Gaussian ultrasonics: theory and practice

A novel way is presented to describe the diffraction field of a Gaussian source. The derivation does not require the parabolic approximation used by previous authors. An improved spherical button Gaussian transducer design is applied successfully to make kilohertz Gaussian transducers. An ultrasonic Gaussian transducer of 15.24 cm (6") diameter, operated at 267 kHz is tested intensively. The experimental results show that the sidelobe suppression is 35 db. Thus, the sound fields generated by Gaussian transducers agree very well with the theoretical predictions.