The Matched Symmetrical Five-Port Junction as the Essential Part of an Ideal Six-Port Network

The basic properties of a novel configuration for six-port measurements, consisting of a matched symmetrical five-port junction and a directional coupler, are described. The proposed six-port is shown to possess several advantageous properties for accurate determination of complex signal ratios. The basis for analysis of planar symmetrical five-port junctions is given and it is demonstrated that stripline junctions can be matched over broad frequency bands by the use of short line segments. An experimental strip-line five-port shows a performance in good correspondence with the theoretically predicted one. Results are given of six-port impedance standard measurements made with the stripline five-port junction.