SHORTENING AND STANDARDIZING THE PULSE SHAPE OF PIEZOELECTRIC TRANSDUCERS IN THE MEGAHERTZ REGION

The optimization of ultrasonic pulse shape by digitally generated excitation functions is demonstrated. Experiments show correspondence of objective function and measured pulse shape. Shortening of pulses down to 1/5 of “natural” −20 dB width was achieved. The enhanced axial resolution can be useful in nondestructive testing and medical diagnosis with ultrasonics.