scholarly journals Magneto-Impedance Sensor Driven by 400 MHz Logarithmic Amplifier

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 355 ◽  
Author(s):  
Tomoo Nakai
Keyword(s):  
Thin Film ◽  
High Frequency ◽  
High Sensitivity ◽  
Smart Manufacturing ◽  
Voltage Controlled Oscillator ◽  
High Frequency Signal ◽  
Logarithmic Amplifier ◽  
Impedance Variation ◽  
Voltage Signal ◽  
Impedance Sensor

A thin-film magnetic field sensor is useful for detecting foreign matters and nanoparticles included in industrial and medical products. It can detect a small piece of tool steel chipping or breakage inside the products nondestructively. An inspection of all items in the manufacturing process is desirable for the smart manufacturing system. This report provides an impressive candidate for realizing this target. A thin-film magneto-impedance sensor has an extremely high sensitivity, especially, it is driven by alternatiing current (AC) around 500 MHz. For driving the sensor in such high frequency, a special circuit is needed for detecting an impedance variation of the sensor. In this paper, a logarithmic amplifier for detecting a signal level of 400 MHz output of the sensor is proposed. The logarithmic amplifier is almost 5 mm × 5 mm size small IC-chip which is widely used in wireless devices such as cell phones for detecting high-frequency signal level. The merit of the amplifier is that it can translate hundreds of MHz signal to a direct current (DC) voltage signal which is proportional to the radio frequency (RF)signal by only one IC-chip, so that the combination of a chip Voltage Controlled Oscillator (VCO), a magneto-impedance (MI) sensor and the logarithmic amplifier can compose a simple sensor driving circuit.

High Saturation Magnetization Fe-Co-N Thin Film Deposited by Facing-Target Direct Current Magnetron Sputtering

2011 ◽  
Vol 415-417 ◽  
pp. 1949-1952
Author(s):  
Kai Yu Yang ◽  
Yin Han Gao ◽  
Cui Mei Zhao ◽  
Xin Wang ◽  
Wei Tao Zheng
Keyword(s):  
Thin Film ◽  
Signal Processing ◽  
Magnetron Sputtering ◽  
Saturation Magnetization ◽  
High Frequency ◽  
Microwave Range ◽  
High Frequency Signal ◽  
The One ◽  
Ferromagnetic Resonance Frequency ◽  
Average Size

Magnetic materials have long been used for signal processing structures in the microwave range. High-frequency signal processing as for band-stop or notch filters, ferromagnetic resonance frequency can be adjusted or set by magnetic properties, such as saturation magnetization Ms. In this work, Fe-Co-N thin films have been synthesized using an improved facing-target magnetron sputtering system, where the sputtering current on Co and Fe targets can be regulated independently. During deposition of Fe-Co-N thin film, parameters on Fe target followed the one for synthesis of ε-Fe3N, while changing the input current on Co target. It was found that on an unheated substrate, with the Co content of about 7 at.%, high value of Ms(265.08Am2kg-1) could be obtained in the Fe-Co-N film, which contained α"-(Fe,Co)16N2nanoparticles with the average size of 7 nm.

Miniaturized high-frequency carrier-type thin-film magnetic field sensor with high sensitivity

2001 ◽  
Vol 37 (4) ◽  
pp. 2042-2044 ◽  
Author(s):  
H. Kikuchi ◽  
N. Ajiro ◽  
M. Yamaguchi ◽  
K.I. Arai ◽  
M. Takezawa
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
High Frequency ◽  
High Sensitivity ◽  
Magnetic Field Sensor ◽  
Field Sensor

scholarly journals Nondestructive Detection of Magnetic Contaminant in Aluminum Casting Using Thin Film Magnetic Sensor

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4063
Author(s):  
Tomoo Nakai
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Single Layer ◽  
Static Field ◽  
Inspection System ◽  
Aluminum Casting ◽  
Logarithmic Amplifier ◽  
Impedance Sensor ◽  
Driving Circuit ◽  
Normal Magnetic Field

The thin film magneto-impedance sensor is useful for detecting a magnetic material nondestructively. The sensor made by single layer uniaxial amorphous thin film has a tolerance against surface normal magnetic field because of its demagnetizing force in the thickness direction. Our previous study proposed the sensitive driving circuit using 400 MHz high frequency current running through the sensor to detect the logarithmic amplifier. We also confirmed the sensitivity of the sensor within 0.3 T static normal magnetic field, which resulted in detection of 5 × 10−8 T of 5 Hz signal. This paper proposes a nondestructive inspection system for how detecting a contaminant of small tool steel chipping in aluminum casting specimen would be carried out. Three channel array sensors installed in the 30 mT static field detecting area were fabricated and experimentally showed a detection of low remanence magnetic contaminant in a bulk aluminum casing specimen.

