• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.8
• /
• pp.790-796
• /
• 2002

In our country, historically beautiful and significant wooden architectures are preserved as the cultural properties. For a long time, however, the architectures are often exposed to rough environmental conditions, such as weathering, insect attack, etc. This may lead to deterioration of structural integrity of the architectures. Therefore, it is necessary to diagnose wooden architectures in advance. In this paper, the possibility of a subsurface-penetrating radar(SPR) fur non-destructive testing(NDT) of wooden architectures is investigated by using the three-dimensional finite-difference time-domain(FDTD) simulation and actual laboratory measurement.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.4
• /
• pp.101-112
• /
• 2004

In this paper, we developed a numerical analysis model by using ADI-FDTD method to analyze three-dimensional interconnect structure. We discretized maxwell's curl equation by using ADI-FDTD. Using ADI-FDTD method, a sampler circuit designed from 3.3 V CMOS technology is simplified to 3-metal line structure. Using this simplified structure, the time delay and signal distortion of complex interconnects are investigated. As results of simulation, 5∼10 ps of delay time and 0.1∼0.2 V of signal distortion are measured. As demonstrated in this paper, the full-wave analysis using ADI-FDTD exhibits a promise for accurate modeling of electromagnetic phenomena in high-speed VLSI interconnect.

• Proceedings of the Optical Society of Korea Conference
• /
• 2004.02a
• /
• pp.222-223
• /
• 2004

• 한국정보통신설비학회:학술대회논문집
• /
• 2007.08a
• /
• pp.238-240
• /
• 2007

본 논문에서는 전자기파 산란 문제를 해석하는데 있어서 중요한 기법의 하나인 유한 차분 시간영역 해석방법(FDTD : Finite-Difference Time-Domain Method)을 이용하여 금속 차폐구조의 틈새인 개구를 통한 EMC 문제를 중점적으로 다루었다. 이와같은 3차원 FDTD를 이용한 전자파 산란 문제의 해석을 통한 연구는 통신 시스템의 차폐 방안과 전자파 내부침투 문제 해결을 위한 중요한 기반 작업이 될 것으로 기대된다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.24 no.1
• /
• pp.98-105
• /
• 2013

This paper presents a finite-difference time-domain(FDTD) simulation and a data processing technique for radar sensing of the internal structure of a wall using an ultra-wide band antenna. We first designed an ultra-wide band anti-podal vivaldi antenna with a frequency range of 0.3~7 GHz which is chosen to be relatively low after considering the characteristics of wave attenuation, wall penetration, and range resolution. In this study the two-dimensional FDTD technique was used to simulate a wall-penetration-radar experiment under practical conditions. The next, the measured radiation pattern of the practical antenna is considered as an equivalent source in the FDTD simulation, and the reflection data of a concrete wall and targets are obtained by using the simulation. Then, a data processing technique has been applied to the FDTD reflection data to get a radar image for remote sensing of the internal structure of the wall. We compared the two different source excitations in the FDTD simulation; (1) commonly-used isotropic point sources and (2) polynomial curve fitting sources of the measured radiation pattern. As a result, when we apply the measured antenna pattern into the FDTD simulation, we could obtain about 2.5 dB higher signal to noise level than using a plane wave incidence with isotropic sources.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.34D no.10
• /
• pp.60-67
• /
• 1997

This paper presents a 3-D finite difference time domain (FDTD) method used for indoor propagation simulations where the electromagnetic wav eis uniformly excited on th eone of the wall in a building and affected by an indoor obstacles. In cases of simulation and measurement, the frequency of 851 MHz is used. The conductivities of walls, floor, ceiling and indoor obstacles are measured and used for simulations. These simulations are carried out using different boundary condition such as mur's absorbing boundary condition (ABC) and perfectly matched layer (PML) technique. The PML technique is found to be well-suited to this analysis because of it's smaller computational domain than mur's ABC. The measured signal strengths are compared to simulated values with good agreement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.12 no.7
• /
• pp.1067-1075
• /
• 2001

The fields at the aperture of conical horn antenna with corrugations parallel to the axis have been analyzed using FDTD(Finite Difference Time Domain). Easy calculation depending on the change of the structure of antenna and time reduction can be achieved by 2-D FDTD coding with the first-order Mur ABC(absorbing boundary condition). It is confirmed that the corrugation can reduce phase difference of field on aperture. also it is investigated that the directivity is increased by 6.1 %, 12.9%, and 28.4% with one corrugation, two corrugations, three corrugations, respectively. It is also found that the improvement of the characteristics of the antenna is not proportional to the number of the corrugation but more dependent on the location of the corrugation near the aperture than that far the aperture.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.8 no.5
• /
• pp.486-487
• /
• 1997

This paper presents the pure capacitive lumped element equivalent circuits for several coplanar waveguide(CPW) discontinuities such as an open-end, an open-end with connected ground planes, a gap and an open-end CPW stub and gives their capacitive element values as a function of physical dimensions of the discontinuity and the frequency for a specific substrate. The capacitive element values are determined from the scattering parameters which are obtained using the finite-difference time-domain(FDTD) method. For an open-end, an open-end with connected ground planes and a gap, the numerical results of the FDTD are compared with the quasi-static results which are calculated using the three- dimensional finite difference method(3D-FDM).

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.8
• /
• pp.52-63
• /
• 2002

In this paper, we developed a numerical analysis model by using ADI-FDTD method to analyze three-dimensional interconnect structure. We discretized maxwell's curl equation by using ADI-FDTD. We introduced PML(Perfectly Matched Layer) absorbing boundary condition to solve the effect of the reflected wave at the interface. Evaluating the numerical model of PML and ADI-FDTD, we simulated the electric field distribution in time domain. We compare standard FDTD with ADI-FDTD, and analysis the result.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.29 no.1
• /
• pp.61-67
• /
• 2018

The effects of subsurface inhomogeneities on the detection of buried metal pipes in ground-penetrating radar(GPR) signals are investigated numerically. To model the electrical properties of the subsurface inhomogeneities, the continuous random media(CRM) generation technique is introduced. For the electromagnetic simulation of GPR signals, the finite-difference time-domain(FDTD) method is implemented. As a function of the standard deviation and the correlation length of the relative permittivity distribution for a randomly inhomogeneous ground, the GPR signals of the buried metal pipes are compared using numerical simulations. As the subsurface inhomogeneities increase, the GPR signals of the buried pipes are distorted because of the effect of the subsurface clutter.