Patent ID: 8324963

Claim:
An analog circuit ( 7 ) for demodulating three mutually phase-shifted components of a baseband signal, in order to provide two quadrature demodulation components (I, Q), characterized in that it includes: three circuit inputs ( 4 , 5 , 6 ), designed to received said three components, respectively, first and second adder circuits ( 77 , 78 ), and a bank ( 70 ) of weighting circuits ( 71 , 72 , 73 , 74 , 75 , 76 ) linked, at input, to the three circuit inputs ( 4 , 5 , 6 ) and linked, at output, to inputs of the first and second adder circuits ( 77 , 78 ) so as to transmit to each adder input, with a determined weighting, at least one of said three components, the weightings being chosen so that the first and second adder circuits ( 77 , 78 ) provide respectively said two quadrature demodulation components (I, Q) before digitization; wherein the first adder circuit ( 77 ) includes a first operational amplifier (AO 1 ) including first and second inputs, inversion and direct inputs, respectively, connected to two said circuit inputs ( 4 , 6 ) by first and fifth weighting circuits ( 71 , 75 ), respectively.