access icon free Hyperbolically frequency modulated transducer in SAW sensors and tags

© The Institution of Engineering and Technology
Received 28/08/2013, Published

A linear frequency modulated transducer was earlier proposed for use in surface acoustic wave (SAW) tags and sensors. This reported work demonstrates that the hyperbolically frequency modulated (HFM) transducer has significant advantages for such devices often operating in a wide range of temperatures. The HFM transducer is practically insensitive to wide temperature variations, which expand or compress signals in time. Owing to the exponential change of the varying period with the electrode number, the expansion of the length of all the periods is equivalent to just a shift in time and the compressed signal remains practically unchanged in shape, just slightly shifted. Such a shift has no importance for SAW sensors/tags, which usually operate on the difference of delays of the compressed peaks.

Inspec keywords: frequency modulation; surface acoustic wave transducers; surface acoustic wave sensors

Other keywords: linear frequency modulated transducer; SAW sensors; electrode number; delays; SAW tags; length expansion; hyperbolically frequency modulated transducer

Subjects: Sonic and ultrasonic transducers and sensors; Transduction; devices for the generation and reproduction of sound; Acoustical measurements and instrumentation; Acoustic wave devices; Sensing devices and transducers

References

    1. 1)
      • 2. Harma, S., Plessky, V.P., Li, X., Hartogh, P.: ‘Feasibility of ultra-wideband SAW RFID tags meeting FCC rules’, IEEE Trans. Ultrason. Ferroelectr. Freq. Control, 2009, 56, (4), pp. 812–820 (doi: 10.1109/TUFFC.2009.1104).
    2. 2)
      • 1. Ianelli, Z., Koslar, M.: ‘Surface-wave transducer device and identification system with such device’. US patent, 6,788,204 B1, 7 September, 2004.
    3. 3)
      • 3. Lamothe, M., Plessky, V.: ‘Temperature measurements with ultra-wideband SAW sensors’. Proc. IEEE Ultrasonics Symp., Dresden, Germany, October 2012, pp. 2089–2093.
    4. 4)
      • 5. Morgan, D.P.: ‘Surface-wave devices for signal processing’ (Elsevier, Amsterdam, The Netherlands, 1985).
    5. 5)
      • 4. Thornton, M.J., Rhodes, J.D.: ‘Temperature-invariant pulse compression using S.A.W. devices’, Microw. Opt. Acoust., 1977, 1, (2), pp. 70–74 (doi: 10.1049/ij-moa.1977.0005).
http://iet.metastore.ingenta.com/content/journals/10.1049/el.2013.2815
Loading

Related content

content/journals/10.1049/el.2013.2815
pub_keyword,iet_inspecKeyword,pub_concept
6
6
Loading