A quadrature receiver calibration apparatus, the apparatus comprising a tone generator configured to generate a calibration tone, a coupler configured to couple the calibration tone to a signal path of the quadrature receiver, a detector configured to detect an in-phase and quadrature signal component when the calibration tone is coupled to the signal path, a gain feedback module configured to adjust a gain of at least one of an in-phase signal path and a quadrature signal path; and a phase feedback module configured to adjust a phase of at least one of the in-phase signal path and the quadrature signal path.