DC-SQUID electronics based on adaptive noise cancellation and a high open-loop gain controller

Heikki Seppä

doi:10.1007/978-3-642-77457-7_62

DC-SQUID electronics based on adaptive noise cancellation and a high open-loop gain controller

Heikki Seppä

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Abstract

A low-noise SQUID readout electronics with a high slew rate and an automatic gain control feature has been developed. Flux noise levels of 5×10⁻⁷Φ₀/√Hz at 1 kHz and 2×10⁻⁶Φ₀/√Hz at 1 Hz have been measured with this readout scheme. The system tolerates sinusoidal disturbances having amplitudes up to 140 φ0 at 1 kHz without loosing lock. The electronics utilizes a cooled GaAs FET to control the cancellation of the voltage noise of the room temperature amplifier, a PI ^3/2 controller to provide a high open-loop gain at low frequencies, and a square-wave flux and offset voltage modulation to enable automatic control of the noise reduction. The cutoff frequency of the flux-locked-loop is 300 kHz and the feedback gain is more than 130 dB at 10 Hz.

Original language	English
Title of host publication	Superconducting Devices and Their Applications
Editors	Hans Koch, Heinz Lübbig
Place of Publication	Heidelberg
Publisher	Springer
Pages	346-350
ISBN (Electronic)	978-3-642-77457-7
ISBN (Print)	978-3-642-77459-1
DOIs	https://doi.org/10.1007/978-3-642-77457-7_62
Publication status	Published - 1992
MoE publication type	A4 Article in a conference publication
Event	4th International Conference SQUID ’91 - Berlin, Germany Duration: 18 Jun 1992 → 21 Jun 1992

Conference

Conference	4th International Conference SQUID ’91
Country/Territory	Germany
City	Berlin
Period	18/06/92 → 21/06/92

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10.1007/978-3-642-77457-7_62

Cite this

@inproceedings{1c1ec84e28fd46c19ffb8d7a447a7834,

title = "DC-SQUID electronics based on adaptive noise cancellation and a high open-loop gain controller",

abstract = "A low-noise SQUID readout electronics with a high slew rate and an automatic gain control feature has been developed. Flux noise levels of 5×10−7Φ0/√Hz at 1 kHz and 2×10−6Φ0/√Hz at 1 Hz have been measured with this readout scheme. The system tolerates sinusoidal disturbances having amplitudes up to 140 φ0 at 1 kHz without loosing lock. The electronics utilizes a cooled GaAs FET to control the cancellation of the voltage noise of the room temperature amplifier, a PI 3/2 controller to provide a high open-loop gain at low frequencies, and a square-wave flux and offset voltage modulation to enable automatic control of the noise reduction. The cutoff frequency of the flux-locked-loop is 300 kHz and the feedback gain is more than 130 dB at 10 Hz.",

author = "Heikki Sepp{\"a}",

note = "Project code: S{\"A}H 2207; 4th International Conference SQUID {\textquoteright}91 ; Conference date: 18-06-1992 Through 21-06-1992",

year = "1992",

doi = "10.1007/978-3-642-77457-7_62",

language = "English",

isbn = "978-3-642-77459-1",

pages = "346--350",

editor = "Hans Koch and Heinz L{\"u}bbig",

booktitle = "Superconducting Devices and Their Applications",

publisher = "Springer",

address = "Germany",

}

TY - GEN

T1 - DC-SQUID electronics based on adaptive noise cancellation and a high open-loop gain controller

AU - Seppä, Heikki

N1 - Project code: SÄH 2207

PY - 1992

Y1 - 1992

N2 - A low-noise SQUID readout electronics with a high slew rate and an automatic gain control feature has been developed. Flux noise levels of 5×10−7Φ0/√Hz at 1 kHz and 2×10−6Φ0/√Hz at 1 Hz have been measured with this readout scheme. The system tolerates sinusoidal disturbances having amplitudes up to 140 φ0 at 1 kHz without loosing lock. The electronics utilizes a cooled GaAs FET to control the cancellation of the voltage noise of the room temperature amplifier, a PI 3/2 controller to provide a high open-loop gain at low frequencies, and a square-wave flux and offset voltage modulation to enable automatic control of the noise reduction. The cutoff frequency of the flux-locked-loop is 300 kHz and the feedback gain is more than 130 dB at 10 Hz.

AB - A low-noise SQUID readout electronics with a high slew rate and an automatic gain control feature has been developed. Flux noise levels of 5×10−7Φ0/√Hz at 1 kHz and 2×10−6Φ0/√Hz at 1 Hz have been measured with this readout scheme. The system tolerates sinusoidal disturbances having amplitudes up to 140 φ0 at 1 kHz without loosing lock. The electronics utilizes a cooled GaAs FET to control the cancellation of the voltage noise of the room temperature amplifier, a PI 3/2 controller to provide a high open-loop gain at low frequencies, and a square-wave flux and offset voltage modulation to enable automatic control of the noise reduction. The cutoff frequency of the flux-locked-loop is 300 kHz and the feedback gain is more than 130 dB at 10 Hz.

U2 - 10.1007/978-3-642-77457-7_62

DO - 10.1007/978-3-642-77457-7_62

M3 - Conference article in proceedings

SN - 978-3-642-77459-1

SP - 346

EP - 350

BT - Superconducting Devices and Their Applications

A2 - Koch, Hans

A2 - Lübbig, Heinz

PB - Springer

CY - Heidelberg

T2 - 4th International Conference SQUID ’91

Y2 - 18 June 1992 through 21 June 1992

ER -

DC-SQUID electronics based on adaptive noise cancellation and a high open-loop gain controller

Abstract

Conference

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