Fixed station`s e.g. RFID reader, amplitude modulated information multilevel digital demodulation method for e.g. card, involves comparing feedback voltage variations and threshold values and summing modulation level jump to preceding level

摘要

The method involves comparing variations of a feedback voltage of a transponder (4) with threshold values, and transforming the result of the comparison into a value of authorized jump of modulation level. The jump is summed with a preceding modulation level for determining another modulation level. Each modulation level is associated with previously stored threshold values. An independent claim is also included for a device for multilevel demodulation of information transmitted by amplitude modulation by a radio frequency identification reader towards a transponder.