Thin-Film-Based SAW Magnetic Field Sensors

In this work, the first surface acoustic-wave-based magnetic field sensor using thin-film AlScN as piezoelectric material deposited on a silicon substrate is presented. The fabrication is based on standard semiconductor technology. The acoustically active area consists of an AlScN layer that can be excited with interdigital transducers, a smoothing SiO2 layer, and a magnetostrictive FeCoSiB film. The detection limit of this sensor is 2.4 nT/Hz at 10 Hz and 72 pT/Hz at 10 kHz at an input power of 20 dBm. The dynamic range was found to span from about ±1.7 mT to the corresponding limit of detection, leading to an interval of about 8 orders of magnitude. Fabrication, achieved sensitivity, and noise floor of the sensors are presented.

Download Full-text

Recent Progress in Devices Based on Magnetoelectric Composite Thin Films

Sensors ◽

10.3390/s21238012 ◽

2021 ◽

Vol 21 (23) ◽

pp. 8012

Author(s):

Deepak Rajaram Patil ◽

Ajeet Kumar ◽

Jungho Ryu

Keyword(s):

Magnetic Field ◽

Thin Film ◽

Electric Fields ◽

High Frequency ◽

Frequency Conversion ◽

Limit Of Detection ◽

Very High Frequency ◽

Magnetic Field Sensors ◽

Magnetoelectric Composite ◽

Band Pass

The strain-driven interfacial coupling between the ferromagnetic and ferroelectric constituents of magnetoelectric (ME) composites makes them potential candidates for novel multifunctional devices. ME composites in the form of thin-film heterostructures show promising applications in miniaturized ME devices. This article reports the recent advancement in ME thin-film devices, such as highly sensitive magnetic field sensors, ME antennas, integrated tunable ME inductors, and ME band-pass filters, is discussed. (Pb1−xZrx)TiO3 (PZT), Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT), Aluminium nitride (AlN), and Al1−xScxN are the most commonly used piezoelectric constituents, whereas FeGa, FeGaB, FeCo, FeCoB, and Metglas (FeCoSiB alloy) are the most commonly used magnetostrictive constituents in the thin film ME devices. The ME field sensors offer a limit of detection in the fT/Hz1/2 range at the mechanical resonance frequency. However, below resonance, different frequency conversion techniques with AC magnetic or electric fields or the delta-E effect are used. Noise floors of 1–100 pT/Hz1/2 at 1 Hz were obtained. Acoustically actuated nanomechanical ME antennas operating at a very-high frequency as well as ultra-high frequency (0.1–3 GHz) range, were introduced. The ME antennas were successfully miniaturized by a few orders smaller in size compared to the state-of-the-art conventional antennas. The designed antennas exhibit potential application in biomedical devices and wearable antennas. Integrated tunable inductors and band-pass filters tuned by electric and magnetic field with a wide operating frequency range are also discussed along with miniaturized ME energy harvesters.

Download Full-text

Development of a Transient Magnetic Field Sensor Based on Digital Integration and Frequency Equalization

Sensors ◽

10.3390/s21134268 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4268

Author(s):

Hongzhi Ouyang ◽

Xueling Yao ◽

Jingliang Chen

Keyword(s):

Magnetic Field ◽

Electromagnetic Compatibility ◽

Dynamic Range ◽

Finite Impulse Response ◽

Low Noise ◽

Magnetic Field Sensor ◽

Fiber System ◽

Digital Integrator ◽

Transient Magnetic Field ◽

Field Sensor

Transient magnetic field sensors are used in various electromagnetic environment measurement scenarios. In this paper, a novel magnetic field sensor based on a digital integrator was developed. The antenna was a small B-DOT loop. It was designed optimally for the simulation. The magnetic field signal was digitally integrated with the improved Al-Alaoui algorithm, resulting in less integration error. To compensate for the bandwidth loss of the optical fiber system, we specially designed an FIR (finite impulse response) filter for frequency compensation. The circuit was described, and the transimpedance amplifier was specially designed to ensure the low noise characteristic of the receiver. The sensitivity of the sensor was calibrated at 68.2 A·m−1/mV, the dynamic range was 50 dB (1–300 kA/m), the linear correlation coefficient was 0.96, and the bandwidth was greater than 100 MHz. It was tested and verified under the action of an A-type lightning current. The sensor exhibited high-precision performance and flat amplitude-frequency characteristics. Therefore, it is suitable for lightning positioning, partial discharge testing, electromagnetic compatibility management, and other applications.

