Calibration enhancement and on line accuracy assessment for single six-port reflectometers employing a nonlinear Kalman filter

The calibration and measurement performance of a single six-port reflectometer is directly affected by the presence of random errors. A technique using a nonlinear Kalman filter that enhances calibration by a factor of two to ten is presented. The technique also provides statistical information, allowing simple online accuracy assessment. The technique is readily extended for use within dual six-port reflectometer systems