• Title/Summary/Keyword: FDTD Algorithm

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Analysis of Stability Condition and Wideband Characteristics of 3D Isotropic Dispersion(ID)-FDTD Algorithm (3차원 ID-FDTD 알고리즘의 Stability Condition과 광대역 특성 분석)

  • Kim, Woo-Tae;Koh, Il-Suek;Yook, Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.4
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    • pp.407-415
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    • 2011
  • The stability condition and wideband characteristics of 3D ID-FDTD algorithm which has low dispersion error with isotropic dispersion are presented in this paper. 3D ID-FDTD method was proposed to improve the defect of the Yee FDTD such as the anisotropy and large dispersion error. The published paper calculated the stability condition of 3D ID-FDTD algorithm by using numerical method, however, it is thought that the examples were not sufficient to verify the stability condition. Thus, in this paper, various simulations are included in order to hold reliability under the conditions that the plane wave propagation is assumed with a single frequency and a wideband frequency. Also, the 3D ID-FDTD algorithm is compared to those that have the similar FDTD algorithm with ID-FDTD such as Forgy's method and non-standard FDTD method in a wideband. Finally, the radar cross section(RCS) for the large sphere with high dielectric constant is calculated.

Construction of a CPU Cluster and Implementation of a 3-D Domain Decomposition Parallel FDTD Algorithm (CPU 클러스터 구축 및 3차원 공간분할 병렬 FDTD 알고리즘 구현)

  • Park, Sungmin;Chu, Kwang-Uk;Ju, Saehoon;Park, Yoon-Mi;Kim, Ki-Baek;Jung, Kyung-Young
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.3
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    • pp.357-364
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    • 2014
  • In this work, we construct a CPU cluster to implement a parallel finite-difference time domain(FDTD) algorithm for fast electromagnetic analyses. This parallel FDTD algorithm can reduce the computational time significantly and also analyze electrically larger structures, compared to a single FDTD counterpart. The parallel FDTD algorithm needs communication between neighboring processors, which is performed by the MPI(Message Passing Interface) library and a 3-D domain decomposition is employed to decrease the communication time between neighboring processors. Compared to a single-processor FDTD, the speed up factor of a-CPU-cluster-based parallel FDTD algorithm is investigated for the normal mode and the hypermode and finally analyze an electrically large concrete structure by the developed parallel algorithm.

The improved FDTD algorithm for modeling of a smooth cured surface (완만한 곡면의 마들링을 위한 개선된 FDTD 앨거리즘)

  • 길병수;이상설
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.143-146
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    • 1999
  • The traditional FDTD method in the stair case, the CP-FDTD method, the modified CP-FDTD method, and Dey method have been developed to analyze smooth-curved- surface structures. These methods have some disadvantages such as inaccuracy of the stair-case FDTD, instability of the modified CP-FDTD, and complexity of Dey method. The improved algorithm presented here is a mixed-form of the modified CP algorithm and Dey algorithm. It is to avoid collinear borrowing approximations and to manipulate field update equations. All of preceding methods are applied to the E-plane sectoral horn antenna to get far-field patterns. The validity and applicability of the presented one is to be shown by comparing computed far-field patterns with measured values.

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Dispersion Analysis of the Waveguide Structures by Using the Compact 2D ADI-FDTD (Compact 2D ADI-FDTD를 이용한 도파관 구조의 분산특성 연구)

  • 어수지;천정남;박현식;김형동
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.39 no.10
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    • pp.38-45
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    • 2002
  • This paper presents the new Compact 2D ADI-FDTD(Alternating-Direction Implicit Finite-Difference Time-Domain) method, where the time step is no longer restricted by the numerical stability condition. This method is an accelerating algorithm for the conventional Compact 2D FDTD method. To validate this algorithm, we have analyzed the dispersion characteristics of the hollow rectangular waveguide and the shielded microstrip line. The results of the proposed method are very well agreed with those of both the conventional analytic method and the Compact 2D FDTD method. The CPU time for analysis of this method is very much reduced compared with the conventional Compact 2D FDTD method. The proposed method is valuable as a fast algorithm in the research of dispersion characteristics of the waveguide structures.

An Alternating Implicit Block Overlapped FDTD (AIBO-FDTD) Method and Its Parallel Implementation

  • Pongpaibool, Pornanong;Kamo, Atsushi;Watanabe, Takayuki;Asai, Hideki
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.137-140
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    • 2002
  • In this paper, a new algorithm for two-dimensional (2-D) finite-difference time-domain (FDTD) method is presented. By this new method, the maximum time step size can be increased over the Courant-Friedrich-Levy (CFL) condition restraint. This new algorithm is adapted from an Alternating-Direction Implicit FDTD (ADI-FDTD) method. However, unlike the ADI-FDTD algorithm. the alternation is performed with respect to the blocks of fields rather than with respect to each respective coordinate direction. Moreover. this method can be efficiently simulated with parallel computation. and it is more efficient than the conventional FDTD method in terms of CPU time. Numerical formulations are shown and simulation results are presented to demonstrate the effectiveness and efficiency of our proposed method.

