一种临近有限尺寸导电平板的圆极化天线的辐射

本文应用反应积分方程及统一几何绕射理论分析了临近有限尺寸导电平板的一种圆极化天线的辐射。首先用反应积分方程求得天线在临近无限大导电平板时的辐射,然后用统一几何绕射理论计算天线在有限尺寸导电平板边缘上产生的绕射,最后应用叠加原理求得天线合成方向图。应用这种方法可计算天线方向图、天线效率、天线电流分布及天线输入阻抗。对一种天线的实验结果与理论计算进行了比较,说明了这种分析是正确的。     

有限长金属圆锥柱侧微带天线辐射特性计算

本文应用一致性几何绕射理论(UTD),导出了有限长金属圆锥柱侧微带天线三维辐射场和增益的计算公式.这些公式同样适用于有限长金属圆柱和圆锥.应用上述公式计算了锥侧微带天线及其排阵的任意平面方向图和增益,并与实测结果进行了比较.两者吻合良好.     

任意形状天线罩的快速分析

将自适应积分算法与体积分方程相结合分析任意形状天线罩对天线辐射特性的影响。将任意形状的天线罩剖分成四面体，基于体积分方程的自适应积分快速算法求出天线罩上的感应电流，即可求出天线-天线罩系统的总场。自适应积分快速算法的应用提高了矩量法的计算速度，并大大缩减了需要的存储量，从而使该方法可用于分析电尺寸较大的天线罩.最后,分别计算了球形、锥形天线罩存在时理想电振子阵列的辐射方向图。     

金属截锥柱侧天线辐射场的研究

根据实测的单元天线方向图,利用几何绕射理论,给出了金属截锥柱侧天线三维辐射场的一种有效的数值分析方法。这些公式同样适用于金属截柱或截锥。应用上述公式计算了截锥侧微带天线及其排阵的任意平面方向图,并与实测结果进行了比较,两者吻合良好。     

金属截锥柱侧天线辐射场的研究

根据实测的单元天线方向图，利用几何绕射理论，给出了金属截锥柱侧天线三维辐射场的一种有效的数值分析方法。这些公式同样适用于金属截柱或截锥，应用上述公式计算了截锥侧微带天线及其排阵的任意平面方向图，并与实测结果进行了比较，两者吻合良好。     

反射器天线的单站雷达截面积

本文用几何光学法计算反射器天线的镜面场,用等效电磁流法(根据物理绕射论与与电流线积分公式导出)计算边缘的绕射场,得到了任意旋转反射器天线在任意极化平面波入射下的单站雷达截面积(RCS)的计算公式,并给出了一些典型的数值计算结果及相应的立体RCS图。在水平和垂直极化入射下,本文理论值与已有的实验结果以及与一致性绕射理论的结果吻合较好。     

一致性绕射理论加速的时域积分方程方法

为计算电大平台上天线间的互耦提出一种一致性绕射理论加速的时域积分方程算法.引入一致性绕射理论中射线寻迹的方法,对占时间步进法主要计算量的迟滞积分项进行加速,以牺牲部分精度为代价,提高了时域积分方程算法的计算速度.数值算例证明了有效性.     

偏置Fresnel透镜天线

本文用矢量Ｋｉｒｃｈｈｏｆｆ绕射理论分析了偏置Ｆｒｅｓｎｅｌ透镜天线。给出了预测共极化和交叉极化辐射方向图的方程。介绍了计算远场积分的两种方法。研究了天线性能，如旁瓣和交叉极化电平，报导了试验性的偏置Ｆｒｅｓｎｅｌ透镜，测量结果完全符合理论预测。     

一种求解电大平台天线互耦的时域积分方程快速算法

该文针对电大尺寸平台天线互耦问题,提出一种基于几何绕射理论加速的时域积分方程快速算法。在求解时域积分方程的经典时间步进法基础上,引入几何绕射理论中的绕射线寻迹,提高了迟滞积分的计算效率。数值算例证明了该方法能够有效地加速时间步进法的求解过程,对电大平台天线布局优化设计具有理论指导意义。     

N层介质覆盖矩形微带天线的分析

本文给出了在三维电流源激励的情况下,N层介质覆盖微带天线结构的谱域格林函数的新的解析公式,建立了分析这类天线的谱域全波分析模型,并利用有效的数值技术求解出积分方程,得到了天线的贴片表面电流,进而可得到天线的输入电压驻波比和辐射方向图等有关特性参数.实验结果证实了理论计算的正确性.     

