Acoustic performance of toroidal caps: A path to constant beam width transducers

Area of Science:

• Acoustics
• Transducer Technology
• Signal Processing

Background:

• Directional acoustic transducers typically exhibit frequency-dependent beam widths, limiting consistent directivity.
• Constant beam width transducers (CBTs) aim to maintain stable radiation patterns across a range of frequencies.
• Existing CBT designs face challenges in achieving stable, multidirectional sound emission.

Purpose of the Study:

• To present a novel continuous toroidal cap source for achieving constant beam width in acoustic transducers.
• To demonstrate frequency-independent, multidirectional sound radiation capabilities.
• To investigate the influence of geometrical parameters and shading techniques on transducer performance.

Main Methods:

• Development of a continuous toroidal cap source model.
• Parametric study of geometrical properties (e.g., toroidal dimensions).
• Evaluation of different shading techniques, including uniform and 2D cosine shading.

Main Results:

• The toroidal cap source successfully achieved a constant beam width pattern in both horizontal and vertical planes.
• 2D cosine shading demonstrated superior performance compared to uniform shading.
• The proposed design offers controlled and frequency-independent sound radiation.

Conclusions:

• The continuous toroidal cap source is a viable design for achieving constant beam width in acoustic transducers.
• The findings provide practical insights for the design of two-dimensional (2D) CBTs.
• This model is suitable for developing stable, multidirectional sound radiation systems for transducer matrices.