Patent ID: 8651230

Claim:
An ultrasonic waveguide-radiator having a total length formed from a predetermined material, comprising: a first cylindrical section having a first diameter and a first length, and including an entrance surface having an entrance cross-sectional area; a first transitional section acoustically coupled to the first cylindrical section having a first variable cross-section and a first transitional length; a second cylindrical section acoustically coupled to the first transitional section and having a second diameter and a second length; a second transitional section acoustically coupled to the second cylindrical section and having a second variable cross-section and a second transitional length; a third section acoustically coupled to the second transitional section and having a third length, and including an exit surface having an exit cross-sectional area; wherein the total length is equal to a multiple of one-half of the acoustic wavelength in the predetermined material accounting for phase velocity dispersion; wherein the length of said first transitional section is less than the value of ln(N)/k where N is the ratio of the first and second diameters of the first and second cylindrical sections, respectively, and k is the wave number representing the angular frequency of ultrasonic vibrations divided by the speed of sound in the predetermined material.