A Numerical Optimization Method for Transducer Transfer Functions by the Linearity of the Phase Spectrum

Area of Science:

• Acoustics
• Materials Science
• Biomedical Engineering

Background:

• Conventional ultrasound transducer design methods struggle with complex structures.
• New imaging and therapeutic modalities necessitate advanced transducer designs.
• Numerical methods are crucial for optimizing complex transducer geometries.

Purpose of the Study:

• To develop a novel numerical method for designing and optimizing ultrasound transducers.
• To linearize the phase spectrum of transducer transfer functions for improved performance.
• To address challenges in material selection for optimized transducer components.

Main Methods:

• A mathematical theorem is used to develop a phase linearization technique.
• A gradient-based algorithm optimizes transducer parameters.
• Simulations are performed on a 4-MHz single-element imaging transducer with matching layers, bondlines, and electrodes.

Main Results:

• The linear phase method optimizes transducer design, resulting in a Gaussian-like magnitude spectrum.
• Time-sidelobe levels are reduced by over 15-dB compared to conventional transducers.
• The method effectively analyzes and compensates for resonant bondlines and identifies alternative material pairs.

Conclusions:

• The proposed linear phase method offers a powerful tool for designing complex ultrasound transducers.
• This approach enhances transducer performance, particularly in reducing time-sidelobe levels.
• The method facilitates material selection for matching layers, overcoming practical manufacturing challenges.