• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1318-1320
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• 1998

We have investigated the electrical characteristics of a MOSFET-structured silicon field emitter by employing Maxwell 2D and Silvaco simulators. The potential distribution is obtained by Maxwell 2D simulator and the field emission current is calculated by Fowler-Nordheim equations. The characteristics of MOSFET is simulated by Silvaco simulator. Simulated results are almost identical to the experimental results. Also, we have studied the emission characteristics as funtions of several geometric parameters.

• 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 IEEK Conference
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• 2001.06a
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• pp.413-416
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• 2001

In high frequency range, RF circuit design without considering shielding effect can cause several significant changes due to increase in parasitic capacitance and inductance between RF signal lines and shielding box. In this paper, bandpass filter has been made to measure the shielding effect and its s-parameter has been measured by Vector Network Analyzer (VNA). Equivalent circuit model including the shielding effect has been constructed with the lumped elements extracted from the 3D electromagnetic simulator, Maxwell SI. Then, the validity of the model is verified using microwave circuit simulator, ADS (Advanced Design System).

• 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.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.11
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• pp.555-561
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• 2001

In this paper, the low power (1.5 W) solenoid-type magnetic thin-film transformers utilizing a $Ni_{81}Fe_{19)$ core material were designed and fabricated for 5 MHz-drive DC-DC converter application. The $20\mum$ thick copper films were used as the coils. The transformers fabricated in this work have the sizes of $3.08 mm\times25.5 mm\; and\; 6.15 mm\times12.75 mm.$ The optimum design of solenoid-type magnetic thin film transformers was performed utilizing the conventional equations, a Maxwell computer simulator (Ansoft HFSS V7.0 for PC), and parameters obtained from the magnetic properties of NiFe magnetic core materials. frequency characteristics of inductance, dc resistance (R), coupling factor (k) and gain of developed transformers were measured using HP4194A impedance and gain-phase analyzer. The fabricated transformers with the size of $6.15 mm\time12.75 mm$ exhibit the inductance of $0.83 \muH$, the dc resistance of $2.3\Omega$$\Omega$, the k of 0.91 and the gain of -1 dB at 5 MHz, which show the comparable results to those reported in the recent literatures. The measured high-frequency characteristics for the fabricated transformers agreed well with those obtained by theoretical calculations .

• Electrical & Electronic Materials
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• v.9 no.5
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• pp.498-505
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• 1996

In the present work, we have developed the simulator to optimize the process conditions of the AR(antireflection) and HR(high-reflection) coatings for the high power laser diode. The simulator can run on the PC. After making the simple optical model, we establish the Maxwell equations for the model by the operator conversion. By using the Mathematica, we derive a matrix for the multilayer system by applying the equations to the model and optimize the AR and HR coating process conditions by obtaining the reflection rate from the matrix. We also prove the validity of the simulator by comparing the simulation with the characteristics of the laser diode which is AR and HR coated according to the optimized conditions.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.847-849
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• 1996

As the power demands increases, one of the most important data is inside electric field of equipment in designing of insulators ami insulated wire for EHV distribution line. So far finite element analysis method is widely used to calculate this electric field. However as the shape of insulator becomes complicated, it is difficult in producing the mesh which suitable the shape. Especially, we have many difficulty that produce dense fine mesh only where the electric field is concentrated. Therefore in this paper, we perform the each conditional analysis of electric field using the Maxwell 3D Simulator to recover this defects. And we try to analyze electric field through the conventional 2 dimensional and 3 dimensional analysis in case of salt contamination on the surface of a insulator.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.119-123
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• 2001

In this paper, a new structure and fabrication method for the wafer level package(WLP) is presented. A packaged VLSI chip is encapsulated by a parylene(which is a low k material) layer as a dielectric layer and is molded by SUB photo-epoxy with dielectric constant of 3.0 at 100 MHz. The electrical parameters (R, L, C) of package traces are extracted by using the Maxwell 3-D simulator. Based on HSPICE simulation results, the proposed wafer level package can operate for frequencies up to 20GHz.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1442_1442
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• 2009

This paper describes electric field analysis and design of direct current arresters for electric traction vehicles. Generally, DC arresters are used to protect the electric traction to limit the overvoltage invading into its inner electrical circuits. We could proposed operating voltage(Uc), the rated voltage(Ur). Finally maxwell 2D simulator based on the boundary element method was also introduced in order to verify the reliability of the DC arresters.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1078-1085
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• 2006

In earthing technologies, the intrusion of the surge wave can be protected when the earthing resistance is as low as several ohms. However, the cost fer realizing such a low resistance is quite high. Therefore it is important to determine appropriate target value of the earthing resistance to install cost-effective grounding system. In this work, we have proposed an optimization method of the earthing resistance according to the various environmental parameters by using a numerical simulator We have also developed new catalyst composed of water-soluble alkaline elements and activated carbon and investigated its electrical characteristics for enhancement of the earthing qualities.