Patent ID: 7844015

Claim:
A method for determining a calibration parameter of a quadrature modulator, the method comprising the stages of: determining a set of sideband calibration frequencies; for each sideband calibration frequency out of the set of sideband calibration frequencies: inputting multiple input signals having the sideband calibration frequency to the quadrature modulator; for at least some of the multiple input signals: measuring a sideband signal power level; and determining a sideband compensation signal that is responsive to at least one calibration parameter, the determining is being responsive to phase and gain imbalances expected at the measured sideband signal power level; and wherein a first calibration parameter is a gain calibration parameter that is responsive to a fraction of a maximal gain imbalance value expected at the measured sideband signal value; wherein a second calibration parameter is a phase calibration parameter that is responsive to a fraction of a maximal phase imbalance value expected at the measured sideband signal value; wherein the multiple input signals comprise: a first input signal that is responsive to a sum of a previously inputted input signal and the first calibration parameter; a second input signal that is responsive to a difference between the previously inputted input signal and the first calibration parameter; a third input signal that is responsive to a sum of a previously inputted input signal and the second calibration parameter; and a fourth input signal that is responsive to a difference between the previously inputted input signal and the second calibration parameter; wherein the method further comprises determining a compensation filter configuration in response to sideband compensation signals for the set of sideband calibration frequencies wherein a real part of the compensation filter is responsive to an in-band component representative of a phase and amplitude of the sideband compensation signals and wherein an imaginary part of the compensation filter is responsive to a quadrature component representative of the phase of the sideband compensation signals.