| 摘要 |
<p>An acoustic transducer apparatus comprises a piezoelectric resonator stack which contains active piezoelectric layers (20,20B,20C,20D,20E,20F), internal conductive electrodes (22A,22B,22C,22D,22E,22F), internal bonding layers (25A,25B,25C,25D), and an optional internal dielectric layer (24A,24B). The electrodes may be connected to provide alternating polarization directions, or any other desired sequence of polarization directions, in the sequence of piezoelectric layers. An optional edge dielectric layer (21A,21B,21C,21D,21E,21F), positioned between side electrodes (23A,23B) and adjacent piezoelectric layers, controls the fringe electrical fields and the lateral piezoelectric modes that would otherwise develop. The piezoelectric layers may have uniform thicknesses with independently selected polarization direction within each piezoelectric layer. Alternatively, the individual piezoelectric layers may have non-uniform thicknesses tn and independently selected polarization direction within each layer. <IMAGE></p> |
