【作者】 林春；

【导师】 王绪本；

【作者基本信息】 成都理工大学 ， 信号与信息处理， 2007， 硕士

【摘要】 超宽带电磁波在空气中的传播特性前人已作过许多工作，也有比较系统的理论，但其散射特性以及在介质中的衰减特性尚无人问津。本文的研究是国家自然科学基金“城市灾害救助的超宽带电磁探测方法研究”(No．40374027)项目的一部分工作。为了解决生命救护难题，填补我国这一领域的空白，本文开展了一系列关于在介质中的超宽带电磁波的传播特性研究，主要工作是研究分析超宽带电磁波波场特征、衰减特性及散射特性。通过对数学物理方程的计算和计算机模拟，研究了超宽带电磁波的传播特性，分析了超宽带电磁波在不同介质中的衰减及散射特性，完成了超宽带电磁波的时域波场分析、波场衰减特性分析，波场散射特性分析，并将其与普通宽带及窄带电磁波进行对比，得出超宽带电磁脉冲作为该基金项目辐射源是合适和有利的。本文的特色之处是所有模拟均使用的是数学物理方程的解析解而非一般常见的数值解。本文围绕着超宽带电磁场辐射传播特性研究，从理论与模拟技术探讨了超宽带电磁场辐射理论、能流密度、与辐射器口径的关系以及在不同介质中的衰减特性及特定目标体的散射情况等问题，主要包括以下内容：1．介绍了超宽带电磁脉冲信号的定义并对该定义进行分析，给定超宽带电磁波的标准激励脉冲信号源，研究了超宽带TEM天线口径辐射场轴线上任意一点的电磁场强度与口径大小及激励脉冲的关系。2．利用Maxwell方程的位函数解探讨了一般均匀圆电流分布的辐射场及能量流动规律。3．研究了介质中超宽带电磁波的衰减特性，定义了超宽带电磁波穿透深度的概念，对具有相同主频的宽带、窄带及超宽带电磁波的穿透能力进行了比较。4．基于应用的要求，分析了介质中及穿墙探测中理想导体对超宽带电磁波的散射特性。5．本文所有计算结果均为解析解，使用Matlab软件进行模拟，并且将所有结果都与数值模拟进行了对比。模拟结果证明了计算结果的正确性与可靠性，从而证明了该项目的可行性。更多还原

【Abstract】 There have been many systemic theories on propagating properties of UWB electromagnetic field in the air, but nothing about its scattering properties as well as decaying properties in medium. This work was one part of research on UWB electromagnetic exploration methods in the field of urban disaster life rescue, No. 40374027, National Natural Science Fund of China. For solving the problem of living security and filling vacancy in the field in our country, this paper were mainly about the simulation and study about the propagating properties of UWB electromagnetic field, which includes: analyzing properties of propagating characteristics, decaying characteristics and scattering properties of UWB electromagnetic field. Through simulation and compute, we analyzed the properties of propagation, decaying and scattering of UWB electromagnetic field in different medium, completed the analysis of time-domain wave field, decaying field and scattering field of UWB electromagnetic field. At last, we compared UWB with the wide band and narrow band electromagnetic wave as the exciting pulse. Specially, all the results were analytical solution of mathematical-physical equation, not the numerical solution.Study around the propagating properties of UWB electromagnetic field involved in this paper, the problems were discussed in different extent using simulation and theories, including: radiation theory of UWB, energy density, the relationship of radiation aperture, the decaying properties and the scattering of ideal target in different medium.1. The definition of UWB electromagnetic pulse signal was introduced and analysis to this definition was carded on. Then a standard driving pulse of UWB electromagnetic wave was assigned, which is used to study the relations of electromagnetic field intensity with the aperture size and the driving pulse on the axis of UWB TEM aperture antennas.2. Radiation field and energy flaw of even current distribution was discussed using potential function solution of Maxwell equation.3. The decaying properties of UWB electromagnetic wave in the medium were studied, and the definition about skin depth of UWB electromagnetic wave was defined. Then the skin depth of wide band, narrow band and UWB electromagnetic wave which have the same basic frequency were compared. 4. Based on the requests of application, the scattering properties of UWB electromagnetic wave in the medium and be put on the ideal conductor in the wall survey were analyzed.5. The results in this paper were analytical, not numerical. Matlab was used to simulate and the results were compared with numerical simulation. The simulation results established the accuracy and reliability of this paper, so the project is feasibility.更多还原