An Ideal Six-Port Network Consisting of a Matched Reciprocal Lossless Five-Port and a Perfect Directional Coupler

A six-port consisting of a matched reciprocal Iossless five-port in series with a perfect directional coupler is shown to have ideal six-port properties according to the theory developed by Engen. The q points are separated by 120° on a common circle. The matched five-port itself is shown to function as a four-way divider network and bears an interesting analogy with a matched nonreciprocal Iossless three-port (circulator). This analogy is used to design several styles of matched symmetrical stripline five-ports for use in making six-port measurements.