A Cylindrical Waveguide Structure with Helical Grooves for High Power TWTs

In this work, the field analysis of a cylindrical interaction structure, with helical grooves, and an inner dielectric lining for possible employment in high power TWT amplifiers in the conventional slow-wave regime, is presented. The Ohmic dominance of the microwave power on the walls of this propagating circuit is deduced.     

测量行波管电子注的法拉第筒的热分析

利用ANSYS软件对测量行波管电子注截面的法拉第筒探头进行了热分析研究.分析了在单脉冲情况下,测量各种直径的不同脉冲功率密度的电子注、不同脉冲宽度对法拉第筒温度的影响,研究了测量不同功率密度的电子注可以使用的脉冲宽度.结果表明,仅法拉第筒上的注斑区域温度迅速上升,温度梯度较大,其它部分温度基本不变,为保证法拉第筒能够持...     

行波管三维非线性计算机模拟的改进

采用宏粒子模型计算空间电荷力,导出行波管三维大讯号工作方程组,开发出ＶｉｓｕａｌＣ＋＋数值分析软件。随后进行计算机模拟,提出将三维空间电荷力处理为二维,大大节省了计算时间,数值结果与三维计算吻合很好。     

Three-Dimensional Numerical Analysis for Millimeter Wave TWTs

Based on Macro–particle model, the electron beam can be subdivided into 3D Macro–particles to calculate space–charge forces and 3D large–signal working equations are obtained. Finally, the numerical results for a uniform magnetic focusing field are given.     

适用于毫米波带状束行波放大器的光子晶体栅慢波电路研究

提出了一种适用于毫米波及THz波行波放大器的光子晶体栅慢波电路,即横向分布光子晶体栅慢波电路,并提出了分析和设计此类光子晶体栅慢波电路的方法.通过计算光子晶体TE极化的带隙和在带隙内将光子晶体栅慢波电路等效为矩形栅波导慢波电路,从而,光子晶体栅慢波电路的设计得以分为两步独立进行,从而简化了光子晶体栅慢波电路的设计.对横向分布光子晶体栅慢波电路进行了设计和计算,结果表明,与矩形栅波导慢波电路相比,横向分布光子晶体栅慢波电路可以降低工作电压并增加带宽,从而可以降低成本. 关键词： 行波放大器 光子晶体 毫米波 慢波电路     

利用等效电路模型计算耦合腔行波管注-波互作用

通过研究Curnow等效电路模型,得到进行单腔计算的矩阵方程,进而获得线路场方程, 结合运动方程和空间电荷场方程,从而推导出耦合腔行波管一维注波互作用非线性理论模型. 该理论能计算任意的切断、跳变、渐变等结构以及多信号模拟.利用该理论编制的软件计算了 59 GHz-64 GHz耦合腔行波管AM-PM相位失真,三阶互调以及五阶互调分量. 同时模拟得到了59 GHz-64 GHz带内饱和输出功率分布,理论结果与热测结果误差在5%以内.     

A method of designing photonic crystal grating slow-wave circuit for Ribbon--Beam microwave travelling wave amplifiers

A method of designing a photonic crystal grating slow-wave circuit in which the cylinders of the 2D photonic crystals dot on a cross-sectional plane is established by calculating the band structures of the 2D photonic crystals, and the eigenfrequency of the equivalent waveguide grating. For calculating the band structures, the eigenvalue equations of the photonic crystals in the system of photonic crystal grating slow-wave circuit are derived in a special polarization mode. Two examples are taken to show the method. The design result is validated by the scattering parameters of the same circuit. The result indicates that there exists no photonic band gap if the metal gratings do not extend into the photonic crystals; the design of the circuit without the metal gratings extending into the photonic crystals is less flexible than that with the metal gratings extending into the photonic crystals.     

Three-dimensional nonlinear theory of travelling wave tubes and simulation

A three-dimensional (3D) nonlinear theory of travelling wave tubes (TWTs) is developed, which includes a fundamental radio frequency (RF) and harmonics. When the instantaneous bandwidth exceeds an octave, the harmonic is generated and the mutual coupling between the harmonic and the fundamental RF can be observed in TWTs due to nonlinear interaction between the electron beam and the RF. At low frequencies the harmonic has an obvious effect.Based upon Tien‘‘s disc model, a plastic 3D super-particle model is proposed to improve the nonlinear analysis of TWTs.Numerical results employing a periodic magnetic focusing field are presented.     

Linear Theory of the Coaxial Ridge-Loaded Helical Groove Waveguide

The coaxial ridge-loaded helical groove waveguide, an all-metal slow-wave circuit, has advantages of good heat dissipation and great size, and thus is suitable for use of millimeter TWTs. In this paper, the dispersion equation of the circuit with an annular electron beam is obtained according to self-consistent field theory. The influence of various electron beam parameters on the small signal gain is investigated and discussed by the numerical computation.