Performance Evaluation of CMUT-Based Ultrasonic Transformers for Galvanic Isolation.

Area of Science:

• Electrical Engineering
• Materials Science
• Acoustic Devices

Background:

• Traditional power switch triggering methods often lack sufficient galvanic isolation.
• The need for efficient and safe triggering mechanisms in power electronics is critical.
• Ultrasonic transducers offer a potential solution for signal transmission with isolation.

Purpose of the Study:

• To develop and characterize a novel acoustic transformer for high galvanic isolation in power switch triggering.
• To investigate the performance of a silicon-based acoustic transformer utilizing micromachined ultrasonic transducers.
• To explore optimization strategies for enhancing power efficiency and transmitted power.

Main Methods:

• Fabrication of a prototype acoustic transformer using two capacitive micromachined ultrasonic transducers on a silicon substrate.
• Characterization through electrical impedance and power efficiency measurements under various load conditions.
• Development and application of a finite-element method (FEM) model for simulation and optimization.

Main Results:

• Successful fabrication and characterization of an initial acoustic transformer prototype.
• Demonstrated high galvanic isolation capability for power switch triggering.
• Experimental results validated against FEM simulations.
• Identified optimization rules leading to a potential power efficiency increase from 35% to 60% and transmitted power increase from 1.6 to 45 mW/Volt.

Conclusions:

• The novel acoustic transformer design offers a promising solution for high galvanic isolation in power switch triggering.
• The developed FEM model accurately predicts performance and guides optimization.
• Significant improvements in power efficiency and transmitted power are achievable through optimization.