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 charge‐mode interfacing and its insensitivity to cable loading. [ABSTRACT FROM AUTHOR]