• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.505-506
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• 2007

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• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.256-259
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• 2011

In this article, new microstrip slow-wave bandpass filters using open loop resonator loaded with inter-digital capacitive fingers is proposed. The filter features not only compact in size, but also exhibits spurious stop-band rejection. Filters of this type with elliptic function and Chebyshev response are demonstrated. There is good agreement between experimental and full-wave electromagnetic (EM) simulation results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.11
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• pp.898-908
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• 1990

This paper applies the moment method to analyze the transverse electromagnetic(TEM) cell with an inner conductor (septum) of arbitrary rectangular shape and location by employing quast static approximation. The EM field and the characteristic impedance so obtained are shown to be in good agreement with the available data from the previously published papers about the typical TEM cell structure with center septum of zero thickness.

• Proceedings of the KIEE Conference
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• 1985.07a
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• pp.344-347
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• 1985

Hew dual integral equation for electromagnetic field scattered by an arbitrary dielectric wedge is formulated. In order to check the validity and physical meaning of the formulated equation, it is applied to the well-known case which is the diffraction by a perfectly conducting wedge.

• Geophysics and Geophysical Exploration
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• v.5 no.4
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• pp.280-290
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• 2002

Three-dimensional (3-D) electromagnetic (EM) modeling algorithm has been developed using finite element method (FEM) to acquire more efficient interpretation techniques of EM data. When FEM based on nodal elements is applied to EM problem, spurious solutions, so called 'vector parasite', are occurred due to the discontinuity of normal electric fields and may lead the completely erroneous results. Among the methods curing the spurious problem, this study adopts vector element of which basis function has the amplitude and direction. To reduce computational cost and required core memory, complex bi-conjugate gradient (CBCG) method is applied to solving complex symmetric matrix of FEM and point Jacobi method is used to accelerate convergence rate. To verify the developed 3-D EM modeling algorithm, its electric and magnetic field for a layered-earth model are compared with those of layered-earth solution. As we expected, the vector based FEM developed in this study does not cause ny vector parasite problem, while conventional nodal based FEM causes lots of errors due to the discontinuity of field variables. For testing the applicability to high frequencies 100 MHz is used as an operating frequency for the layer structure. Modeled fields calculated from developed code are also well matched with the layered-earth ones for a model with dielectric anomaly as well as conductive anomaly. In a vertical electric dipole source case, however, the discontinuity of field variables causes the conventional nodal based FEM to include a lot of errors due to the vector parasite. Even for the case, the vector based FEM gave almost the same results as the layered-earth solution. The magnetic fields induced by a dielectric anomaly at high frequencies show unique behaviors different from those by a conductive anomaly. Since our 3-D EM modeling code can reflect the effect from a dielectric anomaly as well as a conductive anomaly, it may be a groundwork not only to apply high frequency EM method to the field survey but also to analyze the fold data obtained by high frequency EM method.

• Transactions of the Society of Information Storage Systems
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• v.4 no.1
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• pp.23-28
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• 2008

In this paper we suggested the moving magnet type actuator for optical disc drive which has high frequency of flexible mode. Generally, moving magnet type actuator has the advantage for increase the frequency of flexible mode. But it has low driving sensitivity due to the weight of its moving part. To overcome this shortcoming, we designed the model with the closed electromagnetic circuit for tracking direction. In addition, we improved the driving sensitivity and frequency of flexible mode by using of DOE (design of experiment) procedure for EM circuit. Consequently, it is verified that final designed model satisfied with the desired specifications.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.105
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• pp.148-151
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• 2006

The DC power-bus' resonance is frequently attributed to EMI sources in the PCBs. Subsequently, it will ruin the digital signal integrity within one system or between adjacent systems in the form of conducted or radiated emission. Hence, since it is of importance to examine the PCB's emission, this paper sheds a light on the radiated emission from the power-bus with regards to its resonance modes. A full-wave analysis method is used to calculate the impedance and radiated electric fields and is validated by physics and an EM analysis tool.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.143-148
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• 2005

The objective of this study is to estimate RF signal strength over sea and land surfaces. For this work we calculated scattering by land with DEM(Digital Elevation Model) and sea surface with RMS surface height. and we selected two area inland and sea shore as RX point. And for each area, we get VV-pol and HH-pol characteristic of scattering at 2.2GHz.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.429-432
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• 2005

This paper investigates how the PCB power-bus structure's characteristics are influenced by the loading of decoupling capacitors that are placed close to vias, on purpose or not. It is worthwhile to see the correlated effects of the aforementioned lumped elements in that when they inevitably share one DC power-bus they will result in positive or negative changes in the PCB EMC design. The EM fields and impedance profiles are rigously calculated on the PCB power-bus cases loaded with the above components and their effects will be given to bring better PCB EMC countermeasures.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.149-152
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• 2005

The DC power-bus' resonance is frequently attributed to EMI sources in the PCBs. Subsequently, it will ruin the digital signal integrity within one system or between adjacent systems in the form of conducted or radiated emission. Hence, since it is of importance to examine the PCB's emission, this paper sheds a light on the radiated emission from the power-bus with regards to its resonance modes. A full-wave analysis method is used to calculate the impedance and radiated electric fields and is validated by physics and an EM analysis tool.