Patent ID: 7990249

Claim:
A Radio Frequency Identification (RFID) Integrated Circuit (IC) chip for use with an RFID tag that has an antenna for receiving an RF wave, the IC chip comprising: two nodes defining a chip admittance between them, at least one of the nodes for coupling to the antenna; a control circuit for outputting a control signal; a processor for generating a data output signal in response to the received RF wave; a modulator operable to backscatter the received RF wave by alternating the chip admittance responsive to the data output signal between an ON admittance value of the chip admittance that is associated with an ON-state and an OFF admittance value of the chip admittance that is associated with an OFF-state, in which an admittance difference between the ON admittance value and the OFF admittance value is controlled responsive to the control signal; and a controllable admittance circuit distinct from the modulator, coupled between the two nodes, in which the control signal is received by the controllable admittance circuit.