S波段5kW环圈行波管

本文介绍环圈结构的特性和整管的设计。所研制的Ｓ波段环圈行波管在２．３－２．７ＧＨｚ频率范围内脉冲功率大于５．５ｋＷ，饱和增益大于３９ｄＢ，电子效率大于２０％。该管的性能参数和尺寸满足了技术指标的要求。     

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)。     

S波段大功率螺旋线脉冲行波管慢波结构研究

S波段大功率脉冲行波管是雷达系统的核心器件,起到微波放大的作用。本文设计了一种螺旋线慢波结构,可以将频带拓展到700 MHz,通过采用螺旋线螺距和内径双渐变技术,不仅提高了电子互作用效率,而且抑制了返波振荡。利用MTSS软件优化仿真计算,电子互作用效率达到了32%以上,输出功率达17 kW,增益在33.5 dB以上。最终测试样管在10%工作比的情况下,脉冲输出功率达到15 kW以上,电子效率达到30%以上,实现1.5 kW平均输出功率,提高了现有S波段脉冲行波管的功率量级。     

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。     

V波段三种螺旋线类慢波结构高频特性

本文对工作于V波段的三种螺旋线类慢波结构进行了参数设计,在同等参数条件下,分析对比了圆螺旋线,半方环螺旋线以及半矩形环螺旋线的高频特性。结果发现,圆螺旋线在三种慢波结构中的色散最平坦,但是耦合阻抗最小。半方环螺旋线和半矩形环螺旋线的相速度较接近,同时具有比圆螺旋线慢波结构更大的互作用阻抗。     

V波段微带线行波管慢波结构的设计

提出了一种新型的微带线慢波结构。与传统的N型微带线慢波结构相比,新型结构具有相速值较小、工作电压低、功率大、耦合阻抗高等特点。利用HFSS和CST分别对此结构在V波段进行高频特性、传输特性和注-波互作用仿真,得出在60GHz频点耦合阻抗大于20Ω,在55~63GHz频段内VSWR<1.5;当输入功率为100mW时,并且带状电子注的电流和电压分别工作在100mA和5kV的条件下,该行波管慢波结构的最大输出功率为115W,平均互作用效率为14.6%,瞬时3dB带宽为5GHz(56~61GHz)。     

环圈行波管设计新进展

本文介绍了环圈行波管设计上的新方法。用这种方法,使频率从2.0～2.5GHz获脉冲输出功率12kW及平均输出功率600W。平均输出功率比国外报道L波段极限400W的水平还高出200W。     

V波段宽杆半矩形环螺旋线行波管的研究

为满足行波管大功率、高效率、小型化的发展需求,设计了工作于V波段的宽杆半矩形环螺旋线行波管.仿真结果表明:与传统的矩形螺旋线慢波结构对比,宽杆半矩形环螺旋线慢波结构在保持色散平坦度相近的前提下,具有相速值较小、耦合阻抗较高的特点,同时,新结构更加兼容微细加工技术,易于小型化、批量化生产.在采用工作电压8900 V、工作...     

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.     

W波段阶梯型交错双栅慢波结构行波管的研究

为了提高传统交错双栅慢波结构行波管的性能,提出了一种阶梯型交错双栅慢波结构,并基于此新型慢波结构,提出了新型输入输出耦合结构.在此基础上,设计了一只工作在W波段的带状电子注阶梯型交错双栅慢波结构行波管.计算结果显示,阶梯型交错双栅慢波结构行波管的耦合阻抗更高,从而使行波管在更短的互作用电路长度里,实现更高的饱和增益和互作用效率.在90～100GHz频率范围内,阶梯型交错双栅慢波结构的耦合阻抗大于4Ω,高于传统交错双栅慢波结构;W波段带状电子注行波管高频结构的反射系数(S11)小于-15dB;并且行波管的饱和输入功率仅约为0.7W,可以实现最高输出功率约800W,相应的效率大于7.8%,增益大于30.6dB.     

