Patent ID: 8593260

Claim:
A method for controlling a radio frequency identification system, the method comprising: communicating at least one command from a radio frequency identification reader to a chip-based radio frequency identification tag comprising an antenna and a chip in communication with the antenna, the chip comprising power recovery circuitry in communication with the antenna and configured to recover and store energy from the interrogating signals, signal recovery circuitry separate from the power recovery circuitry, in communication with the antenna and configured to demodulate incoming data and tag control electronics in communication with the power recovery circuitry and signal recovery circuitry and configured to control the power recovery circuitry and signal recovery circuitry; modifying an effective reading range of the radio frequency identification tag in response to the communicated command by: controlling a modulation depth of backscatter radiation that the radio frequency identification tag uses to communicate with the radio frequency identification reader using a field-effect transistor comprising a drain and source configured in parallel with the signal recovery circuitry and a gate in communication with the tag control electronics; and modifying power consumption characteristics of the radio frequency identification tag using a field-effect transistor comprising a drain and source configured in parallel with the power recovery circuitry and a gate in communication with the tag control electronics.