多注耦合腔行波管互作用均匀性研究

对多注行波管慢波结构的特性进行了模拟与分析,利用粒子模拟方法,定量模拟了多注行波管的PIC注波互作用过程,通过比较不同电子注位置情况下电场E的振幅、相移、非线性和互作用效率,研究了多注电子注波互作用的均匀性特点,发现电子注位置不同时对电场有不同的影响,这对实际多注耦合腔行波管设计有一定指导意义。     

带状注交错双栅行波管的非线性分析

给出了适用于描述带状注行波管中电子注与慢电磁行波非线性互作用的全三维自洽方程组, 包含场的激发方程、 电子运动方程、电子相位演化方程和能量转化方程。将电子注划分为―粒子线‖的形式,结合交错双栅慢波结构中三维线 路场的形态分布,运用自洽方程组,对0.22THz 带状注交错双栅行波管进行了非线性分析。     

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.     

耦合腔行波管大信号注波互作用研究与设计

行波管中注波互作用的特点是电子的速度调制、群聚及其与高频场的能量转换等过程沿整个慢波结构连续且同时进行,这是行波管可以在很宽频带内得到大输出功率的原因。在研究冷腔特性的基础上,使用三维PIC粒子模拟软件定量分析了耦合腔行波管的大信号注波互作用过程,完成了X波段连续波行波管的设计。设计参数:工作频率7.18.5GHz,带宽18%,最大输出功率3kW。     

S波段耦合腔行波管非线性注-波互作用方程组的数值解

推导了考虑相对论效应的一维非线性注-波互作用自洽工作方程组.借鉴田炳耕的圆盘模型推导空间电荷场.对空间电荷场表达式提出简化假设并使其归一化,该假设将大大节省考虑空间电荷场时的计算时间.编写计算机程序对注-波互作用自洽工作方程组进行了数值求解,利用该程序分析了空间电荷力对注-波互作用的影响,得出S波段耦合腔行渡管的效率,增益和瞬时带宽.计算结果表明:在2.87～3.35 GHz频带范围内效率达到14%以上,增益大于18.5 dB,瞬时带宽达到15%,结果达到设计要求.     

分布作用速调管大信号计算模型的研究

该文建立了分布作用速调管(EIK)注波互作用模拟的大信号计算模型。该模型基于1维电子圆盘模型,考虑了电子圆盘间的空间电荷力。在电子与高频场互作用计算中采用双间隙耦合腔等效电路方法,并在间隙阻抗矩阵的计算中考虑了耦合腔中每个间隙电子电导的影响。依据该模型编写了计算程序,并与MAGIC3D仿真结果进行了比较验证,结果相符合。该计算模型可以扩展到三间隙乃至更多间隙谐振腔的分布作用速调管注波互作用的大信号计算模拟中。     

相对论返波振荡器的非线性理论

本文建立起分析相对论返波管注波互作用过程的自洽非线性工作方程组,理论模型中计及了正向波基波与电子注的异步互作用效应、电子注的空间电荷效应.运用四阶龙格一库塔法编制了数值求解工作方程组的Fortran程序,对均匀耦合阻抗型器件和耦合阻抗单阶跃变型器件的效率进行了仿真和优化.数值模拟结果表明正向波基波与同步波在慢波结构起始处的相差,正向波基波与电子注的异步互作用效应能显著地影响相对论返波管效率,均匀阻抗器件运行于最佳状态时,效率可达到27%,耦合阻抗单阶跃变型器件最优化效率可达到50%.     

一种高效率多注毫米波行波管的设计模拟

对某Ka波段7注耦合腔行波管慢波系统进行了模拟,分析了多注耦合腔行波管的单腔冷测特性、周期永磁聚焦（PPM）系统以及PPM聚焦系统下的注-波互作用,模拟结果表明：在中心频率34.5GHz处,其饱和输出功率达到829W,增益43.16dB,带宽约1.4GHz,电子效率高达30.37%。     

耦合行波管的大信号理论和计算

本文讨论了耦合腔行波管大信号互作用的物理模型和计算方法。本模型考虑了隙缝场场形的幅度和相位分布,返波的影响和相对论修正等,并详细地研究了电子注对场的激励形式。由于把能量守恒直接作为互作用的一个规范,其计算结果精确地符合能量守恒关系。实际管子的计算结果与实验结果大致相符。     

双间隙输出腔速调管的注波互作用程序分析

双间隙耦合腔作为展宽频带、提高效率、提高峰值功率和平均功率的有效手段已广泛用于多注速调管和大功率速调管中,但是目前对速调管双间隙输出腔的理论研究多为利用现有的模拟软件来进行仿真计算,所需时间很长,为了研究大功率速调管特别是在双间隙输出段中的注波互作用过程,作者利用一维单周期时间积分模型开发了一个快速分析程序。利用这一模型计算的电子群聚图形结果与MAGIC模拟所得结果很接近。由于本文所编写程序的耗时很短,因此可以对影响注波互作用的参量进行快速分析。     

A contribution to computer analysis of coupled-cavity traveling wave tubes

A flexible accurate large-signal computer program has been developed for the design of coupled-cavity traveling wave tubes. The program is written for a TSS-360 time sharing system. The beam is described by a disk model and the slow wave structure by a sequence of cavities or cells. The computational approach is arranged so that each cavity may have different geometrical or electrical parameters than its neighbors. This allows the program user to simulate a tube of almost arbitrary complexity. Input and output couplers, severs, complicated velocity tapers, and other features peculiar to one or a few cavities may be modeled by a correct choice of input data. The beam-wave interaction is handled by a new approach in which the RF fields are expanded in solutions to the TM wave equation retaining all significant space harmonics. The program was used to perform a design study of the TWT developed for the CTS satellite. Good agreement was obtained between the predictions of the program and the measured performance of the flight tube. The internal check on power balance was satisfied within ±0.2 percent of input beam power.     