Diamond-studded helical traveling wave tube

A novel method of millimeter-wave traveling wave tube (TWT) slow-wave circuit fabrication, employing laser micromachining and the in situ growth of diamond studs as an insulating dielectric, has been developed, which would enable a new class of very wideband, low distortion, high-efficiency amplifiers. Because the slow-wave circuit is supported by an array of diamond studs, rather than the conventional dielectric rods, we have named this novel device the diamond-studded TWT. Diamond strips have been successfully grown on a molybdenum tube and a diamond-studded helix has been produced using laser micromachining. Computer analysis of the slow-wave structure indicate that this fabrication technique leads naturally to a circuit with nearly flat dispersion over a frequency range, in some configurations, of more than four octaves. Typically, wide bandwidth can only be achieved by reducing efficiency; however, this fabrication technique increases the interaction impedance of the circuit, enabling high efficiency operation without sacrificing bandwidth. The very low dispersion also results in a coupling impedance that is relatively insensitive to frequency that may enable low reflection coupling over a wide frequency band. The resulting slow-wave circuit is essentially a brazed structure and, therefore, inherently robust thermally and mechanically. The manufacturing technology being pursued is applicable to any millimeter-wave helical or helix-derived TWT.     

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。     

Analysis of a dielectrically loaded traveling wave tube

A circular waveguide periodically loaded with dielectric disks forms a slow wave structure which can be used in a traveling wave tube. For solid disks, the field pattern in the guide can be determined exactly and the characteristics of the structure, when used as a traveling wave tube, can be predicted using Pierce's small signal theory. The gain, bandwidth, operating frequency, and required beam voltage have been calculated for a wide range of structure dimensions. The power capability of the disk-loaded guide is also discussed.     

Rational function based predistorter for traveling wave tube amplifiers

A new scheme for the compensation of traveling wave tube amplifier nonlinearities is proposed and analyzed in this paper. The approach is based on rational function models of the amplifier AM-AM and AM-PM conversions. Amplitude and phase predistortion are performed separately. The phase predistortion is a function of the output of the amplitude predistortion part of the predistorter, instead of the input signal amplitude of the predistorter. Computer simulations reveal an improved performance compared to published techniques and suggest that with the proposed technique the transmit power amplifier can operate far into its nonlinear region. The transfer characteristics of the cascade of the amplifier and the proposed predistorter match the optimum transfer characteristics of a saturating device.     

Analysis of the instability in relativistic traveling wave tube

The relativistic traveling wave tube is an important high power microwave source. The corrugated cylindrical waveguide is usually used as slow wave structure of this device. Starting from wave equation and using boundary conditions, dispersion relation is derived for the corrugated waveguide, in which an intense relativistic electron beam propagates along the axis. Two cases which are shorter period and longer period are discussed in this paper respectively. The small signal gain of the relativistic traveling wave tube is analyzed and some conclusions are drawn. The analysis method presented in this paper can be extended to other types of slow wave structures of relativistic traveling wave tube.     

Computation for the gain of ridge loaded ring-plane traveling wave tube

The ridge loaded ring-plane traveling wave tube can provide high output power in a relatively broader bandwidth. The dispersion relation for the interaction between the electron beam and the symmetrical mode propagating in this slow wave circuit is obtained, by means of the Variational method. The method to calculate the arbitrary order Bessel function with complex argument is discussed. The three dimensional trajectory graph of the Bessel function with complex argument is plotted. The instantaneous operating bandwidth can be estimated in terms of the relation between of the gain and frequency.     

行波管金刚石输能窗片金属化影响因素分析

为制备行波管用金刚石输能窗片,分析金刚石金属化影响因素。采用粗糙度、拉曼光谱评估金刚石材料性能。采用酸洗、离子束刻蚀清洗金刚石表面。采用冲压掩膜、光刻掩膜防护非金属化区域。通过物理气相沉积制备Ti/Mo/Ni金属化层,并通过真空热处理方法制备TiC过渡层。结果表明:当金刚石内石墨的质量分数低于1%时,离子束刻蚀方法一方面去除金刚石表面杂质,另一方面将表面粗糙度从0. 256μm提升至0. 343μm;相比冲压掩模,光刻掩模降低界面孔隙率,减少了金属离子对掩模底层的污染,过渡区域宽度从200μm减少至10μm; 700℃保温过程促进了TiC的形成,提升了金属化层结合强度,促进了抗热冲击性能。     

G波段行波管电子枪设计与实验

设计了用于G波段行波管的聚焦极调制皮尔斯电子枪,电子注电压20 kV,电流50.9 mA,注腰半径0.056 mm,射程10.3 mm。利用热-结构耦合分析和电子注轨迹仿真方法,分析了热形变对电子枪性能造成的显著影响。为了消除电子枪热形变的影响,设计了装配模具进行补偿,并得到了实验验证。该电子枪已用于多种G波段行波管,解决了关键部件技术问题。