OBJECT LOCATION SYSTEM AND METHOD USING RFID

摘要

A system and method is provided for locating objects using RFID tags. The system and method uses an RFID reader and a distance calculator to efficiently and accurately determine the location of objects that include an RFID tag. The RFID reader transmits a plurality of signals to the RFID tag, with the plurality of signals having different fundamental frequencies. In response, the RFID tag backscatter modulates the plurality of transmitted signals to create a plurality of backscatter-modulated signals. The RFID reader receives and demodulates the plurality of backscatter-modulated signals. The distance calculator determines the phase of the plurality of backscatter-modulated signals and determines a rate of change of the phase in the backscatter-modulated signals with respect to the rate of change in the fundamental frequency of the transmitted signals and uses this information to calculate the distance to the RFID tag.