Electrical method for crosstalk cancellation in transducer arrays

摘要

In this paper, we report a new and simple electrical method to cancel crosstalk in the acoustical arrays. This solution has several advantages compared with that proposed in a previous paper (Bybi et al 2013) [17] where adapted electrical voltages were applied to each neighboring element of the active element in order to reduce the displacement field on their active surface. Firstly, it allows obtaining accurate correction electrical voltages, since it requires average electrical measurements (impedance and current measurements) instead of the displacement measurement in each point at the surface of the radiated element In addition to this, the method does not need a laser vibrometer which is expensive in terms of time and difficult to use accurately for displacement measurement in water. To demonstrate the ability of the proposed solution an array composed of seven-elements, similar to those used in medical imaging and NDT applications, made of a conventional piezo-ceramic material PZT-27 is fabricated. Then an electrical method based on electromechanical equivalent circuits for piezoelectric materials and motional current measurements is applied. The experimental and numerical results obtained demonstrate the ability of the proposed technique to reduce crosstalk as well as its robustness and ease of implementation.