Low side-lobe PVDF element using a space tapered electrode

This article describes an approach to hydrophone element design which results in a beam pattern with a low side-lobe structure. The method used is called space tapering. Space tapering simulates a conventional amplitude taper by varying the spacing of equally sized segments of electrode material. These segments are tied in parallel to produce the element output. Five prototype elements were fabricated on a single sheet of polyvinylidene difluoride (PVDF), two control elements, and three elements with increasing degrees of spatial tapering. The results show that, as the spatial density of the segments increase, the beam pattern approaches the ideal theoretical prediction.