S-Parameter Measurement and Uncertainty Evaluation of Coplanar Waveguides from 140 to 220 Ghz Using Lrm Calibration

Abstract

A method for evaluating S-parameter measurement uncertainty based on the line-reflect-match (LRM) calibration algorithm is proposed, which is suitable for multi-frequency and wideband applications. The LRM calibration procedure is outlined, and a corresponding uncertainty evaluation framework for S-parameters is established through the derivation of propagation formulas. An on-wafer measurement system using an N5224A vector network analyzer (VNA) and LRM calibration is implemented to characterize S-parameters of a coplanar waveguide within the 140–220 GHz frequency range. Experimental results indicate that the overall performance of the device under test (DUT) is reliable across the measurement frequency band, confirming the feasibility of the proposed method.

Keywords: LRM calibration, Measurement uncertainty, Covariance matrix, VNA, S-Parameters