A 300 GHz Hybrid Form Rotary Attenuator

The modelling, design and test of a variable attenuation standard /1/ for 240 ¿325 GHz is described. The connectors are made in monomode rectangular waveguide technique and the virtual rotary attenuator in quasi-optical technique. Because of, lack of measurement technique for 300 GHz the attenuator is modelled and tested for 60 - 90 GHz. A simple manufacturing is placed in the foreground. Therefore particularly polarization grids are used, which are winded by hand. A special feature appears in utilizing the open optical path by inserting a beam splitter. Thus an internal directional coupler is provided, which allows to control power level or frequency.