Rfid transponder

An RFID transponder comprising a transponder air interface for receiving phase modulated radio frequency carrier signals and a demodulator for demodulating the received phase modulated carrier signals, wherein the demodulator comprises:

• a down-converter being arranged for converting the phase modulated carrier signal down to a modulated baseband signal;
• a filter structure for filtering the modulated baseband signal provided by the down-converter;
• sampling means being adapted to sample the filtered signal provided by the filter structure and to store at least an actual sampling value and a previous sampling value of the filtered signal;
• subtracting means being arranged to calculate a difference between the actual sample value and the previous sample value;
• and
• difference evaluation means being arranged to evaluate the difference according to the following criteria:
• if the difference has a positive sign and the difference value is outside of a predefined zero range a first logical value is determined;
• if the difference has a negative sign and the difference value is outside of the zero range a second logical value is determined;
• if the difference is within the zero range the logical value of the latest evaluation is kept.