Waveguide-to-substrate transition based on unilateral substrateless finline structure: Design, fabrication, and characterization
Journal article, 2020

We report on a novel waveguide-to-substrate transition with prospective use for broadband mixer design. The transition employs a substrateless finline, i.e., a unilateral finline structure with the substrate removed between the fins. This distinctive feature diminishes the overall insertion loss and facilitates matching with the waveguide. The transition is designed on a thin silicon substrate covered by a superconducting niobium thin layer. An auxiliary Au layer situated on top of the Nb layer provides grounding for the fins and facilitates the mounting process in the split-block waveguide mount. Aiming to compare simulations with measurements, a back-to-back transition arrangement for the 211-373 GHz frequency band was designed, fabricated, and characterized at cryogenic temperatures. The simulation results for the back-to-back structure show an insertion loss of less than 0.6 dB in the whole band, i.e., 0.3 dB per transition. Furthermore, a remarkable fractional bandwidth of 55% with a return loss better than 15 dB is predicted. Experimental verification shows consistent results with simulations.

Broadband Waveguide to Substrate Transition

Superconducting Transition

Substrateless Finline

Author

Cristian Daniel López

Chalmers, Space, Earth and Environment, Onsala Space Observatory, GARD Technology

Vincent Desmaris

Chalmers, Space, Earth and Environment, Onsala Space Observatory, GARD Technology

Denis Meledin

Chalmers, Space, Earth and Environment, Onsala Space Observatory, GARD Technology

Alexey Pavolotskiy

Chalmers, Space, Earth and Environment, Onsala Space Observatory, GARD Technology

Victor Belitsky

Chalmers, Space, Earth and Environment, Onsala Space Observatory, GARD Technology

IEEE Transactions on Terahertz Science and Technology

2156-342X (ISSN)

Vol. 10 6 668-676

Subject Categories

Nano Technology

Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1109/TTHZ.2020.3020683

More information

Latest update

3/15/2021