Underwater single crystal piezocomposite transducer with extended usable frequency band.

A single crystal/epoxy 1-3 composite plate transducer with air backing and two acoustic matching layers was modelled, fabricated and compared to a similar PZT transducer. For the relevant underwater applications, the usable frequency band is restricted by reactive electrical power. The design goal was to provide an underwater transmitter that could be operated over a wide range of frequencies, but not necessarily create a single pulse spanning the entire frequency band. The thicknesses and the characteristic acoustic impedances of the matching layers were therefore optimized for a wide passband rather than a maximally flat passband. The resulting single crystal transducer had reactive power below 50 % in a frequency band 132 % wide relative to the center frequency.