Ultrahigh frequency thin film rf-SQUID magnetometer with a cryogenic preamplifier employing a high-electron-mobility transistor

A. Cavalleri, M. Cerdonio, G. Fontana, G. Jung, R. Macchietto, R. Mezzena, S. Vitale, J. P. Zendri

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Ultrahigh frequency rf-SQUID magnetometer employing a cryogenic preamplifier and a commercially available thin film rf-SQUID sensor have been designed, manufactured, and tested. The system has been operated at 316 MHz, which is the maximum pump frequency accepted by the thin film sensor. The cryogenic preamplifier has been built around a microwave high-electron-mobility transistor which was made unconditionally stable at ultrahigh frequency band by means of an appropriate circuit design, namely, a cascode configuration. The total flux noise of the magnetometer has been found to be 8.4 × 10 -6Φ0/√Hz at 4.2 K and 5.8× 10 -6Φ0/√Hz at 1.4 K. The temperature dependence of the fractional step rise α of the current-voltage rf characteristic has been measured to be proportional to the 2/3 power of the SQUID sensor temperature. The noise performance of the system at 4.2 K has been limited by the intrinsic SQUID noise only, in good agreement with theoretical predictions.

Original languageEnglish
Pages (from-to)5403-5407
Number of pages5
JournalReview of Scientific Instruments
Volume63
Issue number11
DOIs
StatePublished - 1 Dec 1992
Externally publishedYes

ASJC Scopus subject areas

  • Instrumentation

Fingerprint

Dive into the research topics of 'Ultrahigh frequency thin film rf-SQUID magnetometer with a cryogenic preamplifier employing a high-electron-mobility transistor'. Together they form a unique fingerprint.

Cite this