A self-calibration technique for microwave multiport measurements

A self calibration technique for a multiport vector network analyzer (VNA), based on the full error model, is presented. Hence, a characterization of the measurement instrument with the help of partially unknown calibration standards is possible. As a consequence, the dependency on absolute defined calibration standards is reduced. Therefore, the accuracy of the measurements increases and the fabrication of the calibration standards can be simplified. In addition, the presented approach enables the characterization of a device under test (DUT) without any knowledge about the error parameters. In this contribution a similarity transformation for multiport VNA measurements is presented. Based on this transformation a set of nonlinear equations for the unknown parameters of the calibration standards can be found. A possible solution for the calibration of a 4-port system is derived. To validate the presented approach a calibration with partially unknown reflection standards of a 4-port VNA is performed.