Journal or Book Title
Journal of the Acoustical Society of America
A spherically focused no mirrors capacitive-film, air-coupled ultrasonic transducer, constructed using a spherically deformed backplate and metalized polymer film, has been designed, fabricated, and its performance characterized. A 1 cm diameter device has a center frequency of 805 kHz and a 6 dB bandwidth of 760 kHz. Comparisons of field strength in the focal zone with theoretical calculations for a spherically focused piston show that the device achieves diffraction-limited focusing. The nominal focal point of 25 mm lies within 0.01 mm of the calculated value for this device.
Acoustical Society of America
Song, Junho; Chimenti, Dale E.; and Holland, Stephen D., "Spherically focused capacitive-film, air-coupled ultrasonic transducer" (2006). Aerospace Engineering Publications. 7.