On Grating Lobe Elimination Of Difference Frequency In Parametric Loudspeaker
Chuang Shi, Woon‐Seng Gan · ePrints Soton (University of Southampton) · 2010
The parametric loudspeaker differs from other audio systems in its ability to create highly focused sound beam in air. This focused sound beam can be steered by adjusting a set of delays and weights of the ultrasonic transducer array (UTA), which is a component of parametric loudspeakers. In this paper, we use two ultrasonic primary signals to generate an audible signal at difference frequency. Grating lobes of primary signals occur when the spacing between ultrasonic transducers is larger than half the wavelength of primary signals, but grating lobes of the difference frequency are rarely observed. Therefore, in this paper, we examine this phenomenon and provide an analytical explanation.