Extended cross-ratio reflection correction at microwave frequencies using waveguide air-fines

It is shown that the extended cross-ratio method of correction of the compl ex reflection coefficient Gamma is applicable not only in coaxial lines but also in waveguides at microwave frequencies when precision waveguide secti ons of well-defined cross dimensions are used as reference air;line impedan ce standards. A detailed uncertainty calculation which includes the influen ce of waveguide imperfections is given. Small total expanded uncertainties less than 0.002 for /Gamma/ less than or equal to 0.25 can be achieved.