Radiated fields of rectangular air-coupled micromachined transducers
UNSPECIFIED (2001) Radiated fields of rectangular air-coupled micromachined transducers. In: IEEE International Ultrasonic Symposium, OCT 07-10, 2001, ATLANTA, GA.Full text not available from this repository.
The radiated fields of surface micromachined capacitive transducers, with single element sizes in the 2-5 mm range, have been measured experimentally. The transducers have been fabricated using a low temperature CMOS compatible process, and consist of a single metallised PECVD silicon nitride membrane (of typically 1 mum thickness), separated by a 1-2 mum air gap from a lower electrode on the silicon substrate. The radiated fields were plotted using a miniature micromachined detector, which was scanned through the radiated fields for both wide bandwidth excitation and tone burst operation. The fields of single elements were seen to have similarities to those expected from the theory for rectangular plane pistons in air over the 200 kHz - 2 MHz frequency range. Larger transducers were also fabricated from arrays of single elements, and the fields again scanned experimentally in air. The results illustrate the usefulness of this approach to the creation of highly directional ultrasonic beams in air. Comparison to theoretical fields in each case demonstrates that the devices are well characterized in terms of their emitted beam patterns.
|Item Type:||Conference Item (UNSPECIFIED)|
|Subjects:||T Technology > TA Engineering (General). Civil engineering (General)
T Technology > TK Electrical engineering. Electronics Nuclear engineering
Q Science > QC Physics
|Series Name:||ULTRASONICS SYMPOSIUM|
|Journal or Publication Title:||2001 IEEE ULTRASONICS SYMPOSIUM PROCEEDINGS, VOLS 1 AND 2|
|Editor:||Yuhas, DE and Schneider, SC|
|Number of Pages:||4|
|Page Range:||pp. 891-894|
|Title of Event:||IEEE International Ultrasonic Symposium|
|Location of Event:||ATLANTA, GA|
|Date(s) of Event:||OCT 07-10, 2001|
Actions (login required)