1.5-D ultrasound transducer array characterization

The objective of this work was twofold. The first was to investigate theoretically and experimentally the acoustical and electrical parameters of 1.5-D ultrasound transducer arrays for 3-D imaging applications. Modeling and simulations of arrays of various geometry, center frequencies, and materials were performed, analyzed and optimized. The optimization criteria was the best achievable lateral and elevation imaging resolution. The second objective was to fabricate several optimally designed prototypes of 1.5-D arrays, measure their acoustic fields in three dimensions, and characterize their performance. Investigated were such vitally important performance issues such as spatial resolution, acoustical and electrical crosstalk, matching techniques, electrical impedance and element size, pulse-echo bandwidth and sensitivity. In this paper results of the study on transducer dispersion and impedance is reported. It is shown that ceramic pillars of the correct aspect ratio must be used to define the active 1.5-D array elements