Radiated fields of rectangular air-coupled micromachined transducers

T. J. Robertson; A. Neild; D. A. Hutchins; J. S. McIntosh; D. R. Billson; R. A. Noble; R. R. Davies; L. Koker

doi:10.1109/ULTSYM.2001.991863

Radiated fields of rectangular air-coupled micromachined transducers

T. J. Robertson, A. Neild, D. A. Hutchins, J. S. McIntosh, D. R. Billson, R. A. Noble, R. R. Davies, L. Koker

Research output: Chapter in Book/Report/Conference proceeding › Conference Paper › Other

4 Citations (Scopus)

Abstract

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 μm thickness), separated by a 1-2 μm 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.

Original language	English
Title of host publication	Proceedings of the IEEE Ultrasonics Symposium
Publisher	IEEE, Institute of Electrical and Electronics Engineers
Pages	891-894
Number of pages	4
Volume	2
DOIs	https://doi.org/10.1109/ULTSYM.2001.991863
Publication status	Published - 2001
Externally published	Yes
Event	IEEE International Ultrasonics Symposium (IUS) 2001 - Atlanta, United States of America Duration: 7 Oct 2001 → 10 Oct 2001 https://ieeexplore.ieee.org/xpl/conhome/7781/proceeding

Publication series

Name	Proceedings of the IEEE Ultrasonics Symposium
ISSN (Print)	1051-0117

Conference

Conference	IEEE International Ultrasonics Symposium (IUS) 2001
Abbreviated title	IUS 2001
Country/Territory	United States of America
City	Atlanta
Period	7/10/01 → 10/10/01
Internet address	https://ieeexplore.ieee.org/xpl/conhome/7781/proceeding

Access to Document

10.1109/ULTSYM.2001.991863

Cite this

Robertson, T. J., Neild, A., Hutchins, D. A., McIntosh, J. S., Billson, D. R., Noble, R. A., Davies, R. R., & Koker, L. (2001). Radiated fields of rectangular air-coupled micromachined transducers. In Proceedings of the IEEE Ultrasonics Symposium (Vol. 2, pp. 891-894). (Proceedings of the IEEE Ultrasonics Symposium). IEEE, Institute of Electrical and Electronics Engineers. https://doi.org/10.1109/ULTSYM.2001.991863

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title = "Radiated fields of rectangular air-coupled micromachined transducers",

abstract = "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 μm thickness), separated by a 1-2 μm 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.",

author = "Robertson, {T. J.} and A. Neild and Hutchins, {D. A.} and McIntosh, {J. S.} and Billson, {D. R.} and Noble, {R. A.} and Davies, {R. R.} and L. Koker",

year = "2001",

doi = "10.1109/ULTSYM.2001.991863",

language = "English",

volume = "2",

series = "Proceedings of the IEEE Ultrasonics Symposium",

publisher = "IEEE, Institute of Electrical and Electronics Engineers",

pages = "891--894",

booktitle = "Proceedings of the IEEE Ultrasonics Symposium",

address = "United States of America",

note = "IEEE International Ultrasonics Symposium (IUS) 2001, IUS 2001 ; Conference date: 07-10-2001 Through 10-10-2001",

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Robertson, TJ, Neild, A, Hutchins, DA, McIntosh, JS, Billson, DR, Noble, RA, Davies, RR & Koker, L 2001, Radiated fields of rectangular air-coupled micromachined transducers. in Proceedings of the IEEE Ultrasonics Symposium. vol. 2, Proceedings of the IEEE Ultrasonics Symposium, IEEE, Institute of Electrical and Electronics Engineers, pp. 891-894, IEEE International Ultrasonics Symposium (IUS) 2001, Atlanta, Georgia, United States of America, 7/10/01. https://doi.org/10.1109/ULTSYM.2001.991863

Radiated fields of rectangular air-coupled micromachined transducers. / Robertson, T. J.; Neild, A.; Hutchins, D. A. et al.
Proceedings of the IEEE Ultrasonics Symposium. Vol. 2 IEEE, Institute of Electrical and Electronics Engineers, 2001. p. 891-894 (Proceedings of the IEEE Ultrasonics Symposium).

Research output: Chapter in Book/Report/Conference proceeding › Conference Paper › Other

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AB - 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 μm thickness), separated by a 1-2 μm 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.

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ER -

Radiated fields of rectangular air-coupled micromachined transducers

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