Transformerless Ultrasound Modem Frontend Using Resonant Filter for Voltage Boost

Abstract

In recent years, an increased interest in underwater communication has been observed. In the countless publications not only new methods of acoustic communication but also low cost designs of suitable modem platforms have been proposed. As modems that are commercially available either are not open enough to design new methods on or are simply too expensive. Many designs share a common design principle: The high voltage used to drive the ultrasound transducer is generated by a transformer. Core material, wire diameter and winding counts must be defined. A transformer can get large and heavy and is often a costly factor in a bill of material. This paper presents a full design concept on how to eliminate the use of transformers without sacrificing the ability to drive several hundred volts. As an example a 40 kHz system is shown but the design principle can be adapted to a wide range of transducers and frequency bands.