The PNA Series of vector network analyzers has capabilities to improve the accuracy of mixer characterization. The frequency-offset measurement capability for the series allows the operator to enter data in a single dialog box, and firmware ensures that all values are within acceptable ranges. The instrument controls all elements of the test set-up, including signal sources for the local oscillators and power meters for system calibration. Reciprocal mixers as well as nonreciprocal types can be accommodated. The capability can be incorporated in any of the PNA series analyzers, including the 67-GHz E8361 model.