Linear Analysis of Folded Double-Ridged Waveguide

A novel slow-wave structure (SWS), the folded double-ridged waveguide structure, is presented and its linear gain properties are investigated. The perturbed dispersion equation is derived and the small signal growth rate is calculated for dimensions of the ridge-loaded region and the parameters of the electron beam. The novel structure has potential applications in the production of high power and broad band radiation. For a cold beam, the linear theory predicts a gain of 1.1-1.27dB/period and a 3-dB small-signal gain bandwidth of 30% in W-band. A comparison between the folded double-ridged waveguide SWS and folded waveguide SWS (FWSWS) shows that with the same physical parameters, the novel SWS has an advantage over the FWSWS on the bandwidth and electron efficiency.     

脊加载螺旋槽行波管的小信号增益计算

脊加载螺旋槽行波管是一类新型毫米波大功率器件,给出了此结构中引入电子注后的“热”色散方程,并利用“牛顿”下山法求解了此复系数超越方程.通过数值计算给出了一个工作电压为20kV频率为474GHz的脊棱加载慢波结构的具体尺寸,并对此结构中小信号增益随脊尺寸的变化情况及电子注参数对其影响进行了研究,计算结果表明：此结构适宜于作为高增益窄带毫米波大功率行波管的慢波线,其3dB增益带宽为34%;为了展宽其工作带宽,可以适当减小间隙宽度,也可在一定范围内提高电子注电流.给出的理论对于研制此类行波管具有一定的指导意 关键词：     

脊加载曲折波导行波管注波互作用的线性理论研究

提出了一类新型毫米波大功率微波器件——脊加载曲折波导行波管,推导出了引入电子注后的"热"色散方程.通过数值求解此方程,研究了加脊尺寸和电子注参数对小信号增益影响.计算结果表明:通过适当的尺寸设计和工作参数的选择,此结构在Kα波段具有18.51%的3 dB增益带宽和1.15 dB/周期的增益;相比于常规曲折波导结构,脊加载结构在保证一定带宽的情况下,具有更高的增益和电子效率;为了进一步提高增益,可以适当增加脊宽度和高度,也可在一定范围内增加电子注电流. 关键词： 毫米波 曲折波导 脊加载 小信号增益     

新型半矩形环螺旋线慢波结构高频特性

针对行波管更高工作频率和更大输出功率的发展需要,提出了一种半矩形环螺旋线慢波结构。基于三维电磁仿真软件HFSS的模拟研究表明:调控慢波结构的尺寸可以获得合适的色散特性和互作用阻抗,与现有技术的半圆环螺旋线慢波结构相比较,半矩形环螺旋线慢波结构的色散变化很小,但是具有更高的互作用阻抗值。新结构具有平坦色散、高互作用阻抗、与微细加工技术相兼容以及方便与带状电子束互作用的综合优点。     

Wave Propagation Along a Helical Step-Loaded Groove Waveguide

A new kind of helical groove structure, step-loaded groove waveguide is presented and analyzed in this paper. The dispersion equation of this structure is derived by means of a field-matching method. This equation may be reduced to the dispersion equation of helical ridge-loaded structure and rectangular one. In order to demonstrate the influence of the step on the dispersion properties, the comparison of the dispersion characteristics is made in these helical rectangular and modified rectangular groove structures. Form the analysis, it is shown that the step loading tends to reduce the dispersion of the helical groove circuit and the step-loaded structure has the weaker dispersion compared with the rectangular one or the ridge-loaded one. The effect of the step shape on the wave properties is also discussed under the deep groove case. The theoretical results explicitly indicate that the V-like step-loaded structure has the weakest dispersion in all step-loaded structures.     

金属柱平板慢波系统高频特性研究

对于离散的金属柱结构构建的周期性平板慢波系统,本文利用3维FDTD方法结合HFSS仿真软件深入分析了该慢波系统的高频特性.研究了金属柱高度、周期长度对色散特性的影响,计算了耦合阻抗,并与传统光栅慢波系统特性进行了对比分析.分析表明金属柱慢波系统既有与传统光栅慢波系统相似的高频特性,又具有独自的特点,位于离散的金属柱周期间隙中的电子注互作用耦合阻抗具有对称性;金属柱结构用作真空电子器件的高频系统可增加发生有效互作用的电子注厚度,降低起振电流密度,提高器件效率.本文的分析结果为设计低电流密度工作的多电子注短毫 关键词： 金属柱平板慢波系统 3维FDTD算法 色散特性 耦合阻抗     

开敞型角向周期加载金属柱圆波导的注波互作用线性理论研究

提出了一种可应用于毫米波功率放大器中的新型慢波结构——-开敞型角向周期 加载金属柱圆波导结构,并且在互作用通道内,引入了薄环形电子注, 推导出了此时的"热"色散方程,并且对基于该新型慢波结构的行波管的 小信号增益特性进行了深入探讨.通过数值方法 研究了金属柱尺寸和电子注参数 对器件线性特性的影响. 结果表明: 通过对金属柱尺寸的适当设计, 可以获得更高的增益值. 与封闭型结构的比较结果表明, 开敞型角向周期加载金属柱圆波导结构能够 有效地提高小信号增益, 并且对带宽的影响不大. 研究结果为研制基于此新型慢波系统的毫米波行波管奠定了理论基础.     

