A reflectometer calibration method resistant to waveguide flange misalignment

A new reflectometer calibration method is described that utilizes four standards: a flush short, two delay shorts with unspecified but different phases, and an open-ended waveguide. The calibration method eliminates the requirement for a precision waveguide matched load, which can be problematic to realize at submillimeter wavelengths. Importantly, it is shown that the technique is resistant to waveguide flange misalignment, which is among the most serious factors that degrade the calibration accuracy of vector network analyzers operating above 100 GHz. Scaled measurements using this method have been performed in the W-band (75-110 GHz) where it is readily compared to other calibration methods such as thru reflect line to assess its utility and performance. Measurement results demonstrate the robustness of this new calibration method and have verified it is superior to the commonly utilized short/delayed-short/load technique with respect to the influence of waveguide flange misalignment.