metallic structures affected by Faraday shielding. A typical channel consists in two piezoelectric transducers bonded across the structure, communicating through elastic mechanical waves. The rate of data communication is proportional to the transmission bandwidth, which can be widened by reducing the thickness of the transducers. However, thin transducers become brittle, difficult to bond and have a high capacitance that would draw a high electric current from function generators. This work focuses on investigating novel transducer shapes that would allow to provide a constant transmission across a large bandwidth while maintaining large-enough thickness to avoid brittleness and electrical impedance constraints. The transducers are shaped according to a staircase thickness distribution, whose geometry has been designed through an analytical model describing its electro-mechanical behavior formulated for this purpose.