Many instances occur in microwave measurements where a 2-port calibration is required but a physical through connection is not available. An example is in antenna range measurements, where is sought but it is impossible to perform a complete 2-port calibration. Another example is calibrating out the effects of cable motion in mechanically automated measurements systems, where manually performing a 2-port calibration for each position is impractical. In this paper, we derive a procedure to determine the 2-port S-matrix of an error circuit from 1-port measurements using three non-standard loads. We then derive calibration procedures to remove this error network in both 1 and 2 port scenarios and demonstrate their effectiveness in bench tests.
Background and Formulation