Switched-Beam Planar Arrays Suitable for High-Resolution Acoustic Sounders

The study of arrays of loudspeaker elements suitable for high-resolution acoustic sounders is presented. Comparison of the predicted radiation patterns with measurements shows a good agreement in all cases examined. Emphasis is given in the case of a 3 × 3 switchedbeam piezoelectric tweeter antenna working at 3 kHz. The elements of this antenna are carefully chosen, to avoid problems resulting from random amplitude variations between the elements, while phase variations are taken into account and corrected when necessary.