A shaped PVDF hydrophone for producing low sidelobe beampatterns

The authors determine if a multi-wavelength continuous hydrophone, shaped to achieve low sidelobes, can produce desired sidelobes and beamwidths. Polyvinylidene fluoride (PVDF) was selected as the sensor material. Theoretical beampatterns are calculated for three different hydrophone shapes (or weighting functions). They are the rectangular aperture, the modified linear taper, and a -40 dB, 26-point Chebyshev aperture. The beampatterns are calculated using the summation of weighted discrete elements as an approximation. The approximation is validated by comparing the element summation results of the modified linear taper case to its exact solution using Fourier transforms. Measured beampatterns of a rectangular aperture hydrophone and a modified linear taper shaped hydrophone are compared to the theoretical beampatterns