VNA Traceability Tool

This paper describes the development of a traceability tool for measurements using a vector network analyzer (VNA). This useful tool for one port devices was developed via residual uncertainty evaluations, i.e. post-calibrations, using complex matrix mathematics and conventional software and using three ldquoknownrdquo standard devices (TKD) previously calibrated by the National Metrology Institute of Japan (NMIJ). In the procedure the measurement of the TKDs yields three measurands which together with the calibration values of the TKDs, yield residuals (i.e. residual directivity, residual matching and residual tracking) via complex matrix methods in the traceability tool. When applied to a device under test (DUT) the residuals of the resulting measurements are determined and then adjusted. The measurement uncertainties of the DUT are also calculated. With a view to installing the ldquoVNA traceability toolrdquo in Japanese industries the NMIJ has validated it in various situations. For example in one configuration open, short and load were used as TKDs and in another three different reflection values (three types of mismatch terminations) were used.