16-Term On-Wafer Calibration with Leaky Standards and Flexible Algorithm Definition

For precise on-wafer measurement of active microwave devices in microstrip or coplanar environment, the 16-term error model with reflection and transmission self-calibration is usecd in a novel combination with four leaky two-port reflection standards for crosstalk calibration. The lack of analytical formulae for calculation of the error terms with leaky standards is solved by an optimizer-based approach which allows the choice of calibration method (e.g. TRL, LRM, LRRM) by defining the unknown calibration standards as optimization parameters. The crosstalks of the reflection and Load standards are obtained from EM structure simulation. An improved microstrip load is realized which enables LR(R)M instead of TR(R)L calibrations up to at least 120 GHz. A measurement of a GaN HEMT with and without crosstalk calibration proves its strong effect on gain and stability factor.