• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.177-180
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• 2001

A decoupled, wide-band, perfectly magnetically conductor(PMC)-backed air waveguide antenna is designed and constructed for the use of the continuous electromagnetic wave ground penetrating radar in the frequency range from 200MHz to 600MHz. Two planar dipoles are located inside air slab covered by PMC on the top side and separated by an air gap from the bottom ground interface. The coupling between the transmitting and the receiving dipoles is calculated by less than -60dB over the frequency from 200MHz to 600MHz.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.493-494
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• 2006

Fabrication-error tolerant directional couplers are designed and analyzed. In the wavelength region of $1.55{\mu}m$, the coupling characteristics of the 3dB coupler is 50${\pm}$4%, when the waveguide width error is ${\pm}0.2{\mu}m$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.149-150
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• 2011

• Journal of the Semiconductor & Display Technology
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• v.9 no.2
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• pp.97-102
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• 2010

Propagation modes of symmetric metal-insulator-metal SPP waveguides are analyzed. Main characteristics of these waveguides such as mode effective index, propagation length, and penetration depths are calculated at the telecom wavelength for different layer thickness. We adopt Au, Al as a metal material and air, glass as a dielectric material and obtain different optical characteristics. The surface plasmon characteristics in this paper provide a numerical insight for designing nanostructure metal plasmon waveguide.

• International Journal of Contents
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• v.8 no.3
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• pp.100-104
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• 2012

In this paper, a unit cell for low pass filter design by using composite right and left-handed transmission line in conductor-backed coplanar waveguide is proposed. The characteristics of the unit cell are analyzed in order to design a low pass filter in small sizes. By changing the sizes of the unit cell, the parameters of right-handed and left-handed immittance components are changed and the desired characteristics of the unit cell are achieved. The equivalent circuit of the unit cell is extracted and analyzed either. As a result, the simulation results of the unit cell and the equivalent circuit are almost identified. The movement and energy distributions of electromagnetic field are shown to confirm the property of the unit cell. In the end, a low pass filter is demonstrated by cascading three proposed unit cells, which shows cutoff frequency of 1.53GHz and deep attenuation from 2.23GHz to 4.49GHz lower than -50dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.99-109
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• 2010

Recently, SIW(Substrate Integrated Waveguide) is intensively studied because of its high Q and easy integration with other devices. However, lacks of analytic characterization of SIW makes it difficult an accurate design of a SIW filter along the conventional filter design method. In this paper, two kinds of a three-stage 10 GHz SIW bandpass filter of fractional bandwidth 10% are designed using 3D EM simulator HFSS based on the recently presented EM filter design method. Two types of a modified CPW to SIW transition is proposed and employed as a SIW to microstrip transition necessary for measurement. The transitions provide an easy measurement with commercial test fixture by TRL calibration. The two proposed transitions are included in the SIW filters. The fabricated filters shows the center frequency of 10 GHz, fractional bandwidth 10%, a return loss of about 12 dB, and insertion loss of about 0.8 dB.

• Proceedings of the Optical Society of Korea Conference
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• 1999.08a
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• pp.120-121
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• 1999

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.2
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• pp.46-55
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• 2002

The key component to accomplish the WDM all optical network is an Arrayed Waveguide Grating(AWG) wavelength filter Numerical analysis is necessary for design and analysis of optical components like AWG wavelength filter. Beam Propagation Method(BPM) is the most widely-used method. In this paper, we analyze the difference between the paraxial BPM and the WA-BPM when they are applied to the analysis of InP/InGaAsP/InP AWG wavelength filter. The paraxial BPM is based on paraxial approximation, and the WA-BPM is based on the low order Pade approximant. The side lobe level(SLL) and insertion loss calculated from both methods are compared. The high order Pade approximant will to used to more accurate design and analysis of AWG.

• Journal of Astronomy and Space Sciences
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• v.27 no.3
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• pp.239-244
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• 2010

A simulation for the design of a $90^{\circ}$ differential phase shifter aimed toward Korean VLBI Network (KVN) 129 GHz band polarizer is described in this paper. A dual-circular polarizer for KVN 129 GHz band consists of a $90^{\circ}$ differential phase shifter and an orthomode transducer. The differential phase shifter is made up of a square waveguide with two opposite walls loaded with corrugations. Three-dimensional electromagnetic simulation has been performed to predict the $90^{\circ}$ differential phase shifter's characteristics. The simulation for the differential phase shifter shows that the phase shift is $90^{\circ}{\pm}3.3^{\circ}$ across 108-160 GHz and the return losses of two orthogonal modes are better than -30 dB within the design frequency band. According to the simulation results the calculated performance is quite encouraging for KVN 129 GHz band application.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.6
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• pp.135-141
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• 2008

In this paper, a design method of broadband horn antenna having 3:1 bandwidth and multiple polarization characteristics is proposed. The feeding section of the antenna adopts quadruple-ridged waveguide type for broadband and multiple polarization characteristics of the antenna. By inserting a shorting bar in the cavity structure with a semi-sphere type back short, the return loss at the feeding section was minimized. A corrugated dielectric lens is designed for phase compensation and lens-surface matching at the antenna aperture, which improves the antenna beam pattern. The validity of the design method is verified by indicating the measured data of the antenna.