An Impedance-Corrected 2x-Thru Calibration

Most microwave calibration methods, such as through-reflect-line (TRL), require using the same fixture in the cal-kits and device-under-test (DUT), which is difficult to meet in practice due to manufacturing nonidealities. The recently developed 2x-thru de-embedding, on the other hand, allows for a partial correction of the fixture mismatch, thereby improving the calibration accuracy. Although many 2x-thru tools now offer such an option, very few sources have disclosed the underlying algorithms. In this short letter, we propose a new impedance-corrected 2x-thru calibration method and validate its performance through simulated and measured data. The results demonstrate that the proposed method can not only reduce the error of the original 2x-thru but also yield comparable, and sometimes better, accuracy than the state-of-the-art approaches in terms of time-domain reflectometry (TDR) and S-parameters.