APPARATUS FOR REDUCING AN AMPLITUDE IMBALANCE AND A PHASE IMBALANCE BETWEEN AN IN-PHASE SIGNAL AND A QUADRATURE SIGNAL

摘要

An apparatus for reducing an amplitude imbalance and a phase imbalance between an in-phase signal and a quadrature signal is provided. The in-phase signal and the quadrature signal are based on a radio frequency receive signal. The apparatus includes an imbalance estimation module configured to generate a first correction signal related to a first phase shift, and to generate a second correction signal related to a second phase shift. Further, the apparatus includes a first digital-to-time converter configured to receive the first correction signal and a local oscillator signal. The first digital-to-time converter is further configured to supply a first replica of the local oscillator signal for a first mixer generating the in-phase signal, wherein the first replica of the local oscillator signal has the first phase shift with respect to the local oscillator signal. The apparatus further includes a second digital-to-time converter configured to receive the second correction signal and the local oscillator signal. The second digital-to-time converter is further configured to supply a second replica of the local oscillator signal for a second mixer generating the quadrature signal, wherein the second replica of the local oscillator signal has the second phase shift with respect to the local oscillator signal.