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     

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％. 关键词： 曲折双脊波导 高频特性 注-波互作用 带宽     

开敞型角向周期加载金属柱圆波导的注波互作用线性理论研究

提出了一种可应用于毫米波功率放大器中的新型慢波结构——-开敞型角向周期 加载金属柱圆波导结构,并且在互作用通道内,引入了薄环形电子注, 推导出了此时的"热"色散方程,并且对基于该新型慢波结构的行波管的 小信号增益特性进行了深入探讨.通过数值方法 研究了金属柱尺寸和电子注参数 对器件线性特性的影响. 结果表明: 通过对金属柱尺寸的适当设计, 可以获得更高的增益值. 与封闭型结构的比较结果表明, 开敞型角向周期加载金属柱圆波导结构能够 有效地提高小信号增益, 并且对带宽的影响不大. 研究结果为研制基于此新型慢波系统的毫米波行波管奠定了理论基础.     

Investigation of a wideband folded double-ridged waveguide slow-wave system

The folded double-ridged waveguide structure is presented and its properties used for wide-band traveling-wave tube are investigated.Expressions of dispersion characteristics,normalized phase velocity and interaction impedance of this structure are derived and numerically calculated.The calculated results using our theory agree well with those obtained by using the 3D electromagnetic simulation software HFSS.Influences of the ridge-loaded area and broad-wall dimensions on the high frequency characteristics of the novel slow-wave structure are discussed.It is shown that the folded double-ridged waveguide structure has a much wider relative passband than the folded waveguide slow-wave structure and a relative passband of 67% could be obtained,indicating that this structure can operate in broad-band frequency ranges of beam-wave interaction.The small signal gain property is investigated for ensuring the improvement of bandwidth.Meanwhile,with comparable dispersion characteristics,the transverse section dimension of this novel structure is much smaller than that of conventional one,which indicates an available way to reduce the weight of traveling-wave tube.     

Theoretical Study for Folded Waveguide Traveling Wave Tube

A wideband folded waveguide traveling-wave tube (TWT) amplifier has advantages of simpler coupling structures and robust structure over the conventional helix TWT. The phase velocity of waves in folded waveguide is slowed down to the velocity of electron beam. Slow-wave interaction with the electron beam in folded waveguide is studied in a linear fashion. For a cold beam, the linear theory predicts a gain of 2 dB/cm and a bandwidth of 37% at the center frequency of 14 GHz. A closed algebraic dispersion relation for the frequency and the axial phase shift per period is obtained using an equivalent circuit model. Numerical solution calculated from the dispersion relation and three-dimensional electromagnetic code, HFSS simulations predict a mode coalescing in the folded waveguide. And a theoretical phase velocity prediction of the electromagnetic wave in this circuit is verified by HFSS simulations.     

螺旋坐标系下考虑厚度的螺旋线行波管小信号研究

采用螺旋坐标系对有限厚度的螺旋带行波管进行了注波互作用的线性理论分析,利用自洽场理论得出了此结构中引入电子注后的热色散方程,数值计算了其小信号增益,分析了电子注参数和螺旋线厚度对于螺旋线慢波系统的色散特性的影响。结果表明：螺旋线厚度的增加,行波管的小信号增益也会增加,且带宽也略有增加。该结论为高增益宽频带的螺旋线行波管放大器的设计提供了理论基础。     

螺旋坐标系下考虑厚度的螺旋线行波管小信号研究(英文)

采用螺旋坐标系对有限厚度的螺旋带行波管进行了注波互作用的线性理论分析,利用自洽场理论得出了此结构中引入电子注后的"热"色散方程,数值计算了其小信号增益,分析了电子注参数和螺旋线厚度对于螺旋线慢波系统的色散特性的影响。结果表明:螺旋线厚度的增加,行波管的小信号增益也会增加,且带宽也略有增加。该结论为高增益宽频带的螺旋线行波管放大器的设计提供了理论基础。     

220 GHz 折叠波导慢波结构

 优化设计了一种220 GHz的折叠波导慢波结构的尺寸,对其冷测特性如色散、耦合阻抗和衰减进行了分析。理论分析和软件仿真结果表明设计的折叠波导慢波结构在中心频率处具有较平缓的色散关系,较高的耦合阻抗和较低的电路衰减。互作用模拟表明,在电子注电压为20 kV,电流为10 mA时,27 mm（50个周期）的折叠波导慢波结构在220 GHz具有14.5 dB的增益,3 dB带宽为16.3 GHz（211.9～228.2 GHz）。     

