Estimation of complex residual errors of calibrated two-port vector network analyzer

This article presents a new method for verification of the residual errors of calibrated two-port vector network analyzers based on a special time-domain technique. The method requires two devices under test including a high-precision air line. Calibration residual errors are extracted from a distance-frequency system model and special estimation algorithm based on the quasi-optimal unscented Kalman filter. Experimental studies were conducted in coaxial measurement environments and at the wafer level. Suitable applications of the proposed verification method are discussed.