螺旋槽回旋行波管高频特性分析

 在Foulds等人对螺旋槽结构进行深入分析的基础上，考虑了槽区内高次模式对慢波结构高频特性的影响。结果表明：槽宽较小时，结论与其结论吻合较好； 槽宽较大时，计算结果与其有较大差别。此外，讨论了螺旋槽结构参数对高频特性的影响，结果表明：除槽宽外的其它结构参数固定时，存在一个最佳的δ/L值，可以获得较弱的色散和较大的横向场幅值，适合做回旋行波管互作用结构。     

矩形波导栅慢波系统的实验研究

 从实验上研究了矩形波导栅慢波系统的色散特性及其耦合装置的驻波系数，用分布加工的方法分别制作了矩形、燕尾形、梯形3种不同槽形的矩形波导栅慢波结构模型和带输入输出结构的矩形波导栅慢波结构实体模型。采用谐振法测量它们的色散特性和驻波系数，实验结果与理论计算值和模拟值吻合良好。     

带开口磁环的周期永磁聚焦系统的2维模拟

 由于目前常用的磁聚焦系统设计方法不能直接计算带有非轴对称开口磁环的磁系统,因此在行波管磁系统实验测试基础上,提出了双面带极靴的开口磁环体积等效概念：将开口磁环等效为相等体积磁性材料的2维轴对称磁环,两者都双面带极靴时轴上的磁场值相等。使用2维电磁计算软件FEMM计算了采用该等效模型后的周期磁聚焦系统的轴上磁场值,计算结果与带有开口磁环的实际系统测试值符合良好,两者相差仅3×10^-3 T。该2维等效模型能代替开口磁环进行计算。     

Ka波段曲折双脊波导行波管的研究

提出了一种曲折双脊波导慢波结构,理论分析了慢波结构的高频特性,并在此基础上设计了工作在Ka波段的曲折双脊波导行波管.利用三维粒子模拟软件MAGIC 3D建立了曲折双脊波导行波管模型,并对行波管中的注-波互作用进行了模拟分析.在相同工作条件下,分析比较了曲折双脊波导行波管和曲折波导行波管的各种性能参量,从中发现：在行波管增益峰值相近的情况下,曲折双脊波导行波管具有更好的带宽性能,其3 dB增益带宽为22％;同时具有更高的电子效率,其峰值接近9％.     

同轴相对论速调管周期永磁聚焦系统的初步研究

为了探索相对论速调管放大器(RKA)的小型化技术,开展了同轴RKA周期永磁聚焦的物理与设计技术研究。周期永磁聚焦系统采用Halbach阵列结构,产生的磁场类型为周期性会切磁场。首先给出该系统的磁场各个分量的表达式,分析该系统磁场分布的特点,并推导得出该系统聚焦强流环形电子束的稳定条件。根据该稳定条件,对Ka波段同轴RKA设计了一个周期永磁聚焦系统,并优化了周期磁场参数,确定了磁场系统设计的最佳周期和幅值。研究结果显示,周期永磁(PPM)聚焦系统在周期长度18 mm和磁场幅值0.33 T的条件下可引导500 kV、6 kA的同轴RKA,得到1 GW的微波输出功率,物理分析确定了周期永磁聚焦系统应用于高功率同轴RKA的技术可能性。     

A novel slotted helix slow-wave structure for high power Ka-band traveling-wave tubes

A novel slotted helix slow-wave structure （SWS） is proposed to develop a high power, wide-bandwidth, and high reliability millimeter-wave traveling-wave tube （TWT）. This novel structure, which has higher heat capacity than a conven- tional helix SWS, evolves from conventional helix SWS with three parallel rows of rectangular slots made in the outside of the helix tape. In this paper, the electromagnetic characteristics and the beam-wave interaction of this novel structure operating in the Ka-band are investigated. From our calculations, when the designed beam voltage and beam current are set to be 18.45 kV and 0.2 A, respectively, this novel circuit can produce over 700-W average output power in a frequency range from 27.5 GHz to 32.5 GHz, and the corresponding conversion efficiency values vary from 19% to 21.3%, and the maximum output power is 787 W at 30 GHz.     

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     

太赫兹折叠波导行波管再生反馈振荡器非线性理论与模拟

行波管再生反馈振荡器是一种新型太赫兹源器件.基于560GHz折叠波导慢波结构,对此类器件的工作原理与物理模型进行分析阐述.采用非线性互作用模型对行波管再生反馈振荡器进行详细振荡过程模拟.模拟结果显示,在550—600GHz频率下可以获得稳态振荡频率,并在560GHz处获得最大单频输出功率.结果同时表明,振荡频率随电子注电压发生跳变现象,并简要分析了其产生原因.     

Analysis of a Novel Ka-band Folded Waveguide Amplifier for Traveling-Wave Tubes

A novel Ka-band folded waveguide （FW） amplifier for traveling wave tubes （TWT） is investigated. The dispersion curve and interaction impedance are obtained and compared to the normal FW circuit by numerical simulation. The interaction impedance is higher than a normal circuit through the whole band. We also study the beamwave interaction in this novel circuit, and the nonlinear large-signal performance is analyzed by a 3-D particlein-cell code MAGIC3D. A much higher continuous-wave （CW） output power with a considerably shorter circuit compared to a normal circuit is predicted by our simulation. Moreover, the novel FW even has a broader 3-dB bandwidth. It therefore will be useful in designing a miniature but high-power and broadband millimeter-wave TWT.     

Linear Analysis of Folded Double-Ridged Waveguide Slow-Wave Structure for Millimeter Wave Traveling Wave Tube

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 caleulated 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.