An Edge-Bonded Surface Acoustic Wave Transducer Array

Abstract
A new type of transducer array has been designed and built for Imaging surface defect in metals such as aluminum. The array is formed by edge-bonding a piece of piezoelectric material to a substrate of the same material as the sample to be tested. The individual  elements in the array are formed by photolithography, and each element acts as an edge-bonded surface wave transducer. The array has 32 elements resonant at a center frequency of 3.1 MHz with a round trip 6 dB and a ±35°, 3 dB acceptance angle at its center frequency. A theory has been developed which predicts the angular response of the array accurately.