P1D-5 A Periodicity Break Technique in 1D Array without Eliminated Elements Using cMUTs Technology for the Layout

The use of technologies of capacitive micromachined ultrasonic transducers (cMUTs) offers a new way of development ultrasonic transducers. They are built using standard silicon integrated circuit fabrication technology, and this permits to integrate electronic components in the probes, and a more flexible layout of the array elements. If the distribution of the elements of such arrays is periodic, and separated more than lambda/2, grating lobes will appear and the maximum scan angle will be limited. The flexibility in cMUT technology allows break the periodicity of the arrays and avoids suffering of grating lobes or limitations in scan angles. In this respect, the periodicity in the distances between elements of the array is the main contribution to growing of grating lobes for this reason we propose break this periodicity, without eliminating elements in the array, in order to reduce them. In order to accomplish this goal we use genetic algorithms (NSGA-II) for the array optimization, which allows us to find a suitable layout elements reducing grating lobes.