A simplified calibration procedure for on-wafer power levelled S-parameter measurements at mm-wave

In this paper, we present a simplified calibration procedure to obtain on-wafer power levelled s-parameters when employing VNA extender modules. The approach presented removes the required calibration at the module interface (i.e., waveguide), by assuming symmetry in the tracking terms of the error coefficient and only requiring an on-wafer calibration and the knowledge of the two port s-parameters of the wafer probe. The calibration procedure with its mathematical approximation is then validated and compared to a conventional absolute power calibration using an equivalent model of the VNA front-end realized in a circuit simulator environment. The calibration technique is then implemented in a WR10 system employing OML inc. modules. The experimental results, demonstrating an error lower than 0.5dB in the entire waveguide band, are reported.