Method of reducing imbalance in a quadrature frequency converter, method of measuring imbalance in such a converter, and apparatus for performing such method

摘要

A method is provided for reducing imbalance in a quadrature frequency converter. A test tone generator controlled by an alignment controller supplies a test signal to the input of the frequency converter. A starting point is selected in a solution space addressed by I and Q corrections. The starting point comprises in-phase (I) and quadrature (Q) phase correction values. A test is then performed to determine the best direction of movement in the I/Q phase correction plane in order to reduce phase imbalance. The I and Q phase correction values are then moved in that direction towards a phase imbalance minimum.