Expressions for the radiation of elliptical and bicylindrically focused piston transducers are derived within the Fresnel approximation. For the axial fields, the result takes the form of either a simple analytical expression (small perturbations from the circular piston case), a single quadrature in a real variable (unfocused and some focused cases), or a single quadrature in a complex variable (near focal points). The full fields are represented by a series of localized, Gauss–Hermite eigenfunctions. Numerical examples are used to illustrate the agreement of the two solutions for on‐axis fields and to shed light on questions of the convergence and the selection of initial scaling parameters of the Gauss–Hermite expansion.
Available at: http://works.bepress.com/rbruce_thompson/36/