Small-signal analysis of a rectangular helix structure traveling-wave-tube

This paper investigates the properties of traveling wave-beam interaction in a rectangular helix traveling-wave-tube (TWT) for a solid sheet electron beam. The `hot' dispersion equation is obtained by means of the self-consistent field theory. The small signal analysis, which includes the effects of the beam parameters and slow-wave structure (SWS) parameters, is carried out by theoretical computation. The numerical results show that the bandwidth and the small-signal gain of the rectangular helix TWT increase as the beam current increases; and the beam voltage not obviously influences the small signal gain. Among different rectangular helix structures, the small-signal gain increases as the width of the rectangular helix SWS increases, however, the bandwidth decreases whether structure parameters a and L or ψ and L are fixed or not. In addition, a comparison of the small-signal gain of this structure with a conventional round helix is made. The presented analysis will be useful for the design of the TWT with a rectangular helix circuit.     

220 GHz 折叠波导慢波结构

优化设计了一种220 GHz的折叠波导慢波结构的尺寸,对其冷测特性如色散、耦合阻抗和衰减进行了分析。理论分析和软件仿真结果表明设计的折叠波导慢波结构在中心频率处具有较平缓的色散关系,较高的耦合阻抗和较低的电路衰减。互作用模拟表明,在电子注电压为20 kV,电流为10 mA时,27 mm（50个周期）的折叠波导慢波结构在220 GHz具有14.5 dB的增益,3 dB带宽为16.3 GHz（211.9～228.2 GHz）。     

Ultrawide-bandwidth gain in a coaxial dielectric Cherenkov maser

A coaxial waveguide partially filled with a dielectric as the slow-wave structure of a dielectric Cherenkov maser is investigated. The dispersion of the fundamental mode of this waveguide is very weak at phase velocities close to the velocity of light, and for this reason a very wide gain bandwidth is possible under conditions of an interaction with a relativistic electron beam. The dispersion equation for an infinitely thin tubular beam in a coaxial waveguide with a dielectric liner adjoining either the outer or inner conducting surface is derived. The gain bandwidth as a function of the parameters of the electron beam and the slow-wave system are investigated on the basis of numerical solution of the dispersion equation, and a comparison with similar dependences for the conventional configuration of a dielectric Cherenkov maser is made. The structural features of the coaxial configuration which enable novel approaches to the problems of matching the microwave signal at the entrance and exit of the system are discussed. Zh. Tekh. Fiz. 67, 66–72 (May 1997)     

Design of a Novel Folded Waveguide for 60-GHz Traveling-Wave Tubes

The 60-GHz traveling-wave tube(TWT) prevails nowadays as the amplifier for the satellite communication and electronic countermeasures.The folded waveguide(FW) is a promising all-metal slow-wave structure(SWS)for the 60-GHz TWT with advantages of robust performance,fine heat dissipation,considerable power and bandwidth.A novel FW periodically loaded with rectangular grooves is analyzed for the purpose of gaining higher power and gain.The rf characteristics are investigated by numerical simulation,and the nonlinear largesignal performance of such a TWT is analyzed by a 3D particle-in-cell code MAGIC.Compared with normal circuits,relatively higher continuous-wave power(40-56 W) and similar bandwidth(5 GHz) are predicted by simulation.Meanwhile,the designed operation voltage is 10.5kV,which keeps the low-voltage advantage of the popular helix TWT competitor.The novel FW will favor the design of a broadband and high-power 60-GHz TWT.     

结构参数对折叠波导行波管工作性能的影响

分析和计算了互作用区折叠波导截面长宽比(b/a)、直边高度和电子束通道大小等结构参数对太赫兹波段折叠波导行波管工作性能的影响。结果表明:互作用区衰减常数随b/a的增大而减小, 耦合阻抗和小信号增益则随b/a的增大先增加而后减小, 存在最优值。电子束通道越大, 衰减常数越大, 耦合阻抗和小信号增益降低得越多。相对于电子束通道, 增益和损耗对直边高度的敏感程度显著降低。因此为了提高器件功率容量, 可适当增加折叠波导的高度;在保证电子束能够顺利传输的前提下, 电子束通道越小越好。在折叠波导行波管的实际研制中, 可依据具体的实验条件和要求, 在适当的范围内合理选取互作用区各结构参数的值。     

