In this paper, ultrasonic air transducers which use the lowest order antisymmetric (A/sub 0/) mode Lamb waves in a thin plate as a means of efficient coupling of ultrasonic energy to air are discussed. For a silicon plate ...

The successful fabrication of ultrasonic immersion transducers is reported. Transducers are observed to operate from 1 MHz to 20 MHz in water, with the frequency range limited by electronics, not the transducers. Transmission ...

A new directional acoustic lens is introduced. The geometry is very similar to the line-focus lens except the lens cavity, which is shaped as a groove with flat-bottom V cross section. The slanted planar edges of the groove ...

A synthetic aperture acoustic imaging system with a novel inversion algorithm is described. Data is obtained by using a transducer insonifying the sample surface at a critical angle which is excited by a short electrical ...