抑制空间行波管三阶交调失真的信号注入技术

为了抑制空间行波管非线性特性产生的交调失真,本文通过理论分析、计算机仿真和实验验证,分别研究了谐波、交调和混合信号注入技术对空间行波管三阶交调（IM3）分量的抑制情况。实验结果表明：IM3注入技术能够得到25.2 dB的IM3最大抑制量,明显大于谐波注入技术的12.7 dB,两者对IM3失真分量的抑制效果都很良好,且就窄带空间行波管而言IM3注入技术比谐波注入技术更具优势。通过进一步仿真实验,证明双IM3注入技术可以在两个IM3频率处分别产生46 dB和53 dB的最佳抑制量,且混合注入谐波和交调信号也能最大抑制36.9 dB。     

K频段自适应前馈行波管放大器设计

空间通信系统高保真转发对大功率行波管放大器的线性化度提出了更高的要求。针对高频段和大功率应用,基于预失真和前馈线性化技术,设计了一种K频段50 W自适应前馈线性化行波管放大器,介绍了其基本原理和参数,研究了前馈双检波电路结构及并行变步长的组合自适应控制算法。在K频段400 MHz带宽内,实现了输入功率20 dB大动态调整情况下失真信号自适应对消抑制,在相对于单载波饱和输出功率回退3 dB点,三阶交调小于-35 dBc,验证了前馈线性化技术在线性度改善方面的巨大优势。     

一种应用于Ka频段空间行波管放大器的宽带线性化器

为了降低行波管放大器(TWTA)的非线性,介绍了一种采用传输拓扑的宽带二极管预失真线性化器的设计。分析了用于补偿TWTA非线性的线性化器增益和相位扩张特性。测试结果表明,在19.5~21.3 GHz频率范围内,TWTA的交调指标得到改善。     

压控振荡器的非线性对三阶交调的影响

三阶交调的大小表明了在一个线性系统中所包含非线性系数的大小。本实验选用TJTOS-200P来组成锁相环电路,在副载波调制过程中,输出信号中三阶交调了达到-25dBc,影响了副载波调制信号的质量。分析原因是由于该振荡器调谐电压范围很小,输出信号的载波电平很低,导致存在更多的非线性因素造成的结果。在选用线性更好的JTOS-200后,改善了三阶交调5-6dBc,解决了出现的问题。     

行波管谐波注入技术新进展

根据Rowe理论计算行波管的1D圆盘模型生成的TWTRF2.0程序用来计算谐波注入对基波功率增长及管内谐波抑制的影响。LMSuite程序用来计算谐波注入对交调(IM3)的抑制。两程序的计算结果与实验符合得比较好。     

一种螺旋线型空间行波管的线性设计

本文介绍一种螺旋线行波管的线性设计,该行波管用于通信。为保证通信信号的质量,该型行波管必须具有较好的线性性能,如相移、三阶交调等,文中将结合一种Ka频段空间行波管的改进过程,以相移作为线性参数的代表性指标,分析所采取的改进措施对行波管线性性能的提升。目前,该行波管的主要高频参数为:相移50°(饱和回退20dB)、饱和增益50dB、互作用效率20%。     

空间行波管辐射散热器的优化设计

大多数空间行波管采用了辐射型收集极,通过增加结构的辐射散热面积对其进行有效的散热。本文通过使用ANSYS有限元分析软件,对不同结构辐射散热器的散热性能进行模拟对比,得到一种优化的散热器结构。该结构能够在不影响散热性能的前提下,使散热器的质量显著降低。模拟分析为空间行波管辐射散热器的优化设计提供了有效的参考依据和手段。     

探测器非线性对三阶交调失真的影响

建立了基于双电极马赫-曾德尔调制器和非线性光电探测器的双音调制直接探测链路模型,推导了探测器非线性条件下系统基阶信号和三阶交调信号功率表达式,分析了探测器非线性对链路三阶交调失真的影响.结果表明,探测器非线性在特定参数条件下会更好地抑制三阶交调失真,在其它情况下则会导致系统性能恶化.     

