Final Report

MM - Wave Components - SIS (Superconductor-Insulator-Superconductor) Mixers

Stephen R. Whiteley

Published Apr 26, 1989• 0 citations

Abstract

Abstract : Superconductor-Insulator-Superconductor (SIS) tunnel junction mixers are known to provide ultra-high sensitivity receiver applications above 30 GHz. In this two year (Phase II) program, HYPRES, in collaboration with the National Radio Astronomy Observatory, have developed novel fully integrated SIS mixer circuits, and demonstrated a unique high efficiency cooling system. The integrated SIS mixer chip contains, aside from the actual mixer elements, passive tuning components, an IF filter, a coplanar transmission line, and a waveguide coupler, necessary components heretofore realized off-chip. Fabrication of the integrated mixer required development of a nine level process and optimization of the process dependent electrical parameters of the SIS devices. The device performs efficiently in the range of 75-115 GHz. A novel dewar-based cooler, which makes use of the extremely low thermal conductivity of the fused silica chip substrate to achieve an incremental thermal load of 25 mW, was fabricated and demonstrated. Such a cryostat allows relatively long term unattended operation of SIS, or other, cryogenic devices.

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