Three-Port Vector-Network-Analyzer Calibrations Using the NIST Microwave Uncertainty Framework

We have implemented methods for calibrating three-port vector network analyzers (VNAs) and propagating correlated uncertainties using the NIST Microwave Uncertainty Framework. We describe our calibration procedures, which utilize measured wave-parameters rather than scattering parameters to account for switch-term corrections, and present results for a three-port power splitter. We compare our calibrated measurements with those performed using the firmware of a commercial VNA, and show the results agree to within our confidence intervals at most frequencies.