固态功率放大器在卫星地球站的应用

本文通过对固态功率放大器和行波管、速调管放大器的比较，说明了固态功放在卫星地球站应用的可行性和必要性。     

空间行波管

各种应用卫星迫切需求长寿命高可靠空间行波管，广泛的应用使空间行波管在近年里获得了长足的长进。采用先进的计算机模拟设计技术，使用长寿命阴极以及各种先进的微加工制造技术必使空间行波管更完善，得到更大的发展。     

Modified Tunneladder Slow-Wave Structures for High-Power Millimeter-Wave TWTs

In this paper, five modified Tunneladder slow-wave structures (SWS), the ridge-loaded stub-supported meander line with circular electron tunnel (CET-RSML), ring-plane frame line (RPFL), the ridge-loaded thick ladder line (RLTLL), the ridge-loaded pole-piece folded-waveguide circuit (RLPFWL), and the double-period Tunneladder line (DPTL) were discussed. The dispersion characteristics and the interaction impedances of the five modified Tunneladder SWS were calculated by simulation and the corresponding analytic models. The calculation results explain that the CET-RSML and the RLTLL hold wider bandwidth in comparison with the Tunneladder, when the volume dimensional lengths are same. When the bandwidth is definite, the interaction impedance of RLTLL can be higher than Tunneladder, but that of CET-RSML can’t. The dispersion curves of the RLPFWL and the DPTL are more linear in comparison with Tunneladder, but the interaction impedances are very low.     

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.     

钮销支撑螺旋线慢波结构色散特性及二次谐波抑制研究

寻求频带更宽、输出功率更大、体积更小的螺旋线行波管一直是研制工作的目标,二次谐波是影响宽带行波管工作的重要因素,本文对不同形式介质加载的螺旋线慢波结构进行了模拟,并对其中色散曲线最为平坦的钮销慢波结构进行了一维大信号模拟,证明改变螺距或夹持介质形状可有效展宽带宽、降低二次谐波功率。     

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.     

过渡段螺距渐变对相速跳变的螺旋线行波管电子效率的改善

通过注波互作用机理的定性讨论得到了过渡段螺距合理渐变能改善螺旋线行波管效率的初步结论,而由过渡段螺距改变前后的螺旋线行波管色散方程和工作方程的理论分析得出的数值计算结果与初步结论相一致,并得出了过渡段螺距恰当的渐变方式对改善相速跳变螺旋线行波管的边频效率起很大作用的重要结论。得出的结论对螺旋线慢波系统设计工作的进一步开展指明了一个方向。     

用于行波管螺旋慢波组件的挤压新方法

在螺旋慢波结构行波管制作中，螺旋慢波组件冷挤压是其中工序之一。本文提出了一种用于行波管螺旋慢波组件的挤压新方法并自制了相应的冷挤压设备样机。该设备可以用于以弹压法制作行波管的螺旋慢波结构，能够满足行波管的工艺要求，所制作慢波组件在一致性上有所提高。     

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.     

Research on the Characteristic of the Disk-Loaded Waveguide, Rib-Loaded Disk-Loaded Waveguide and Helix Slow-Wave Structures

The fast development of modern electronic warfare, broadband high power array radar system, high power jammer and microwave directional power weapon imposes high demand on high power microwave resource. With such features as high power, broadband, multi-mode, etc., traveling wave tubes (TWTs) play an important role in the high power microwave amplifiers. Since the slow-wave system is the core of beam-wave interaction in TWTs, the function and performance of it directly determine the capability of the TWTs.     

螺旋线型毫米波行波管的散热问题

文章分析了解决螺旋线型行波管散热问题的几种主要方法,包括降低螺旋线的损耗和提高高频慢波结构散热能力。     

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.