翼片加载螺旋线慢波结构色散和耦合阻抗的测量与模拟

运用非谐振微扰法，利用Aglient8510C矢量网络分析仪对两个不同翼片加载螺旋线慢波结构的色散和耦合阻抗特性进行了测试。运用HFSS软件对实验中两个被测的螺旋线慢波结构进行建模，分别计算了它们的色散和耦合阻抗特性，在模拟中考虑了空间谐波对耦合阻抗的影响。结果表明，模拟与实验的色散和耦合阻抗有较好的一致性。     

毫米波行波管返波振荡的仿真研究

该文利用HFSS仿真了工作在Ka波段的螺旋线、反绕双螺旋线及耦合腔等慢波系统,通过傅里叶分析得到空间谐波,进而分析和比较了上述慢波系统的返波振荡特性.结果表明:螺旋线慢波系统中出现明显的角向谐波次数和轴向谐波次数不相等的窄问谐波分量,在π模附近,有产生返波振荡的危险:而反绕双螺旋线通过提高基波耦合阻抗及可工作的归一化频率来提高了抑制返波振荡的能力;为了避免返波振荡,耦合腔工作频带的选择应尽可能远离单腔相移为π,2π的频点.     

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     

一种有限厚度翼片加载螺旋线色散特性及耦合阻抗研究

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.一般的计算未考虑翼片加载所引起的角向空间谐波,本文考虑空间谐波,建立了有限厚度翼片加载螺旋线慢波结构的模型,推导出实用的色散方程和耦合阻抗表达式.利用导出的方程对实际行波管的螺旋慢波结构进行计算,并与测量结果和简单翼片模型进行了比较.首次通过分析的方法得到加载翼片有最佳中心夹角(θ)存在.     

螺旋线行波管中场的数值分析

该文对螺旋线行波管中的场进行了数值分析。研究表明数值求解时主从边界条件的位置决定场传播的方向,螺旋线旋转方向决定场的旋转变化方向。螺旋线外各类夹持杆和翼片对螺旋线内部场分布影响很小,场基本随贝塞尔函数分布,但耦合阻抗变化较大,这主要是由于场受螺旋线外结构影响而影响功率分配。同时,对场的各次空间谐波的研究,特别是零次和负一次空间谐波,有利于准确地求解各次空间谐波的耦合阻抗,对提高螺旋线行波管放大器和返波振荡的大信号注波互作用计算的准确性有重要的意义。     

纵向金属条加载螺旋线的滤波性质和理论分析

本文首次指出了纵向金属条加载螺旋线的滤波性质这一新问题。这种慢波结构的滤波性质有别于过去国外所提出的滤波螺旋线。它不仅能够构成窄通带的行波管,而且也可以构成超宽通带行波管。其次,用它作为行波管的慢波线时,它的横向阻抗可以压低,易于与外接耦合头直接匹配,而它的耦合阻抗仍可保留较高的数值,使行波管在超宽通带范围内仍可获得较大的增益分贝数。滤波性慢波线行波管的另一优点,是它的抑止返波振荡的性质。纵向金属条加载螺旋线同样具有此一性质。 本文对纵向金属条加载螺旋线的滤波性质作了理论分析,对它的色散特性作了冷测试验,两者有良好的相符。 纵向金属条加载螺旋线的计算,在美国系用Paik的方法,而在苏联有方法。这二个方法仅解决了色散的计算,而完全没有涉及滤波的性质,因而也没有提出诸如通带、禁带、抑止返波振荡、金属条数目、金属条宽窄和激励头地位等等的性质和问题。本文的理论分析对这许多问题均作出了回答,理论分析符合冷测结果,因而它可供设计计算之用。     

形杆夹持翼片加载螺旋线的色散特性

Ｖ形杆夹持、翼片加载的螺旋线慢波结构很适合于宽频带行波管应用。本文对不同的翼片加载结构的色散特性进行了计算，计算数据与实验测量结果一致性较好。最后讨论了Ｖ形杆与圆形杆夹持时的介质负载和色散特性。     

