Accuracy investigation of the de-embedding technique using open and short patterns for on-wafer RF characterization

Accurate de-embedding technique to remove the effect of pads is highly desired in on-wafer RF characterization, especially in the millimeter wave band. There are several calibration techniques such as TRL, Through-Only, Multi-Line, the method using Thru and Line patterns, etc. But the most commonly used technique is the de-embedding technique using open and short patterns, referred to as the open-short de-embedding technique. One of disadvantages of the open-short de-embedding technique is that pads are approximated by an equivalent circuit model, whose accuracy may be not sufficiently high. This paper investigates the accuracy of the open-short de-embedding technique through numerical simulations and measurements. It was found that the accuracy of the open-short de-embedding technique is high when lengths of the open and short patterns are small. The propagation constant of a guided microstrip line was extracted from measured data, and results of numerical simulations were verified.