• Title/Summary/Keyword: Solenoid Core

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Nanoparticle Contrast in Magneto-Motive Optical Doppler Tomography

  • Kim, Jee-Hyun;Oh, Jung-Hwan
    • Journal of the Optical Society of Korea
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    • v.10 no.3
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    • pp.99-104
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    • 2006
  • We introduce a novel contrast mechanism for imaging superparamagnetic iron oxide (SPIO) nanoparticles (average diameter ${\sim}100nm$) using magneto-motive optical Doppler tomography (MM-ODT), which combines an externally applied temporally oscillating high-strength magnetic field with ODT to detect the nanoparticles flowing through a glass capillary tube. A solenoid cone-shaped ferrite core extensively increased the magnetic field strength ($B_{max}=1\;T,\;{\Delta}|B|^2=220T^2/m$) at the tip of the core and also focused the magnetic force on targeted samples. Nanoparticle contrast was demonstrated in a capillary tube filled with the SPIO solution by imaging the Doppler frequency shift which was observed independent of the flow rate and direction. Results suggest that MM-ODT may be a promising technique to enhance SPIO nanoparticle contrast for imaging fluid flow.

Mechanism Design of Optical Pickup Actuator for Fast Access of Optical Disk Drive (광디스크 드라이브의 고속 액세스를 위한 광픽업 액추에이터 메커니즘 설계)

  • 박준혁;이상헌;백윤수
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.12
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    • pp.109-119
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    • 2002
  • In this paper, mechanism design of optical pickup actuator for fast access is proposed. This actuator is composed of moving magnet type actuator and moving coil type actuator for tracking and fine motion, respectively. Moving magnet type tracking actuator is configurated by two permanent magnets and four air-core solenoids. Additional damper by induced current in tracking actuator can reduce the transient vibration between the coarse seeking servo and fine seeking servo. Variable stiffness can be acquired by applying current to air-core solenoid simply. This actuator can achieve fast access by these additional damper and stiffness. Performance of this actuator is predicted through the FEM, simulation and simple experiment. Settling time for transient vibration is reduced to 14.7% according to simulation result.

Development of Microscale RF Chip Inductors for Wireless Communication Systems (무선통신시스템을 위한 극소형 RF 칩 인덕터의 개발)

  • 윤의중;김재욱;정영창;홍철호
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.40 no.10
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    • pp.17-23
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    • 2003
  • In this study, microscale, high-performance, solenoid-type RF chip inductors were investigated. The size of the RF chip inductors fabricated in this work was 1.0${\times}$0.5${\times}$0.5㎣. The materials (96% Al2O3) and shape (I-type) of the core were determined by a Maxwell three-dimensional field simulator to maximize the performance of the inductors. The copper (Cu) wire with 40${\mu}{\textrm}{m}$ diameter was used as the coils. High frequency characteristics of the inductance (L), quality-factor (Q), and capacitance (C) of developed inductors were measured using an RF Impedance/Material Analyzer (HP4291B with HP16193A test fixture). The inductors developed have inductances of 11 to 39 nH and quality factors of 28 to 50 over the frequency ranges of 250MHz to 1 GHz, and show results comparable to those measured for the inductors prepared by CoilCraf $t^{Tm}$ that is one of the best chip inductor company in the world. The simulated data predicted the high-frequency data of the L, Q, and C of the inductors developed well.l.

Variation of Characteristics of Solenoid-Type RF Chip Inductors on Inductor Size (인덕터 크기에 따른 솔레노이드 형 RF 칩 인덕터 특성 변화)

  • Yun, Eui-Jung;Kim, Jae-Wook
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.7
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    • pp.339-343
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    • 2006
  • In this study, the variations of the important characteristics of solenoid-type RF chip inductors utilizing a low-loss A1203 core material on inductor dimensions were investigated systematically. Four dimensions of the chip inductors fabricated in this work were $1.0\times0.5\times0.5mm^3,\;1.5\times1.0\times0.7mm^3,\;2.1\times1.5\times1.0mm^3,\;and\;2.4\times2.0\times1.4mm^3$ and copper (Cu) wire with $40{\mu}m$ diameter was used as the coils. High frequency characteristics of the inductance, quality factor, and impedance of developed inductors as a function of inductor dimensions were measured using an RF Impedance/Material Analyzer (HP4291B with HP16193A test fixture). It was observed that the developed inductors with the number of turns of 6 have the inductance (L) of 12 to 82 nH and exhibit the self-resonant frequency (SRE) of 3.6 to 1.2 GHz. The SRF of inductors decreases with increasing the inductor size while the L increases with the inductor size. The smallest inductors of $1.0\times0.5\times0.5mm^3$ exhibited the L of 12 nH, SRF of 3.6 GHz, and the quality factor of 67 near the frequency of 1.1 GHz. The calculated data predicted the high-frequency data of the L, and Q of the developed inductors well.

