AN RFID TRANSPONDER AND A METHOD OF COMMUNICATING IDENTIFICATION CODE IN ELECTROMAGNETIC NOISY ENVIRONMENTS

摘要

The invention relates to an RFID transponder for communication of an identification code with an RFID-reader, where the transponder includes a parallel resonance circuit including a capacitor (C) and a first antenna (L1) for receiving of a carrier wave sent by the RFID-reader, wherein the transponder further includes a contact (SW1) for respectively breaking or closing of a resonance voltage in the parallel resonance circuit, wherein a peak voltage over the capacitor (C) is held by breaking of the contact (SW1), wherein the contact is controlled based on the first signal and is connected in series with the capacitor (C), a clock regenerator arranged for providing a clock signal based on the sent carried wave, phase-locked loop (PLL) for locking the phase of the clock signal to the phase of the sent carrier wave, and signal means arranged to provide the first signal based on the said clock signal. Hereby, a transponder is provided which makes a reliable reading possible, even in electromagnetically noisy environments and over longer distances. The invention also includes a method for the same purpose.