A radio-frequency identification (RFID) system including an RFID tag and an RFID-enabled object. The RFID tag may include a pair of antennas and an RFID circuit. The antennas receive activation energy from a reader, and the RFID circuit modulates tag energy when activation energy is received by one of...http://www.google.com/patents/US7501952?utm_source=gb-gplus-sharePatent US7501952 - RFID tags for enabling batch reading of stacks of cartons
