Superdirectional Parametric Array Loudspeaker
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...
Guardado en:
| Autores principales: | , , , |
|---|---|
| Formato: | Artículo publishedVersion |
| Lenguaje: | Español |
| Publicado: |
FIUBA
2019
|
| Materias: | |
| Acceso en línea: | https://elektron.fi.uba.ar/elektron/article/view/56 https://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=elektron&d=56_oai |
| Aporte de: |
| Sumario: | 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. |
|---|