The Optimum Structure Design of 1005 RF Chip Inductors for GHz Band (GHz 대역을 위한 1005 RF 칩 인덕터의 최적 구조 설계)

  • Kim, Jae-Wook;Ryu, Chang-Keun
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.785-788
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    • 2005
  • In this study, micro-scale, high-performance, solenoid-type RF chip inductors were investigated. The size of the RF chip inductors fabricated in this work was $1.0{\times}0.5{\times}0.5mm^3$ The material and shape of the core were 96% $Al_2O_3$ and I-type. The material and number of turn of coil were copper (Cu) and 6. The diameter ($40{\mu}m$) of coil and length (0.35mm) of solenoid were determined by a Maxwell three-dimensional field simulator to maximize the performance of the inductors. High frequency characteristics of the inductance (L) and quality-factor (Q) of developed inductors were measured using an RF Impedance/Material Analyzer (HP4291B with HP16193A test fixture). The inductors developed have inductances of 10.8nH and quality factors of 25.2 at 250MHz, and show results comparable to those measured for the inductors prepared by CoilCraftTm that is one of the best chip inductor company in the world. The simulated data predicted the high-frequency data of the Land Q of the inductors developed well.

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A Study on Design of Magnetic Thin Film Inductors for DC-DC Converter Applications (DC-DC Converter용 자성박막 인덕터 설계에 관한 연구)

  • 윤의중;김좌연;박노경;김상기;김종대
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.1
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    • pp.74-83
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    • 2001
  • In this study, the optimum structure of a magnetic thin film inductor was designed for application of DC-DC converters. The Ni$\sub$81/Fe$\sub$19/ (at%) alloy was selected as a high-frequency($\geq$MHz) magnetic thin film magnetron sputtering system. As-deposited NiFe thin films show similar magnetic properties compared to bulk NiFe alloys, indicating that they have a good film quality. The optimum design of dolenoid-type magnetic thin film inductors was performed utilizing a Maxwell computer simulator (Ansoftt HFSS V7.0 for PC) and parameters obtained from the magnetic properties of magnetic core materials selected. The high-frequency characteristics of the inductance(L) and quality factor(Q) obtained for the designed inductors through simulation agreed well with those obtained by theoretical calculations, confirming that the simulated result is realistic. The optimum structure of high-performance (Q$\geq$60, L = 1${\mu}$H, efficiency $\geq$90%), high-frequency ($\geq$5MHz), and solenoid-type magnetic thin film inductors was designed successfully.

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MEMS-BASED MICRO FLUXGATE SENSOR USING SOLENOID EXCITATION AND PICK-UP COILS (MEMS 공정 제작방법에 의한 솔레노이드형 여자 코일과 검출코일을 사용한 마이크로 플럭스게이트 센서)

  • 나경원;박해석;심동식;최원열;황준식;최상인
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07a
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    • pp.172-176
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    • 2002
  • This paper describes a MEMS-based micro-fluxgate magnetic sensing element using Ni$\_$0.8/Fe$\_$0.2/ film formed by electroplating. The micro-fluxgate magnetic sensor composed of a thin film magnetic core and micro-structured solenoids for the pick-up and the excitation coils, is developed by using MEMS technologies in order to take advantage of low-cost, small size and lower power consumption in the fabrication. A copper with 20um width and 3um thickness is electroplated on Cr(300${\AA}$)/Au(1500${\AA}$) films for the pick-up(42turn) and the excitation(24turn) coils. In order to improve the sensitivity of the sensing element, we designed the magnetic core into a rectangular-ring shape to reduce the magnetic flux leakage. An electroplated permalloy film with the thickness of 3 $\mu\textrm{m}$ is obtained under 2000Gauss to induce magnetic anisotropy. The magnetic core has the high DC effective permeability of ∼1,100 and coercive field of -0.1Oe. The fabricated sensing element using rectangular-ring shaped magnetic film has the sensitivity of about 150V/T at the excitation frequency of 2MHz and the excitation voltage of 4.4Vp-p. The power consumption is estimated to be 50mW.

