Patent ID: 8115637

Claim:
A radio frequency identification (RFID) system, comprising: an RFID reader having a plurality of reader antennas of different polarizations to transmit radio frequency signals; and at least one RFID tag, the RFID tag comprising a plurality of tag antennas of different polarizations, a plurality of diodes coupled to the plurality of tag antennas respectively, a receiver coupled to the plurality of diodes to receive the radio frequency signals from the tag antennas when the diodes are forward biased, and a set of one or more current controllers coupled to the plurality of diodes, in a receiving mode the set of current controllers to forward bias at least one of the diodes to receive signals from the RFID reader, in a transmitting mode the set of current controllers to change a backscatter state of at least one of the tag antennas to transmit data via backscattering the radio frequency signals.