Patent ID: 7519141

Claim:
A method for converting a real signal into a complex signal inherently in quadrature, comprising the step of: starting from a real signal to be converted, adding to said real signal, designed to be converted into a complex signal, a signal whose frequency is four times the band-center frequency of said real signal to be converted; selecting, from said sum signal, a first component and a second component which are in phase and in quadrature; removing components below a given level from said first and second components in phase and in quadrature, in order to obtain a first and a second signal component at DC zero level, said removing step being performed by threshold circuits; multiplying said DC zero level components respectively by 1 and −1, with a frequency equal to the center frequency of said signal to be converted in input, obtaining a complex signal with an inherent quadrature, wherein said selection step is performed by selection means, which send signals to said threshold circuits with a frequency which is twice said band-center frequency of the signal to be converted.