High Speed and High Sensitivity Slip Sensor for Dexterous Grasping

2012 ◽  
Vol 24 (2) ◽  
pp. 298-310 ◽  
Author(s):  
Seiichi Teshigawara ◽  
◽  
Takahiro Tsutsumi ◽  
Yosuke Suzuki ◽  
Makoto Shimojo ◽  
...  
Keyword(s):  
High Frequency ◽  
High Speed ◽  
High Sensitivity ◽  
Frequency Component ◽  
High Frequency Component ◽  
Robot Hand ◽  
Voltage Signal ◽  
Frequency Components ◽  
Slip Sensor ◽  
Gripping Force

Slip-detecting tactile sensors are essential if robot hands are ever to achieve the gripping motions of human hands. In our previous research, we developed a flexible, thin, and lightweight slip sensor that exploits resistance changes in pressure conductive rubber. However, using this sensor, it was difficult to distinguish between object slip and changes in normal force. Therefore, in this research, we investigate a method of identifying object slip by analyzing the frequency components of the output signal from the sensor. As a result, we find that high-frequency components of several kilohertz or more are included in the complex voltage signal immediately before object slip. Therefore, using this high-frequency component, we develop a simple structure sensor that distinguishes between both contact and a state of immediately before slip with high sensitivity. Moreover, we design a slip sensor for a robot hand and examine the effects of noise by manipulation. Finally, we describe an experiment involving the adjustment of the gripping force of a robot hand.

High Sensitivity pH Sensors based on Amorphous Indium-gallium-zinc Oxide Thin-film Transistors

2015 ◽  
Vol 135 (6) ◽  
pp. 192-198 ◽  
Author(s):  
Shinnosuke Iwamatsu ◽  
Yutaka Abe ◽  
Toru Yahagi ◽  
Seiya Kobayashi ◽  
Kazushige Takechi ◽  
...  
Keyword(s):  
Thin Film ◽  
Zinc Oxide ◽  
Thin Film Transistors ◽  
High Sensitivity ◽  
Oxide Thin Film ◽  
Indium Gallium Zinc Oxide ◽  
Ph Sensors ◽  
Zinc Oxide Thin Film ◽  
Indium Gallium

scholarly journals High-frequency rectifiers based on type-II Dirac fermions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Libo Zhang ◽  
Zhiqingzi Chen ◽  
Kaixuan Zhang ◽  
Lin Wang ◽  
Huang Xu ◽  
...  
Keyword(s):  
High Frequency ◽  
Dynamic Range ◽  
High Sensitivity ◽  
High Dynamic Range ◽  
Anisotropy Ratio ◽  
Dirac Fermions ◽  
Topological States ◽  
Topological Semimetals ◽  
Polarized Surface ◽  
Symmetry Protected

AbstractThe advent of topological semimetals enables the exploitation of symmetry-protected topological phenomena and quantized transport. Here, we present homogeneous rectifiers, converting high-frequency electromagnetic energy into direct current, based on low-energy Dirac fermions of topological semimetal-NiTe2, with state-of-the-art efficiency already in the first implementation. Explicitly, these devices display room-temperature photosensitivity as high as 251 mA W−1 at 0.3 THz in an unbiased mode, with a photocurrent anisotropy ratio of 22, originating from the interplay between the spin-polarized surface and bulk states. Device performances in terms of broadband operation, high dynamic range, as well as their high sensitivity, validate the immense potential and unique advantages associated to the control of nonequilibrium gapless topological states via built-in electric field, electromagnetic polarization and symmetry breaking in topological semimetals. These findings pave the way for the exploitation of topological phase of matter for high-frequency operations in polarization-sensitive sensing, communications and imaging.

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