1.5 dimensional arrays for effective dynamic focusing and receiving

The traditional one dimensional (1-D) array transducers can produce thin slices only within a fixed focal zone. 1.5-D arrays, however, provide the capability of performing dynamic focusing and receiving to change focal zone by varying elevational apertures. This paper demonstrates improved elevational beam pattern by using an advanced 1.5-D phased array consisting of over 400 array elements. Discussions on design criterion, simulation results and acoustic performance of the array are presented. A computer code is developed to optimize the design of elevational apertures for the 1.5-D array with or without an acoustic lens. The optimization of elevational apertures for the 1.5-D array is determined based on simulation results that show smooth transitions of beam pattern between focal zones associated with different elevational apertures. Experimental results for beam profile and acoustic performance of the array are obtained by using needle hydrophone and reflector measurements