1 Dand 2 D-Sparse-Array-Optimization

3D-ultrasonic imaging can be achieved by steering conventional single-element-scanners (pseudo 3D imaging). The use of 2D arrays offers a wide range of possibilities, which will lead beyond the limitations of pseudo 3D imaging. The introduction to market of a high-end ultrasonic device for real 3D imaging was announced for fall 97. The transducer of this device is a electronically steered and focused 2D sparse array, which uses only a fraction of the channels required for a fully sampled array. The distribution of the reduced number of channels can be optimized by the use of different methods to achieve acceptable properties for the radiation pattern. An improved genetic algorithm for sparse array optimization will be presented. For a linear array the optimization results according to this algorithm and two other methods have been compared to measurements and were presented in [1]. For a 2D-array the optimization results of the improved algorithm will be presented.