Numerical study of the cross-talk effects in acoustical transducer arrays and correction

Abstract

Cross-talk in acoustical transducer arrays is an undesirable phenomenon which decreases seriously the performances of these sensors. Indeed, when one element of the array is driven, it generates parasitic displacement fields at the radiating surfaces of the neighboring elements, which changes the directivity of the antenna. To well understand this phenomenon a transducer array similar to those used in medical imaging and NDT applications is modeled by finite element method. The research work, investigated systematically the effects of the cross-talk. First, it inspected the acoustical and mechanical cross-talk throughout the propagating medium and the filling material. Second, it studied the influence of the matching layer and the backing on the acoustical performances of the transducer. It is shown that the filling material and the matching layer are the major factor contributing to this phenomenon. In order to cancel the cross-talk a correction method previously developed by the author has been used. This solution consisted in applying adapted electrical voltages on each neighboring element of the active one in the purpose to reduce the displacement field on their active surface. This method was tested numerically and the obtained results clearly demonstrated its ability to reduce the cross-talk.