Title :
Characterization and assessment of an integrated matching layer for air-coupled ultrasonic applications
Author :
Kelly, Stephen P. ; Hayward, Gordon ; Alvarez-Arenas, Tomás E Gómez
Abstract :
A novel ultrasonic matching layer for improving coupling between piezoelectric transducers and an air load is presented and the results of a theoretical and experimental program of work are provided. A combination of a porous material that has very low acoustic impedance with a low-density rubber material forms the basis of the approach. These matching layers were first analyzed experimentally using scanning electron and optical microscopy to determine the microscopic structure. Air-coupled resonance measurements were then performed to reveal the acoustic parameters of the individual layers that were identified within this multilayered structure. These data were then incorporated into a conventional linear model, and this has been verified and used to study performance and produce designs. Close correlation between experiment and theory is demonstrated. The most efficient designs have been implemented in a pitch/catch air-coupled system, and an improvement in received signal amplitude of 30 dB was achieved when compared with the unmatched case.
Keywords :
acoustic impedance; impedance matching; multilayers; optical microscopy; piezoelectric transducers; porous materials; rubber; scanning electron microscopy; ultrasonic transducers; acoustic impedance; air-coupled resonance measurements; air-coupled ultrasonic applications; conventional linear model; integrated matching layer; low-density rubber material; microscopic structure; multilayered structure; optical microscopy; piezoelectric transducers; pitch-catch air-coupled system; porous material; scanning electron microscopy; ultrasonic matching layer; Acoustic applications; Acoustic materials; Electron optics; Impedance; Optical materials; Optical microscopy; Piezoelectric transducers; Resonance; Rubber; Scanning electron microscopy;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2004.1350960