An algorithm for the design of transformerless broadband equalizers of ultrasonic transducers

Abstract

A new design strategy for broadbanding ultrasonic transducers was recently presented, which generates a lossless equalizer, matching a resistive source to a piezoelectric transducer with power gain displaying a maximally flat (Butterworth) characteristic. However, three undesirable restrictions are part of the existing algorithm; (i) the center frequency of the design is fixed, limiting its usage to certain passbands, (ii) the design requires the use of an ideal transformer for all source resistance and tranducer combinations but one, and (iii) the resulting element values are often impractical. The purpose of this paper is to present a generalization of the algorithm which broadens its applicability. The main result is an algorithm for the design of a lossless transformerless broadband equalizer with maximally flat power gain, and a delineation of the exact latitude on passbands and source resistances.