Antenna systems for passive radio-frequency identification (RFID) tags. The antenna systems have a very small form factor with good power harvesting and good performance in proximity to other antennas. The antenna system includes at least one, and preferably two, parallel serpentine antenna elements...http://www.google.de/patents/US7855697?utm_source=gb-gplus-sharePatent US7855697 - Antenna systems for passive RFID tags
