Patent attributes
The RFID sensor tag may include normal RFID circuits and functions (such as rectifier, modulator, logic and memory) as well as a resonator-based clock generator or oscillator. The oscillator is a stable resonator-based oscillator having a high Q value. The resonator-based oscillator is loaded with a sensor element which tunes the oscillation frequency, i.e. the oscillation frequency is sensitive to the measured quantity. Thereby, a passive RFID sensor with a resonator-based oscillator and a sensor element is provided, wherein the oscillation frequency can be made dependent on the sensor element if sensing is required. The concept is compatible for existing RFID tags and can enable the possibility to measure external quantities with-out reducing the read-out distance.
