无截获栅控环圈结构周期聚焦行波管

本文介绍了无截获栅控环圈结构周期聚焦行波管的研制概况。在S波段、20%的带宽内、1%工作比的条件下,脉冲功率大于2千瓦,饱和增益大于43分贝。该管采用了无截获栅控电子枪,环圈结构慢波线,钐钴磁钢周期永磁聚焦,同轴传输装置。具有体积小、重量轻的优点。     

具有一定形状的介质加载慢波线的计算机分析

慢波线的特性受介质加载形状的影响。它的相速和阻抗是轩状线的每根杆(或螺旋线每圈螺旋)与地之间相对介质加载和杆与杆之间(或螺旋线圈与圈之间)介质加载的函数。业已找到了慢波线每节相移为零和π的静态场解。相移在零到π之间的解由这两个解的线性组合得到。为了对各种不同的慢波线求解,引进了适当的边界条件。本文介绍了曲折线,组合螺旋线和 T 型螺旋线等慢波结构的理论计算和实验结果。     

Ku波段环圈慢波结构高功率行波管设计

更高的工作频率和更大的输出功率是当前行波管发展的主要方向。为满足Ku波段行波管日益提升的大功率和高效率发展需求,本文在分析慢波结构参数对色散和互作用阻抗影响的基础上,开展了Ku波段环圈慢波结构高功率行波管研究。研究显示,在12.8 kV和0.4 A的工作条件下,环圈行波管可以提供2672.9 W的峰值输出功率,对应的增益和电子效率分别为51.26 dB和26.10%,瞬时3 dB带宽达到2.5 GHz(14～16.5 GHz)。     

平面型慢波结构色散特性和耦合阻抗的测量

Ⅰ、引言慢波结构是行波管和返波管不可缺少的部件。管子功率的高低、频带的宽窄均与慢波结构有密切的关系。例如早期的小功率行波管多采用螺旋线慢波结构,但随着功率的不断提高,螺旋线的热耗散能力已显得不够,因此,一般中功率行波管多采用环杆结构。到更高功率电平,环杆结构也不能满足要求了,而必须采用耦合腔链式的慢波结构。所有这些慢波结构都     

矩形环双杆慢波结构高频特性

提出了一种适合于高功率行波管的新型矩形环双杆慢波结构.利用电磁仿真方法分析了慢波结构参数对色散和互作用阻抗的影响,并与圆环双杆慢波电路进行了对比.结果显示:矩形环双杆慢波电路的色散平坦度和归一化相速受横截面宽高比的影响较小,在横截面周长相同情况下,矩形环双杆慢波结构可以提供更平坦色散,并且在中高频段拥有更大的互作用阻抗...     

S波段慢波线成型技术

介绍了一种新型的S波段慢波线,对慢波线结构形式的工艺性优化设计、成型工艺方法作了详细介绍。采用该成型技术制造出的慢波线达到了优良的电性能指标,满足了某型雷达蛇形慢波线系统的电性能要求。     

翼形环圈慢波线行波管设计

本文首次介绍了翼形环圈慢波形波管结构。在一支２ｃｍ高占空比的行波管中介绍了它的热设计优势以及高频性能方面的优势。其高频性能达到了国际领先水平。     

大功率行波管新型慢波线技术的进展

全金属慢波结构由于具有热耗散能力强，功率容量大，比耦合腔慢性线带宽度，结构整体性好，尺寸大等一系列优点而备受人们关注。本文着重介绍了螺旋槽、环板、曲折波导及周期加载波导四类结构的发展现状，包括理论研究与实际应用情况，探讨了新型慢波线在技术上存在的问题及今后的努力方向，指出全金属慢波结构将在毫米波行波管、返波管、毫米波回旋行波管及相对论器件等方面得到广泛应用。     

W波段带状注耦合腔慢波结构行波管的设计与冷测

对W波段三槽梯形线耦合腔慢波结构(包括大功率输入输出耦合器和射频窗)的加工和冷测进行了研究。此慢波结构由一个矩形波导耦合器馈电,该耦合器由放置在输入腔短边上的三阶阶梯变换矩形波导组成。首先,利用仿真方法研究了慢波结构的色散、互作用阻抗、传输特性和注-波互作用。结果表明,采用三槽梯形线耦合腔慢波结构的行波管能够在91~96 GHz的频率范围内提供大于1000 W的饱和输出功率,并且在94 GHz频点,饱和输出功率最大,可以达到1125 W。其次,采用高精度数控铣床加工出三槽梯形线慢波结构,并将其固定在非磁性不锈钢外壳中。文中给出了带有耦合器和射频窗的三槽梯形线慢波系统的测试结果,表明在90 GHz到100 GHz的频率范围内,S11<-10 dB。因此,三槽梯形线慢波结构在W波段大功率行波管方面具有应用前景。     

环板慢波线的色散分析

本文以变分原理对毫米波行波管用的环板慢波线进行了理论分析,讨论了变分方程的建立和方程的求解,并用计算机进行了数值计算。计算结果与冷测实验结果良好相符。本文的理论方法可用于环板慢波线的分析和设计。     

Investigation of the bandpass properties of the local impedance of slow-wave structures

The properties of the local coupling impedance that determines the efficiency of the electron-wave interaction in periodic slow-wave structures are investigated. This impedance is determined (i) through the characteristics of the electromagnetic field in a slow-wave structure and (ii) through the parameters of a two-port chain simulating the structure. The continuous behavior of the local coupling impedance in the passbands of slow-wave structures, at the boundaries of the passbands, and beyond the passbands is confirmed with the help of a waveguide-resonator model.     

