Kuypers J H, Reindl L M, Tanaka S, Esashi M
Dept. of Nanomech., Tohoku Univ., Sendai, Japan.
IEEE Trans Ultrason Ferroelectr Freq Control. 2008 Jul;55(7):1640-52. doi: 10.1109/TUFFC.2008.840.
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.
本文描述了一种防止表面声波（SAW）延迟线传感器相位模糊的评估方案。尽管众所周知，相位评估的精度比时延评估高150至1500倍，但相位模糊问题阻碍了工作范围大于2π的传感器的相位评估。本文用一种完整的策略解决了这个未解决的问题。此外，还表明了在传感器上存在相对反射器位置的最佳选择。所提出的关系有助于设计出精度最高的SAW延迟线传感器。
