• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.340-347
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• 2004

Ultra-small size, high-performance, solenoid-type RF chip inductors utilizing low-loss A1$_2$O$_3$ core materials were investigated. The dimensions of the RF chip inductors fabricated were 1.0mm${\times}$0.5mm${\times}$0.5mm and copper coils were used. The materials (96％ A1$_2$O$_3$) and shape (I-type) of the core, the diameters (40${\mu}{\textrm}{m}$) and position (middle) of the coil, and the lengths (0.35mm) of solenoid were determined by a high-frequency structure simulator (HFSS) to maximize the performance of the inductors. The high-frequency characteristics of the inductance (L) and quality-factor (Q) of the developed inductors were measured using a RF impedance/material analyzer (E4991A with E16197A test fixture). The developed inductors exhibit an inductance of 11 to 11.3nH and a qualify factor of 22.3 to 65.7 over the frequency ranges of 250 MHz to 1.7 GHz, and show results comparable to those measured for the inductors prepared by Coilcraft$^{TM}$. The simulated data described the high-frequency data of the L and Q of the fabricated inductors well.

• 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.

• Journal of the Korean Magnetics Society
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• v.11 no.5
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• pp.222-225
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• 2001

The planar type inductors have a good potential for the application of miniaturized low power DC-DC converters. For those high quality application, the reduction of coil loss and also magnetic films which have good high frequency properties are required. Fabricated inductor was consisted of FeTaN/Ti magnetic film and electroplated Cu coil thickness of 100$\mu\textrm{m}$ and $SiO_2$ as a insulating layer. The inductor was designed double rectangular spiral shape for magnetic field highly confining within the device. The measured value of inductance and resistance were 980 nH and 1.7 $\Omega$ at 1 MHz as operating frequency of device. The Q factor is 3.55 at 1 MHz.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.231-237
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• 2016

This paper presents a multiband low phase noise CMOS VCO with wide frequency tunability using switched bondwire inductor bank. The combination of bondwire inductor and CMOS switch transistor enhances frequency tunability and improves phase noise characteristics. The proposed multiband VCO operates from 2.3GHz to 6.3GHz with phase noise of -136dBc/Hz and -122dBc/Hz at 1 MHz offset frequency, respectively. Switched bondwire inductor bank shows high quality factor(Q) at each frequency band, which allows better tradeoff between phase noise and power consumption. The proposed VCO is designed in TSMC 0.18um CMOS process and consumes 7.2 mW power resulting in figure of merit(FOM) of -189.3dBc/Hz at 1 MHz offset from 6GHz carrier frequency.

• 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.

• Proceedings of the KIEE Conference
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• 2008.10a
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• pp.107-108
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• 2008

This article describes optimization for PGS(Patterned Ground Shield) of rectangular spiral inductor using Taguchi's Design of Experiment. PGS is decrease method of parasite component by silicon substrate among dielectric loss reduction method. Using taguchi's design of experiment, each parameter is fixed upon that PGS high poison(A), slot spacing(B), strip width(C) and overlap turn number(D) of PGS design parameter. Then we verified that percentage contribution and design sensitivity analysis of each parameter and level by signal to noise ratio of larger-the-better type. We consider percentage contribution and design sensitivity of each parameter and level, and then verify that model of optimization for PGS is lower inductance decreasing ratio and higher Q-factor increasing ratio by EM simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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• pp.1471-1475
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• 2007

In this paper, a novel embedded ultra wideband (UWB) band-pass filter is presented on a FR-4 package substrate including high Dk resin coated copper (${\varepsilon}_r=30$) film. The proposed UWB filter is comprised of a parallel resonator with meander-type uniform impedance resonator (UIR) and two series resonators with high Q circular stacked spiral inductor and metal-insulator-metal (MIM) capacitor. In order to obtain excellent attenuation characteristics by generating attenuation poles in lower and upper stop bands, a single MIM capacitor is added to each resonator. The fabricated FR-4 embedded UWB filter has insertion loss of -1.0dB and return loss of -11dB, respectively. It has also extremely wide bandwidth (over 50%) and small size ($3.7{\times}4{\times}0.77\;mm^3$) which is compatible with LTCC devices.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.10-16
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• 2021

This paper proposes a model that considers the parity-time symmetric structure as a state detection circuit for sensor applications using a stretchable inductor. In particular, to obtain a more practical computer simulation result, the stretchable inductor model was applied to this study model by referring to previously reported experimental results. The resistance component and phase component were controlled through the negative differential resistance circuit used in this study. In addition, the imbalance of the circuit caused by a change in the characteristics of the stretchable inductor could be compensated for using a negative differential resistance circuit. In particular, an analysis of the frequency characteristics of the sensor driving circuit of the parity-time symmetric structure proposed in this study confirmed that the Q-factor could be increased up to 20 times compared to the conventional resonant circuit.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.37-44
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• 2007

A low-voltage high-linear bipolar OTA and its application to IF bandpass filter for GSM cellular telephone are presented. The OTA consists of a low-voltage linear transconductor, a translinear current gain cell, and three current mirrors. The bandpass filter is composed of two cascaded identical second-order bandpass filters, which consist of a resistor, a capacitor, and a grounded simulated inductor realized with two OTA's and a grounded capacitor. SPICE simulations using an 8 GHz bipolar transistor-array parameter show that the OTA with a transconductance of 1 mS exhibits a linearity error of less than ${\pm}2%$ over an input voltage range of ${\pm}0.65\;V$ at supply voltages of ${\pm}2.0\;V$. Temperature coefficient of the transconductance is less than $-90ppm/^{\circ}C$. The bandpass filter has a center frequency of 85 MHz and Q-factor of 80. Temperature coefficient of the center frequency is less than $-182ppm/^{\circ}C$. The power dissipation of the filter is 128 mW.