@article{822e41df0920403eb3e5f6ddb46b640f,
title = "Fabrication of a Nb-based 180-degree if hybrid for balanced SIS mixers",
abstract = "180-degree IF hybrids are potentially useful for balanced superconductor-insulator-superconductor (SIS) mixers. We have developed a compact Nb-based 180-degree hybrid for 4-12 GHz which addresses concerns of element size, ohmic loss, and IF bandwidth. The fabrication scheme developed for these elements will be discussed, including the use of a thin overlayer Au process for via contacts, RF diode sputtered SiOx in lieu of sublimated SiO films in order to improve the wafer yield, and diagnostic Nb capacitors to evaluate these SiOx films. Experimental results will be presented and compared with simulations of these lumped element transmission line {"}rat-race{"} hybrids. It should be noted that the hybrids can be used in cryogenic balanced mixers for any RF band.",
keywords = "Hybrid integrated circuit fabrication, Hybrid junctions, Lumped element microwave circuits, Superconductor-insulator-superconductor mixers",
author = "Lyons, {Christine M.} and Lichtenberger, {Arthur W.} and Kerr, {Anthony R.} and Lauria, {Eugene F.} and Ziurys, {Lucy M.}",
note = "Funding Information: Manuscript received August 25, 2006. This work was supported in part by the Arizona Radio Observatory, Steward Observatory, University of Arizona, and by NSF Grant AST-0242525. C. M. Lyons and A. W. Lichtenberger are with the University of Virginia Mi-crofabrication Laboratories, Charlottesville, VA 22904 USA (e-mail: cml3p@ virginia.edu; awl1l@virginia.edu). A. R. Kerr is with the National Radio Astronomy Observatory, Charlottesville, VA 22903 USA (e-mail: akerr@nrao.edu). E. F. Lauria and L. M. Ziurys are with the Arizona Radio Observatory, Tucson, AZ 85721 USA (e-mail: glauria@steffens.as.arizona.edu; lziurys@ as.arizona.edu). Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TASC.2007.897384 Fig. 1. Modified Parisi hybrid equivalent circuit. Parasitic inductances and capacitances (unlabeled in this figure) must be considered when optimizing main L and C parameters (labeled L , L , C , C ).",
year = "2007",
month = jun,
doi = "10.1109/TASC.2007.897384",
language = "English (US)",
volume = "17",
pages = "194--197",
journal = "IEEE Transactions on Applied Superconductivity",
issn = "1051-8223",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "2",
}