To improve image resolution of sandwich metal plate flaw, high sensitivity transducers are needed. We developed Broadband Short Pulse Single-Element Ultrasonic Focused Transducers (center frequencies in the 10~20 MHz range ) for Auto Ultrasonic Feature Imaging System (F-Scan). Lead Titanate (PbTiO_3) was selected for piezoelectric ceramics. The key material of acoustic lens and insertion are wolframium powders of different grain fineness. The ultrasonic focused acoustic field and focused spot diameter of tr...