Abstract: A slab of piezoelectric ceramic plated on all surfaces is bonded to quarter wavelength impedance matching layers of glass and plastic. The top surface of the ceramic is slotted and parallel cuts orthogonal to the slots are made through the ceramic and into the glass to delineate an array of elements each with a signal electrode between slots and a wrap-around ground electrode. After making ground connections and flying lead connections to the signal electrodes, the matching layers are fully cut through from the front. A covering or wear plate is attached to the front surface and a relatively large mass of acoustic damping material covers the backs of the elements.

Abstract: A linear transducer array for 90.degree. or other wide angle sector scans is covered by a body contacting wear plate made of a material such as filled silicone rubber or polyurethane epoxy in which the longitudinal sound velocity is equal to or less than that in the body and in which the acoustic impedance for longitudinal sound waves is approximately equal to that of the body. Refraction, if it occurs, enhances the field of view without reducing the transmission of acoustic energy. The wear plate provides mechanical support for a fragile front surface matched array.

Abstract: An ultrasonic transducer array with high sensitivity, for use in water tanks and with human subjects in steered beam imagers to make wide angle sector scans, has narrow transducer elements and one or more quarter-wavelength impedance matching layers on the front surface of each element. The matching layers as well as the piezoelectric ceramic are completely cut thorugh and guide acoustic energy incident at any angle to the ceramic. A continuous covering or wear plate is attached to the matching layers and a continuous damping material can cover the backs of the elements.