| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface acoustic wave sensor capable of lessening influences of temperature changes, and provide a pressure measuring method of the surface acoustic wave sensor. SOLUTION: The surface acoustic wave sensor 1 includes oscillation circuits 11-14 and frequency mixers 21-24. The frequency mixer 21 outputs a frequency Fx1_T being a difference between output frequencies of the oscillation circuit 11 and the oscillation circuit 12, and the frequency mixer 22 outputs a frequency Fx2_T being a difference between output frequencies of the oscillation circuit 12 and the oscillation circuit 13, wherein a reference state is set so as to make following equality to be true: Fx2_0=Fx1_0. Furthermore, the third frequency mixer 23 outputs a frequency Fx3_T being a difference between output frequencies of the fourth oscillation circuit 14 and the second frequency mixer 22, wherein Fx3_T=Fx2_T-F4 is satisfied. The fourth frequency mixer 24 outputs a frequency being a difference between the frequency Fx1_T and the frequency Fx3_T. COPYRIGHT: (C)2010,JPO&INPIT |
