Suboptimal Class DE Operation for Ultrasound Transducer Arrays

Abstract

Recently, integrated class DE amplifiers without matching networks have been proposed as a compact solution to drive piezoelectric ultrasound transducers for high-intensity focused ultrasound (HIFU) therapy. However, when driving a transducer array, it is not always possible to drive all transducers in ideal Class DE conditions due to variations in the impedance of each array element. This paper outlines a method to predict switching losses and to select good driving parameters for an entire array without using matching networks. To the best of the authors knowledge, this is the first paper to present such a method. The method is experimentally validated using an integrated driver developed by the authors.