Workshop on Computational Electromagnetics in Time-Domain, 2005. CEM-TD 2005.最新文献

{"title":"Splitting error reductions for the ADI-FDTD method","authors":"I. Ahmed, Z. Chen","doi":"10.1109/CEMTD.2005.1531698","DOIUrl":"https://doi.org/10.1109/CEMTD.2005.1531698","url":null,"abstract":"The ADI-FDTD method has attracted much attention for its unconditional stability and efficient simulations in the time domain with large time-steps. However, the associated errors are found to be relatively large in comparisons with another unconditionally stable FDTD scheme, the Crank-Nicolson (CN) technique, although the ADI-FDTD method presents higher computational efficiency. In this paper, we propose new ADI-FDTD methods that are based on the CN method but with the computational efficiency similar to that of the original ADI scheme. Numerical results are used to validate the methods.","PeriodicalId":407683,"journal":{"name":"Workshop on Computational Electromagnetics in Time-Domain, 2005. CEM-TD 2005.","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133241311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adding generic sources to high-order finite-difference schemes","authors":"M. White","doi":"10.1109/CEMTD.2005.1531700","DOIUrl":"https://doi.org/10.1109/CEMTD.2005.1531700","url":null,"abstract":"General electromagnetic problems may require specialized incident fields that may not be easily accommodated in the traditional scattered field formulation. In implementing such incident fields in a high-order formulation, care should be taken to insure that the source is implemented in a consistent manner with the numerical scheme. The details of implementing a scattered field / total field interface for compact-difference schemes will be addressed. Additionally, a modified algorithm for implementing sources in the standard Runge-Kutta time integration schemes will be proposed to reduce numerical error.","PeriodicalId":407683,"journal":{"name":"Workshop on Computational Electromagnetics in Time-Domain, 2005. CEM-TD 2005.","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123286816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time domain born type formulation for low frequency scattering","authors":"I. Koh, H. Kim, Wootae Kim, J. Yook","doi":"10.1109/CEMTD.2005.1531704","DOIUrl":"https://doi.org/10.1109/CEMTD.2005.1531704","url":null,"abstract":"1. Introduction For past decades many numerical methods have been developed in electromagnetics for time and frequency domains. The capability of individual method has continuously been improved, and these techniques have been successfully applied to a wide range of applications from a calculation of radar cross section of a complicated object to a RF circuit optimization. However, due to computing capability numerical methods have been usually used for a moderate frequency range and/or scatterers of a moderate size. In very high or low frequencies, analytical techniques may have advantages over numerical methods yet. Low frequency band has been widely used in many applications such as medical imaging since the band provides specific advantages, for example good penetration through highly lossy media such as human body. At very low frequencies, however, it is well known that the conventional numerical methods fail to generate correct results, and as a result to solve the problem a special basis function such as loop-star basis function has to be used [1]. In this frequency range, any time domain technique such as finite difference time domain (FDTD) also may fail since to accurately model a scatterer, a very small cell should be used and so the time step is automatically very small, but global simulation time may be very large. Therefore, due to the dispersion error of FDTD algorithm, the overall simulation accuracy may not be sufficient. Since in very low frequencies a scatterer may be electrically very small, interactions inside the scatterer may be very weak, and thus negligible. Hence in frequency domain, (distorted) Born approximation has been widely used for the frequencies [2]. To calculate time domain response for a complex scatterer, a frequency domain response is computed first and then using Fourier transform, the desired time domain solution can be constructed. However, this procedure is not computationally efficient. Therefore, in this paper, an efficient time domain Born type approximation is formulated, based on sampling theorem to maximize the time step.","PeriodicalId":407683,"journal":{"name":"Workshop on Computational Electromagnetics in Time-Domain, 2005. CEM-TD 2005.","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130119149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accuracy and convergence of the time domain wave equation methods","authors":"N. Nikolova, Y. Rickard, Y. Li","doi":"10.1109/CEMTD.2005.1531706","DOIUrl":"https://doi.org/10.1109/CEMTD.2005.1531706","url":null,"abstract":"Time-domain electrodynamics is formally described either by Maxwell’s equations or by the wave equation. In the former case, the system state is described by the field vectors E and H, while the electromagnetic potentials are the usual choice in the latter case. Here, we investigate the accuracy and the convergence of the time domain wave equation method based on the scalar wave potentials in the treatment of edges and corners. Comparisons are provided with the commonly used finite-difference time domain (FDTD) method based on Yee’s discretization and with the time domain transmission-line matrix (TLM) method.","PeriodicalId":407683,"journal":{"name":"Workshop on Computational Electromagnetics in Time-Domain, 2005. CEM-TD 2005.","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130142178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational modeling of uncertainty in time-domain electromagnetics","authors":"C. Chauvière, J. Hesthaven, L. Lurati","doi":"10.1137/040621673","DOIUrl":"https://doi.org/10.1137/040621673","url":null,"abstract":"We discuss computationally efficient ways of accounting for the impact of uncertainty, e.g., lack of detailed knowledge about sources, materials, shapes, etc., in computational time-domain electromagnetics. In contrast to classic statistical Monte Carlo--based methods, we explore a probabilistic approach based on high-order accurate expansions of general stochastic processes. We show this to be highly efficient and accurate on both one- and two-dimensional examples, enabling the computation of global sensitivities of measures of interest, e.g., radar-cross-sections (RCS) in scattering applications, for a variety of types of uncertainties.","PeriodicalId":407683,"journal":{"name":"Workshop on Computational Electromagnetics in Time-Domain, 2005. CEM-TD 2005.","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129028698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Time-domain simulation of wave propagation in an overhead wire with a lossy ground return","authors":"J. Paul, C. Christopoulos, D.W.P. Thomas","doi":"10.1109/CEMTD.2005.1531717","DOIUrl":"https://doi.org/10.1109/CEMTD.2005.1531717","url":null,"abstract":"This paper describes the application of a thin-wire TLM approach to the simulation of wave propagation in an overhead wire with a ground return. An outline of the formulation of the thin-wire technique is given. The character- istic impedances and propagation coe-cients of overhead lines are calculated for various typical ground properties. The results are similar to those reported in the literature obtained from analytic formulations.","PeriodicalId":407683,"journal":{"name":"Workshop on Computational Electromagnetics in Time-Domain, 2005. CEM-TD 2005.","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125927105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of characteristic impedance of asymmetric coplanar waveguide using finite-difference time-domain method","authors":"Chen Peng, Fang Shao-jun, Wang En-cheng","doi":"10.1109/MAPE.2005.1617855","DOIUrl":"https://doi.org/10.1109/MAPE.2005.1617855","url":null,"abstract":"The paper presents a detailed analysis of characteristic impedance of asymmetric coplanar waveguide (ACPW) using the finite-difference time-domain (FDTD) method, and the results agree well with available theoretical and experimental data over a wide frequency range. The transient propagating waveforms along the ACPW, which are excited by retarded Gaussian pulse, are found in the time domain. After the time-domain field distributions are obtained, frequency-domain parameters such as the characteristic impedance are calculated using Fourier transformations","PeriodicalId":407683,"journal":{"name":"Workshop on Computational Electromagnetics in Time-Domain, 2005. CEM-TD 2005.","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132319569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}