| 摘要 |
In a RFID sensor tag, a sensing element (25) is connected to an oscillator 23 such that an oscillation frequency (fOSC) of the oscillator (23) is dependent on a value of a predetermined variable sensed by the sensing element (25). The oscillation frequency (fOSC) of the oscillator (50) is a harmonic multiple N of a modulation frequency (fMOD) required for a backscattering modulator (24). A frequency divider (51) is arranged at the output of the oscillator (50) to produce the modulation frequency (fMOD) from the oscillation frequency (fOSC). The oscillator (50) can be designed and dimensioned such that a high sensitivity is obtained with all sensor values (Cs), and the desired modulation frequency (fMOD) is derived resulting oscillation frequency (fOSC) by selecting a suitable division ratio N. |
