Metrology of vector modulation error: Problems and solution

The paper points out the current problems about calibration of vector modulation error: first, the signal source and vector signal analyzers calibrates each other, and forms a closed-loop, so it´s lack of traceability. Second, signal lacks setting of vector modulation error in calibration. To solve the problems, this paper proposes new solution to calibrate vector demodulation error: use combination of two CW, analog AM or PM signal, construct an “equivalent MPSK signals” with certain modulation error. The equivalent MPSK signals´ EvmRms, EvmPeak, MagErrRms, MagErrPeak, PhaseErrRms and PhaseErrPeak are solely decided by CW power ratio, AM depth or PM phase deviation, and can be calculated accurately, and are continuously adjustable within a wide range. Experiments confirm that the above-mentioned solutions are effective.