Title :
Broadband quasi-optical SIS mixers with large area junctions
fDate :
4/1/1994 12:00:00 AM
Abstract :
A broadband quasi-optical superconducting tunnel junction (SIS) mixer with integrated tuning elements was designed and tested. We are able to achieve very low noise performance using commercially available niobium integrated circuit (IC) technology. The low critical current density (980 A/cm2) and large area (12 μm2) of the commercial SIS´s is compensated by the ability to fabricate accurate integrated tuning structures in the mature niobium IC process available from Hypres, Inc. Noise measurements were made in the frequency range from 70 to 105 GHz. The best uncorrected double sideband receiver noise is 38 K at 77 GHz, with receiver noise temperatures less than 100 K from 75 to 102 GHz
Keywords :
critical current density (superconductivity); electron device noise; microwave integrated circuits; mixers (circuits); niobium; superconducting integrated circuits; superconducting junction devices; superconducting microwave devices; tuning; 70 to 105 GHz; MM-wave mixer; Nb; Nb IC technology; Nb integrated circuit technology; broadband; critical current density; integrated tuning elements; large area junctions; low noise performance; quasi-optical SIS mixers; superconducting tunnel junction; Circuit optimization; Circuit testing; Critical current density; Integrated circuit noise; Integrated circuit technology; Josephson junctions; Niobium; Superconducting device noise; Superconducting devices; Superconducting integrated circuits;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
