Patent ID: 8400269
Filing Date: 2013-03-19
Classification: G06K

Abstract:
1. A system comprising: a radio frequency identification (RFID) reader; and an RFID tag communicatively coupled to the RFID reader; wherein the RFID tag comprises a patch antenna comprising a first feed point, a second feed point and a third feed point, wherein the RFID tag is configured to transmit binary data bits to the RFID reader, the RFID reader being responsive to a particular combination of the binary data bits received from the RFID tag, wherein, in the event that the first feed point is active and the second and third feed points are inactive, the binary data bits are encoded in a first electric field polarization of electromagnetic waves transmitted from the RFID tag, a particular magnitude of the first electric field polarization corresponding to a binary zero, wherein, in the event that the second feed point is active and the first and third feed points are inactive, the binary data bits are encoded in a second electric field polarization of electromagnetic waves transmitted from the RFID tag, a particular magnitude of the second electric field polarization corresponding to a binary one, wherein, in the event that the first and second feed points are active and the third feed point is inactive, the binary data bits are encoded in a third electric field polarization of electromagnetic waves transmitted from the RFID tag, a particular magnitude of the third electric field polarization corresponding to a binary zero, and wherein, in the event that the first and third feed points are active and the second feed point is inactive, the binary data bits are encoded in a fourth electric field polarization of electromagnetic waves transmitted from the RFID tag, a particular magnitude of the fourth electric field polarization corresponding to a binary one.