Error propagation from OSL calibration standards: Analytical solution and experimental validation

OSL (Open-Short-Load) calibration is the commonly used technique for one-port RF reflection/impedance measurement. Generally, the calibration standards are assumed to be “perfect” or traceable to “perfect standards”. With no doubts, the imperfections on calibration standards or process of traceability will create a second-level error for measurement. Recent attempts focus on predicting the second-level error with numerical simulations. However, direct analytical expression and experimental validation have not been demonstrated yet. In this paper, analytical solution to error propagation from OSL calibration standards is derived with introducing small perturbations to these standards and using first-order approximations. It leads to sensitivity analysis for OSL calibration with imperfect standards. In order to validate the analysis, a female-to-male adapter is adopted as an error source for OSL calibration standards. By comparing the reflection measurements for the cases of calibration with/without the adapter, the analytical solution is validated experimentally.