X波段环圈结构行波管研究

详细研究了环圈结构的高频特性和返波振荡特性.通过MTSS仿真计算得出:相同尺寸时，环圈结构基波耦合阻抗远高于螺旋线基波耦合阻抗；在10.65 GHz处，环圈结构饱和增益比螺旋线饱和增益高10.28 dB；在10 GHz处，环圈结构的起振电流比螺旋线起振电流高2.35 A，起振长度为53 mm.仿真结果表明，X波段内环圈结构和螺旋线的起振电流随着频率的升高而降低，环圈结构的起振电流和起振长度为螺旋线的起振电流和起振长度的两倍以上；使用CST仿真分析得出了环圈结构中的圈宽度和圈高度对环圈高频特性影响的一般规律.文中结果表明环圈结构性能优良且不易起振，在大功率行波管中具有广阔的应用前景.     

V形杆夹持翼片加载螺旋线的色散特性

Ｖ形杆夹持、翼片加载的螺旋线但波结构很适合于宽频带行波管应用。本文对不同的翼片加载结构的色散特性进行了计算，计算数据与实验测量结果一致性较好。最后讨论了Ｖ形杆与圆形杆夹待时的介质负载和色散特性。     

关于“螺旋耦合型慢波结构的研究”一文中导纳的计算

“螺旋耦合型慢波结构的研究”(以下简称为“研究”)一文,利用多导体传输线方法对螺旋耦合型慢波结构进行了理论分析。其中用一个简化公式计算了矩形螺旋线各段导纳与翼片导纳,进而计算了大量的色散和耦合阻抗曲线。大家知道,在多导体传输线分析方法中,导纳的计算对色散和耦合阻抗是十分重要的,尤其是耦合阻抗直接与导纳的大小成反比。通过研究,我们认为该文在计算各段导体的导钠时,假     

Analysis of a U-shaped vane-loaded helical slow-wave structure for wideband travelling-wave tubes

The dispersion equation and interaction impedance of a U-shaped vane-loaded helical slow-wave structure (SWS) is obtained by considering the azimuthal space harmonic in the non-vane region and the helical tape thickness, using the field theory matching method in the azimuthal field discontinuity. The theoretical calculation by electromagnetic analysis is consistent with the simulation result by MAFIA, which can explain some physical essence of the SWS. In the helical SWS, negative dispersion is reported to reduce the second harmonic content of a wideband travelling-wave tube at the low-frequency end of the band. When the SWS is assembled, the support rods are easily located in the groove of the vane. The solution provides a new instruction method for other types of vane-loaded helical SWS.     

Study on rectangular waveguide grating Slow-Wave Structure with cosine-shaped grooves

This paper focuses on a new rectangular waveguide grating Slow-Wave Structure （SWS） with cosine-shaped grooves and studies the propagation characteristics of the wave in the SWS. By using the approximate field-matching conditions, the dispersion equation and the coupling impedance of this circuit are obtained. The dispersion curves and coupling impedances of the fundamental wave are calculated and the influences of the various geometrical dimensions are discussed. The results show that the bandwidth of the cosine-shaped groove SWS is much wider than that of rectangular-shaped groove one. And reducing the groove width can broaden the frequency-band and decrease the phase-velocity, while increment of the groove-depth can also decrease phase-velocity. For above cases, the coupling impedance is more than 16Ω. The present analysis will be helpful on further study and design of the RF systems used in millimeter wave Traveling Wave Tube （TWT）.     

适用于Ka波段圆形电子注行波管的半圆形卷绕微带线慢波结构

提出了一种基于开槽介质基底的卷绕微带线慢波结构.由于金属曲折微带线印制在介质基底的半圆形槽中,这种卷绕微带线慢波结构非常适合圆形电子注行波管,从而使得采用这种新型慢波结构的行波管可以利用传统的周期永磁磁场进行聚焦.文章对提出的卷绕微带线慢波结构的色散特性,耦合阻抗,传输特性及注-波互作用进行了分析.和传统的平面微带线慢波结构相比,提出的卷绕微带线慢波结构具有更低的相速、更弱的色散和更高的耦合阻抗,从而使得其适合于低电压、宽频带、小型化的毫米波行波管.将同步电压及直流电流分别设置为6 550 V及0.1 A的情况下,基于该卷绕微带线慢波结构的Ka波段行波管在35 GHz处能够输出42.32 W的功率,对应增益为26.26 dB,且均匀聚焦磁场只需0.4 T.     

