辛卜生算法在微机保护半周积分算法中应用分析

在微机保护中，一个正弦量的绝对值在任意一个半周期内的积分为一常数，其积分值与积分起始点的初相角无关。利用半周积分值为常数的特性在微机保护中实现电流、电压保护。普遍情况下，用梯形算法近似求出半周积分值，进而求得有效值。本文中介绍了梯形算法求半周积分值算法，而且还提出了辛卜生算法在求半周积分值中的应用。通过理论分析了辛卜生算法代替梯形算法求半周积分值，得以提高计算精度，并且得到了仿真验证。     

复宗量菲涅耳积分的计算及其性质

复宗量菲涅耳（Ｆｒｅｓｎｅｌ）积分的计算，是有耗介质劈电磁散射中遇到的一个难题。本文综合运用了复宗量菲涅耳积分的小宗量级数展开和大宗量渐近展开，并且找到了大宗量展开与小宗量展开的衔接部，圆满地解决了菲涅耳积分在整个复平面内的计算机计算问题。本方法计算速度快，精度高。此外，本文还研究了菲涅耳积分在复平面上的对称性、零点等性质，给出了菲涅耳积分在复平面上的三维立体图和二维等值线图。     

单面鳍线的正则解

本文建立了分析鳍线的新方法－奇异积分方程解的正则化方法。这里，我们采用了积分化程序，而场的唯一性由奇异积分方程的解在导电片边缘的正则化条件确定。计算结果表明：本文方法以导致更快的级数收敛速率，与目前国内外公认的最好方法谱域法相比，精度提高而且所耗计算时间大大减少，与已有的奇异积分方程法相比，精度明显提高，所耗计算机时间减少了，同时公式更为简洁，概念更加清楚。     

导体线面连接问题中奇异函数积分的计算

在线面连接问题中，电流展开函数包含体展开函数、线展开函数和连接点展开函数三类。求解电场积分方程的积分项是电流基函数及其散度分别与自由空间格林函数的乘积，由于连接点展开函数含有一个奇异点，所以被积函数中含有两个奇异点。本文通过积分变换消除了奇异点，并将二重积分化为一重积分，使计算精度得到提高。计算实例验证了本文方法的正确性。     

波导宽边中心倾斜孤立辐射裂缝的分析

本文首先建立波导宽边中心倾斜孤立辐射裂缝的积分方程，然后用矩矩量法求解得到了孤立的Ｓ参数及归一化等效阻抗。在积分方程的求解中，将三重积分化为二重积分，既 三重积分计算时间长，精度和收敛性差的缺点，又不致于使表达式过于重复和杂。本文分析计算所得到的裂缝特性参数可以用于波导宽边中心倾斜裂缝阵的设计。     

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

在电磁场边界元法中，域积分和奇异积分的计算是经常遇到的困难之一。本文概述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元法。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。     

聚合物电光波导调制器中微带电极的几何参数对重叠积分的影响

本文对有机聚合物导调制器的重叠积分进行了详细计算，着重讨论了器件的几何参数对重叠积分的影响。     

一种简单廉价的16位A／D转换器

本文根据运放的积分特性，提出了一种１６位双积分Ａ／Ｄ转换器。在分析ＴＡ／Ｄ转换器的缺陷后，找出了解决途径—即采用三次双积分Ａ／Ｄ转换器．此电路是简单易行的．     

一种减小伺服系统动态滞后的控制算法

高精度伺服系统的调节器必然包含积分调节，本文论述了通过减小调节器的积分时间常灵敏来减小伺服系统的动态滞后。     

晶体管爆裂噪声的积分双谱检测方法研究研究

本文根据积分双谱分布特性分析，论证了晶体管爆裂噪声是服从非高斯坦非对称分布的，并提出可利用积分双谱方法来检测晶体管爆裂噪声。     

An integral equation formulation of the direct scattering problem for an inhomogeneous slab

A numerical technique based on an integral equation scheme is developed for solving the direct scattering problem for an inhomogeneous slab. The integral equation is derived, using the induced current concept and the Green's function technique. The numerical method of solving the integral equation is presented. The method is proved to be numerically satisfactory and is applied to the slab of specific profiles. Numerical results for several cases are also included.     

点单元电流模型的数值计算方法

本文提出了一种新的积分计算方法,消除了面块模型方法积分计算中的伪奇点,有效地解决了高频情况下积分的数值计算,为将面块模型方法应用于高频问题提供了理论依据。     

Multimode Equivalent Networks for the Design and Analysis of Frequency Selective Surfaces

A modular technique originally proposed for waveguide junctions, the multimode equivalent network approach based on the integral equation formulation (IEMEN), is extended to the analysis of multilayer frequency selective surfaces integrated with waveguide array antennas. This technique represents each layer and transition between layers in terms of a generalized impedance or admittance matrix, obtained directly from the solution of an integral equation with reduced kernel. Thanks to the adopted formulation, the integral equation needs to be solved only in a limited set of frequency points. The IEMEN method is validated by comparison with results available in literature.     

