| 摘要 |
PROBLEM TO BE SOLVED: To accurately detect tire information such as pneumatic pressure, for example, while reducing an influence other than the tire information desired to be measured. SOLUTION: A transponder 10 is provided with an antenna 11, a modulating and demodulating device (diode) 12 for modulating and demodulating a signal transceived to/from a controller, a resonator 14 for pressure having a piezoelectric single crystal resonator 17 and a pressure sensor 19, and a resonator 16 for a reference having a piezoelectric single crystal resonator 21 and a capacitor 22, and the controller transmits signals for resonating the resonators for the pressure and the reference, receives signals of resonance frequencies for the resonators for the pressure and the reference, and calculates measured values in response to both resonance frequencies extracted from the signals. COPYRIGHT: (C)2008,JPO&INPIT |
