New Type of Acoustic Filter Using Periodic Polymer Layers for Measuring Audio Signal Components Excited by Amplitude-Modulated High-Intensity Ultrasonic Waves

摘要

A new acoustic filter that uses four polymer films with half-wavelength spacing was designed and used for detailed measurements of the audio signal components from amplitude-modulated high-intensity ultrasonic waves. The filter provided strong attenuation of the carrier frequency, which is a major cause of microphone nonlinearity. The measurements clearly showed parametric array effects from 300 to 8000 Hz and modulated radiation pressure above 30 Hz.