Novel limiter using biploar power transistors for high frequency ultrasonic transducer applications

Novel limiter circuit using bipolar power transistors for high frequency ultrasonic transducers is presented. The performances of the limiter such as magnitude response, noise figure and total harmonic distortion were measured. Furthermore, pulse-echo responses were obtained to compare the performances between novel limiter and commercial diode limiter with a 100MHz single element ultrasonic transducer. The wider -6dB bandwidth and higher amplitude of echo signals would be achieved with novel limiter.