2015 Volume 36 Issue 3 Pages 216-224
The generation of high-intensity aerial ultrasonic waves is achieved by focusing the acoustic waves radiated from a vibration plate into a point. We developed a new point-converging source of high-intensity aerial ultrasonic waves that comprises a striped-mode rectangular vibrating plate to radiate an aerial ultrasonic wave with high efficiency and paraboloid reflectors. The roughness corresponds to the stripe interval arranged on the surface of the paraboloid reflector. The roughness difference depends on the wavelength of the sound wave. The new convergence method that we propose can converge all ultrasonic waves radiated by the vibrating plate. In addition, the reflectors used to converge the radiated ultrasonic waves are characterized by a much simpler construction than the conventional reflectors. The ultrasonic source fabricated on an experimental basis produced the maximum ultrasonic pressure of about 15,000 Pa (178 dB) at the supplied electric power of 50 W.
