Superdirectional Parametric Array Loudspeaker
In: Revista Elektrón, Jg. 3 (2019), Heft 2, S. 58-66
Online
academicJournal
Zugriff:
In this work, a directional loudspeaker, also known as a parametric array loudspeaker (PAL), is designed and constructed. The operation is based on the phenomenon called self-demodulation that happens when high-frequency beams interact in a viscous medium, due to its non-linear properties. The sound obtained after the self-demodulation is formed in the beam of the ultrasonic carrier signal propagating beyond the absorption distance in which the carrier has been sufficiently attenuated. This generates a focused audible signal and therefore a directional polar pattern of narrow angle. In this paper two modulation methods are evaluated: double-sideband amplitude (AM-DBL) and pulse-width modulation (PWM). Its effect on directionality, sound pressure level and harmonic distortion is experimentally analyzed.
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Superdirectional Parametric Array Loudspeaker
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Autor/in / Beteiligte Person: | Axel Montes de Oca ; Verne, Santiago ; Vechiatti, Nilda ; Muravchik, Carlos |
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Zeitschrift: | Revista Elektrón, Jg. 3 (2019), Heft 2, S. 58-66 |
Veröffentlichung: | Universidad de Buenos Aires, 2019 |
Medientyp: | academicJournal |
ISSN: | 2525-0159 (print) |
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