Standards Definition Impact on Impedance-Based VNA Calibration Methods

Vector network analyzer (VNA) calibration methods, such as short-open-load-reciprocal (SOLR), require precise definition of calibration standards. However, practical challenges as fabrication tolerances and material uncertainties can restrict the precise definition of these standards, potentially leading to calibration inaccuracies. This paper investigates the impact of these challenges on calibration accuracy and compares SOLR against other self-calibration impedance-based methods, specifically line-reflect-match (LRM) and symmetric-reciprocal-match (SRM). The calibration techniques were compared in two experimental scenarios: printed circuit board (PCB)-based measurements and synthetic coplanar waveguide (CPW) data simulations. Results demonstrate that SRM deliver lower error in the presence of errors in standard definitions compared to SOLR and LRM methods.