The present disclosure is directed to determining speeds of radio frequency tags. In some implementations, a method includes sampling a Radio Frequency (RF) signal from an RFID tag at a plurality of different times as the RFID tag approaches an RFID reader and recedes from the RFID reader. A phase of...http://www.google.fr/patents/US8169312?utm_source=gb-gplus-shareBrevet US8169312 - Determining speeds of radio frequency tags
