非线性平板波导中均匀芯区场的归一化形式

通过理论分析及典型实例计算，分析了包层及衬底均为非线性Kerr型介质、芯区为线性均匀介质的对称3层平板波导的TE0模出现均匀场分布的条件及其归一化形式。给出了自聚焦和自散焦情况下对称3层平板波导TE0模的归一化场分布曲线以及功率随归一化模折射率变化曲线。     

多层电厚微带天线的阻抗特性

本文提出了一种多层介质电厚微带天线的一种分析方法。从无界空间中的电并矢格林函数出发,导出了分层介质中任意一点具有任意取向的水平电偶极子场的表达式。以此为基础,利用Richmond反作用积分方程,建立了关于贴片上电流分布的积分方程。通过适当选取电流基函数,使本方法适用于电厚介质微带天线。应用Galerkin方法建立矩阵方程。借助于计算机求解该矩阵方程,可得到天线的各项特性。文中用实例进行了验证。     

平面波导基模的衍射特性

在平面坐标系中简化电磁波的瑞利-索末菲标量衍射积分公式，推导出折射率对称阶跃分布的介质平面波导的基模衍射场分布的计算公式，给出由sinc函数形式描述的端口衍射场空间频谱和光强分布。首次提出介质平面波导衍射场存在中央亮条纹的概念，中央亮条纹的功率大于波导总功率的99.49%，中央亮条纹的最大空间频率介于π和1.5π，它可用于计算中央亮条纹的角半径。     

应用广义阻抗边界条件分析介质填充凹槽波导的散射

本文应用广义阻抗边界条件研究了二维平板结构上介质填充凹槽的散射特性。通过选择合适的系数，广义阻抗边界条件可以模拟槽内任何特征的材料．将凹槽内的介质填充层由其表面上的简单边界条件来替代，所得的积分公式可用CGFFT法求解，且对任意入射角的表面散射场能作出精确的预估。     

基于曲面口径积分/几何光学的天线罩混合分析

提出了发射模式下，曲面口径积分／几何光学的混合分析方法。利用等效原理，将天线罩内表面上的反射场等效为面电流和面磁流，沿等效源所在曲面作口径积分，确定二次入射到罩壁上的入射场，经过局部平面的多层介质传输到天线罩外表面，在外表面上将一次传输场和二次反射场矢量叠加，对外表面切向场的表面积分得到天线带罩系统的远场方向图。该方法解决了发射模式下一次传输场和二次反射场的矢量叠加问题，计算精度高；仿真预测结果均为试验所证实。     

微波箱式加热器中场分布的研究

本文应用求解波导管和分层介质加载的矩形腔组合问题的矩量法,对由波导激励的分层加载微波箱式加热器负载中的微波场分布,激励口面上的场和输入电压驻波比等进行了计算。根据改善加热均匀性的要求对激励口的位置和取向等参数进行了优化。     

加载介质覆盖层的圆柱共形微带天线的全波分析

基于严格的全波方法分析计算了介质薄层覆盖下由探针激励的圆柱共形微带天线的输入阻抗和辐射方向图.首次详细地推导出了此结构下适于数值计算的微带帖片上的表面电流形式,并通过矩量法求解电场积分方程得到感应电流的分布.最终,通过数值结果揭示出了覆盖介质层对天线特性的影响并且与已发表文献及其他数值方法的结果进行对比,证明了方法的正确性.     

新型前栅极CNT-FED的研究

传统的前栅极场致发射显示板由于介质层和栅极的制作在生成或制作阴极场致发射源之后，在制造过程中容易破坏场致发射源；另外阴极发射对介质层厚度、阳极电压和调制极开口等参数非常敏感，所以器件的发射均匀性难以保证。为了解决这些问题，引入了类似HOP玻璃的结构。阴极上只需要丝印碳纳米管，无需制作介质层和栅极，解决了场致发射源被破坏的问题。阴极与栅极之间真空取代了介质层，由于真空的绝缘性能高于介质层，所以阴极与栅极之间的距离可以减小，栅极的调制效果更显著。由于玻璃的平整度高于一般方法制作的介质层的平整度，所以器件的发射均匀性比较好。     

用变形玻恩迭代法反演电导率的二维非均匀分布

本文把变形玻恩迭代方法用于求解二维轴对称逆散射问题。该方法提供一种迭代收敛较快的反演成像算法。利用对称轴上２０ｋＨｚ电场的测量值在二维非均匀介质中对电导率分布进行反演。首先给出对于未知电导率分布的非线性积分方法，并用玻恩近似使积分方程线性化，然后用吉洪诺夫与正则化方法求出电导率分布。在迭代过程中，数值模式匹配法用于求解正演场．数值实例表明，用简单的对称轴上测量场能得到好的好的成像结果。     

用于雷达反隐身的低可探测目标电磁散射高效数值分析

本文介绍基于多层快速多极子方法（MLFMA）分析框架下的高效处理新方法和相关研究成果,重点讨论用于厚介质层散射分析的电流磁流混合场积分方程（JMCFIE）、用于多薄层介质散射的多层薄介质层（TDS）边界条件方法及其应用等;最后介绍了所研发的P-UEST软件及其在隐身飞行目标散射特性计算中的应用成果。     

The electrodynamic characteristics of a finite-width metal/dielectric/ferroelectric/dielectric/metal layer structure

The electrodynamic characteristics of a finite-width metal/dielectric/ferroelectric/dielectric/metal layer structure are investigated. The eigenmode spectra, field distributions, and dispersion characteristics are calculated with the help of simulation based on the finite element method. It is demonstrated that the properties of the width modes of the layer structure can be controlled through changing the external electric and magnetic fields.     

