Sensitivity analysis of wafer-level over-temperature RF calibration

This paper analyzes the commonly used wafer-level S-parameter calibration methods LRRM, multiline TRL and LRM+ for the sensitivity to the thermal variation of electrical characteristics of planar calibration standards. We demonstrate that the calibration error of lumped-standard based methods can be significantly reduced by taking into account the variation of Load standard resistance over the temperature. The obtained results proved that for the evaluated commercially available calibration standards and for a given frequency range, the overall calibration error due to the temperature variation is in order of magnitude of repeatability of the manual system calibration. The proposed method can be successfully applied for different calibration substrates, temperature and frequency ranges, as well as to the in-situ calibration element.