【作者】 周恩；

【导师】 徐善驾；

【作者基本信息】 中国科学技术大学 ， 电磁场与微波技术， 2006， 博士

【摘要】 微带线是目前混合微波集成电路和单片微波集成电路中使用最多的一种平面型传输线。电磁波沿微带线轴线一边传播一边不断地向空间辐射能量而产生漏波。这种漏波在某些情况下是有害的，因为它将造成系统各部分间的干扰而使系统总体性能下降；但在另一些场合下则是有用的，譬如各种形式的微带线漏波天线和应用漏波来实现检测和定位的雷达系统等等。本论文围绕微带线漏波的利用与抑制问题，系统的分析了微带线漏波的物理机制和工作原理，科学的提出了利用微带线高次模泄漏构成漏波天线，以及抑制微带线高次模泄漏的方法。 论文首先简要介绍了微带线漏波的物理机制。然后，采用一种基于模匹配过程的横向散射矩阵方法，系统分析了微带导波结构的特征值问题。该方法不仅适用于微带线，同样也适用于一大类波导和传输线结构。该方法的有效性和精确性已被文献中用其他方法得到的结果所证实。 随后，论文对微带线的漏波现象进行了深入的研究。微带线泄漏一般分为表面波形式和空间波形式两类，其中微带线高次模泄漏一般以空间波的形式发生。论文首先分析了几种常见微带线第一高次模的漏波特性，求出不同参数下微带线漏波的辐射特性，重点研究辐射区中天线区内的漏波现象。然后，基于对这些不同结构微带线漏波特性的理解，提出了一种新型多层介质悬置微带线结构。该结构不仅可以确保天线工作在效率较高的天线模区，而且它的泄漏常数在相当宽的范围内随频率都能平坦地变化。这个特性保证了天线在频率扫描时可以保持一个稳定的不畸变的辐射方向图。 与漏波利用相对应的就是漏波抑制问题。目前，人们对于抑制微带线主模泄漏方法的研究相对成熟；然而，对于微带线高次模泄漏的抑制，则没有什么简单而有效的方法。这主要是由于微带线主模泄漏与高次模泄漏的物理机制不同而造成的。微带线高次模的空间波泄漏几乎很难被完全抑制掉；但是，我们可以想办法在所需要的频段内减小泄漏。文中提出一种在微带线表层导体带下增加一条导体带的方法来抑制漏波。结果表明，这种结构可以在所需要的频段内明显地减小微带线第一高次模的泄漏常数。 左手材料是目前国际电磁学界研究的前沿和热点。与传统的右手材料相比，更多还原

【Abstract】 Microstrip line is a mostly used planar transmission line in hybrid microwave integrated circuit and monolithic microwave integrated circuit. Microstrip line continuously leaks power into space while the electromagnetic wave propagates along the metal strip. Sometimes this kind of leakage is harmful because it will generate cross-talk between nearby components to deteriorate the system performance. However, it is useful in other cases, such as deferent kinds of leaky-wave antenna and radar system using leaky-wave to detect and localize the objects etc. In this thesis, focused on the utilization and suppression of leaky-wave on microstrip line, the physical mechanism of leaky-wave for microstrip line is systematically analyzed. Based on which, we proposed how to utilize the higher order mode on microstrip line to form leaky-wave antenna, and how to suppress the higher order leaky mode on microstrip line.The physical mechanism of leaky-wave on microstrip line is briefly introduced at the beginning of the thesis. Then, a transverse scattering matrix approach based on mode matching technique is used to analyze the eigenvalue problem of microstrip guiding wave structures. This approach is not only appropriate for microstrip line structure, but also applicable for a large kind of waveguiding and transmission line structures. The accuracy and validity of this method is verified by the results obtained with other methods in the literate.Then, the leakage phenomena on microstrip line are analyzed. The leakage of microstrip line has two forms: the surface wave form and the space wave form, and the higher order modes on microstrip line mostly leak as space wave form. In the thesis, the leaky characteristics of the first higher order mode on several microstrip line structures are analyzed and the radiation characteristics of leaky-wave on microstrip line with different parameter are given. A modified suspended microstrip line with multilayer dielectric structure is proposed, and the leaky characteristics of the antenna structure are theoretically investigated. It is demonstrated that a suitable choice of the dimension of the structure can guarantee the antenna working in the antenna-mode region to make the antenna operate in an efficient way. Besides, very更多还原