Patent ID: 8085863

Claim:
A radio receiver comprising: an in-phase channel and a quadrature channel, said channels being provided in parallel at a respective input with quadrature modulated radio frequency signals; and an error correction loop for detecting and correcting an imbalance in gain between at least part of said in-phase channel and a corresponding part of said quadrature channel, wherein said error correction loop comprises: a detector adapted to calculate Error_det new =|I′|−|Q′|, where I′ and Q′ are the in-phase and quadrature channels respectively; a loop filter arranged to receive Error_det new from the detector and calculate loop_filter_out new +=K i * Error_det new , where K i is the loop filter constant and loop_filter_out new has an initial value of 1; and a multiplier arranged to receive loop_filter_out new from the loop filter and adjust the signal of the quadrature channel by multiplying the signal by loop_filter_out new .