A flux-driven Josephson parametric amplifier for sub-GHz frequencies fabricated with side-wall passivated spacer junction technology

Research output: Contribution to journalArticleScientificpeer-review


  • Slawomir Simbierowicz
  • Visa Vesterinen
  • Leif Grönberg
  • Janne Lehtinen
  • Mika Prunnila
  • Juha Hassel

Research units

  • VTT Technical Research Centre of Finland


We present experimental results for a Josephson parametric amplifier tailored for readout of ultra-sensitive thermal microwave detectors. In particular, we discuss the impact of fabrication details on the performance. We show that the small volume of deposited dielectric materials enabled by the side-wall passivated spacer niobium junction technology leads to robust operation across a wide range of operating temperatures up to 1.5 K. The flux-pumped amplifier has gain in excess of 20 dB in three-wave mixing and its center frequency is tunable between 540-640 MHz. At 600 MHz, the amplifier adds 105 mK 9 mK of noise, as determined with the hot/cold source method. Phase-sensitive amplification is demonstrated with the device.


Original languageEnglish
Article number105001
Pages (from-to)1-7
JournalSuperconductor Science and Technology
Issue number10
Publication statusPublished - 24 Aug 2018
MoE publication typeA1 Journal article-refereed

    Research areas

  • Josephson junction, parametric amplifier, SQUID array

ID: 28341883