EVALUATION OF INTEGRATED TUNING ELEMENTS WITH SIS DEVICES

The resonances of integrated tuning stubs in combination with SIS dete ctors are measured and calculated. The predicted resonances are compar ed with measurements of stubs integrated with Nb/Al2O3/Nb junctions in a log-periodic antenna. Stubs of different lengths have been investig ated on different substrates (on 200 mum thick quartz and on a 7 mum t hick silicon membrane) and the results show a fairly good agreement wi th the model calculations. Quartz substrates showed resonances up to 6 40 GHz, while for silicon membranes stub resonances reach up to as 480 GHz. An observed resonance at 560 GHz is probably a substrate effect from the membrane. The gap frequency for all the samples is 670 GHz an d no resonances are detected above this frequency. Up to the maximum d etected frequency dispersion is found to be negligible.