Patent ID: 7014111

Claim:
Reader ( 10 ) for identifying passive transponders ( 12 ) of the type including an antenna for receiving a first signal (Tx) from the reader and for transmitting a second signal (Rx), including: a time base ( 54 ) generating a sinusoidal signal, a control circuit ( 64 ), a modulator ( 56 ) for transmitting the data to the control circuit ( 64 ) for the purpose of modulating the sinusoidal signal in order to generate a signal carrying commands which, received by the antenna of said transponder, forms said first signal (Tx), a demodulator ( 58 ), a decoder ( 60 ), a communication interface ( 62 ), and an antenna ( 14 ), characterized in that said demodulator ( 60 ), which is connected to the antenna ( 14 ) to receive the second signal (Rx), includes two multipliers ( 76 , 78 ), one ( 78 ) being of the inverter type, and an adder ( 70 ) arranged for combining the data originating from said multipliers ( 76 , 78 ).