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Highly tunable cryogenic resonance circuit for radio frequency magnetic field generation using in situ switch-bank tuning

Lindén, M. LU orcid ; Gustavsson, D. LU orcid ; Shortiss, K. LU and Rippe, L. LU (2025) In Review of Scientific Instruments 96(11).
Abstract

This study presents a cryogenic resonant radio frequency (RF) transmitter coil design for magnetic field generation that utilizes electromechanical switches to match and tune the resonance frequency with capacitor banks in situ. The design enables magnetic field generation at any frequency across a wide frequency range of 25-140 MHz (560% tuning range) while operating at 1.5 K. Magnetic field generation efficiencies ranged from 10 to 15 (Formula presented) up to 70 MHz using a coil volume of 5.4 cm3. An average loaded Q-factor of ∼50 was achieved in the lower frequency range, with a gradual performance degradation observed toward higher frequencies. The circuit design is discussed to outline the main design choices, followed... (More)

This study presents a cryogenic resonant radio frequency (RF) transmitter coil design for magnetic field generation that utilizes electromechanical switches to match and tune the resonance frequency with capacitor banks in situ. The design enables magnetic field generation at any frequency across a wide frequency range of 25-140 MHz (560% tuning range) while operating at 1.5 K. Magnetic field generation efficiencies ranged from 10 to 15 (Formula presented) up to 70 MHz using a coil volume of 5.4 cm3. An average loaded Q-factor of ∼50 was achieved in the lower frequency range, with a gradual performance degradation observed toward higher frequencies. The circuit design is discussed to outline the main design choices, followed by results on circuit characteristics, tunability, and magnetic field generation efficiency. By mapping usable configurations at cryogenic temperatures, we show that overlapping resonances enabled by capacitor banks permit magnetic field generation at any frequency within the range of interest. This is achieved by allowing for slight detuning of the RF drive to bridge the gaps between discrete configurations. The use of capacitor banks also enables selection of the operating range, making the system highly flexible.

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Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Review of Scientific Instruments
volume
96
issue
11
article number
114701
publisher
American Institute of Physics (AIP)
external identifiers
  • scopus:105020670912
  • pmid:41186458
ISSN
0034-6748
DOI
10.1063/5.0280946
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2025 Author(s).
id
0175f20b-fbeb-4fd5-b507-ef7b8675d413
date added to LUP
2025-12-15 14:25:57
date last changed
2025-12-19 14:06:51
@article{0175f20b-fbeb-4fd5-b507-ef7b8675d413,
  abstract     = {{<p>This study presents a cryogenic resonant radio frequency (RF) transmitter coil design for magnetic field generation that utilizes electromechanical switches to match and tune the resonance frequency with capacitor banks in situ. The design enables magnetic field generation at any frequency across a wide frequency range of 25-140 MHz (560% tuning range) while operating at 1.5 K. Magnetic field generation efficiencies ranged from 10 to 15 (Formula presented) up to 70 MHz using a coil volume of 5.4 cm<sup>3</sup>. An average loaded Q-factor of ∼50 was achieved in the lower frequency range, with a gradual performance degradation observed toward higher frequencies. The circuit design is discussed to outline the main design choices, followed by results on circuit characteristics, tunability, and magnetic field generation efficiency. By mapping usable configurations at cryogenic temperatures, we show that overlapping resonances enabled by capacitor banks permit magnetic field generation at any frequency within the range of interest. This is achieved by allowing for slight detuning of the RF drive to bridge the gaps between discrete configurations. The use of capacitor banks also enables selection of the operating range, making the system highly flexible.</p>}},
  author       = {{Lindén, M. and Gustavsson, D. and Shortiss, K. and Rippe, L.}},
  issn         = {{0034-6748}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{11}},
  publisher    = {{American Institute of Physics (AIP)}},
  series       = {{Review of Scientific Instruments}},
  title        = {{Highly tunable cryogenic resonance circuit for radio frequency magnetic field generation using in situ switch-bank tuning}},
  url          = {{http://dx.doi.org/10.1063/5.0280946}},
  doi          = {{10.1063/5.0280946}},
  volume       = {{96}},
  year         = {{2025}},
}