LRM: A quantitative look at reference impedance contradictions and other uncertainty impacts

摘要

LRM and its derivatives have been popular VNA calibration techniques, particularly on-wafer, for many years. The quantitative effects of standards problems (line impedance issues, match issues, reflect asymmetries) have not always been well-understood including the cases where the standards present internal contradictions to the calibration. These effects will be studied here through the use of constructed measurements and simulations based on a parameter space consistent with commercial VNAs and common test situations.