A novel directional ultrasonic radiator

A novel radiator capable of producing ultrasonic waves in water or in any other liquid has been developed for single- and double-plate configurations. The main component of the radiator consists of a cantilever plate on which a pair of piezoelectric ceramics are mounted. These, the so-called excitation gauges, are fixed on both sides of a thin rectangular plate near the clamped end. An alternating signal within a frequency range of 90 to 900 kHz is applied to the excitation gauges. The significant impedance mismatch between the plate and water results in standing waves developing on the plate. The direction of propagation of ultrasound in water is solely steered by the frequency of the applied signal