Small-signal analysis of a rectangular helix structure traveling-wave-tube

This paper investigates the properties of traveling wave-beam interaction in a rectangular helix traveling-wave-tube (TWT) for a solid sheet electron beam. The `hot' dispersion equation is obtained by means of the self-consistent field theory. The small signal analysis, which includes the effects of the beam parameters and slow-wave structure (SWS) parameters, is carried out by theoretical computation. The numerical results show that the bandwidth and the small-signal gain of the rectangular helix TWT increase as the beam current increases; and the beam voltage not obviously influences the small signal gain. Among different rectangular helix structures, the small-signal gain increases as the width of the rectangular helix SWS increases, however, the bandwidth decreases whether structure parameters a and L or ψ and L are fixed or not. In addition, a comparison of the small-signal gain of this structure with a conventional round helix is made. The presented analysis will be useful for the design of the TWT with a rectangular helix circuit.     

397 GHz斜注管互作用系统的设计模拟

斜注管是返波振荡器的一种，通过电子注的倾斜，电子距离慢波结构更近，高频场更强，耦合阻抗和互作用效率更高，显著增加输出功率。对带状注斜注管的互作用系统进行了设计，并首次将双排齿慢波结构应用于斜注管。利用电磁模拟软件和3D粒子模拟软件对设计的斜注管的色散曲线和场分布进行了分析，并对其注-波互作用进行了模拟，可以得到大于100 mW的输出功率以及50 GHz的调谐带宽。输出功率在370.5 GHz频点处处达到峰值2.3 W，电子注电压7.0 kV，注电流120 mA，聚焦磁场1.0 T。     

螺旋坐标系下考虑厚度的螺旋线行波管小信号研究(英文)

采用螺旋坐标系对有限厚度的螺旋带行波管进行了注波互作用的线性理论分析,利用自洽场理论得出了此结构中引入电子注后的"热"色散方程,数值计算了其小信号增益,分析了电子注参数和螺旋线厚度对于螺旋线慢波系统的色散特性的影响。结果表明:螺旋线厚度的增加,行波管的小信号增益也会增加,且带宽也略有增加。该结论为高增益宽频带的螺旋线行波管放大器的设计提供了理论基础。     

具有任意槽的矩形波导栅慢波结构高频特性的研究

将任意形状槽的连续轮廓近似用一系列相连的矩形阶梯近似，利用各阶梯面上导纳的匹配，以及槽与互作用区边界场的连续与匹配条件，获得了具有任意槽的矩形波导栅慢波结构的色散方程和耦合阻抗的表达式，并进行理论上的验证.加工制作了矩形槽波导栅模型，冷测表明理论值与测量值相吻合.分别求解几种特殊槽形矩形波导栅慢波结构的色散特性及耦合阻抗，其中，三角形结构的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. 关键词： 矩形波导栅 任意槽 色散特性 慢波结构     

Investigation of a wideband folded double-ridged waveguide slow-wave system

The folded double-ridged waveguide structure is presented and its properties used for wide-band traveling-wave tube are investigated.Expressions of dispersion characteristics,normalized phase velocity and interaction impedance of this structure are derived and numerically calculated.The calculated results using our theory agree well with those obtained by using the 3D electromagnetic simulation software HFSS.Influences of the ridge-loaded area and broad-wall dimensions on the high frequency characteristics of the novel slow-wave structure are discussed.It is shown that the folded double-ridged waveguide structure has a much wider relative passband than the folded waveguide slow-wave structure and a relative passband of 67% could be obtained,indicating that this structure can operate in broad-band frequency ranges of beam-wave interaction.The small signal gain property is investigated for ensuring the improvement of bandwidth.Meanwhile,with comparable dispersion characteristics,the transverse section dimension of this novel structure is much smaller than that of conventional one,which indicates an available way to reduce the weight of traveling-wave tube.     

Analysis of the Coaxial Ridge-Loaded Helical Groove Waveguide

The coaxial ridge-loaded helical groove waveguide is proposed in this paper. As an all-metal slow-wave circuit, it has advantages of good heat dissipation and great size, and thus is suitable for use of millimeter TWT. By means of field theory, the expressions of the dispersion equation and the coupling impedance of the coaxial ridge-loaded helical groove waveguide are obtained. The influence of various circuit dimensions on the dispersion relation and the coupling impedance is investigated by the results of numerical computation.     