位于介质覆盖的导电基底中水平电偶极子的场

讨论了位于有介质层覆盖的非理想导电基底中的水平电偶极子激励起的电磁场,获得了方便于计算的解析表达式,并进行了数值计算和讨论。     

基于并矢格林函数分析环绕微带共形天线

本文导出了涂覆无耗介质层的无限长金属圆柱结构的并矢格林函数以及与这种结构共形的微带天线辐射场的一般表达式,并利用表面电流模型法研究了介电常数、介质层厚度和金属圆柱体半径对环绕微带共形天线方向图的影响。     

Calculation of the spectral characteristics of an acoustic resonator containing layered multiferroic structure

Multifrequency composite acoustic resonators for bulk acoustic waves with piezoelectric and ferromagnetic layers are studied. The structures with a thick ferrite substrate layer and a thin ferrite film on a nonmagnetic dielectric substrate and multilayer structures are considered. A thin piezoelectric layer that is placed between two metal electrodes serves as a transducer. Analytical expressions for the input electric impedance of the electroacoustic transducer are derived for various structures under study in the presence of the transverse control magnetic field. The amplitude-frequency and phase-frequency characteristics of the cavity are numerically calculated. The resonance frequency can be controlled in the interval ±1.2 MHz (about 25% of the intermode distance) due to variations in the magnetic field.     

垂直电偶极子在涂敷介质导电平面上激起的场Ⅱ

对垂直电偶极子（VED）在涂敷介质层的非理想导电基底上激起的电磁场进行了讨论,获得了便于计算的解析表达式,并进行了数值计算。     

Theory of a multiply fed and loaded insulated linear antenna in air

Analytic expressions are derived for the input admittance and the current distribution along the multiply fed and loaded insulated antenna in air which is excited across feed gaps of nonzero widths. The Wiener-Hopf type analysis for a center fed insulated antenna is combined with the axial field discontinuity (AFD) method to develop the current and admittance expression. This AFD method considers the metallic surface of the linear antenna as a series combination of longitudinal, electric-field surface functions that exist due to feeding and/or loading. The analysis, which does not employ superposition of even and odd distributions of sources and loads, yields final expressions in terms of the excitation location, its aperture electric field within the feed gaps, impedance locations, and their values. The current distribution for cases of unity dielectric constant shows an excellent agreement with data based on the moment method. The input admittances and current distributions are reported for different multiple excitations and loads and dielectric constants of the insulator     

NETWORK ANALYSIS OF EIGENVALUE PROBLEM FOR MULTILAYER DIELECTRIC WAVEGUIDE CONSISTING OF ARBITRARY NUMBER OF LAYERS

In this paper,the eigenvalue problem of a multilayer dielectric waveguide consisting of arbitrarynumber of layers is solved by the microwave network method.A general program with the function of com-puter graphics has been developed for analyzing the dispersion characteristics and the electromagnetic fielddistributions of an N layer dielectric waveguide.As an example of practical applications,the procedure ofmode conversion and mode separation in dielectric branching waveguides is vividly demonstrated throughanalyzing the field distributions of asymmetric multilayer dielectric structures and the general rules of modeconversion are discussed.     

Dielectric ring-gap resonator for application in MMIC's

A dielectric resonator, the dielectric ring-gap resonator, is introduced and analyzed. The dielectric ring-gap resonator is obtained by sawing a narrow gap into a dielectric resonator. Resonant frequencies and unloaded Q-factors of quasi-TE_0pq mode in the ring-gap resonator have been calculated by an appropriate equivalent circuit starting from the resonant frequencies and the field distributions of the TE_0pq modes in the ring resonator. The calculated resonant frequencies of the fundamental quasi-TE₀₁₁ mode show an accuracy of <1% compared with the experimental results. Coupling techniques to couple the ring-gap resonator to a microstrip line on a thin substrate, using the electric fringing field near the gap, have been experimentally investigated. A rigorous method for determining resonant frequencies and field distributions of TE modes in a multicomposite multilayered cylindrical resonator is presented. This resonator consists of numbers of cylinders that are arbitrarily layered in the axial direction     

Electromagnetic Backscattering from a Layer of Vegetation: A Discrete Approach

Electromagnetic backscattering from a layer of vegetation over a flat lossy ground is studied. The vegetated region is composed of leaves which are modeled by lossy circular dielectric discs with prescribed orientation statistics. The mean field in the layer is computed by using the Foldy approximation and a two-variable technique which is valid for small fractional volume. Simple expressions are given for the skin depth of the mean wave. Following this, the distorted Born approximation is used to calculate the co-polarized and cross polarized backscattering coefficients. These are then computed as a function of angle of incidence for different layer depths and leaf configurations.     

Network analysis of eigenvalue problem for multilayer dielectric waveguide consisting of arbitrary number of layers

In this paper, the eigenvalue problem of a multilayer dielectric waveguide consisting of arbitrary number of layers is solved by the microwave network method. A general program with the function of computer graphics has been developed for analyzing the dispersion characteristics and the electromagnetic field distributions of an N layer dielectric waveguide. As examples of practical applications of the program, first, the dispersions and field patterns for the planar waveguides with refractive index of parabolic and exponential profiles are analyzed. Secondly, the procedure of mode conversion and mode separation in dielectric branching waveguides is vividly demonstrated through analyzing the field distributions of asymmetric multilayer dielectric structures and the general rules of mode conversion are discussed. The examples show that the present method possesses the advantages of versatility, rapidity, simplicity and accuracy.