螺旋线慢波结构的参数变化对其冷测特性的影响

本文介绍了用MAFIA软件的准周期边界条件计算螺旋线行波管慢波结构的色散和耦合阻抗等冷测特性的方法,并重点对慢波结构中各参数,特别是矩形螺旋线截面的宽度和厚度对其冷测特性的影响进行了分析.这是目前理论上没有解决的难题.分析结果表明,螺旋线的宽度和厚度对其色散影响不大,而对耦合阻抗有一定影响.对耦合阻抗而言,螺旋带宽度和厚度都存在一个最佳值.     

螺旋慢波系统高频特性的计算机仿真

介绍了用德国CST(Computer Simulation Technology)公司提供的微波工作室MWS(Microwave Studio)4．2软件模拟计算螺旋线慢波系统的色散特性和耦合阻抗的理论方法。通过对矩形夹持杆支撑螺旋慢波结构的模拟计算,与测试结果相比色散特性的平均模拟误差为1．5%左右,耦合阻抗的平均误差为0．3％左右;相比于MAFIA仿真,计算精度更高,计算时间更短。     

螺旋带径向厚度对色散和耦合阻抗的影响

该文将有限厚度的实际螺旋带等效为存在无限薄螺旋带的等厚真空层,从场分析和软件模拟两个方面研究了等效慢波结构的色散特性和耦合阻抗.将理论计算、软件模拟和实验测试结果进行了比较,结果表明,用真空层等效有限厚度的实际螺旋带时,将无限薄螺旋带置于等厚真空层的中央,其螺旋慢波结构的色散特性和耦合阻抗的理论计算、软件模拟和实验测试结果三者取得了很好的一致.     

电子器件

0309376翼片加载螺旋线慢波结构的螺旋带模型[刊]/张勇//强激光与粒子束.—2002,14(6).—887～891(K)翼片加载螺旋线慢波结构广泛应用于大功率、宽频带行波管中,建立了翼片加载螺旋线慢波结构的螺旋带模型,得到了实用的色散方程、耦合阻抗和衰减常数的表达式。利用导出的方程对实际行波管螺旋慢波结构进行计算,井与测量结果和导电面模型进行了比较,计算结果与测量结果具有良好的一致性。分析了不同管壳半径对色散特性的影响。参8     

螺旋双脊波导慢波结构的理论计算

本文用理想“螺旋钩”导电模型对螺旋双脊波导的慢波结构参量进行了理论分析计算。从而推导出此慢波导结构的冷、热色散曲线(即有电子注的),藕合阻抗、特性阻抗及衰减常量。计算和冷测实验证明它是毫米波段大功率行波管的理想慢波结构。     

脊加载同轴径向线慢波结构设计

提出脊加载同轴径向线慢波结构,并用高频结构仿真器(HFSS)电磁仿真软件对其色散特性和耦合阻抗进行研究,分析了不同结构参数变化对其高频特性的影响。结果表明:脊加载同轴径向线慢波结构的色散曲线平坦,减小内径和周期长度可以明显降低慢波结构的相速,从而减小工作电压;加载脊的宽度对耦合阻抗的影响明显,随着加载脊宽度的增加,耦合阻抗得到提高,相速减小;加载脊的长度对结构的色散特性和耦合阻抗影响不明显;这种脊加载方式有利于增加慢波结构的耦合阻抗,提高行波管的增益和效率。脊加载同轴径向线慢波结构是一种全金属结构,工作频带宽,散热性能好,在毫米波波段的行波管中有较好的应用前景。     

螺旋耦合翼片慢波结构的研究

本文分析了螺旋耦合翼片慢波结构,给出了该结构的色散特性及耦合阻抗的理论公式。其理论计算与实测值一致性较好。文中还讨论了慢波结构几何形状的变化对色散特性及耦合阻抗的影响。     

螺距对螺旋慢波系统色散和耦合阻抗的影响

螺距是慢波系统的一个重要参数,直接影响螺旋慢波系统的色散特性和耦合阻抗.严格求解螺距对慢波系统色散和耦合阻抗的影响是不方便的,而通过计算机模拟可以方便快速地研究螺距对慢波系统色散和耦合阻抗的影响.模拟结果表明,对于工程项目当螺距变化小于4%时,螺距对色散和耦合阻抗的影响是很小的.     

大功率π型慢波结构的特性研究

采用π型慢波结构的大功率行波管具有１５％带宽，无“兔耳”效应以及可实现１００ｋＷ甚至更高的峰值功率，本文运用场匹配法对行波管用的π型慢波结构进行了理论分析，给出了这种结构的色散方程和耦合阻抗，对π型慢波结构进行精细冷测后表明，计算机数值计算的理论值与冷测实验结果吻合良好，为使行波管单模工作而在π型结构中增加搭扣带后的主模色散计算方法也已给出，并取得了与实测较一致的满意结果，本文还叙述了该结构的尺寸     

带状螺旋慢波结构耦合阻抗的研究

本文运用螺旋坐标系计算了带状螺旋慢波线结构的耦合阻抗,本文给出了螺肇带缝隙内的电磁场解,因而明确地计算了螺旋带缝隙内的传输功率,分析这一部分功率对耦合阻抗的影响,结果发现螺肇带缝隙传输功率对耦合阻抗的影响较大,包括这一部分功率后,理论与实验符合得很好。     

Fast Design and Cold-Circuit Properties Simulation for the Slow Wave Structure of a 0.14 THz Broadband Folded Waveguide Traveling Wave Tube

This article applies an explicit method to the fast structural design for the slow wave circuit of a 0.14 THz broadband folded waveguide traveling wave tube. To valid the primary design, cold-circuit properties, such as dispersion and interaction impedance, were calculated by using both theoretical method and electromagnetic software (CST MWS) simulation. The S parameter S ₁₁ was also calculated by CST MWS with lossy metal being considered. Simulation results show that, the cold pass band is about 70 GHz, and the interaction impedance is about 1 ohm, and indicate that the design method is reasonable for obtaining a 0.14 THz broadband slow wave structure.     

