An ultrasonic Gaussian transducer with a spherical button electrode

An ultrasonic transducer with a Gaussian profile has been made by using a spherical button electrode. The theory behind this design is developed. In addition to ease of fabrication, this transducer combines the advantages of Gaussian transducers using electrical fringing and electrode shaping methods. The experimental results with a 2.03-MHz transducer with a 1-in diameter show that sidelobe suppression is at least 31 dB, and that the sound field agrees very well with the theoretical prediction.<>