Title

Orthogonal Frequency Coded SAW Sensors for Aerospace SHM Applications

Authors

Authors

W. C. Wilson; D. C. Malocha; N. Kozlovski; D. R. Gallagher; B. Fisher; J. Pavlina; N. Saldanha; D. Puccio;G. M. Atkinson

Abbreviated Journal Title

IEEE Sens. J.

Keywords

Orthogonal frequency code (OFC); structural health monitoring; surface; acoustic wave (SAW) detector; Engineering, Electrical & Electronic; Instruments & Instrumentation; Physics, Applied

Abstract

National Aeronautics and Space Administration (NASA) aeronautical programs require structural health monitoring (SHM) to ensure the safety of the crew and the vehicles. Future SHM sensors need to be small, lightweight, inexpensive, and wireless. Orthogonal frequency coded (OFC) surface acoustic wave (SAW) reflectors and transducers have been recently introduced for use in communication, as well as in sensor and radio-frequency identification (RFID) tag applications (Malocha et al., 2004, Puccio et al., 2004). The OFC SAW technology approach has been investigated by NASA for possible inclusion in ground, space flight, and space exploration sensor applications. In general, SAW technology has advantages over other potentially competitive technologies, because the devices can operate in ranges from cryogenic to furnace temperature. SAW devices can also be small, rugged, passive, wireless, and radiation hard and can operate with variable frequency and bandwidth. SAW sensor embodiments can provide onboard device sensor integration or can provide integration with an external sensor that uses the SAW device for encoding the sensor information and transmission to the receiver. SAW OFC device technology can provide RFID tags and sensors with low loss, large operating temperatures, and a multiuse sensor platform. This paper will discuss the key parameters for OFC device design, which includes reflector and transducer design, coding diversity approaches, and insertion loss considerations. Examples of several OFC device sensors and RFID tags are presented to show the current state-of-the-art performance for several NASA applications. Projections for future sensor and RFID tag platform performance are discussed, along with some of the current challenges and issues of the technology.

Journal Title

Ieee Sensors Journal

Volume

9

Issue/Number

11

Publication Date

1-1-2009

Document Type

Article

Language

English

First Page

1546

Last Page

1556

WOS Identifier

WOS:000270548800006

ISSN

1530-437X

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