Patent ID: 6704558
Filing Date: 2004-03-09
Classification: H03D

Abstract:
A method for down-converting an electromagnetic (EM) signal wherein the EM signal is comprised of a desired signal and an undesired signal, the desired signal having a frequency of fD, and the undesired signal being an image signal having a frequency of fI, comprising the steps of:(1) splitting the EM signal into a first signal and a second signal, said first signal being substantially the same as said second signal; (2) aliasing said first signal with a control signal to produce a first down-converted signal; (3) shifting the phase of said control signal resulting in a phase-shifted control signal; (4) aliasing said second signal with said phase-shifted control signal to produce a second down-converted signal; (5) shifting said first down-converted signal to create a first shifted down-converted signal; and (6) combining said first shifted down-converted signal and said second down-converted signal to create an image rejected down-converted signal; wherein step (2) comprises sub-sampling said first signal using said control signal; and wherein step (4) comprises sub-sampling said second signal using said phase-shifted control signal.