共查询到19条相似文献,搜索用时 109 毫秒
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《中国无线电电子学文摘》2001,(4)
()盆4 1 01040720保角变换FDTD算法的数值稳定性与数值色散/周晓军,喻志远,林为千(电子科技大学)“电子科学学刊.一2 000,22(一全)一618一625文中提出了新的保角变换FDTD算法,推导了保角变换F DTD算法的时间稳定性和数值色散方程.此外,文中以圆波导为例计算了不同网格下TE模数值波长的相对误差,分析了不同传播常数和对极点不同半径的半圆电壁近似下数值波长的相对误差通过适当地选择网格数,可得到高精度.图3参6(李)值作计算(通常对每一采徉时间选用12个S值)因而是一种计算速度较决的算法.但是,要对大量采徉时间作计算,其计算量仍太大.… 相似文献
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本文提出了新的保角变换FDTD算法,推导了保角变换FDTD算法的时间稳定性和数值色散方程。此外,本文以圆波导为例了不同网格下TE模数值波长的相对误差。分析了不同传播常数和对极点不同半径的半圆电壁近似下数值波长的相对误差,通过适当地选择网格数,可得到高精度。 相似文献
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There is a growing interest in using cylindrical transmission line structures in microwave applications. In this paper, the finite difference time domain (FDTD) method is used to characterize several three-dimensional cylindrical coplanar waveguide (CCPW) geometries. Specifically, a CCPW series stub and a three-section CCPW filter are studied both theoretically and experimentally. Moreover, CCPW gap is characterized and the FDTD results are compared to those obtained using conformal mapping techniques. Effective absorbing boundary conditions are employed to truncate the FDTD mesh at the end walls and the outer radial boundary. 相似文献
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Shuhui Yan Bing-Zhong Wang Wenhua Yu Raj Mittra 《Journal of Infrared, Millimeter and Terahertz Waves》2003,24(6):985-992
This paper describes a modified locally conformal algorithm for finite-difference time-domain (FDTD) method. Fields in the entire computational domain are computed by a regular FDTD algorithm except those near curved metallic surfaces, where special techniques proposed in this paper are applied. The computation efficiency of a regular FDTD method is maintained while a high space-resolution is obtained by this new algorithm. To validate the reliability of the algorithm, coaxial continuous transverse stub arrays at millimeter wave Ka-band and microwave X-band are tested, and the simulated results show good agreement with the experimental results from an HP-8510B Network Analyzer and the simulation results from software package HFSS. 相似文献
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提出一种使用保角变换结合矩量法,计算复杂形状波导截止频率的新方法,该方法采用解析法或数值法,把复杂截面的波导变换为圆形区域,再采用矩量法求解波导的截止频率。实验结果验证了该方法的有效性。 相似文献
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A new fourth-order finite-difference time-domain (FDTD) scheme has been developed that exhibits extremely low-phase errors at low-grid resolutions compared to the conventional FDTD scheme. Moreover, this new scheme is capable of combining with the standard Yee (1966) scheme to produce a stable hybrid algorithm. The problem of wave propagation through a building is simulated using this new hybrid algorithm to demonstrate the large savings in computing resources it could afford. With this new development, the FDTD method can now be used to successfully model structures that are thousands of wavelengths large, using the present day computer technology 相似文献
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Hu Chi 《Journal of Infrared, Millimeter and Terahertz Waves》2003,24(11):1999-2006
Semicircular groove guide is a kind of waveguide for millimeter waves. In this paper, a conformal mapping technique is used to analyze it. Several semicircular groove guides are calculated with the method. It is shown that their cutoff wavelength calculated by the method are very close to those calculated by the transverse resonance method. 相似文献
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A robust and automatic discretization algorithm for complex conformal finite-difference time-domain (C-FDTD) simulation is presented in this publication. The targeted application range is to enable C-FDTD simulations for real-word engineering problems. Based on computer-graphics methods, complex CAD models with thousands of distinct parts can be efficiently and robustly discretized. A versatile concept is introduced to avoid numerical inaccuracies while calculating intersections, and to lead to a symmetric discretization without the overhead of "virtual lines." In addition, a necessary three-dimensional consistency check/correction, as well as merging of conformal cells of different CAD parts, are explained. The conformal geometric information is incorporated into the conventional FDTD algorithm using the conventional updating coefficients, which are conformally enhanced. Due to the derived stability criterion, the conformal updating scheme is always stable. The robustness and performance of the discretization algorithm presented is demonstrated with CAD models of increasing complexity towards real-world benchmarks. A conformal FDTD simulation with 80 million computational cells and 229 distinguished parts, representing a complete mobile phone and a head with hand, demonstrates the capabilities of the versatile technique. 相似文献
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He Mang Xu Xiaowen 《Antennas and Propagation, IEEE Transactions on》2004,52(7):1749-1757
The input impedance and radiation pattern of the probe-fed multilayered cylindrical-rectangular microstrip antennas (PMCMSA) are analyzed by using a novel approach which combines the conformal finite-difference time-domain (FDTD) and Gedney's unsplit version of the perfectly matched layer absorbing boundary condition method and the Green's functions in cylindrically stratified media. The near fields of such antennas and the current distributions on the patches are obtained by the conformal FDTD method numerically and then the modified spectral-domain Green's functions in arbitrary cylindrically stratified media are used to determine the radiation pattern. The effect of the small radius of the probe on the performance of antennas is investigated through the thin-wire algorithm in cylindrical coordinates. A simple design scheme of the probe-fed cylindrically stacked antennas is also proposed for increasing the impedance bandwidth. 相似文献
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Wenhua Yu Arakaki D. Mittra R. 《Antennas and Propagation, IEEE Transactions on》2000,48(12):1810-1817
This paper presents an efficient method to accurately solve large body scattering problems with partial circular symmetry. The method effectively reduces the computational domain from three to two dimensions by using the reciprocity theorem. It does so by dividing the problem into two parts: a larger 3-D region with circular symmetry, and a smaller 2-D region without circular symmetry. An finite-difference time-domain (FDTD) algorithm is used to analyze the circularly symmetric 3-D case, while a method of moments (MoM) code is employed for the nonsymmetric part of the structure. The results of these simulations are combined via the reciprocity theorem to yield the radiation pattern of the composite system. The advantage of this method is that it achieves significant savings in computer storage and run time in performing an equivalent 2-D as opposed to a full 3-D FDTD simulation. In addition to enhancing computational efficiency, the FDTD algorithm used in this paper also features one improvement over conventional FDTD methods: a conformal approach for improved accuracy in modeling curved dielectric and conductive surfaces. The accuracy of the method is validated via a comparison of simulated and measured results 相似文献
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A novel hybrid cylindrical-Cartesian finite difference time domain (FDTD) method is presented, which permits a dramatic increase in the flexibility of the basic FDTD algorithm. It is shown to be particularly well-suited to the analysis of faceted conformal antenna arrays and its accuracy is demonstrated by comparison with experimental measurements of couplings within a 17-element array 相似文献