In general, the disclosure describes an RFID tag designed such that the tag is both covert and not easily blocked from the interrogation signal by the hand or other body part of a person. In particular, the RFID tag is designed to have a long, narrow aspect that allows placement of the tag in locations...http://www.google.fr/patents/US20090096696?utm_source=gb-gplus-shareBrevet US20090096696 - RFID TAG WITH A MODIFIED DIPOLE ANTENNA
