[工程科技]不同变形下梯形脊波导传输特性研究---毕业设计.doc

摘 要 自1947年由Cohn引入脊波导后，脊波导引起了人们的重视，对脊波导的研究从未间断。与传统的矩形波导相比，脊波导有以下优点：宽的单模带宽、主模截止波长长，使得脊波导在微波和毫米波工程中得到广泛应用。早期脊波导的研究主要是单脊波导和双脊波导，而近期的研究则主要是更加复杂的脊波导结构，比如对趾波导（antipodal-ridge waveguide）、梯形脊波导等。在现代微波工程中，为了满足微波传输系统性能的某些需要，需要不断探索和研究具有特殊截面形状的各类新型波导，但在生产实际中，由于生产制造、装配及使用等原因，会造成脊波导的多种变形，分析研究变形对脊波导传输特性的影响，有助于加强实际应用。 本论文介绍了脊波导的发展以及本课题的实际意义；阐述了波导理论基础、规则脊波导的传输特性；介绍了有限元法原理；应用有限元方法分析了多种脊波导在不同变形下的传输特性。根据现有资料，选取脊波导传输特性较优时的几何尺寸，计算结果与已有的国内外权威刊物上发表的数据资料进行对比，数据误差很小，这就证明了所选方法在计算上的有效性和所编程序的精确性。 本文采用Matlab环境下的有限元PDE工具箱分析了多种脊波导在错位和不同受力变形下的传输特性，求出了归一化截止波长，单模带宽，并绘出了其对应的场结构图。计算结果表明：脊波导错位变形后，传输特性变化较小；脊波导双边受力变形时，传输特性变化最大，特性变差；脊波导下侧受力变形后，传输特性变好。这些参数为脊波导器件的设计和使用提供了参考。 关键词：脊波导；有限元法；截止波长；单模带宽 论文类型：应用基础研究 Abstract Since the introduction of the waveguides by Cohn in 1947, they have received considerable attention, and research on them has continued steadily. Compare to the normal rectangular waveguide, ridge waveguide has the character of broader bandwidth, smaller dimension, lower equivalent characteristic impedance, etc. Because of these merits, it is used more and more widely in micro-wave and millimeter-wave devices. In early research of ridge waveguide, they mainly research single-ridge waveguide and double-ridge waveguide, then, the recent research is more complicated structure of ridge waveguide, for example, antipodal-ridge waveguide, trapezoidal-ridge waveguide, etc.. In order to meet some requirements in modern microwave transmit systems, it needs to research some new waveguides with especial sections. Then in production and practice, owing to some reasons, such as production, assembly, use, and so on, which can bring about deformations of ridge waveguide. And it is helpful to reinforce practice use to analyze deformations of ridge waveguide to influence of transmission characteristic. There are four chapters in this paper. In first chapter, development of ridge waveguide, and the importance in practice of this paper are introduced; In second chapter, there are waveguide theory, the transmissio