Uncertainty Propagation in S-Parameter Measurement Due to Nonideal Calibration Standards and Noise

This paper investigates uncertainty propagation in scattering parameter measurement based on short-open-load-thru (SOLT) calibration. It focuses on the uncertainty caused by nonideal calibration standards, noise, and their correlation. The measurement uncertainties are quantified by utilizing the Monte Carlo method (MCM). Then a 40 dB attenuator is used as the device under test (DUT) for experimental validation, confirming the effectiveness of the proposed approach in assessing S-parameter uncertainties. Assessment results show that the reflection coefficient uncertainty is primarily influenced by calibration standard, while the transmission coefficient uncertainty arises comparably from both calibration standards and noise. Correlation analysis shows the impacts of nonideal calibration standards and noise are largely independent. This framework provides a robust method for uncertainty evaluation in practical applications.