A concentric-ring equivalent phased array method to model fields of large axisymmetric ultrasound transducers

An equivalent concentric-ring ultrasound phased array method was developed to estimate ultrasonic continuous wave fields generated by axisymmetric single-source transducers. The method models a given source as a concentric-ring phased array by mathematically segmenting it into many rings and subsequently finding the amplitude and phase for each ring that produces an acoustic field similar to the field of the single-source transducer. The excitation source of each ring was calculated using an inverse technique based on complex pressure measurements along a radial line close to the source. The predicting abilities of the method are evaluated by comparing measured and estimated ultrasound fields for six different transducers. The results show that the concentric-ring equivalent phased array method (CREPAM) is able to estimate quantitatively the ultrasound fields generated by large axisymmetric planar and focused transducers.