单层和双层手征介质柱域的并矢格林函数理论及其应用

本文应用散射叠加法,分别导出了单层和双层手征介质圆柱区域中的并矢格林函数。由此分析了位于手征介质圆柱和手征介质圆柱罩中心轴线上点偶极天线的辐射特性。结果表明,通过改变手征介质圆柱的尺寸和手征介质圆柱罩的厚度,可以任意调节辐射场的极化特性。另外,本文给出的并矢格林函数公式还可用于分析柱形手征微带天线的辐射特性。     

单层和双层手征介质柱域的并矢格林函数理论及其应用

本文应用散射叠加法，分别导出了单层和双层手征介质圆柱区域中的并矢格林函数。由此分析了位于手征介质圆柱和手征介质圆柱罩中心轴线上点偶极天线的辐射特性。结果表明，通过改变手征介质圆柱的尺寸和手征介质圆柱罩的厚度，可以任意调节辐射场的极化特性。另外，本文给出的并矢格林函数公式还可用于分析柱形手征微带天线的辐射特性。     

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。     

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。     

矩形介质谐抵腔的格林函数问题

本文讨论了求解平面分层媒质系统的并矢格林函数问题的一种新方法。这一方法的特点就是把并矢格莱函数问题转化为标量格林函数来解决。文中详述了介质加载的矩形腔的并矢格林函数的求解方法和结果。     

无限大导电平面上复盖介质结构的并矢格林函数

本文用圆柱连续本征矢量波函数级数和积分形式表示的自由空间并矢格林函数构成了无限大导电平面上复盖介质结构的两种并矢格林函数。这些并矢格林函数对于求解微带天线、表面复盖介质板的缝隙天线或表面波天线都是有用的。源位于介质中的并矢格林函数(?)的表示式是     

无辐射介质波导中的并矢格林函数

本文利用本征函数展开法推导了无辐射介质(NRD)波导中的并矢格林函数,给出了其中电型并矢格林函数的完备形式。     

圆柱共形微带线的场分析

基于并矢格林函数导出的圆柱微带共形天线电场的一般表达式,研究圆柱共形微带线的辐射和散射特征,分析介电常数、介质厚度和金属圆柱半径对圆柱共形微带线方向图的影响,并证实圆柱共形微带线的雷达目标散射宽度图与其方向图一致。     

不均匀电介质中的并矢格林函数问题

本文讨论了不均匀电介质系统中的电磁场的边值问题。把相对介电常数ε_r(R)作为权函数,证明了不均匀介质系统中本征函数系的正交性和完备性;因而可以应用本征函数展开法求出并矢格林函数的普遍形式。由于不均匀介质中的电磁场有和均匀介质中的类似的性质,所以我们最终也可以通过对标量格林函数的直接求解方法来解决介质加载系统的并矢格林函数问题。     

圆柱共形微带线的场分析

基于并矢格林函数导出的圆柱微带共形天线电场的一般表达式,研究圆柱共形微带线的辐射和散射持性。分析介电常数、介质厚度和金属圆柱半径对圆柱共形微带线方向图的影响,并证实圆柱共形微带线的雷达目标散射宽度图与其方向图一致。     

左手分层媒质微带天线的辐射特性研究

在推导左手分层媒质谱域并矢格林函数的基础上,分析得出了左手媒质谱域格林函数的慢收敛特性。为了将谱域格林函数转换到空域并对其进行准确的数值计算,根据左手媒质的特性,对传统的离散二级离散复镜像法提出一些改进,计算结果与变形路径的直接积分法吻合较好,验证了改进方法的正确性、精确性。运用此格林函数对一些不同参数的左手媒质微带天线辐射特性进行了全波分析,并得出它们主瓣宽度窄、低仰角等特点。     

矩形波导和腔体的电并矢格林函数的完备本征函数展开

本文以无散的Hansen矢量波函数和算子谱理论为基础,导出了矩形波导和腔体的电并矢格林函数的完备本征函数展开式,这些展开式与采用其他方法得到的结果相同.此法提供了推导正交坐标系下电并矢格林函数的完备展开式的一种有效途径.     

