Patent ID: 6337634
Filing Date: 2002-01-08
Classification: G06K,H01Q,H03L

Abstract:
A radio frequency communications device comprising:a dipole antenna having first and second portions which define, in operation, first and second poles of the dipole antenna, respectively; an integrated circuit coupled to the dipole antenna and including a transmitter and a receiver, the transmitter being switchable between a backscatter mode, wherein a carrier for the transmitter is derived from a carrier received from an interrogator spaced apart from the radio frequency communications device and the integrated circuit alternately reflects or does not reflect the carrier from the interrogator by shorting or isolating the first and second portions of the dipole antenna to transmit data to the interrogator, and an active mode, wherein a carrier for the transmitter is generated by the integrated circuit itself, the transmitter being configured to switch between the backscatter and active modes in response to a radio frequency command received by the receiver.