Focal Size Reduction and Displacement in a Single-Element Biaxial Ring Transducer at 510 kHz and 1.66 MHz

The biaxial driving method is a technique where a transducer is driven by the application of two orthogonal dephased electric fields. It has been demonstrated that biaxial driving produces a steering response and an improved focalization on single-element transducers as a function of the phase and power applied between the electric fields. In this study, we present the capability of this method to reduce the focal area up to 66% and to produce a controlled focal displacement of 8 mm at different frequencies in a single-element PZT ring transducer.