Ku波段光子晶体加载曲折波导慢波结构

研究了Ku波段光子晶体加载曲折波导慢波结构的色散特性和耦合阻抗。用电磁仿真软件CST MWS进行了仿真, 讨论了慢波结构外光子晶体对慢波通道内电磁波的选择通过性。对具有相同结构尺寸慢波结构的研究结果表明:光子晶体加载慢波结构的色散比传统曲折波导慢波结构的色散低;和传统曲折波导慢波结构相比,光子晶体加载曲折波导慢波结构的耦合阻抗略高。     

毫米波沟道梯型慢波结构行波管的线性理论

 在电子通道内引入一薄层空心电子注，对沟道梯型慢波结构行波管进行了线性理论研究，推导出了沟道梯型结构行波管的工作色散方程，计算了沟道梯型行波管的小信号增益和工作相速。计算结果表明：沟道梯型结构行波管每周期的增益高，带宽窄；当沟宽度由零增加到环内径的2倍时，增益减小量不足1%，这表明沟宽度对增益的影响不大；当脊高度增大10%时，增益增加62%，当环内径增大10%，增益减小57%，因此增益与脊高度正相关，与环内径负相关，且相关性十分明显。     

The Small Signal Analysis of a Centered Dielectric-Rod Loaded, Arbitrarily-Shaped Helical Groove Traveling-Wave-Tube

Properties of traveling wave-beam interaction in a centered dielectric-rod loaded, arbitrarily-shaped helical groove slow-wave structure (SWS) are investigated for a thin annular electron beam. The “hot” dispersion equation is obtained by means of the self-consistent field theory, and the small signal analysis is carried out including the effects of the dielectric-rod parameters and the groove shapes. The numerical results show that the bandwidth of the helical groove TWT is expanded by loading dielectric-rod, however, the small-signal gain is reduced; and when the groove shape changes from the swallow-tail shape to the triangle shape, the working frequency increases , while the peak gain decreases. Project supported by the National Nature Science Foundation of China (Granted NO.60401005 and 60532010).     

曲折圆形槽波导慢波系统的高频特性

 对曲折圆形槽波导新型慢波系统的高频特性进行了研究，通过理论分析和数值计算，得到了它的色散曲线和耦合阻抗表达式，并分析了结构参数变化对色散特性和耦合阻抗的影响。研究表明：当周期变小时色散减弱，耦合阻抗增加；而增大直波导长度时色散变弱，但同时耦合阻抗也会下降。因此较小的周期有利于改善曲折圆形槽波导慢波电路的高频特性。鉴于这种电路的耦合阻抗较低，可以适当地减小直波导长度来提高耦合阻抗。曲折槽波导结合了曲折波导散热能力强、色散特性好、容易加工和槽波导单模工作、低损耗、大尺寸等优点，在毫米波及亚毫米波段的行波管中具有较好的发展前景。     

Chodorow型耦合腔慢波结构色散特性和耦合阻抗理论分析

本文建立了Chodorow型耦合腔慢波结构的解析模型, 利用并矢格林函数结合矩量法求解了场匹配方程, 给出了色散方程和耦合阻抗的计算式, 并数值计算出一个X波段Chodorow型慢波结构的高频特性. 结果表明, 本文方法的色散特性以及耦合阻抗与仿真软件HFSS计算的结果有很好的一致性, 且计算效率更高, 同时精度远高于等效电路法, 对工程设计有好的参考价值. 关键词： Chodorow型耦合腔慢波结构 色散特性 耦合阻抗 场匹配     

含等离子体柱的介质慢波波导中的注波互作用分析

提出了一种新的注波互作用慢波系统——在部分填充介质的波导中放置一等离子体柱．利用线性自洽场理论，对这一新慢波系统中的相对论电子注与波的互作用进行了分析．具体针对薄环形相对论电子注包围等离子体柱和在等离子体柱内穿过慢波系统这两种情况，分别导出了决定注波互作用的色散方程．并对色散方程直接进行了数值求解，求得了系统的截止频率、工作频率和波增长率等．讨论了等离子体柱等有关参数对它们的影响． 关键词：     

双频磁绝缘线振荡器二维周期结构研究

推导了双频磁绝缘线振荡器（BFMILO）慢波结构的本征方程,并研究了其色散特性和场分布.通过研究发现,通过引入角向分区,使BFMILO慢波结构表现出二维周期性的特点,在该慢波结构中,不同电磁模式集中在角向不同区域,传统磁绝缘线振荡器（MILO）中呈现竞争关系的两个不同电磁模式可以同时独立稳定地参与束-波换能,从而产生双频输出.该分析方法可以适用于多频磁绝缘线振荡器的研究. 关键词： 磁绝缘线振荡器 高频特性 双频 高功率微波