MIWAVE 411 Series Waveguide to Coax Adapter, Frequency Range: 50-75GHz, Insertion Loss: 0.7dB(Typ), Return Loss: 20dB(Typ), Configuration : End Launched Type, Waveguide Port: WR-15 Waveguide with UG-385/U Flange, Coaxial Port: 1.85mm Female, Note: The limitations of 1.85 mm Coax cause performance to degrade from 67GHz to 75GHz