过模论文：过模转弯波导的研究.doc

过模论文：过模转弯波导的研究【中文摘要】高功率微波技术是在上世纪七十年代兴起的一门新兴学科。在短短的几十年里,这门学科得以迅猛发展并受到广泛的重视。目前,被广泛应用于军事、科学研究、工业加工、新材料制备以及医学、生物等多方面领域。随着高功率微波技术的发展,适用于高功率微波传输系统中的馈线,与一般馈线相比,要求能更进一步承受高功率。因而,在高功率微波的馈线系统中,常采用功率容量较高的波导元件,并且在波导内部避免使用介质。圆波导和同轴波导是两种常用的微波元件,广泛应用于高功率微波系统中。例如相对论返波管、锥形慢波结构发生器等采用圆波导提取微波的器件输出的微波模式为圆波导TM01模；如渡越管、相对论速调管等采用同轴波导提取微波的器件输出的微波模式为同轴TEM模。TM01模不是圆波导内的最低阶模,必须在过模波导内传输；同轴波导传输TEM模时由于需要提高功率容量,一般也采用过模波导进行传输。在过模波导内传输的模式,若在传输过程中遇到波导转弯,很容易引发其他模式,从而降低自身传输效率。为避免或减小转弯波导中杂模的产生,保证输出模式与输入模式的一致性,是应用中亟需解决的一个困难,具有重要的研究价值和应用价值。鉴于此背景,本文对过模圆转弯波导和过模同轴转弯波导进行了理论分析,设计了转弯45度的过模圆转弯波导和转弯45度的过模同轴转弯波导,并分别进行了数值模拟和实验研究。本论文主要工作如下：1.分析了转弯波导的研究现状。2.过模圆转弯波导的设计。通过对圆波导和半圆波导的理论分析,设计了一种过模圆转弯波导。其设计思路为沿过模圆转弯波导的转弯平面插入一块金属板,将圆波导转换为两个半圆波导。圆波导TMol模在半圆波导中转换为半圆波导TE11模,经转弯传输后,重新将半圆波导TE11模转换为圆波导TM01模,从而实现圆波导TM01模的转弯传输,并对该过模圆转弯波导进行了数值模拟。在此基础上设计了一种同轴TEM-圆TM01模式变换器,作为圆波导TM01模的激励源,并对按照优化尺寸加工的过模圆转弯波导进行了实验研究。3、过模同轴转弯波导的设计。通过对同轴波导和180度扇形波导的理论分析,设计了一种过模同轴转弯波导。其设计思路为沿转弯平面插入一块金属板,将同轴波导转换为两个180度扇形波导。同轴波导TEM模在扇形波导中转换为扇形波导TE11模,经转弯传输后,重新将扇形波导TE11模转换为同轴波导TEM模,从而实现过模同轴波导TEM模的转弯传输,并对该过模同轴转弯波导进行了数值模拟。4、过模同轴转弯的优化设计。由于上述过模同轴转弯波导转弯处存在内导体,增加了加工难度。通过采用将同轴波导转换为半圆波导再进行波导的优化方式,解决同轴波导转弯部分存在内导体的问题。【英文摘要】High-power microwave technology was a newly developing subject in the 1970s.In a few decades,this subject had rapidly developed and received extensive attention.At the present time,it could be widely used in military,scientific research,industrial processing,making new material and medical science,biology et.With the development of high-power microwave,high-power microwave transmission plays an important role in high-power microwave system. high-power microwave transmission system has increasingly received public attention.The feeder which is applicable to high-power microwave,compared with common feeder,is further required to support high power.Therefore,in the high-power microwave feeding system,we always use waveguide elements with high power capacity,and avoid using medium in the waveguides.Circular waveguide and coaxial waveguide are two commonly used microwave elements.For example,relativistic backward-wave oscillator and tapered slow-wave structure generator et,which use circular waveguide to extract energy,output circular waveguide TM01 mode; Transit management and relativistic klystrode et,which use coaxial waveguide to extract energy,output coaxial TEM mode. The TMoi mode is not the lowest order mode of circular waveguide,so that it must transmit in overmode waveguide,and for coaxial waveguide transmitting TEM mode need improve the power capacity,it generally uses overmode waveguide for transmitting,too.While the modes transmitting in overmode waveguide meet some inhomogeneity,it easily arouses other modes,thereby reducing the their efficiency. Avoiding or reducing the complicated modes generating in turn waveguide,and keeping the consistency of output mode with input mode,are difficulties that need urgently solve,and have important value of research and application.In view of this background,this paper makes theoretical research of overmode bend circular mode waveguide and overmode bend coaxial waveguide,and respectively designs 45bend overmode bend circular mode waveguide and 45bend overmode bend coaxial waveguide,then does numerical simulation as well as experimental research.TThe main work of this paper is as follows:1. Analyze the research status of bend waveguide.2. Design and experiment study of overmode bend circular waveguide. Through the theoretical analysis of half-circular waveguide,design an overmode bend circular waveguide. The design principle is as follows:the circular waveguide TM01 mode is converted to half-circular waveguide TE11 mode by inserting fins into the overmode bend circular waveguide along the plane of bend. After transmission by the bend,the half-circular waveguide TE11 mode is re-converted to the circular waveguide TM01 mode. Then do numerical simulation as well. On this basis,we design a coaxial TEM to circular TM01 mode convertor, which make coaxial TEM mode convert to circular waveguide TM01 mode. Do experimental research of overmode bend circular waveguide which is processed accordance with optimal size of machining.3. Design of overmode bend coaxial waveguide.Through the theoretical analysis of 180fan-shaped waveguide,Design an overmode bend coaxial circular waveguide. The design principle is as follows:the coaxial waveguide TEM mode is converted to fan-shaped waveguide TE11 mode by inserting fins into the overmode bend coaxial waveguide along the plane of bend. After transmission by the bend,the fan-shaped waveguide TE11 mode is re-converted to the coaxial waveguide TEMmode.Then do numerical simulation as well as optimized design of this overmode bend coaxial circular waveguide.4. Optimization design of overmode bend coaxial waveguide. Because of the existence of inner conductor at the overmode bend coaxial waveguide, the difficulty of processing is added. For solving this problem, we do some improvement of overmode bend coaxial waveguide. The method of Using the coaxial transformed into half-circular waveguide, then bend transmission.【关键词】过模 功率容量 同轴波导 圆波导 转弯波导【英文关键词】overmode power capacity coaxial waveguide circular waveguide bend waveguide【目录】过模转弯波导的研究摘要6-8Abstract8-9第1章 绪论12-191.1 高功率微波概述12-141.2 转弯波导的国内外研究现状14-171.2.1 圆转弯波导的研究现状14-151.2.2 同轴转弯波导的研究现状15-171.3 论文的研究意义171.4 本文研究内容及主要工作17-19第2章 过模圆转弯波导的设计19-402.1 圆波导的理论分析19-212.2 半圆波导的理论分析21-252.3 基于模式耦合理论设计圆波导