Comparison of junctions in both dielectric guides and metallic guides above 75 GHz

One of the limitations in measuring transmission and insertion losses of guided waves at frequencies above 75 GHz is the performance of waveguide flange connections. This involves not only the repeatability of a pair of flange connectors but also the interconnectability to other connectors. The authors show, by using practical measurements in the range 75-100 GHz and comparing them with the theoretical calculations mentioned above, that dielectric guide connections are capable of better performance than waveguide connections. Some aspects of the design of impedance standards for an all-dielectric multistate reflectometer are discussed. Such a dielectric guide reflectometer should have a better performance than its waveguide equivalent for microwave impedance measurements above 100 GHz.