On the Influence of Thru- and Line-Length-Related Effects in CPW-Based Multiline TRL Calibrations

Abstract

The quality of calibration standards in on-wafer measurements has a strong impact on the accuracy of the multiline Thru-Reflect Line (TRL) calibration. Especially the thru standard is one of the most critical calibration standards. For instance, it has been demonstrated recently that the probe effects are more pronounced, if the length of the thru is selected too small. In this case, the mTRL calibration is more sensitive towards probe coupling effects. Therefore, this paper reports on a systematic study on the impact of the thru length on the mTRL calibration accuracy. Additionally, the influence of the length of the calibration standards will be discussed together with the influence of probe and neighborhood effects for coplanar waveguides (CPW).