title: Maximum accuracy evaluation scheme for wireless saw delay-line sensors.
abstract: This paper describes an evaluation scheme that prevents phase ambiguity of surface acoustic wave (SAW) delay-line sensors. Although it is well-known that phase evaluation yields accuracies of 150~1500 times higher than time-delay evaluation, the problem of phase ambiguity has prevented phase evaluation of sensors operating over a range larger than 2 pi. This paper addresses this unsolved problem with a complete strategy. Furthermore, the existence of an optimum choice of the relative reflector positions on the sensor is shown. The presented relations enable the design of maximum accuracy SAW delay-line sensors.
authors.affiliation: Dept. of Nanomech., Tohoku Univ., Sendai, Japan. jan@mems.mech.tohoku.ac.jp
authors.forename: J H
authors.initials: JH
authors.lastname: Kuypers
authors.forename: L M
authors.initials: LM
authors.lastname: Reindl
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Esashi
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D000465:Algorithms; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013686:Telemetry / Q000295:instrumentation*; D014159:Transducers