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Convention Paper

Parametric Array Using Amplitude Modulated Pulse Trains: Experimental Evaluation of Beamforming and Single Sideband Modulation

Authors: Hahn, Nara; Ahrens, Jens; Andersson, Carl

AES Convention 151 · Paper 10541 · October 2021

Abstract

We present a parametric array system realized with a microcontroller and MOSFET drivers. Pulse train signals with fundamental frequency of 40 kHz are generated by the microcontroller. The pulse trains are amplitude modulated by exploiting the switching mechanism of the MOSFETs. The higher-order harmonics are attenuated by the band-pass characteristic of the ultrasonic transducers, emitting only the carrier frequency and the sideband components. The sound beam can be steered by applying phase shifts to the pulse signals, which can be implemented by relatively inexpensive hardware. A new single sideband modulation is also introduced, where the upper sidebands of two double sideband modulation signals are acoustically cancelled. The proposed approaches for beamforming and single sideband modulation are evaluated by anechoic measurements.

Details

Published in
AES Convention 151
AES Convention
151
Paper number
10541
Publication date
October 6, 2021
Session subject
Applications in audio
Affiliation
Institute of Communications Engineering, University of Rostock, Rostock, Germany; Division of Applied Acoustics, Chalmers University of Technology, Gothenburg, Sweden (See document for exact affiliation information.)
Type
Convention Paper