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MEMS-based Micro Fluxgate Sensor Using Solenoid Excitation and Pick-up Coils (MEMS 공정 제작방법에 의한 솔레노이드형 여자 코일과 검출코일을 사용한 마이크로 플럭스게이트 센서)

  • 나경원;박해석;심동식;최원열;황준식;최상언
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.2
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    • pp.120-124
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    • 2003
  • This paper describes a MEMS-based micro-fluxgate magnetic sensing element using Ni$\_$0.8/Fe$\_$0.2/ film formed by electroplating. The micro-fluxgate magnetic sensor composed of a thin film magnetic core and micro-structure solenoids for the pick-up and the excitation coils, is developed by using MEMS technologies in order to take advantage of low-cost, small size and lower power consumption in the fabrication. A copper with 20${\mu}$m width and 3${\mu}$m thickness is electroplated on Cr (300${\AA}$) / Au (1500${\AA}$) films for the pick-up (42turn) and the excitation (24turn) coils. In order to improve the sensitivity of the sensing element, we designed the magnetic core into a rectangular-ring shape to reduce the magnetic flux leakage. An electroplated permalloy film with the thickness of 3${\mu}$m is obtained under 2000 gauss to induce magnetic anisotropy. The magnetic core has the high DC effective permeability of ~1,100 and coercive field of ~0.1 Oe. The fabricated sensing element using rectangular-ring shaped magnetic film has the sensitivity of about 150 V/T at the excitation frequency of 2 MHz and the excitation voltage of 4.4 V$\_$p p/. The power consumption is estimated to be 50mW.

A Study for Frequency Characteristics of Solenoid-Type RF Chip Inductors (크기에 따른 솔레노이드 형태 RF 칩 인덕터의 주파수 특성 연구)

  • Kim, Jae-Wook
    • Journal of IKEEE
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    • v.11 no.4
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    • pp.145-151
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    • 2007
  • In this work, small-size, high-performance solenoid-type RF chip inductors utilizing a low-loss ${Al_2}{O_3}$ core material were investigated. The size of the chip inductors fabricated in this work were $0.86{\times}0.46{\times}0.45m^3$, $1.5{\times}1.0{\times}0.7m^3$, $2.1{\times}1.5{\times}1.0m^3$, and $2.4{\times}2.0{\times}1.4m^3$ and copper (Cu) wire with $27{\sim}40{\mu}m$ diameter was used as the coils. High frequency characteristics of the inductance, quality factor, and impedance of developed inductors were measured using an RF Impedance/Material Analyzer (HP4291B with HP16193A test fixture). It was observed that the developed inductors with the number of turns of 7 have the inductance of 13 to 100nH and exhibit the self-resonant frequency (SRF) of 6.4 to 1.1GHz. The SRF of inductors decreases with increasing the inductance and the inductors have the quality factor of 50 to 80 in the frequency range of 300MHz to 1.3GHz. In this study, small-size solenoid-type RF chip inductors with high inductance and high quality factor were fabricated successfully.

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Design and Evaluation of Pulsed Electromagnetic Field Stimulation Parameter Variable System for Cell and Animal Models (세포 및 동물모델용 펄스형 전자기장 자극 파라미터 가변장치 설계 및 평가)

  • Lee, Jawoo;Park, Changsoon;Kim, Junyoung;Lee, Yongheum
    • Journal of Biomedical Engineering Research
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    • v.43 no.1
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    • pp.11-18
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    • 2022
  • An electromagnetic generator with variable stimulation parameters is required to conduct basic research on magnetic flux density and frequency for pulsed electromagnetic fields (PEMFs). In this study, we design an electromagnetic generator that can conduct basic research by providing parameters optimized for cell and animal experimental conditions through adjustable stimulation parameters. The magnetic core was selected as a solenoid capable of uniform and stable electromagnetic stimulation. The solenoid was designed in consideration of the experimental mouse and cell culture dish insertion. A voltage and current adjustable power supply for variable magnetic flux density was designed. The system was designed to be adjustable in frequency and pulse width and to enable 3-channel output. The reliability of the system and solenoid was evaluated through magnetic flux density, frequency, and pulse width measurements. The measured magnetic flux density was expressed as an image and qualitatively observed. Based on the acquired image, the stimulation area according to the magnetic flux density decrease rate was extracted. The PEMF frequency and pulse width error rates were presented as mean ± SD, and were confirmed to be 0.0928 ± 0.0934% and 0.529 ± 0.527%, respectively. The magnetic flux density decreased as the distance from the center of the solenoid increased, and decreased sharply from 60 mm or more. The length of the magnetic stimulation area according to the degree of magnetic flux density decrease was obtained through the magnetic flux density image. A PEMF generator and stimulation parameter control system suitable for cell and animal models were designed, and system reliability was evaluated.