Geometrical dispersion in spherically divergence Gaussian beam

Spatial characteristics of harmonic wave in the sound beams in a homogeneous medium without dispersion from spherically convex axial symmetric radiator with Gaussian amplitude distribution, are analyzed. Quasi-optical approximation for beams with a narrow angular spectrum is applied. Combined influence of geometrical divergence and diffraction on amplitude-phase structure of a field, on spatial dynamics of dispersive parameter and on phase distortions in a spectrum of a three-frequency wave is considered.