Frequency-Agile High-Power-Density Transducers: Draft/Final Technical Report.

Abstract : This report documents a design study aimed at producing broader bandwidth, high- power transducers for Navy applications in littoral waters. The top-to-bottom study included both ceramic driver processing and the transducer design itself. Active Signal Technologies and Alfred University investigated a novel processing method involving coating the ceramic particles prior to densification and it substantially increased the room-temperature electrically-induced strains available from the ceramic without significantly increasing dielectric loss. This strain increase could translate to a >3-dB increase in power density for the broadband transducers. Active Signal investigated a range of transducer classes including Class IV and VII Flextensional, Tonpilz, Moment Bender, Flexural Disk, and Split Cylinder. Substituting graphite-epoxy for aluminum in the radiating surface produced ^ 30% increases in bandwidth in most of the classes. With this and other parametric adjustments, designs that met feasibility criteria (power, efficiency, depth dependence, etc.) but had fractional bandwidths > 80% were prepared. The recommended design was a graphite-epoxy Class-TV Flextensional.