Periodically Estimated Reflection Coefficient Measurement Uncertainties for a Vector Network Analyzer

This paper describes the model and method used to obtain the periodically estimated uncertainties for measurement of the scattering parameters S11 and S22 on a Vector Network Analyzer (VNA). A thru-reflect-line (TRL) method is employed as a second tier calibration to obtain uncertainty estimates using an NIST-calibrated standard. An example of tabulated listings of these uncertainty estimates is presented and the uncertainties obtained for a VNA with 7 mm, 3.5 mm, and type N coaxial interfaces used in our laboratory over several years are summarized.