结构参数对折叠波导行波管工作性能的影响

分析和计算了互作用区折叠波导截面长宽比(b/a)、直边高度和电子束通道大小等结构参数对太赫兹波段折叠波导行波管工作性能的影响。结果表明：互作用区衰减常数随b/a的增大而减小, 耦合阻抗和小信号增益则随b/a的增大先增加而后减小, 存在最优值。电子束通道越大, 衰减常数越大, 耦合阻抗和小信号增益降低得越多。相对于电子束通道, 增益和损耗对直边高度的敏感程度显著降低。因此为了提高器件功率容量, 可适当增加折叠波导的高度;在保证电子束能够顺利传输的前提下, 电子束通道越小越好。在折叠波导行波管的实际研制中, 可依据具体的实验条件和要求, 在适当的范围内合理选取互作用区各结构参数的值。     

脊加载螺旋槽行波管的小信号增益计算

脊加载螺旋槽行波管是一类新型毫米波大功率器件,给出了此结构中引入电子注后的“热”色散方程,并利用“牛顿”下山法求解了此复系数超越方程.通过数值计算给出了一个工作电压为20kV频率为474GHz的脊棱加载慢波结构的具体尺寸,并对此结构中小信号增益随脊尺寸的变化情况及电子注参数对其影响进行了研究,计算结果表明：此结构适宜于作为高增益窄带毫米波大功率行波管的慢波线,其3dB增益带宽为34%;为了展宽其工作带宽,可以适当减小间隙宽度,也可在一定范围内提高电子注电流.给出的理论对于研制此类行波管具有一定的指导意 关键词：     

0.14 THz行波管的设计与实验研究

以折叠波导作为为慢波结构进行研究分析,利用三维电磁仿真软件HFSS和CST,对0.14 THz行波管模型进行了折叠波导慢波结构、电子光学系统和输入输出窗等的模拟设计,并完成了整管的PIC注波互作用的仿真计算与优化。进行了整管的焊接工艺设计和热测实验,研制出的样管在电压15.4 kV、电流17.4 mA下,脉冲工作输出最大功率为8.3 W,输出中心频率为140.8 GHz,最大增益为28 dB,-3 dB带宽为2.9 GHz。     

基于双排矩形梳状慢波结构的W波段宽频带行波管模拟研究

提出采用圆形电子注和双排矩形梳状慢波结构作为W波段宽频带行波管注波互作用回路. 对该慢波回路的"冷"态特性、输入输出结构等方面进行了模拟仿真和分析, 研究结果表明, 该结构色散特性较好, 带宽较宽; 通过调整双排矩形梳状慢波结构之间的距离和电子注通道半径的尺寸, 圆形电子注系统取得了和带状注系统相同的耦合阻抗; 且该结构传输特性较好, 优化后整管的驻波比能在较宽的频带内保持在2以下. 此外, 对该慢波系统的大信号理论计算和PIC粒子模拟结果一致. 在50 mW驱动功率下, 输出功率在10 GHz带宽内大于40 W, 增益高于29 dB.     

345 GHz折叠波导行波管中电磁传输损耗的分析计算

利用电导率等效方法对345GHz折叠波导行波管中的电磁信号的传输损耗进行了仿真研究,考察了流通管孔径、加工粗糙度等对冷腔传输损耗的影响。结果表明,流通管孔径较大或加工粗糙度较大都会导致电磁信号传输严重衰减。模拟分析了热腔中电磁信号衰减对慢波结构净增益、带宽、最佳周期数等器件特征参数的影响,结果显示,电磁信号衰减会使得增益下降和带宽降低。     

345 GHz折叠波导行波管中电磁传输损耗的分析计算

利用电导率等效方法对345 GHz折叠波导行波管中的电磁信号的传输损耗进行了仿真研究,考察了流通管孔径、加工粗糙度等对冷腔传输损耗的影响。结果表明,流通管孔径较大或加工粗糙度较大都会导致电磁信号传输严重衰减。模拟分析了热腔中电磁信号衰减对慢波结构净增益、带宽、最佳周期数等器件特征参数的影响,结果显示,电磁信号衰减会使得增益下降和带宽降低。     

High-gain wide-band gyrotron traveling wave amplifier with a helically corrugated waveguide

First bandwidth measurements of a novel gyrotron amplifier are presented. The coupling between the second harmonic cyclotron mode of a gyrating electron beam and the radiation field occurred in the region of near infinite phase velocity over a broad bandwidth by using a cylindrical waveguide with a helical corrugation on its internal surface. With a beam energy of 185 keV, the amplifier achieved a maximum output power of 1.1 MW, saturated gain of 37 dB, linear gain of 47 dB, saturated bandwidth of 8.4 to 10.4 GHz ( 21% relative bandwidth), and an efficiency of 29%, in good agreement with theory.