CARRIER SIGNAL GENERATION CIRCUIT FOR A RADIO-FREQUENCY IDENTIFICATION TRANSPONDER DEVICE AND METHOD FOR GENERATING A CARRIER SIGNAL

In an embodiment a carrier signal generation circuit for an RFID transponder device comprises a frequency divider circuit (FDV) with a first input (10) to receive a first frequency signal (Fg1), a second input (11) to receive a division ratio signal (Sdr), and an output (12) to provide the carrier signal (Falm) as a function of the first frequency signal (Fg1) and the division ratio signal (Sdr), a phase difference determining unit (PDDU) with a first input (13) to receive an analogue reader device carrier signal (Sin), a second input (14) to receive the carrier signal (Falm) or a second frequency signal (Fg2) dependent on the first frequency signal (Fg1) and an output to provide a digital phase difference signal (Spd) as a function of the reader device carrier signal (Sin) and the carrier signal (Falm) or as a function of the reader device carrier signal (Sin) and the second frequency signal (Fg2), and a signal processing unit (SPU) which is coupled by its input to the output of the phase difference determining unit (PDDU), the signal processing unit (SPU) being adapted to provide the division ratio signal (Sdr) dependent on the phase difference signal (Spd) such that the division ratio signal (Sdr) is a function of a slope of the phase difference signal (Spd).