Analysis of a Chiral Dielectric Supported Broadband Helix Slow-Wave Structure for Millimeter-Wave TWTs

A novel technique of broadbanding a helical slow-wave structure through negative dispersion shaping is proposed. The model considers a simple continuous chiral dielectric support for the helix inside a metallic barrel, unlike conventional helix slow-wave structures with three discrete dielectric supports at 120⁰ apart. The dispersion relation of the slow-wave structure was derived following sheath-helix abstraction, suitably benchmarked for special cases, and was used for analyzing the dispersion behavior of a typical slow-wave structure. Chiral dielectric loading could easily provide negative dispersion characteristics (required for broadband operation) by merely controlling the chirality parameter alone. The scheme with its simple geometric configuration is expected to be useful for millimeter-wave devices providing better thermal management.     

Slow-Wave Characteristics of a Frame–Rod Structure Based on Micro-Fabricated Technology for THz Vacuum Electron Devices

A simple equivalent circuit analysis of the frame–rod slow-wave structure (SWS) on dielectric substrates of a traveling-wave tube (TWT) is developed, using the quasi-TEM approximation approach for the dispersion and coupling impedance characteristics of the structure. Moreover, the obtained complex dispersion equation and coupling impedance are numerically calculated. The calculation results by our theory method agree well with the results obtained by the 3D EM simulation software HFSS. It is shown that the dispersion of the frame–rod circuit is decreased; the phase velocity is reduced and the bandwidth becomes greater, while the coupling impedance decreases after filling the dielectric materials in the frame–rod SWS. In addition, a comparison of slow-wave characteristics of this structure with a rectangular helix counterpart is made. As a planar slow-wave structure, this structure has potential applications in compact TWTs based on the micro-fabrication technology, which could be scaled to millimeter wave, even to THz frequency.     

梯形慢波结构的研究

梯形慢波结构是应用于中功率和大功率行波管的一种重要且实用的周期慢波系统,具有结构简单,成本低,功率容量大,散热性好等优点。目前,国内外对梯形慢波结构的研究工作一直在进行中。分析了梯形慢波结构模型,分析了谐振法在运用CST 软件本征模求解器计算色散特性中的理论和过程。在此基础上,设计了工作点为100GHz 和225GHz 的梯形慢波结构尺寸,并研究了梯形慢波结构的尺寸对色散特性的影响。     

Compact defected ground structure in microstrip technology

A meander microstrip line with defected ground structure is proposed in this paper. Its radiation loss and slow-wave effect are evaluated. The compact configuration presents broad stopband and improved slow-wave characteristics. A good agreement between simulation and measurement verifies the designed circuit     

Design and Characterization of a W-Band Folded-Waveguide Slow-Wave Structure

A single-section slow-wave structure for a W-band folded-waveguide traveling-wave tube with operating bandwidth of around 4% was designed for delivering the output power of 50 W at the operating voltage of 13.5 kV and operating beam current of 80 mA. The design was carried out using analytical formulations and 3D electromagnetic simulations. The beam-wave interaction analysis was carried out using large signal Lagrangian analysis and particle-in-cell simulation. The folded-waveguide slow-wave structure along with input-output couplers and RF windows were fabricated. Cold test measurements were carried out for dispersion characteristics of the slow-wave structure and voltage standing-wave ratio and insertion loss characteristics of the RF window. The measured cold circuit parameters show close agreement with the analysis.     

An Improved Version of Split-folded Waveguide Slow-wave Structure†

An improved version of split-folded waveguide slow-wave structure for crossed-field tubes is described. The equivalent capacitance type analysis is given that predicts the dispersion characteristics of the structure accurately. The experimental slow-wave structure demonstrates a usable band from 1·4 to 3·1 Gc (bandwidth 2·25 : 1), The interaction impedance of the modified structure being reasonably largo, allows the use of fundamental backward or first forward-wave harmonics over wide bandwidths.     

Equivalent Circuit Analysis of Serpentine Folded-waveguide Slow-wave Structures for Millimeter-wave Traveling-wave Tubes

A simple equivalent circuit model for the analysis of dispersion and interaction impedance characteristics of serpentine folded-waveguide slow-wave structure was developed by considering the straight and curved portions of structure supporting the dominant TE ₁₀-mode of the rectangular waveguide. Expressions for the lumped capacitance and inductance per period of the slow-wave structure were derived in terms of the physical dimensions of the structure, incorporating the effects of the beam-hole in the lumped parameters. The lumped parameters were subsequently interpreted for obtaining the dispersion and interaction impedance characteristics of the structure. The analysis was simple yet accurate in predicting the dispersion and interaction impedance behaviour at millimeter-wave frequencies. The analysis was benchmarked against measurement as well as with 3D electromagnetic modeling using MAFIA for two typical slow-wave structures (one at the Ka-band and the other at the W-band) and close agreement observed.     

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.     

任意槽形矩形慢波结构高频特性分析

矩形慢波结构及其变态具有易于微加工、横向尺寸大、散热好等优点,是一种有潜力工作于毫米波段或亚毫米波段的高频系统.文中利用场匹配的方法推导出了任意槽形状开放式矩形波导慢波结构的统一色散方程,并利用数值计算方法分析了几种特殊槽形状加载慢波结构的色散特性及耦合阻抗,得到三角形结构色散和耦合阻抗均最弱,而倒梯形结构色散最强,耦合阻抗最大.