Download Full-text

Non-Uniform Bridge Connection of a High-Frequency Carrier-Type Thin-Film Magnetic Field Sensor

Journal of the Magnetics Society of Japan ◽

10.3379/jmsjmag.23.1621 ◽

1999 ◽

Vol 23 (4_2) ◽

pp. 1621-1624 ◽

Cited By ~ 2

Author(s):

M. Takezawa ◽

H. Ohdaira ◽

M. Baba ◽

M. Yamaguchi ◽

K. I. Arai ◽

...

Keyword(s):

Magnetic Field ◽

Thin Film ◽

High Frequency ◽

Magnetic Field Sensor ◽

Field Sensor

Download Full-text

Highly Sensitive Surface Acoustic Wave Magnetic Field Sensor Using Multilayered TbCo2/FeCo Thin Film

Proceedings ◽

10.3390/proceedings2130902 ◽

2018 ◽

Vol 2 (13) ◽

pp. 902 ◽

Cited By ~ 1

Author(s):

Aurelien Mazzamurro ◽

Abdelkrim Talbi ◽

Yannick Dusch ◽

Omar Elmazria ◽

Philippe Pernod ◽

...

Keyword(s):

Magnetic Field ◽

Thin Film ◽

Acoustic Waves ◽

Surface Acoustic Waves ◽

Magnetic Field Sensor ◽

Nanostructured Thin Film ◽

Highly Sensitive ◽

Magnetic Model ◽

Field Sensor

Over the last decades, the use of Surface Acoustic Waves (SAW) has emerged as a promising technology in many applications such as filters, signal processing but also sensors. We report the fabrication and the characterization of a SAW delay line magnetic field sensor using uniaxial multi-layered 14×[TbCo2(3.7nm)/FeCo(4nm)] nanostructured thin film deposited on Y36° Lithium Niobate (Figure 1a). The sensor shows an interesting dependency to a tunable bias magnetic field with different orientations relative to the easy axis. The obtained results are well explained using an equivalent piezo-magnetic model described in a previous work.

Download Full-text

A thin film magnetic field sensor of sub-pT resolution and magnetocardiogram (MCG) measurement at room temperature

Journal of Magnetism and Magnetic Materials ◽

10.1016/j.jmmm.2008.11.083 ◽

2009 ◽

Vol 321 (7) ◽

pp. 675-678 ◽

Cited By ~ 19

Author(s):

S. Yabukami ◽

K. Kato ◽

Y. Ohtomo ◽

T. Ozawa ◽

K.I. Arai

Keyword(s):

Magnetic Field ◽

Thin Film ◽

Room Temperature ◽

Magnetic Field Sensor ◽

Field Sensor

Download Full-text

Magnetic Communication Using High-Sensitivity Magnetic Field Detectors

Sensors ◽

10.3390/s19153415 ◽

2019 ◽

Vol 19 (15) ◽

pp. 3415 ◽

Cited By ~ 4

Author(s):

Maurice Hott ◽

Peter A. Hoeher ◽

Sebastian F. Reinecke

Keyword(s):

Magnetic Field ◽

Mobile Applications ◽

Data Communication ◽

High Sensitivity ◽

Magnetic Data ◽

Receiver Coil ◽

Magnetic Field Sensors ◽

Resistive Sensor ◽

Field Sensor ◽

Multiple Detectors

In this article, an innovative approach for magnetic data communication is presented. For this purpose, the receiver coil of a conventional magneto-inductive communication system is replaced by a high-sensitivity wideband magnetic field sensor. The results show decisive advantages offered by sensitive magnetic field sensors, including a higher communication range for small receiver units. This approach supports numerous mobile applications where receiver size is limited, possibly in conjunction with multiple detectors. Numerical results are supported by a prototype implementation employing an anisotropic magneto-resistive sensor.

Download Full-text