Patent ID: 6892060

Claim:
A fully integrated self-tuned image rejection downconversion system with feedback for use in low intermediate frequency (IF) receivers with high image rejection ratio, comprising: a forward path, receiving a radio frequency (RF) and image (IM) signal, said forward path comprising quadrature I and Q (I/Q) channel mixers with an I/Q local oscillator (LO) each, and a complex filter signal extractor, said complex filter signal extractor extracting an IF and an IF image signal, said forward path used for frequency conversion; and a feedback path, receiving the output of said forward path, said feedback path comprising a correlator, a gain mismatch estimator and variable gain amplifiers (VGAs), said VGAs disposed between said I/Q mixers and said complex filter signal extractor, said closed loop feedback path used for detecting, estimating, and canceling I/Q mismatches between said I/Q mixers and said I/Q local oscillators (LOs).