Design of a 350 GHz circular waveguide superconductor-insulator-superconductor mixer for array applications

Conference item

We present the design of a superconductor-insulator-superconductor (SIS) mixer fed with a 2-probe antenna mounted in a circular waveguide, hence avoiding the need for a rectangular waveguide that is often difficult to machine at high millimetre and sub-millimetre frequencies. The mixer is designed to operate from 275–375 GHz, covering a similar frequency range to the HARP-B receiver of the James Clerk Maxwell Telescope. Each antenna probe is connected to a separate but identical mixer circuit comprising three SIS junctions connected in series to reduce the parasitic capacitance, and the relevant tuning circuits and RF chokes. The down-converted IF power at the output of each mixer branch is expected to be combined using either a microwave Wilkinson power combiner or a 180◦ hybrid, to recover the full signal strength. In this paper, we present in the detail the electromagnetic simulations of each RF component making up the mixer chip, as well as the performance of the entire 2-probe mixer including the RF and IF performance predicted using SuperMix, a software package developed based on Tucker’s theory of quantum mixing. Finally, we show how such circular waveguide SIS mixers can be easily populated onto a simple split-block to form a 16-pixel array. © 2022 32nd International Symposium of Space Terahertz Technology, ISSTT 2022 All rights reserved.

Authors: Tan, B; Wenninger, J; Kittara, P; Noptosporn, P; Jaroenjittichai, P

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: National Radio Astronomy Observatory
• Host title: Proceedings of the 32nd Symposium on Space Terahertz Technology
• Publication date: 2023-03-30
• Acceptance date: 2023-03-29
• Event title: ISSTT 2022
• Event location: Baeza, Spain
• Event website: https://www.isstt2022.com/
• Event start date: 2022-10-16
• Event end date: 2022-10-20
• ISBN: 978-1-7138-8988-5
• Language: English