| 摘要 |
PROBLEM TO BE SOLVED: To extend the measurable range of physical amounts without changing the length of the propagation path of a surface acoustic wave(SAW) element.SOLUTION: This SAW sensor includes: a SAW element (11); and a sensing device (12) for detecting the phase angle of a SAW detected by the SAW element. Also, the sensing device includes: a signal source (30) for generating a burst signal to be input to the SAW element; and a phase angle calculation section (35) for calculating a phase angle from the burst signal and a detection signal output after the burst signal is delayed by the SAW element. Then, the signal source generates a first signal having a predetermined frequency and a second signal having a frequency different from that of the first signal as a burst signal. Also, the phase angle calculation section includes a difference processing section (36) for calculating a difference between a first phase angle obtained from the first signal and a second phase angle obtained from the second signal among the phase angles. |
