ACOUSTIC DEVICE COMPRISING AN ADJUSTABLE PHOTONIC CRYSTAL MADE FROM PIEZOELECTRIC ELEMENTS

摘要

The invention concerns an acoustic device comprising a periodic photonic structure (1) having an adjustable band of prohibited charge frequencies appearing when an electrical charge displacement comes from an external electrical reference via an electrode, characterised in that it comprises: - a set of piezoelectric elements (2) connected mechanically in series, a piezoelectric element (2) comprising a piezoelectric material and being polarised in a polarisation direction (dpol), the polarisation directions of two successive elements (2) being parallel or antiparallel and said piezoelectric elements (2) being directed in a main direction (dprinc); - a set of electrodes (3) arranged between two adjacent piezoelectric elements (2) and perpendicular to the main direction; - the set of said electrodes comprising at least one subset of electrodes connected periodically to an external electrical reference (4); - said subset of electrodes being connected to the electrical reference (4) via an electrical circuit (5).