Abstract: Phase errors and gain errors are reduced in a receiver to increase the dynamic range of the receiver. An input signal is shifted to an intermediate frequency (IF) and divided into a first channel and a second channel. The first and second channels are multiplied by a complex intermediate frequency signal having a frequency equal to the negative of the IF and by the complex conjugate of the intermediate frequency signal to produce a complex normal signal and a complex conjugate signal. A gain correction factor and a phase correction factor are adjusted based on a correlation signal produced by multiplying the complex normal signal by the complex correlation signal.

Abstract: Two automatic gain control (AGC) loops are connected by a feedforward signal. An intermediate frequency (IF) filter may be located between the output of the front-end loop and the input of the back-end loop. Stability and responsiveness are improved because neither AGC loop includes a narrowband filter. The front-end loop may include an analog gain-controlled element, but the remainder of the invention may be implemented digitally. The front-end loop prevents overloading of the A/D converter that feeds the gain-controlled signal to the remainder of the invention, and the back-end loop compensates for actions taken in the front-end loop.