Patent attributes
A quadrature modulator (QM) may be calibrated by determining total equivalent offsets in the I- and Q-channels, a total equivalent gain imbalance between the I- and Q-channels, and a total equivalent phase skew between the I- and Q-channels. These values may be obtained by taking various scalar measurements of the image to signal ratio (ISR) and carrier to signal ratio (CSR) of the QM, while alternatively altering the system gain imbalance, system phase skew, I-channel offset and Q-channel offset using a respective gain parameter, phase parameter, I-channel offset parameter, and Q-channel parameter. The gain and phase parameters may be defined in terms of the ISR, and the channel offset parameters may be defined in terms of the CSR. The system gain imbalance, system phase skew, and total offset in the channels may then be calculated based on the various ISR and CSR measurements.
