Abstract: An ultrasound transducer is constructed to be under damped at higher overtone frequencies by reducing losses through one or more of the following: even pressure shaped surfaces on masses, reversed drive to at least one piezoelectric ceramic, an ultrasonically formed metallic bond between the transducer's front mass and the radiating surface, high current carrying strain relieved electrodes, fine grain structure masses, low internal friction masses and radiating materials, and zero bias stress change due to temperature variations. Improved methods and construction details for bonding the higher overtone frequency transducer to quartz are disclosed and include: front masses with cross-hatched or concentric circle patterns and invar front masses or an invar transition mass that is bonded to the quartz.

Abstract: A transducer includes a resonator assembly having a first surface and a second surface on opposite sides thereof, a front mass having a surface adjacent to the first surface of the resonator assembly, a back mass having a surface adjacent to the second surface of the resonator assembly, and a compression assembly mounted on the front mass and the back mass. The compression assembly is adapted to effect compression across the resonator assembly. At least one of the surfaces of the front mass and the back mass adjacent to the resonator assembly and first and second surfaces of the resonator assembly is curved when the compression assembly is not in the compression state, and when the compression assembly effects the compression across the resonator assembly, the transducer has a substantially constant pressure across the surfaces of the resonator assembly.