Patent ID: 8306157
Filing Date: 2012-11-06
Classification: H03D,H04B,H04L

Abstract:
1. A method of calibrating a quadrature receiver, the method comprising: generating a calibration tone using a local oscillator; generating a first oscillator signal using the local oscillator; injecting the calibration tone to the quadrature receiver; mixing the calibration tone with the first oscillator signal; detecting an amplitude and phase imbalance of the quadrature receiver; adjusting a gain of at least one of an in-phase and a quadrature signal path based on the amplitude imbalance; adjusting a phase of at least one of the in-phase and quadrature signal paths based on the phase imbalance, wherein the calibration tone is one of a first quadrature or a first in-phase signal of the first oscillator signal, wherein the calibration tone is mixed with the in-phase signal to produce a first DC component and mixed with the quadrature signal to produce a second DC component; digitizing the first DC component to a first digital DC component and the second DC component to a second digital DC component; upconverting the first digital DC component to a first intermediate frequency (IF) digital signal with a second in-phase LO signal and the second digital DC component to a second digital IF signal with a second quadrature LO signal; combining the first and second digital IF signals to generate a third digital IF signal; mixing the third digital IF signal with the second in-phase LO signal to generate a third DC component and the third digital IF signal with the second quadrature LO signal to generate a fourth DC component; and summing the third and fourth DC components to generate a DC composite component.