TRANSPONDER AND ARCHIVE MANAGER USING SAME

摘要

The invention concerns transponders of the type comprising: a transmitter-receiver (14, 16) for receiving an interrogation signal and transmitting a return signal in response to the interrogation signal; a storage unit (21) formed by a plurality of cells containing data for identifying said object; and an electronic control circuit (18) for analysing the interrogation signal and commanding the transmitter (16). Said transponders are essentially characterised in that the return signals which they send are of two types (a) and (b), depending on the information contained in one of the cells of said storage unit (21), both sequentially modulated such that the modulated part (m) of the second-type signal (b) is transmitted when the first-type signal (a) is not modulated and inversely.