耦合腔行波管腔长渐变对电子效率的影响

为了进一步提高耦合腔行波管(CCTWT)的电子效率,需要可以计算CCTWT的大信号程序。本文叙述了利用程序CCTaper计算CCTWT腔长渐变对电子效率的影响情况。     

螺旋线行波管注-波互作用三维粒子模拟

结合时域有限差分方法和粒子模拟方法,开发了螺旋线行波管的三维注-波互作用粒子模拟程序。从最基本的电磁场运动规律和力学规律出发,利用高速计算机直接求解完整的麦克斯韦方程组和洛伦兹方程,完成了对C 波段螺旋线行波管的注-波互作用的模拟计算,得到了电子的相位和空间分布以及管子的功率、增益等电性能参量,验证了程序的正确性,为后期优化和设计奠定了基础。     

Ka波段连续波500W螺旋线行波管研究

Ka波段螺旋线大功率行波管在大容量的通信系统中具有重要作用,本文介绍了目前大功率连续波螺旋线行波管的现状,对相关技术进行了分析。通过对高频结构的互作用分析、热分析、多级降压收集极等分析,设计了一个Ka波段连续波500 W行波管的螺旋线互作用结构,计算机模拟结果表明可以满足设计要求。     

Novel high-gain, improved-bandwidth, finned-ladder V-bandtraveling-wave tube slow-wave circuit design

In this paper, the three-dimensional electrodynamic simulation code MAFIA (Solution of MAxwell's Equations by the Finite-Integration-Algorithm) is used to investigate methods of increasing the bandwidth and lowering the operating voltage of the ring-plane circuit. Calculations of frequency-phase dispersion, beam on-axis interaction impedance, attenuation, and small-signal gain per wavelength were performed for various geometric variations and loading distributions of the ring-plane TWT slow-wave circuit. Based on the results of the variations, a circuit termed the finned-ladder TWT slow-wave circuit was designed and is compared here to the scaled prototype ring-plane and a conventional ferruled coupled-cavity TWT circuit over the V-band frequency range. The simulation results indicate that this circuit has a much higher gain, significantly wider bandwidth, and a much lower voltage requirement than the scaled ring-plane prototype circuit, while retaining its excellent thermal dissipation properties. The finned-ladder circuit has a much larger small-signal gain per wavelength than the ferruled coupled-cavity circuit, but with a moderate sacrifice in bandwidth     

The Beam-Wave Interaction in a Ka-Band Relativistic Coupled-Cavity TWT

By the method of the eigen mode expansion, a full three-dimensional (3-D) model has been developed that can be used to investigate the beam-wave interaction in a high-power, Ka-band relativistic coupled-cavity traveling-wave tube (TWT). In the tube studied by us, a sever in the interaction section is used to restrain the oscillation of RF electromagnetic fields between the input and output end. In this case, the asymmetric hybrid HTM₁₁ mode has little impact on the main interaction process ^[1,2], so the RF electromagnetic fields mainly interacting with the modulated electron beam belong to the symmetric mode TM₀₁. The presented model includes three-dimensional RF fields, three-dimensional electron motions, and improved three-dimensional space-charge fields including dc and ac space-charge fields. Moreover, this model can also calculate backward radiation excited by modulated electron beam and the direct effect of the transverse electron motion on the energy exchange. Our calculation results show that the space-charge field has evident effect on the interaction process, the transverse electron motion has some, and the backward radiation has little.     

Electron trajectories in the PPM-focused coupled-cavity TWT

Trajectories of electrons in a coupled-cavity TWT with ppm focusing are plotted in bothr-zandx-yviews. Plots are given for magnetic fields from 1.0 to 1.9 times the Brillouin field, and for small signal and saturated RF conditions. It is shown that a suitably programmed field can control the beam entry problem and minimize the RF debunching, while significantly reducing the beam exit angle. The computer program is briefly described.     

太赫兹行波管级联倍频器

太赫兹行波管(TWT)级联倍频器基于行波管非线性互作用后电子注中的谐波电流,利用行波管和级联谐波系统组成的倍频器获得电磁波倍频放大。以 W 波段行波管二倍频器为例,对器件的正确性和可行性进行验证。利用微波管模拟器套装(MTSS)软件对设计的倍频器进行三维非线性互作用模拟,结果显示,级联了二次谐波系统的 W 波段行波管倍频器与其他工作在140 GHz~220 GHz 波段的小型太赫兹辐射源相比较,具有优越的性能：谐波输出功率在8 GHz 范围内大于2 W,转换增益大于37 dB。利用 CST公司的粒子工作室软件进行三维粒子注波互作用模拟,结果显示,太赫兹行波管级联倍频器作为潜在的太赫兹源具有高功率、宽频带和高实用化的特点。