【作者】 罗全珍；

【导师】 姬五胜；

【作者基本信息】 兰州理工大学 ， 通信与信息系统， 2011， 硕士

【摘要】 随着微波电路的快速发展,用于电磁场分析的数值方法也随之不断发展。但是大多数传统方法都有着大内存的需求和长时间的计算,像目前很常用的矩量法,有限元法和有限差分法等。本文引入一种基于空域结合、谱域变换的波概念迭代方法(WCIP)。该方法对平面电路的不连续性表面剖分网格,在此表面上建立波源和反射波之间的迭代关系,采用傅立叶模式变换,避免了基函数的选取和大矩阵的逆转换,节省了内存,可以有效提高计算速度。本文主要工作如下:首先,本文阐述了波概念迭代法的原理。推导了空域散射算子的表达形式;引入了多端口网络中WCIP的建立方法;描述了具有周期结构的频率选择表面的波概念迭代法分析原理;通过与传统数值计算方法在计算复杂度方面的对比,证明了该方法的优势所在。其次,本文运用WCIP对几种微波平面电路展开分析,验证了该方法分析微波平面电路的准确性和高效性,并扩展了该方法的应用范围。第一,对微带贴片天线进行分析,仿真了的贴片所在表面的电场分布,求解了微带贴片天线的回波损耗、电压驻波比等参数。接着分析了H型贴片天线以及缝隙加载H型双频天线,得到了满意的效果。第二,对微带滤波器进行分析,计算了开环耦合微带带通滤波器的S参数。第三,将WCIP应用于频率选择表面的研究,通过计算一个谐振单元的特性,结合周期结构固有的规律,达到分析频率选择表面整个电路特性的目的,简化了分析过程,提升了计算效率;并通过改变相关参数,得到了频率选择表面传输系数随参数变化时的频率响应变化规律。更多还原

【Abstract】 With the rapid development of microwave circuit, various kinds of numerical methods for electromagnetic field analysis are also developed to accommodate with it. But most traditional methods, such as MOM, FEM and FDTD, need a large memory requirements and long computation. In this paper, the wave concept iterative procedure (WCIP), based on transformation between spatial domain and spectral domain, is introduced. In this method, the discontinuity plane of microwave circuit is divided into small rectangular cells. Iterative relationship of wave sources and reflected waves is created on the plane. The Fast Fourier Mode Transform is used, which avoids the selection of base function and inverse conversion of large matrix, saves some memory, and improves computing speed effectively. The work of this dissertation is as follows:On the one hand, in this paper, the principle of the wave concept iterative procedure is described. The expression form of spatial diffraction operation is further concluded. The spatial diffraction operation is derived under the multiple port networks. The principle of the WCIP for FSS of periodic structure is studied. The operation’s number is compared between WCIP and the traditional algorithm, which verifies the efficiency of this method.On the other hand, the microwave planer circuit is analyzed by using the WCIP, which verifies the correctness and efficiency of the WCIP, expands the use of this method. Firstly, Microstrip patch antenna is analyzed. The fields distribution of the patch surface is simulated, the return loss and VSWR of Microstrip patch antenna are solved. Then an H-shaped patch antenna and slot-loaded H-shaped dual-frequency antenna are studied, satisfactory results are achieved. Secondly, the Microstrip filter is studied and S parameter of the open loop resonator band-pass filter is calculated. Ultimately, the WCIP is extended to analysis the frequency selective surfaces (FSS). By calculate the characteristics of one cell, combining with the law of periodic structure, the characteristics of whole FSS circuit are analyzed, which simplifies the process and enhance the efficiency of analysis. By changing the relevant parameters, the frequency response of FSS transmission coefficient are obtained.更多还原