An IQ amplitude balance estimator is described herein which uses a positive frequency mixer to generate two outputs. The first output is the standard output from a positive frequency mixer and the second output corresponds to a spectrum inverted output from a negative frequency mixer. The second output is generated, however, using the same partial products as the first output and no negative frequency mixer is used. An IQ amplitude imbalance metric is generated by taking the real part of the output from correlation logic which performs a correlation of the two outputs from the mixer. This metric may then be used in a closed loop to compensate for any IQ amplitude imbalance.