Repeatability of waveguide flanges with worst-case tolerances in the 500–750 GHz band

Dimensional tolerances of waveguide flanges impose a major limitation on precise measurements above ~100 GHz. At present, the P1785 working group of the IEEE is considering several improved flange designs for rectangular waveguides used above 110 GHz. This paper presents a study of the connection repeatability of some competing designs with worst-case dimensions. Measurements are performed in the 500-750 GHz (WR-1.5 or WM-380) frequency band.