Second harmonic distortion suppression of thermoacoustic transducer using square root circuit

Abstract

Suppression of the second harmonic distortion intrinsic to a thermoacoustic transducer was studied using a square root circuit. The thermoacoustic transducer used in this study is composed of aluminum film, polyimide, and graphite film in order for it to be thin and bendable. A theoretical model was developed to calculate the radiated sound pressure on the basis of a fundamental equation for the heat transfer between the transducer and surrounding air. A square root circuit was designed to enable real-time signal processing and the effectiveness of the circuit regarding the second harmonic distortion suppression was experimentally confirmed.