A robust six-to-four port reduction technique for the calibration of six-port microwave network analysers

The authors introduce a simple method by which the robust calibration technique developed by S.K. Judah (1985) may be unified with the thru-reflect-line technique, yielding initial estimates of the six-port instrumental parameters that are insensitive to noise and random errors. This calibration technique has been employed in a single six-port reflectometer operating at 2 GHz. Experimental experience has shown the technique to be robust; problems encountered using the method recommended by G.F. Engen (1979) have not arisen. Investigation by computer simulation has also shown the technique to be reliable. This methodology requires a substantial increase in software effort owing to the effective operational requirement of two full calibration techniques