Patent ID: 8160191

Claim:
A correction network for correcting a difference between a transmission characteristic of an in-phase signal path and a transmission characteristic of a quadrature signal path, said in-phase signal path being for the transmission of in-phase parts of a signal and said quadrature signal path being for the transmission of quadrature parts of a signal and the signal comprising frequency components within a base band, wherein the correction network comprises an in-phase input port, a quadrature input port, an in-phase output port and a quadrature output port, wherein each input port is connected to each output port by a digital filter network, the digital filter network comprising a set of filter tap coefficients and configuration means for configuring values of said set of filter tap coefficients, and the digital filter network comprises: a first digital filter connecting the in-phase input port to the in-phase output port; a second digital filter connecting the in-phase input port to the quadrature output port; a third digital filter connecting the quadrature input port to the in-phase output port; and a fourth digital filter connecting the quadrature input port to the quadrature output port, wherein each digital filter comprises a respective set of filter tap coefficients and respective configuration means for configuring values of said respective set of filter tap coefficients.