任意槽形螺旋槽慢波结构的色散方程

在本文的分析中,将任意槽形的螺旋槽的连续轮廓近似用一系列相连的矩形阶梯代替,利用各阶梯面上导纳的匹配,以及槽与中心互作用区边界场的连续和匹配条件,获得了任意形状螺旋槽慢波结构的色散方程;同时加工制作了一半圆形螺旋槽模型,对其色散特性的冷测实验表明理论与测量值相吻合。     

利用MWS设计螺旋线行波管耦合结构

利用CST MWS仿真软件对螺旋线行波管耦合结构进行设计.首先,利用MWS仿真结果得出同轴线与螺旋线慢波结构连接部分的反射系数;接着,对高频窗进行了设计与优化;最后,计算出整个耦合结构可能产生的最大驻波系数小于2.0.对比理论值与冷测试数据表明,实测值小于理论计算的最大驻波系数.因此,在螺旋线行波管耦合结构的设计过程中,通过对驻波系数最大值的控制,可以满足实际工程的要求.     

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.     

Analysis of the circular-arc-shaped helical groove slow-wave structure

This paper concerns a new circular-arc-shaped helical groove all-metal structure, and emphasizes the propagation characteristics of the slow wave. By using approximate field-matching conditions, the dispersion equation and the coupling impedance of this circuit are obtained. The dispersion curves and coupling impedances of the fundamental wave and some harmonics are calculated and the influences of various circuit dimensions are discussed. The calculation results show that the bandwidth can be improved by increasing the arc angle or decreasing the pitch of the structure; a 50% bandwidth is achieved by deviating the phase velocity within ±5%. As a new slow-wave structure for a travelling wave tube, this circuit has an attractive feature, namely the bandwidth is broad while power capacity is high.     

ANALYSIS OF RECTANGULAR WAVEGUIDE GRATING SLOW-WAVE STRUCTURE WITH THE ARBITRARY SHAPED GROOVES

The rectangular waveguide grating slow-wave structure (SWS) with arbitrary shaped grooves is presented and analyzed in this paper. As an all-metal slow-wave circuit, it has properties that can be used in high-power millimeter-wave or sub-millimeter wave traveling wave tube (TWT). The unified dispersion equation and the expression of coupling impedance are obtained in this paper by means of an approximate field-theory analysis, in which the profile of the groove is approximately replaced by a series of steps and the field continuity at the interface of two neighboring steps together with the field matching conditions at the interface between the groove region and the interaction region are employed. A rectangular groove SWS was manufactured and the cold measurement was made. The experimental data are in good agreement with the numerical calculation. The derived transcendental equations are resolved numerically for four classical structures such as rectangular, dovetail, ladder and cosine. Finally, taking the rectangular waveguide grating SWS with rectangular grooves for example, the influences of physical dimensions on dispersion relation and coupling impedance are discussed.     

Validation of HFCS-I on Calculation of High-Frequency Parameters of Helical Slow-Wave Structures

To validate HFCS-I, a newly developed design tool for high frequency circuits of microwave tubes, the high-frequency parameters (including dispersion, interaction impedance and attenuation constant) of a typical helical slow-wave structure (SWS) for millimetre wave travelling-wave tube are calculated by HFCS-I and MAFIA. Both the direct calculation method and the Non-Resonant Perturbation (NRP) technique are adopted to get the interaction impedance. The obtained high-frequency parameters from HFCS-I and MAFIA are compared in detail and the consistency has proved the reliability and validity of HFCS-I.