Power MOSFET-diode-based limiter for high-frequency ultrasound systems

Area of Science:

• Electrical Engineering
• Biomedical Engineering
• Ultrasound Technology

Background:

• Limiter circuits protect sensitive front-end electronics in ultrasound systems from high-voltage pulses.
• Traditional resistor-diode limiters are cost-effective but exhibit significant signal loss at high frequencies.
• High-frequency ultrasound applications require advanced limiter designs to maintain signal integrity.

Purpose of the Study:

• To introduce and evaluate a novel power MOSFET-diode-based limiter architecture for ultrasound imaging systems.
• To assess the performance of the new limiter in terms of insertion loss, total harmonic distortion, and response time.
• To compare the proposed limiter's efficacy against conventional designs, particularly at high operating frequencies.

Main Methods:

• Developed a power MOSFET-diode-based limiter circuit.
• Evaluated limiter performance metrics: insertion loss (IL), total harmonic distortion (THD), and response time (RT).
• Conducted comparative analysis against three conventional limiter designs and performed pulse-echo tests.

Main Results:

• The power MOSFET-diode limiter achieved the lowest insertion loss (-1.33 dB) and fastest response time (0.10 µs) at 70 MHz.
• It demonstrated the lowest suppressed output voltage (3.47 Vp-p) among tested limiters.
• Pulse-echo tests revealed a 130% increase in transducer sensitivity and 129% increase in bandwidth with the new limiter compared to resistor-diode limiters.

Conclusions:

• The power MOSFET-diode-based limiter offers superior performance over conventional designs, especially at high frequencies.
• This new architecture significantly reduces signal attenuation, enhancing ultrasound imaging system efficiency.
• The improved sensitivity and bandwidth indicate the potential of this limiter for advanced ultrasound applications.