Upon these , the fdtd parallel method is primarily studied , and the radiation character of the pbg round wave - guide open antenna that need a great mount of computing is analyzed by applying parallel modified locally conformal fdtd method 在此基础上，对fdtd方法的并行实现做了初步研究，并利用并行的共形fdtd技术分析了一种具有较大计算量的pbg圆波导开口天线的辐射特性。
Starting with analysis on the field of gaussian feed ' s aperture , the relations of radiation characteristic and power capacity and gaussian beam waist radius are investigated particularly by using the circular waveguide intrinsic mode expansion method <中文摘要> =本文从圆锥高斯馈源口面场分析入手，利用高斯场展开成规则圆波导场的方法，细致的讨论了高斯束腰对馈源辐射特性和功率容量的影响。
Many high - power microwave ( hpm ) sources utilize an azimuthally symmetric output mode such as the tm 01 circular waveguide or the coaxial tem mode as output mode . if radiated directly these azimuthally symmetric modes will generate a doughnut - shaped pattern , with a null on boresight 许多高功率微波源产生的微波模式都是圆波导轴对称模式,由于其输出端口的口径场分布具有圆对称性,将导致轴向为零的环状远场方向图。
The profile of arbitrary shaped groove is approximated by a series of rectangular steps and the " hot " dispersion equation of the coaxial arbitrary - shaped - groove slow - wave structure is derived by the self - consistent theory 摘要用阶梯近似的方法分析任意槽形加载的圆波导慢波系统中的场，采用自洽场理论，得到了任意槽形周期加载圆波导慢波系统在小信号条件下的“热”色散方程，并对结构参数对小信号增益的影响情况进行了研究。
The influence of various electron beam parameters on the small signal gain is investigated and discussed by the numerical results . 5 . the model of the coaxial disk - loaded cylindrical waveguide is manufactured to testify the dispersion properties of this structure 五、加工了同轴膜片加载圆波导慢波系统实验模型，用谐振法测得的色散特性与理论数据良好吻合，从而验证了同轴膜片加载圆波导慢波系统色散特性理论分析的正确性。
3 . more , the investigation of wave propagation characteristic in round waveguide filled periodically changeful plasma in density is done , by numerical calculation , to analyze the effect on the propagation characteristic when background plasma density and the amplitude of plasma density change 3 .研究了电磁波在填充密度周期变化等离子体金属圆波导中的传输特性,通过数值计算分些了不同等离子体密度和背景密度情况下对波的传播特性的影响
4 . finally , the investigation of wave propagation characteristic in round waveguide filled uniformity plasma periodically magnetized is done , by numerical calculation , to analyze the effect on the propagation characteristic when additional magnetic field amplitude , background magnetic field and plasma density change 4 .研究了电磁波在填充周期磁化均匀等离子体金属圆波导中的传输特性,推导出该周期慢波结构的色散方程,通过数值计算,绘出了色散曲线图
In the dissertation , the coaxial disk - loaded cylindrical waveguide used in sws of relativistic traveling wave tube ( rtwt ) is discussed . the types of the coaxial disk - loaded cylindrical waveguide and the coaxial ridge - disk - loaded cylindrical waveguide are all - metal slow - wave structures and have advantages of large size , good thermal conductivity ? high precision of manufacturing and assembling 本文分析了同轴膜片加载圆波导和脊加载同轴膜片圆波导两种慢波系统，它们均采用全金属结构，具备尺寸大、散热性能好，易加工的特点。
First , the theory of the coaxial disk - loaded cylindrical waveguide sws is analysed , and the dispersion equation and the coupling impedance of this structure are obtained . through the numerical caculation , it is discussed that the influence of various circuit dimensions on the dispersion and the coupling impedance . 2 本文的主要研究工作和创新点如下：一、首先完善了同轴膜片加载圆波导慢波系统的理论分析，得到该系统色散方程和耦合阻抗表达式，并通过数值模拟计算，详细讨论了慢波系统几何尺寸对色散特性和耦合阻抗的影响。
For the first time , the coaxial ridge - disk - loaded cylindrical waveguide as sws is presented . its dispersion equation and the expression of coupling impedance are given by application of the field matching method . a series of numerical results show that the influence of structure dimensions on the dispersion characteristics and interaction impendance 三、创造性地提出脊加载同轴膜片圆波导慢波结构，并对其采用严格的场匹配法，详细推导了色散方程和耦合阻抗表达式，并得到一系列有关系统结构参量与色散和耦合阻抗之关系的数值模拟结果。
