Patent ID: 8629763

Claim:
An RFID transponder comprising: an automatic gain control (AGC) stage for amplifying a radio frequency (RF) signal and for providing an amplified RF signal, the AGC stage configured to detect a change in the RF signal level from a nonzero level to a predetermined level and generating a control signal indicating an increase of the amplitude of the RF signal, the AGC stage having 3 control loops one for each antenna in a three-dimensional configuration and a state machine providing a fast response before a transition in the RF signal and a slower response to the RF signal after a transition in the RF signal above a predetermined level, wherein a correct but weaker than noise signal can be correctly demodulated; a demodulator coupled to receive the amplified RF signal for demodulating the amplified RF signal and for providing a data signal; a burst detector coupled to receive the control signal of the AGC stage and adapted to provide a start signal in response to a change of the control signal; and 3 wake pattern detectors coupled to receive the data signal and the start signal, wherein the wake pattern detector is adapted to detect a predefined wake pattern in the data signal after having received the start signal and to issue a wake signal if the predefined wake pattern is detected for switching the RFID transponder from a first operating mode into a second operating mode having higher power consumption than the first operating mode.