【作者】 丘四海；

【导师】 吕英华；

【作者基本信息】 北京邮电大学 ， 电磁场与微波技术， 2013， 博士

【摘要】 缝隙不可避免的在各种各样的电子设备中大量的存在。可看作孔缝的结构在环境中也频繁的出现,如窗口、门缝、通风管道等等。孔缝在电磁兼容研究中是一个重要的领域。尤其是在越演越烈的现代电子战争中,防护自身电子设备和攻击敌方设备成为克敌制胜的关键。而孔缝在这些因素当中是重中之重。缝隙在微波器件当中的应用也十分的广泛。如目前随处可见的微带天线中,孔缝有被用作激励耦合结构,也有被用作辐射器。虽然目前人们能借助强大的计算机来分析这些结构的电磁特性,但是由于实际环境当中的孔缝复杂,而且通常连接两个或几个同样复杂的区域,以致很难分析,所以孔缝一直是电磁学中研究的热点、重点和难点。到目前为止,广大学者针对简单的或是相对复杂的孔缝进行了大量的研究,并得到相当成熟的建模方法和详细的电磁特性。但是对于多区域多电气尺寸的情况,研究还相当的欠缺。环境中的实际孔缝结构多为这种情况,如：三维任意形状的孔缝,三维电气细长孔缝,三维的孔缝阵列和孔缝后接微波网络。本文依托国家自然科学资金项目,研究了这些结构特殊的孔缝的建模方法及其电磁特性,以期用之以指导实际工程中遇到的电磁防护、辐射和耦合设计。论文的主要内容和创新体现在以下几个方面：1.详细分析和讨论了各种等效问题的等效性,深入分析了等效面的选择问题,并针对优化选择提出了一般性规则。2.以入射波为TE的后接微波网络的孔缝模型为基础,结合模式匹配法扩展了这种常见结构的分析模型。3.应用等效原理建立了三维任意形状孔缝的新模型,导出了相应的积分方程,并利用矩量法求解了孔缝处的等效磁流和表面感应电流以及分析区域内的场分布。在此基础上对处在非光滑表面上的一般性孔缝进行了分析。4.改进了前面提出的模型,使之适用于特殊形状的结构,并利用此改进模型对三维电气细长缝隙和孔缝阵列进行了研究和分析。更多还原

【Abstract】 There are a lot of apertures(or cracks, slots, ducts, holes and so on) in(or on) all kinds of electronic equipments. There are many kinks of the apertures with the structures in the living environment, such as windows, doors, ventilation pipes, and so on. The electromagnetic characteristics of the aperture is an important research area in electromagnetic compatibility. Especially when the modern electronic warfare is getting worse, protecting our electronic devices and attacking the enemy’s become the key to win the victory over the enemy. Among these, the aperture is a top priority. Apertures which are used in the microwave devices are also very widespread. They are used in the microstrip antenna which is a popular communication antenna today. They are used as a coupling structure, also as a radiator. Although people use powerful computers to analyze the electromagnetic characteristics of the structures nowadays, but because of the complexity of the actual environment, and usually the aperture is connecting two or more areas which are the same complex, so that it is still difficult to analysze such a problem. So, the aperture has been an interesting topic in electromagnetics for many years.So far, many scholars have done a lot of work on the aperture problems which are simple or complicate shapes. There are a few successful models for complicate slots, such as arbitrary shape in flat plane, having depth, of filled with different materials. And their electromagnetic characteristics are analyzed. But there are rare researches on the multi-scale and multi-region apertures. The apertures are this kind in the living environment, such as arbitrary shaped3D aperture,3D eletrical thin-long slots,3D aperture arrays and apertures which are backed by microwave networks. This thesis concentrates on the modeling of the multi-scale and multi-region apertures, studying their eletromagnetic characteristics. And it wishes to be used in the design. The main contents and several innovations are shown bellow:1. The equivalence of the equivalent problems is discussed in detial. And the selections of the different equivalence surface are deeply analized. A few rules are proposed for optimal modeling.2. Based on the model of the double2D slots backed by microwave network which is illuminated by a plane wave, an extended model which is combined with the mode matching technique is developed.3. By using the uniqueness theorem and the equivalence principle, a new model which is capable analyzing the arbitrary3D shape aperture is developed. The integral fromulations are deduced. Then, the matrix equations are formed by using the moment procedure. And the equivalence magnetic currents which are on the aperture’s equivalence sruface are solved. The electric currents which are on the inside and outside of the cavity are calculated, and the electric fields as well. A3D aperture which is on the edge of the cavity is analyzed by applying the model.4. An improvement of the new model is developed. The optimal model is capable handling the multi-scale and multi-region apertures. And a few canonical examples are analyzed under the application of the optimal model.更多还原