A new method for solving Dyadic Green’s Function of electromagnetic field

A new method for solving electromagnetic field boundary value problem is given. By using this method, the boundary value problem of the vector wave equation can be transformed into the independent boundary value problem of scalar wave equations and the two additional vector differential operations. All the dyadic Green’s functions got by eigenfunction expansion of the dyadic Green’s function can be got by this method easily and some of the dyadic Green’s functions for complex systems which are very difficult to get by the ordinary method have been got by this new method. The dyadic Green’s function for a dielectric loaded cavity is one of the given examples. This project is supported by the National science Fundation of China     

A NEW METHOD FOR SOLVING DYADIC GREEN''''S FUNCTION OF ELECTROMAGNETIC FIELD

A new method for solving electromagnetic field boundary value problem is given.Byusing this method,the boundary value problem of the vector wave equation can be transformedinto the independent boundary value problem of scalar wave equations and the two additionalvector differential operations.All the dyadic Green's functions got by eigenfunction expansionof the dyadic Green's function can be got by this method easily and some of the dyadic Green'sfunctions for complex systems which are very difficult to get by the ordinary method have beengot by this new method.The dyadic Green's function for a dielectric loaded cavity is one of thegiven examples.     

求解电磁场并矢格林函数的新方法

本文提出了求解电磁场边值问题的新方法:把矢量波方程的边值问题化为对应的标量波方程的边值问题加上两个附加的矢量微分运算的问题。用这种方法可以很方便地求解所有现在用并矢格林函数的本征展开法所能求得的各种并矢格林函数。可以求解用现有的方法很难求解的比较复杂系统的并矢格林函数。文中给出了加载的谐振腔的并矢格林函数就是其中的一例。     

Singularity Extraction from the Electric Green's Function for a Spherical Resonator (Short Papers)

The electric dyadic Green's function for a spherical resonator is expressed as a sum of two dyadics given in closed form and a dyadic given in the form of a series. The first two dyadics diverge at the source point and they represent a low-frequency approximation for the Green's function, valid up to frequencies moderately lower than the resonant frequency of the dominant mode. The dyadic given in the form of a series is finite at the source and takes into account cavity resonances. It is given either as a one-index series, whose terms are transcendental functions of the frequency, or as a double series, whose terms are rational functions of the frequency. Both series have very good converging properties everywhere inside the cavity.     

新型圆锥加脊TEM喇叭天线的分析

ＴＥＭ喇叭是一种超宽带天线，在瞬态场和超宽带雷达的研究中具有良好的理论和应用价值，本文首先应用格林函数法分析了壁无限薄的圆锥加脊ＴＥＭ喇叭天线，计算了喇叭上的电荷分布及截面阻抗，并分析这种ＴＥＭ喇叭天线在不同辐射方向的波形，结果表明这 超宽带和波形保真性。     

Input impedance of microstrip patch in the quasi-optical cavity resonator

The dyadic Green's function in an active loaded quasi-optical oscillator is presented. An expression is derived for the input impedance of a single microstrip patch cavity excited by a coaxial probe using the method of moment. Using the present formulation the input impedance of a rectangular microstrip patch is determined.     

Cavity-Backed Aperture Antennas with Dielectric and Magnetic Overlay

A method is presented for a full wave analysis of an aperture antenna backed by a rectangular cavity. The antenna may be covered by one or more dielectric and magnetic layers. The aperture antenna may be arbitrarily shaped but must be small compared to the cross section of the cavity. The analysis includes ohmic, dielectric, and magnetic losses in the cavity as well as in the overlay. Deriving a modified magnetic field integral equation, the treatment of the cavity and of the layered overlay is separated. A dyadic Green's function describing the topology of the cavity is formulated in the space domain. Another dyadic Green's function for the layered overlay is derived in the spectral domain. Subsequently, the integral equation is solved by the method of moments. The theoretical treatment is worked out for arbitrarily shaped apertures. Finally, the proposed method is applied to narrow slot antennas backed by rectangular cavities. Some numerical results are compared with experimental data     

Efficient analysis of shielded meander line for mobile communication application

An innovative miniature cavity-shielded infinitely thin meander line on a stratified medium is presented in this paper. The dispersion characteristic of this periodic meander line is firstly formulated in terms of a rigorous hybrid-mode representation by use of the Floquet theorem. Numerical results are included for several different structural parameters. The results are compared with other available data and good agreements are observed. This rectangular cavity is also designed to be a quarter-wave section of the shielded meander line and its dyadic Green's function is derived. After the simplification of the enumeration of the dyadic Gree's function, the input impedance of the coaxial line-excited rectangular cavity is determined by a multifilament method-of-moments solution. Good numerical results are also obtained and the rectangular cavity is proved to be an aforementioned quarter-wave section of shielded meander line, grounded at one end and open-circuited at the other.