共查询到20条相似文献,搜索用时 156 毫秒
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采用有限元边界积分方法,通过把所求解区域分成内外两部分,内场用有限元计算,外场用边界积分计算,分析了线天线辐射问题.边界积分采用伽略金方法处理,并用变换解决了积分方程的奇异性问题,最后给出了仿真结果. 相似文献
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对二维热传导方程的Dirichlet初边值问题,采用带时间变量的基本解,利用基于单层位势的间接边界积分方程及其等价的Galerkin变分形式求解,该方法涉及到与时空相关的四重奇异积分的计算.在采用常单元离散的情况下,推导了具体实施数值计算所需的积分公式,完成了数值实验,验证了该方法的有效性和可行性. 相似文献
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《中国无线电电子学文摘》1994,(5)
(〕月4,024 94050850电磁场边界元法分析中的域积分和奇异积分问题及一种改进边界元法/马西奎(西安交通大学)11光纤与电缆及其应用技术一1 994,(2)一1一7 概述了几种把域积分化为边界积分及计算奇异积分的有效方法,并介绍用齐次方程的基本解系作权函数的一种改进型边界法。改进边界元法消除了传统边界元法中的固有奇异性,计算精度和效率都较高,是更为有效的一种方法.表1参5(北)数.表1参8(北)044 94050851最小二乘边界配点法在电磁场边值问题数值分析中的应用/马西奎(西安交通大学)lj微波学报一1994,(2)一17~22 进行了最小二乘边界配点法在电… 相似文献
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Wu H.H. Meyer J.W. Keunmyung Lee Barber A. 《Advanced Packaging, IEEE Transactions on》1999,22(3):259-266
In this paper, we derive a theory and method for the use of two-dimensional (2-D) discrete transmission lines (TL's) or discrete coupled transmission lines (CTL's) in modeling power supply and ground planes accurately. If the stray coupling between power or local ground and global ground is not significant, the discrete TL's model is used. Otherwise the discrete CTL's model is used. An arbitrarily shaped plane pair is discretized into a 2-D TL or CTL array by an automatic mesh algorithm. The equivalent distributed circuit, including skin loss effect at high frequencies, represents this power ground plane pair. The theory is extended to be applicable to a generic multiple dielectric layer structure. The model computation results are in excellent agreement with S parameter measurements for practical frequency ranges, including the first major resonant nulls and peaks. The null or peak of the S parameter frequency response represents the test port interaction with the resonant standing wave of these planes at that frequency. The resultant S parameter data of these models can be condensed into a simpler N port equivalent circuit to represent a larger hierarchical power and ground plane network for fast simulation 相似文献
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Efficient Simulation of Power Distribution Network by Using Integral-Equation and Modal-Decoupling Technology 总被引:1,自引:0,他引:1
Xing Chang Wei Er Ping Li En Xiao Liu Vahldieck R. 《Microwave Theory and Techniques》2008,56(10):2277-2285
A novel integral-equation equivalent-circuit method is proposed for the efficient electrical simulation of the power distribution network in the electronic package and printed circuit board. The total electromagnetic field inside the power distribution network is decoupled into two modes: the parallel-plate mode sandwiched between the power and ground planes and the transmission line mode propagating along the signal traces. An integral-equation method is then proposed to solve the parallel-plate mode. By discretizing the integral equation, the power-ground planes pair is equivalent to a ground network. Finally, this ground network is recombined with the transmission line mode to simulate the entire power distribution network. Meanwhile, the discontinuity due to the thru-hole via is also considered by an analytic formula. The proposed method decomposes the complex 3-D problem into two simple 2-D problems, and then extracts the equivalent circuits. Therefore, it greatly reduces the computing time and memory requirement. Through several examples, its accuracy and efficiency are validated. 相似文献
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Multilayer printed circuit boards (PCBs) are currently used in various areas of electronics such as telecommunications. However, high crosstalk between signal vias can cause degradation of performance for these kinds of structures. Resonances of parallel ground or power planes can increase this crosstalk. In this study, a simplified approach to the modeling of these resonances is described. It is assumed that the fields inside the board have characteristically only two-dimensional (2-D) variation. When this hypothesis is valid, it is shown that resonances can be measured on two-layer prototyping boards and simulated using a 2-D finite-difference model. It is additionally noted that a previously suggested method of using coaxial ground vias to suppress coupling between vias is not necessarily effective if there are resonant parallel plates on the board. Agreement between measured and modeled results is good enough for practical design purposes. The main advantages of the method used in this study compared to the more robust three-dimensional (3-D) simulation models are savings in time and costs. Additionally, prototyping is much easier on two than multilayer boards 相似文献
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《Microwave Theory and Techniques》2009,57(8):2047-2054
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A novel method for analyzing the bounces on structure of parallel power/ground planes by using the even-odd mode partition is presented in this paper. Based on the distributed RLCG circuit model derived from the two dimensional electromagnetic field equations of the power/ground planar structure, this method can speed up the circuit simulation of the bounces on power/ground planes by using even-odd mode partition. Furthermore, the method can be used to evaluate the effects of the terminated decoupling capacitors and the hole structures on power/ground plane. The numerical examples demonstrate that the method has both high efficiency and good precision. 相似文献
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This paper presents a nonrigid registration two-dimensional/three-dimensional (2-D/3-D) framework and its phantom validation for subject-specific bronchoscope simulation. The method exploits the recent development of five degrees-of-freedom miniaturized catheter tip electromagnetic trackers such that the position and orientation of the bronchoscope can be accurately determined. This allows the effective recovery of unknown camera rotation and airway deformation, which is modelled by an active shape model (ASM). ASM captures the intrinsic variability of the tracheo-bronchial tree during breathing and it is specific to the class of motion it represents. The method reduces the number of parameters that control the deformation, and thus greatly simplifies the optimisation procedure. Subsequently, pq-based registration is performed to recover both the camera pose and parameters of the ASM. Detailed assessment of the algorithm is performed on a deformable airway phantom, with the ground truth data being provided by an additional six degrees-of-freedom electromagnetic (EM) tracker to monitor the level of simulated respiratory motion. 相似文献
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Mahmoud S.F. Antar Y.M.M. Hammad H.F. Freundorfer A.P. 《Antennas and Propagation, IEEE Transactions on》2004,52(8):2057-2063
The problem of optimum excitation of surface waves on a grounded dielectric slab by means of slots in the ground plane is considered. By adopting a two-dimensional (2-D) model, analysis lead to closed forms for the power launched as surface waves and power leaked as radiation. Input admittance of a single slot source and mutual admittance between two slots are derived and utilized to design a three element Yagi array of slots to achieve a prescribed ratio of forward to backward surface wave power. As a development of the 2-D model, we allow finite extent of slot excitation by assuming a Gaussian E-field distribution across the slot. The effect of the Gaussian width on the excited surface wave power is studied. The analysis is relevant to the study of surface waves on printed circuits. Specifically, it applies to the implementation of power combiners based on quasioptical slab beam that have been recently introduced in the literature for use in the millimeter wave band. 相似文献
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《Advanced Packaging, IEEE Transactions on》2009,32(3):636-643