Farfield performance of parametric transmitters

Since Westervelt's original proposal [J. Acoust. Soc. Am. 35, 535–537(1963)] that nonlinear acoustic interactions may be used to produce relatively narrow beams of sound at relatively low frequencies, a great deal of effort has gone into the study of parametric transmitting arrays, both experimentally and theoretically. In this paper, the behavior of such arrays in their farfield is studied, neglecting higher‐order interaction effects. Results are presented in the form of normalized curves and simplified equations which can be used for the preliminary design of such devices.