• Journal of electromagnetic engineering and science
• /
• 제3권1호
• /
• pp.39-44
• /
• 2003

An unconditionally stable compact 2D Alternating-Direction Implicit (ADI) FDTD method for calculating dispersion characteristics of waveguide structures is proposed. The numerical stability and numerical dispersion relation of the proposed method are also presented and discussed. Numerical wavelengths for the dominant and higher order modes in a hollow waveguide are obtained from numerical simulations and compared with those from the analytical dispersion relation. The numerical results show that the proposed scheme has the potential to successfully analyze a class of waveguides having locally fine geometry with reduced numerical costs.

• 한국전자파학회논문지
• /
• 제10권6호
• /
• pp.935-950
• /
• 1999

A multiresolution time-domain analysis scheme is derived for the analysis of microwave structures by using Haar wavelets to discretize the Maxwell's curl equation. This technique requires less computational effort than the conventional FDTD method because larger space grid can be used in the simulations. To validate this scheme, several 2-D·3-D microwave structures are simulated and the results are compared with those of the conventional FDTD scheme.

• 한국정보통신학회논문지
• /
• 제3권3호
• /
• pp.533-540
• /
• 1999

본 논문에서는 구형 패치를 이용하여 GPS용 마이크로스트립 안테나를 설계하였으며 안테나의 특성을 확인하기 위하여 시뮬레이션을 통해 단일 구형 마이크로스트립 패치 안테나의 폭과 급전선을 변화 시켰다. 그리고 축비를 이용하여 우선회 원형편파 특성을 확인하였고, 결과를 통해 유한차분 시간영역법은 마이크로스트립 안테나를 설계하기 위한 효과적인 방법임을 확인하였다. 시뮬레이션을 통한 GPS위성으로부터 수신된 주파수의 공진점을 확인하였고, 측정치와 비교적 잘 일치하였다.

• Journal of electromagnetic engineering and science
• /
• 제11권1호
• /
• pp.11-15
• /
• 2011

Preserving high-order accuracy in high-order FDTD solutions across dielectric interfaces is very important for practical time-domain electromagnetic simulations. This paper presents a fourth-order accurate numerical boundary scheme for the planar dielectric interface to be used in the fourth-order FDTD method proposed earlier by the author. The interface scheme for the two-dimensional (2-D) transverse magnetic (TM) polarization case is derived and validated by monitoring the $L_2$ norm errors in the numerical solutions of a partially-filled cavity demonstrating its fourth-order convergence and long-time numerical stability in the presence of the planar dielectric interface.

• 전자공학회논문지D
• /
• 제36D권8호
• /
• pp.19-26
• /
• 1999

개방단말 동축선 프로브의 제작오차가 프로브에 접촉된 매질의 복소유전율 측정에 얼마나 강한 영향을 미치는 지를 살펴보기 위한 수치계산을 수행하였다. 몇 가지 종류의 유전체를 접촉시킨 개방단말 동축선 프로브의 반사계수는 FDTD 방법을 적용해 수치계산 하였다. 이러한 계산된 반사계수들을 새로운 가상의 전송선 모델에 적용시켜 복소유전율로 확산하였는데, 본 논문에서 사용한 방법은 기존의 방법보다 물리적으로 더 의미가 있는 방법이다. 개방단말 프로브에 약간의 제작오차가 있을 때에도 복소유전율에는 큰 오차가 발생함을 알 수 있었다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
• /
• pp.218.1-218.1
• /
• 2014

In order to measure the absolute plasma density, various probes are proposed and investigated and microwave probes are widely used for its advantages (Insensitivity to thin non-conducting material deposited by processing plasmas, High reliability, Simple process for determination of plasma density, no complicate assumptions and so forth). There are representative microwave probes such as the cutoff probe, the hairpin probe, the impedance probe, the absorption probe and the plasma transmission probe. These probes utilize the microwave interactions with the plasma-sheath and inserted structure (probe), but frequency range used by each probe and specific mechanisms for determining the plasma density for each probe are different. In the recent studies, behaviors of each microwave probe with respect to the plasma parameters of the plasma density, the pressure (the collision frequency), and the sheath width is abundant and reasonably investigated, whereas relative diagnostic characteristics of the probes by a comparative study is insufficient in spite of importance for comprehensive applications of the probes. However, experimental comparative study suffers from spatially different plasma characteristics in the same discharge chamber, a low-reproducibility of ignited plasma for an uncertainty in external discharge parameters (the power, the pressure, the flow rate and so forth), impossibility of independently control of the density, the pressure, and the sheath width as well as expensive and complicate experimental setup. In this paper, various microwave probes are simulated by finite-different time-domain simulation and the error between the input plasma density in FDTD simulations and the measured that by the unique microwave spectrums of each probe is obtained under possible conditions of plasma density, pressure, and sheath width for general low-temperature plasmas. This result shows that the each probe has an optimum applicable plasma condition and reliability of plasma density measurement using the microwave probes can be improved by the complementary use of each probe.

• 대한전자공학회논문지TC
• /
• 제42권12호
• /
• pp.159-164
• /
• 2005

최근 정보량의 증가로 고속 디지털 회로를 요구하고 있다. 이에 따라 소형 고주파 회로에 전자기 특성이 중요하게 대두되었다. 그래서 불완전한 그라운드 상에 PCB 회로의 고속 디지털 전송라인에 대한 신호 집적도와 두 평행 선로 사이의 결합특성을 3차원 전자기 해석법인 시간영역 유한차분법을 이용하여 해석하였다. FDTD 시뮬레이션 결과는 상용 회로 소프트웨어 툴인 ADS 시뮬레이터와 비교하였고, 집중 소자 모델링, 주파수에 따른 슬롯에 의한 전자파의 방사 등을 해석하였다. 결과로써 마이크로스트립 선로 아래 슬롯이 있는 경우 신호의 전송에 큰 영향을 끼치는 것을 알 수 있다.

• 전자공학회논문지D
• /
• 제34D권10호
• /
• 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.

• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
• /
• pp.340-343
• /
• 2002

Electromagnetic(EM) radiation problems and their possible solutions are addressed in this paper for the split power plane of high-speed digital systems. Stitching and decoupling capacitors are proved to be very effective fur reducing signal noise, ground bounce as well as electromagnetic radiation from the split power plane. Simulations based on 3D-Finite Difference Time Domain (FDTD) method are utilized for the analysis of practical high frequency multi-layered PC main board

• Journal of electromagnetic engineering and science
• /
• 제2권2호
• /
• pp.75-80
• /
• 2002

Signal integrity problems and their possible solutions are addressed in this paper for split power plane of high-speed digital systems. Stitching and decoupling capacitors are proved to be very effective for reducing signal noise, ground bounce as well as electromagnetic radiation from the split power plane. Simulations based on 3D-Finite Difference Time Domain (FDTD) method are utilized for the analysis of practical high frequency multi-layered PC main board.