Analysis of the Dispersion Characteristic and Interaction Impedance of a Tape Helix Slow Wave Structure with Novel Supporting Mode

In order to enhance the power capability of the helix travelling wave tube, a novel tape helix slow wave structure (SWS), which is supported by helically arrayed radial dielectric-support posts, is developed. Each dielectric post can be easily brazed with the tape helix and the metal envelope by means of a special soldering. This kind of supporting mode can protect the dielectric supporting posts from being broken by the thermal stress in the case of high temperature. A hybrid model is set up in consideration of the influences of both the radial thickness of the tape helix and these discrete dielectric-support posts. The dispersion equation and interaction impedance of the helical SWS are obtained. The calculated results using this hybrid model presented in the paper show good agreements with the HFSS simulation results. All the results presented here can provide a good basis for designing the novel tape helix SWS.     

0.14 THz折叠波导行波管慢波结构设计与加工

使用一种显式方法对0.14 THz折叠波导行波管慢波结构进行了快速设计,并通过解析模型、等效电路模型以及电磁场仿真软件(CST MWS)对结构的色散关系和耦合阻抗进行了计算。计算结果表明,0.14 THz附近的色散较为平坦,耦合阻抗在1Ω左右。为了满足大功率输出需求,对初始结构尺寸进行了部分调整。CST PS互作用模拟结果表明,在0.14 THz附近,输出功率大于1 W。用微电火花(EDM)和微铣削方法分别进行了加工实验,结果表明,两种方法在尺寸精确度上均能满足指标要求,微铣削加工能获得更平整、表面粗糙度更好的槽底。     

Study on Effects of Different Metallic Vane-Loaded Helix Slow-Wave Structures in Traveling-Wave Tubes

The effects of different metallic vane-loaded helix slow-wave structures of a traveling-wave tube are proposed based on the analysis of the Fourier expansions of the exterior region with metallic vanes. The influences of the metallic vanes dimensions on the phase velocity and interaction impedance are considered in detail. The computed data is compared with the reference data in the 0−16 GHz frequency range with a good consistency. The analytical results reveal that the method of using Fourier expansions can contribute effectively to the reducing of the error between the theoretical and experimented data (around 1.2%). By analyzing the computed results, the performances of the helix slow-wave structure, with T-shaped metallic vanes are superior to the sector-shaped with the same designed parameters. Adjustments can be made to the outer radius of T-shaped metallic vanes which then control the dispersion relation showing either negative or positive, and it is similar to sector-shaped vanes by adjusting its inner radius. And with increasing the distance between the helix and metallic vanes, the dispersion characteristics and interaction impedance of the helix slow-wave structure with T-shaped/sector-shaped metallic vane are all improved.     

Analysis of Helix Slow Wave Structure for High Efficiency Space TWT

This paper describes the analysis of helix slow-wave structure (SWS) for a high efficiency space traveling wave tube that is carried out using Ansoft HFSS and CST microwave studio, which is a 3D electromagnetic field simulators. Two approaches of simulating the dispersion and impedance characteristics of the helix slow wave structure have been discussed and compared with measured results. The dispersion characteristic gives the information about axial propagation constant (Beta). Which in turn yields the phase velocity at a particular frequency. The dispersion and impedance characteristics can be used in finding the pertinent design parameters of the helix slow-wave structure. Therefore a new trend has been initiated at CEERI to use Ansoft HFSS code to analysis of the helix slow wave structure in its real environment. The analysis of the helix SWS for Ku-band 140W space TWT has been carried out and compared with experimental results, and found is close agreement.     

一种具有新型分立介质支撑的翼片加载螺旋带慢 波结构的研究

本文研究了一种具有新型分立介质支撑的翼片加载螺旋带慢波系统,该种慢波系统具有较高的功率容量和较宽的带宽.通过用切比雪夫多项式来展开螺旋带上的面电流,用真空层来模拟螺旋带的厚度,用均匀分层介质来等效新型分立介质支撑,考虑到过渡连接金属块的影响,用场论的方法得到了非常实用的色散方程和耦合阻抗的表达式,同时进行了HFSS模拟,发现用场论的方法所得出的结果与用HFSS模拟的结果吻合良好.本文的结果对这种新型慢波结构的设计具有指导意义.     

S、C、X波段螺旋线慢波结构的宽频带行波管研究

为满足现代信息化战争对宽带行波管的需求,对S、C、X波段螺旋线行波管慢波结构的性能进行了研究分析。为适应宽频带要求,选用了带有T形加载翼片以及品形氮化硼夹持杆的螺旋线慢波结构;通过采用动态速度渐变技术,得到了较高的电子效率,并根据仿真计算结果成功研制出了S、C、X波段螺旋线行波管样管。