Characterization of Micromachined Waveguide Hybrids at 350 and 650 GHz

We present measurement results of two different hybrid couplers at submillimeter wavelengths. The devices under test were a 650 GHz coupler, which has been micromachined in Silicon by deep reactive ion etching, and two versions of a 345 GHz coupler machined out of brass. In order to determine the amplitude and phase balance of the coupling section the differences between the connecting waveguides have to be taken into account. We corrected the measurements under the assumption that the coupling section itself is fully symmetrical, which results in a good matching between the measured and the simulated performance.