A Reformulation and Stability Study of TRL and LRM Using $S$ -Parameters

This paper derives a unified thru, reflect, match (TRL) and line, reflect, match (LRM) calibration algorithm using S-parameters instead of traditional T-parameters. The advantage of this approach is that we get a solution where the LRM is an integral part of the TRL algorithm. The expression for the transmission coefficient of the line standard has the convenient property that, in many cases, the transmission coefficient is obtained directly without a need for a root choice.