Improvements in design of six-port reflectometer comprising symmetrical five-port waveguide junction and directional coupler

A six-port reflectometer that comprises a symmetrical five-port waveguide junction and a directional coupler is discussed. Computer models of the waveguide junction by itself and as part of a six-port setup are used to improve the design of the reflectometer. Two types of improvements were effected: the waveguide junction structure was redesigned to improve its overall residual mismatch; and the interconnections among the constituent components were rearranged to alter the way the reflected waves from the various components combine in the power-detection arms. The combination of these two schemes yielded a six-port reflectometer that has a well-spaced q_k distribution over the entire waveguide bandwidth