一种低仰角雷达射线的准确快速描迹方法

探讨了对流层中雷达射线的准确快速描迹技术。和国内一直沿用积分方程进行对流层射线描迹不同，该文基于射线微分方程进行射线描迹，使用了高阶Runge-Kutta数值微分解法，它可避免积分算法计算效率低、零度仰角附近难以计算等方面的局限。模拟结果和已有研究结果的比较表明，该方法可以获得较为理想的准确结果和计算速度。     

A highly robust and versatile finite element-boundary Integral hybrid code for scattering by BOR objects

A hybrid technique is presented that combines the finite element and boundary integral methods for simulating electromagnetic scattering from body-of-revolution (BOR) objects. This technique correctly models the boundary conditions along the axis of revolution in both the finite element and boundary integral formulations and yields highly accurate solutions. Because of the decoupled computations for the finite element and boundary integral equations, the technique is highly efficient as compared to the method of moments, especially for BORs comprising layered or inhomogeneous materials. It is applicable to a variety of complex, large-size BOR objects consisting of perfect conductors, anisotropic impedance surfaces, anisotropic resistive surfaces, and anisotropic inhomogeneous materials.     

Modeling and improved current control of series resonant converterwith nonperiodic integral cycle mode

A dynamic modeling and an improved current control technique for a series resonant power converter with nonperiodic integral cycle mode are proposed to overcome the disadvantages of an integral cycle mode-controlled series resonant converter. The internal operational characteristics, are investigated in detail and an improved current control technique is developed based on this analysis. Using the proposed control technique, the minimized current ripple with reduced offset current and the fast transient response with negligible overshoot can be obtained. Furthermore, the continuous output voltage levels can also be available by accurately controlling the average filter input current. The usefulness of the proposed technique is verified through computer simulations and experiments     

Hybrid2: combining the three-dimensional hybrid finiteelement-boundary integral technique for planar multilayered media withthe uniform geometrical theory of diffraction

The fully three-dimensional (3-D) hybrid finite element (FE)-boundary integral (BI) technique is extended by further hybridization with the uniform geometrical theory of diffraction (UTD) resulting in a so-called hybrid² FE-BI-UTD approach. The formulation is capable of modeling arbitrarily shaped strongly inhomogeneous objects together with electrically large obstacles of relatively simple shape within the common environment of a planar-multilayered medium. The arbitrarily shaped inhomogeneous objects are discretized by finite elements, whereas, the electrically-large obstacles are described by the UTD and both of these models are included into an integral equation derived from the equivalence principle for planar-multilayered media. Thus, full-electromagnetic coupling is realized between all parts of the formulation. The integral equation is implemented using mixed potentials with appropriate Green's functions derived from Sommerfeld integral representations for planar-multilayered media. The UTD contributions are accounted for by corresponding modifications of the Green's functions and the FE technique is coupled to the integral equation via introduction of equivalent surface current densities in the bounding surfaces of the discretized objects. After presenting the formulation of this novel fully 3-D hybrid² technique, the implemented computer code is validated against conventional hybrid FE-BI computations and a wireless base station antenna is analyzed in several situations of complex real world, microcell environments     

Digital magnification of three-dimensional integral images

The methods for obtaining a controlled magnification of three-dimensional (3-D) integral images are usually based on the increase of the spatial ray-sampling rate of elemental image arrays. This is usually done by use of the moving array-lenslet technique. The major drawback of this technique is the alignment complexity due to the small lenslet movement. In this paper, we are proposing a digital magnification method that uses interpolation principles to increase the spatial ray sampling rate of elemental image arrays without lenslet movement in the pickup procedure. We compare the reconstructed 3-D integral images obtained when using the optical or the digital magnification methods, and show that the quality of both reconstructed 3-D integral images is the same.     

On computation of electromagnetic fields on planar surfaces from fields specified on nearby surfaces

A technique is presented for solution of the inverse problem of calculating the electric field on a planar surface from the electric field specified on a nearby surface. An integral equation is derived that relates two orthogonal components of the electric field on the nearby surface to the respective components of the plane wave spectrum of the planar electric field. The integral equation is solved by an iterative technique, and the planar near field is calculated by an inverse Fourier transform of the plane wave spectrum.     

An integral transform technique for analysis of planar dielectricstructures

This paper presents a novel efficient technique for the study of planar dielectric waveguides for submillimeter-wave and optical applications. In an appropriate integral transform domain, which is determined by the Green's function of the substrate structure, higher-order boundary conditions are enforced in conjunction with Taylor expansions of the fields to derive an equivalent one-dimensional integral equation for the corresponding two-dimensional waveguide geometry. This reduction in the dimensionality of the boundary-value problem can easily be extended to three-dimensional planar structures, with equivalent two-dimensional integral equations being formulated. The reduced integral equations are solved numerically by invoking the method of moments, in which the transform-domain unknowns are expanded in a smooth localized entire-domain basis. It is demonstrated that using orthogonal Hermite-Gauss functions as an expansion basis provides very satisfactory results with only a few expansion terms. For the validation of the technique, single and coupled dielectric slab waveguides are treated