Cubic splines as expansion functions for the current distribution of microstrip stub antennas

The current distribution on microstrip stub antennas is calculated with the appropriate Green's functions via an integral equation, which is solved with the moment method. As expansion functions for the current cubic spline functions are used. The calculated data are used for the design of a microstrip array with Chebyshev characteristics.     

Efficient analysis of input impedance and mutual coupling of microstrip antennas mounted on large coated cylinders

An efficient and accurate hybrid method, based on the combination of the method of moments (MoM) with a special Green's function in the space domain is presented to analyze antennas and array elements conformal to electrically large material coated circular cylinders. The efficiency and accuracy of the method depend strongly on the computation of the Green's function, which is the kernel of the integral equation that is solved via MoM for the unknown equivalent currents representing only the antenna elements. Three types of space-domain Green's function representations are used, each accurate and computationally efficient in a given region of space. Consequently, a computationally optimized analysis tool for conformal microstrip antennas is obtained. Input impedance of various microstrip antennas and mutual coupling between two identical antennas are calculated and compared with published results to assess the accuracy of this hybrid method.     

全等效电流积分方程法分析微带天线

提出了一种分析微带天线的新方法——全等效电流积分方程法。根据等效原理，用等效表面电流表示金属导体影响，用等效体极化电流来取代介质结构影响，建立全等效电流积分方程，结合空域矩量法来求解整个微带结构的电流分布。采用该方法可以分析任意结构的微带天线，只需用最简单的自由空间格林函数而无须求解复杂的谱域或空域格林函数，避免了无穷积分或Sommerfeld积分，且在分析中精确考虑了有限尺寸金属接地板的影响。用该方法分析了矩形微带天线，计算结果与其它文献给出的结果一致，证实了该方法的有效性。     

Analysis of wraparound microstrip phased array by infinite arrayapproach

A moment method analysis of an infinite array of wraparound microstrip antennas fed with idealized current probes on a cylindrical body is presented. The integral equation is formulated through the use of periodic grounded dielectric slab Green's function. The method accounts for the blind angles and allows efficient computation of the reflection coefficient at all other angles. Illustrative results are given     

The effect of a dielectric cover on the current distribution and input impedance of printed dipoles

The effect of the thickness and relative permittivily of a dielectric cover on a printed microstrip dipole has been analyzed. It is shown that the current distribution and the input impedance are, in general, very sensitive to variations of the cover parameters. For a dielectric plate with a constant thickness the dipole resonant length decreases substantially with an increase of the relative permittivity. Because of the limited bandwidth presented by single-element microstrip antennas the effects of the dielectric cover on the design of these antennas have to be carefully considered. For the calculation of the current distribution, the Hertz vector potential associated with the problem was determined for an element of current located in a stratified medium with four layers. Pocklington's integral equation was solved for the currents, using Galerkin's method with piecewise-sinusoidal expansion and weighting functions.     

Theoretical and experimental investigations on microstrip active array antennas and power combiners

In this paper, microstrip active array antennas and power combiners are investigated. The mutual impedance of a rectangular microstrip patch array is analyzed based on the Richmond's reaction integral equation and Galerkin technique in spectral-domain. The computer-aided analysis and design of the active array are then carried out by coupling the mutual impedances to the large-signal characteristics of Gunn diodes with a harmonic balance technique. Based on the theoretical study, microstrip active patch array antennas are investigated experimentally.     

A fast full-wave analysis of scattering and radiation from largefinite arrays of microstrip antennas

A fast full-wave analysis technique that can be used to analyze the scattering and radiation from large finite arrays of microstrip antennas is presented. The technique discretizes the mixed potential integral equation (MPIE) in the spatial domain by means of a full-wave discrete complex image method. The del operators on the Green's functions are transferred from the singular kernel to the expansion and testing functions. The resultant system of equations is solved using the biconjugate gradient (BCG) method in which the matrix-vector product is evaluated efficiently using the fast Fourier transform (FFT). This results in an efficient and accurate computation of the scattering and radiation from finite arrays of microstrip antennas. Several numerical results are presented, demonstrating the accuracy, efficiency, and capability of this technique     

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.     

Electromagnetic modeling of passive circuit elements in MMIC

A spatial domain mixed-potential integral equation method is developed for the analysis of microstrip discontinuities and antennas of arbitrary shape. The algorithm is based on roof-top basis functions on a rectangular and triangular mixed grid and analytical evaluation of the quadruple moment integrals involved. The algorithm has been successfully implemented into an accurate, efficient, and versatile computer program. The numerical results agree with the measured ones very well