Adapter evaluation using three-adapter technique with ‘Thru-Line’ two-tier calibration in one-port measurements

This paper presents a method using a two-tier calibration with `Thru-Line´ for evaluating the S-parameters of adapters based on three-adapter technique. It uses a one-port VNA (Vector Network Analyzer) to avoid cable movements with `OSL´ (Open-Short-Load) calibration standards, which are widely used for one-port measurements, being used at the first and second calibrations. Formulas are also derived for estimating the uncertainties of the S-parameters of adaptors using the proposed method.