Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Bulletin of the American Physical Society

A RF Preamplifier Design For Low Temperature NMR Experiments.

Sung Su Kim, Chao Huan, L. Phelps, Jian-Sheng Xia, Neil S. Sullivan, Donald Candela

Published Mar 15, 2010• 0 citations
OpenAlex

Related papers

DC SQUID preamplifier for low temperature NMR

Jaakko Henrik KOIVUNIEMI, Yasushi Kondo, M. Krusius

Czechoslovak Journal of Physics•May 1, 1996•3 citations

Cryogenic amplifiers with superconducting LC resonator for low Temperatur NMR

Jaakko Henrik KOIVUNIEMI, M. Krusius

•Jan 1, 1998•0 citations

Performance and Characterization of a Wide IF SIS-Mixer-Preamplifier Module Employing High-J c SIS Junctions

Takafumi Kojima, M. Kroug, Kazunori Uemizu +3 more

This paper reports the simulation, performance, and detailed characterization of a low-noise heterodyne module with very wide intermediate frequency (IF) bandwidth in the 385-500-GHz radio frequency (RF) range. The module integrates a superconductor-insulator-superconductor (SIS) mixer with a 3- 21-GHz cryogenic low-noise preamplifier (CLNA). The utilization of high current density SIS junctions offers wide RF bandwidth and facilitates better matching between SIS junctions and the CLNA. Based on an equivalent circuit of the SIS mixer chip, we calculate the IF output impedance and simulate how different matching conditions affect the performance of the CLNA. Simulations predict that low-noise module performance can be obtained over a 3-18GHz IF range, limited mainly by parasitic elements in theSIS mixer chip. The measurement results of the heterodyne module demonstrate flat gain and a typical noise temperature of 70-80 K over the 3-18-GHz IF range, at local oscillator frequencies of 400-480 GHz. Mixer chip output impedance and CLNA input impedance have been directly measured by recording S-parameters at cryogenic temperatures. The results enabled us to quantify the contribution of various parasitic elements in the mixer IF circuitry. Calculations based on our model are in good agreement with measurements.

IEEE Transactions on Terahertz Science and Technology•Nov 1, 2017•25 citations

Improved sensitivity of planar microwave based RF-SQUIDs using a cryogenic HEMT preamplifier

Giorgio Fontana, R. Mezzena, Stefano Vitale +4 more

The design and performance of a planar microwave RF-SQUID (superconducting quantum interference device) read out by a cryogenic high-electron-mobility-transistor (HEMT) preamplifier are described. The SQUID sensor consists of a planar half-wavelength microstrip resonator, into which the SQUID loop is integrated. The SQUID is operated at a pump frequency of 1.7 GHz. The cryogenic preamplifier uses a microwave HEMT, located close to the SQUID sensor. Measurements of the flux noise and the fractional step rise parameter were carried out in the temperature range between 4.2 K and 1.5 K. In an open loop, a flux noise of 2*10/sup -6/ Phi /sub 0// square root Hz was measured at 4.2 K, resulting in an energy resolution of about 100 h. The design of a 3-GHz magnetometer is also described, and the preliminary results of the measurements are reported.>

IEEE Transactions on Applied Superconductivity•Mar 1, 1993•5 citations

A simple digital phase-shifter for multiple-quantum NMR

Geoffrey Bodenhausen

Journal of Magnetic Resonance (1969)•May 1, 1979•15 citations

An ultra-low-noise preamplifier using superconducting quantum devices

A. Davidson, Ronald S. Newbower, M. R. Beasley

The application of superconducting (SQUID) galvanometers as low-noise preamplifiers with considerable bandwidth is explored. The important role of negative feedback in maximizing the bandwidth of these preamplifiers is carefully analyzed. Also discussed is the design and construction of superconducting impedance matching transformers suitable for making the unexcelled noise characteristics of these amplifiers available over a wide range of source impedances. A working preamplifier is described which has exhibited a maximum bandwidth of 10 kHz and noise temperatures in the liquid helium temperature range or below for all source impedances up to a few ohms. The operating characteristics of this preamplifier are compared to the best conventional room temperature amplifiers and are found to be superior for source impedances less than ∼10 Ω.

Review of Scientific Instruments•Jun 1, 1974•25 citations
This paper reports the simulation, performance, and detailed characterization of a low-noise heterodyne module with very wide intermediate frequency (IF) bandwidth in the 385-500-GHz radio frequency (RF) range. The module integrates a superconductor-insulator-superconductor (SIS) mixer with a 3- 21-GHz cryogenic low-noise preamplifier (CLNA). The utilization of high current density SIS junctions offers wide RF bandwidth and facilitates better matching between SIS junctions and the CLNA. Based on an equivalent circuit of the SIS mixer chip, we calculate the IF output impedance and simulate how different matching conditions affect the performance of the CLNA. Simulations predict that low-noise module performance can be obtained over a 3-18GHz IF range, limited mainly by parasitic elements in theSIS mixer chip. The measurement results of the heterodyne module demonstrate flat gain and a typical noise temperature of 70-80 K over the 3-18-GHz IF range, at local oscillator frequencies of 400-480 GHz. Mixer chip output impedance and CLNA input impedance have been directly measured by recording S-parameters at cryogenic temperatures. The results enabled us to quantify the contribution of various parasitic elements in the mixer IF circuitry. Calculations based on our model are in good agreement with measurements.
The design and performance of a planar microwave RF-SQUID (superconducting quantum interference device) read out by a cryogenic high-electron-mobility-transistor (HEMT) preamplifier are described. The SQUID sensor consists of a planar half-wavelength microstrip resonator, into which the SQUID loop is integrated. The SQUID is operated at a pump frequency of 1.7 GHz. The cryogenic preamplifier uses a microwave HEMT, located close to the SQUID sensor. Measurements of the flux noise and the fractional step rise parameter were carried out in the temperature range between 4.2 K and 1.5 K. In an open loop, a flux noise of 2*10/sup -6/ Phi /sub 0// square root Hz was measured at 4.2 K, resulting in an energy resolution of about 100 h. The design of a 3-GHz magnetometer is also described, and the preliminary results of the measurements are reported.>
The application of superconducting (SQUID) galvanometers as low-noise preamplifiers with considerable bandwidth is explored. The important role of negative feedback in maximizing the bandwidth of these preamplifiers is carefully analyzed. Also discussed is the design and construction of superconducting impedance matching transformers suitable for making the unexcelled noise characteristics of these amplifiers available over a wide range of source impedances. A working preamplifier is described which has exhibited a maximum bandwidth of 10 kHz and noise temperatures in the liquid helium temperature range or below for all source impedances up to a few ohms. The operating characteristics of this preamplifier are compared to the best conventional room temperature amplifiers and are found to be superior for source impedances less than ∼10 Ω.