Optimization of noise parameters of SQUID magnetometers with external negative feedback

✍ Scribed by V. Zrubec; J. Maňka

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 514 KB
• Volume: 35
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(95)93579-o

✦ Synopsis

The noise and transfer parameters of superconducting quantum magnetometers (SQMs) with external feedback (used in multichannel systems to exclude the crosstalk in the antenna system) are analysed. An input equivalent noise circuit is designed and the relations for its parameters in terms of dependence of spectral density of the magnetometer output voltage noise are derived. The optimum s/n ratio conditions in relation to the dependence of antenna inductance are derived. The term input equivalent energy sensitivity is introduced, which enables a simple comparison of the SQMs with external and conventional internal feedback. The procedure of noise parameter measurement and the experimental results supporting the theoretical analysis are given.