Charge-mode interfacing of piezoelectric interdigital Lamb wave transducers.

The adoption of charge-mode amplification, rather than the classical voltage-mode, to interface piezoelectric interdigital transducers made of polymer film to the data acquisition electronics is described. The circuit and operating principles of a charge amplifier are briefly explained, followed by the experimental comparison of a charge amplifier implementation with a solution based on an instrumentation amplifier. The experiments, based on A0-mode Lamb wave transmission over an aluminium plate, demonstrate the effectiveness of chargemode interfacing and its insensitivity to cable loading. [ABSTRACT FROM AUTHOR]