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Dispersive FDTD Modeling of Human Body with High Accuracy and Efficiency (정확하고 효율적인 인체 FDTD 분산 모델링)

  • Ha, Sang-Gyu;Cho, Jea-Hoon;Kim, Hyeong-Dong;Choi, Jae-Hoon;Jung, Kyung-Young
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.1
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    • pp.108-114
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    • 2012
  • We propose a dispersive finite-difference time domain(FDTD) algorithm suitable for the electromagnetic analysis of the human body. In this work, the dispersion relation of the human body is modeled by a quadratic complex rational function(QCRF), which leads to an accurate and efficient FDTD algorithm. Coefficients(involved in QCRF) for various human tissues are extracted by applying a weighted least square method(WLSM), referred to as the complex-curve fitting technique. We also presents the FDTD formulation for the QCRF-based dispersive model in detail. The QCRFbased dispersive model is significantly accurate and its FDTD implementation is more efficient than the counterpart of the Cole-Cole model. Numerical examples are used to show the validity of the proposed FDTD algorithm.

Application of 3D ADI-FDTD Method for GPR System Simulation (GPR 시스템 시뮬레이션을 위한 3차원 ADI-FDTD 기법의 적용)

  • Jeon Won Sok;Yeo Woonsik;Yun Seung Hyun;Kim Hyeongdong
    • Proceedings of the IEEK Conference
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    • 2004.06a
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    • pp.131-134
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    • 2004
  • This paper has been studied a ADI-FDTD(Alternating Direction Implicit Finite Difference Time Domain ) algorithm using an alternating Direction time-stepping scheme for GPR( Ground-Penetrating Radar ) system simulation. We did the numerical formulations for three-dimensional ADI-FDTD algorithm and PML(Perfect Matched Layer), and made an simple experiment on a arbitrary cube with programed algorithms. And then we compared its computed results with those of conventional FDTD.

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The Design of Microstrip Bandpass Filter for Wireless LAN using FDTD Parallel Algorithm (FDTD 병렬화 알고리즘을 이용한 무선랜용 마이크로스트립 대역통과 펄터 설계)

  • 최성열;박경수;고영호
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.7
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    • pp.395-400
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    • 2004
  • In this paper, the four-pole elliptic function microstrip filter at 2.4GHz band with fractional bandwidth of 4% is realized using compact miniaturized hairpin resonators. The parallel algorithm FDTD method is used to analyze S-parameter of hairpin resonator filter more accurately, and to calculate the electric coupling and magnetic coupling among the hairpin resonators. Absorbing boundary conditions for mesh termination used Sulivan's simplified PML and the FDTD code was paralleled by MPI for IBM SP2 which had enhanced calculation speed. The experimental measurements are performed by HP8720D vector network analyzer. Measured results on fabricated hairpin type cross coupled bandpass filters show good agreements with theoretic results.

Parallel Computation of FDTD algorithm using CUDA (CUDA를 이용한 FDTD 알고리즘의 병렬처리)

  • Lee, Ho-Young;Park, Jong-Hyun;Kim, Jun-Seong
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.47 no.4
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    • pp.82-87
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    • 2010
  • Modern GPUs(Graphic Processing Units) provide computing capability higher than that of the general CPUs(Central Processor Units). With supports of programmability of graphics pipeline GP-GPU(General Purpose computation on GPU) has gained much attention expanding its application area. This paper compares sequential and massively parallel implementations of FDTD(Finite Difference Time Domain) algorithm using CUDA(Compute Unified Device Architecture). Experimental results show upto 45X speedup over conventional CPU execution.

Analysis on the Planar Bowtie Antenna for IMT-2000 Handset (IMT-2000 핸드셋용 평면형 Bowtie 안테나 해석)

  • Lee, Hee-Suk;Kim, Nam
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.5
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    • pp.681-688
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    • 2000
  • In this paper, a planar antenna that is small and light, is designed and analyzed aiming handset antenna of IMT-2000. Employing the Ensemble simulator based on a MoM, design-parameters are found to determine a resonant frequency. Therefore, it is analyzed with the Ensemble simulation and FDTD numerical for resonating at the allocated frequency for IMT-2000 in the fixed antenna dimension of 21$^{\circ}$wing angle that is a design parameter. Analyzing with FDTD method, Though the results of FDTD are very exact, this analysis introduces errors due to the staircasing approximation in the slope of bowtie. To reduce this error, it is divided to 4-ranges where the cell contains the boundary of perfect conductor/free space. Then, each range is calculated by different by different equation, which modify the H-field to add the component of the area and length of the cell filled with free space. Therefore, the modified FDTD algorithm provided with a narrow bandwidth of return loss calculated with a standard FDTD algorithm that can be extended to the desired ranges.

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