Analysis of a dual-six-port network analyser and derivation of calibration equations

Application of the 6-port reflectometer to the measurement of complex reflection coefficient, without the direct measurement of phase, is extended to a dual 6-port system for the characterisation of general 2-port networks of voltage-wave S-parameters. The manner in which previously-published calibration equations were derived is described in detail. Current calibration techniques are very complicated and involve extensive matrix-manipulation procedures. In this analysis the 6-ports are assumed to be calibrated as reflectometers by an established method. They are operated alternately in passive and active modes as well as simultaneously and this leads to a simple explicit solution for the four parameters of the unknown, and no matrix manipulation is involved. Calibration of the complete system requires only three complex constants which are measured by the calibrated reflectometers using the `through¿¿ connection, and no additional standards are needed.