Investigation of Probe Pitch Influence on On-Wafer Multiline TRL Calibrations up to 110 GHz

Recently, much progress has been made in the traceability of on-wafer measurements of planar devices on coplanar calibration substrates. However, reliable uncertainties for on-wafer S-parameters can only be given for a specific combination of substrate material, planar transmission line and probes, and only if single-mode propagation is ensured. This condition limits the use of uncertainties for probes with different dimensions. Therefore, this paper presents a systematic investigation of the influence of probe pitches on selected devices under test. The effects of probe pitch in conjunction with the influence of neighbourhood effects are investigated via simulations up to 110 GHz and compared with measurement results of example DUTs with expanded uncertainties at a coverage probability of 95 % (k=2).