Orthogonal Frequency Coded SAW Sensors for Aerospace SHM Applications

    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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