ELECTROACOUSTIC TRANSDUCER WITH PERIODIC FERROELECTRIC POLARIZATION PRODUCED ON A MICROMACHINED VERTICAL STRUCTURE

摘要

A piezoelectric and ferroelectric bulk wave transducer operating at a predetermined frequency includes a block of substrate, having a first thickness and in a first material, and a piezoelectric and ferroelectric transduction plate, having a length, a width and a second thickness, and in a second piezoelectric material, first and second metal electrodes covering the plate in the direction of the length thereof. The plate has first and second ferroelectric domains with alternating polarizations, distributed along the length of the plate according to a periodic pattern of pitch. The plate is attached perpendicularly to the block so that the width of the plate and the first thickness of the block are the same direction. The first and second material, the first thickness of the block, the length, the width, the second thickness, the pitch of the plate are configured for generating and trapping bulk waves at the operating frequency of the transducer, guided between both electrodes.