An improved ring-centered waveguide flange for millimeter- and submillimeter-wave applications

Existing waveguide flanges impose a major limitation on measurement precision above ≃100 GHz. A ring-centered waveguide flange was proposed in [1, 2] and its electrical performance characterized in the WR-5 band. This paper explores an improved ring-centered waveguide flange which is backward compatible with the original UG-387 flange and with all its known variants, and facilitates standard TRL VNA calibration using a properly aligned "through" waveguide shim. The modifications to the ring-centered waveguide flange are discussed and measurements in the WR-2.2 (330–500 GHz) band presented.