A 700 GHz unilateral finline SIS mixer fed by a multi-flare angle smooth-walled horn

Boon Kok Tan, Ghassan Yassin, Paul Grimes, Jamie Leech, Karl Jacobs, Stafford Withington, Mike Tacon, Christopher Groppi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations

Abstract

We present the design of a broadband superconductor-insulator- superconductor (SIS) mixer operating near 700 GHz. A key feature of our design is the utilisation of a new type of waveguide to planar circuit transition comprising a unilateral finline taper. This transition is markedly easier to design, simulate and fabricate than the antipodal finline we employed previously. The finline taper and the superconducting circuitry are deposited on a 15 μm thick silicon substrate. The employment of the very thin substrate, achieved using Silicon-On-Insulator (SOI) technology, makes it easy to match the incoming signal to the loaded waveguide. The lightweight mixer chip is held in the E-plane of the waveguide using gold beam leads, avoiding the need for deep grooves in the waveguide wall. This new design yields a significantly shorter chip, free of serrations and a wider RF bandwidth. Since tuning and all other circuits are integrated on the mixer chip, the mixer block is extremely simple, comprising a feed horn and a waveguide section without any complicated mechanical features. We employ a new type of smooth-walled horn which exhibits excellent beam circularity and low cross polarisation, comparable to the conventional corrugated horn, and yet is easier to fabricate. The horn is machined by standard milling with a drill tool shaped into the horn profile. In this paper, we describe the detailed design of the mixer chip including electromagnetic simulations, and the mixer performance obtained with SuperMix simulations. We also present the preliminary measurements of the smooth-walled horn radiation patterns near the mixer operating frequencies.

Original languageEnglish (US)
Title of host publicationMillimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V
DOIs
StatePublished - Sep 7 2010
EventMillimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V - San Diego, CA, United States
Duration: Jun 29 2010Jul 2 2010

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume7741
ISSN (Print)0277-786X

Other

OtherMillimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V
CountryUnited States
CitySan Diego, CA
Period6/29/107/2/10

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Keywords

  • Silicon-On-Insulator technology
  • Superconductor-Insulator-Superconductor mixer
  • direct-drilling technique
  • smooth-walled horn
  • unilateral finline taper

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

Tan, B. K., Yassin, G., Grimes, P., Leech, J., Jacobs, K., Withington, S., Tacon, M., & Groppi, C. (2010). A 700 GHz unilateral finline SIS mixer fed by a multi-flare angle smooth-walled horn. In Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V [774110] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 7741). https://doi.org/10.1117/12.856711