Dual-Resonant Search Coil for Natural Electromagnetic Waves in the Near-Earth Environment

Author

Ozaki, Mitsunori ; Yagitani, Satoshi ; Takahashi, Koichi ; Nagano, I.

Author_Institution

Kanazawa Univ., Kanazawa, Japan

Volume

13

Issue

2

fYear

2013

fDate

Feb. 2013

Firstpage

644

Lastpage

650

Abstract

A dual-resonant search coil (DRSC) is designed as a wideband magnetometer for natural electromagnetic waves in the near-Earth environment. Since the frequency response of a search coil is determined by its resonant frequency, its bandwidth can be increased by using multiple resonances. Two resonances are obtained by capacitive coupling with negative mutual inductance between two coils. The resulting measurement band of the DRSC is from 10 Hz to 1 MHz for a sensor 100 mm in length, 25 mm in diameter, and 0.11 kg in mass. A theoretical analysis of the resonant frequencies and gain profile of the DRSC agree with measurements. The noise equivalent magnetic induction of the DRSC is 40 fT/Hz^1/2 at 3 kHz and 14 fT/Hz^1/2 at 140 kHz. This magnetometer is the first to realize two resonances using a single sensor and preamplifier.

Keywords

coils; electromagnetic devices; electromagnetic wave propagation; frequency response; inductance; magnetic double resonance; magnetic sensors; magnetometers; preamplifiers; DRSC; capacitive coupling; dual resonant search coil; frequency 10 Hz to 1 MHz; frequency response; magnetic sensors; mass 0.11 kg; natural electromagnetic wave; near Earth environment; negative mutual inductance; noise equivalent magnetic induction; preamplifier; resonant frequency; size 100 mm; size 25 mm; wideband magnetometer; Capacitance; Coils; Frequency measurement; Inductance; Magnetic cores; Resonant frequency; Windings; Coupling circuit; magnetic sensors; multiple resonances; negative mutual inductance;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2012.2224863

Filename

6330978