Patent ID: 7031686
Filing Date: 2006-04-18
Classification: H03D

Abstract:
1. An image rejection mixer comprising: first and second mixers, each of which mixes an input signal with each of first local oscillation in-phase signal and first local oscillation quadrature-phase signal, respectively, wherein the first local oscillation quadrature-phase signal is resulted by shifting the first local oscillation in-phase signal by −90°; first and second analogue to digital converting means, each of which transforms each output of said first and second mixers to digital signal; third mixer mixes output of said first analogue to digital converting means with second local oscillation in-phase signal; fourth mixer mixes output of said first analogue to digital converting means with second local oscillation quadrature-phase signal; wherein the second local oscillation quadrature-phase signal is resulted by shifting the second local oscillation in-phase signal by −90°; fifth mixer mixes output of said output of said second analogue to digital converting means with second local oscillation in-phase signal; sixth mixer mixes output of said second analogue to digital converting means with second local oscillation quadrature-phase signal; means for subtracting output of said sixth mixer from output of said third mixer; means for adding outputs of said fourth and fifth mixers; and means for compensating gain mismatch between said first and second mixers by controlling output of said means for subtracting and said means for adding.