【作者】 徐捷；

【导师】 宫玉彬；

【作者基本信息】 电子科技大学 ， 物理电子学， 2012， 博士

【摘要】 高功率微波器件广泛应用于毫米波雷达、制导、战略战术通信、电子对抗、遥感、辐射测量等领域，它的性能直接决定着武器装备的水平，因此对新型高功率短毫米波行波管的研究具有很重要的现实意义。本文对一类用于微波源的慢波结构进行了深入的研究，主要工作和创新点如下：第一点：在介质加载圆柱波导的基础上，研究了上下底板加载介质的矩形波导慢波结构。首先采用等效电路和场匹配的方法给出了上下底板加载介质的矩形波导慢波结构的色散方程和场分布，并通过计算R/Q值求得了电子束传输通过慢波结构激励的电磁波功率；然后分析了反对称模式对电子束稳定性的影响，给出了电子束在偏离中心位置处传播时，产生的横向作用力；最后设计了采用上下底板加载介质的矩形波导慢波结构的功率源器件。第二点：提出了一种采用光子晶体作为行波管慢波结构屏蔽筒的新方案，论证了方案的可行性，并进行了模式分析。在充分研究光子晶体禁带特性的基础上，计算了光子晶体慢波结构的色散特性和耦合阻抗，对计算结果的分析表明，光子晶体在行波管慢波结构中起到了定向选模的作用，为行波管实现高次模式工作奠定了基础。第三点：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，使得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较，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。第四点：为解决工作在3mm波段及以上频段的折叠波导行波管因加工精度和功率容量的局限性，提出了无渐变规律的有限变周期折叠波导慢波结构，首先给出了这种结构能够有效增大高次空间谐波耦合阻抗的理论基础，并导出了色散和耦合阻抗表达式，然后进行数值计算，给出一组优化后的设计参数，并以此确定行波管的工作点，最后利用MAFIA粒子模拟软件进行大信号互作用模拟，获得有效增益。从而在结构比较大和周期比较大的情况下，实现了相对工作电压比较低的行波管设计。更多还原

【Abstract】 Traveling wave tube (TWT) is the most important type of microwave vacuumtube. It has been frequently used as millimeter wave radar, guidance, tactical andstrategic communication, electronic countermeasure, remote sense, radiationmeasurement and so on. Its performance directly influences the level of the weaponequipments, and it has importantly realistic significance for the study on the new typeof high power and short mm-wave traveling wave amplifiers. In this dissertation, wehave made detailed study on a type of slow wave structures (SWS). Several importantand valuable results which bring forth new ideas are achieved and listed as thefollowing:First, rectangular waveguide structure with dielectric loaded on the up-and-downplates is studied based on dielectric loaded cylindrical waveguide. First, the dispersionrelation is given by equivalent circuit and field matching, and the electromagneticenergy excited by a bunched relativistic electron beam is obtained by calculating theR/Q value. Second, the influence of dipole mode on the stability of electron beam isanalyzed. Finally, we design a high power microwave generation device. Test resultsare in good agreement with the predictions.Second, a new scheme using the photonic crystal as the shielding tube of travelingwave tube (TWT) slow wave structure (SWS) is put forward, and the feasibility of thisscheme is proved. Mode analysis is done as to this structure. Based on the forbiddenband characteristic of photonic crystal, the dispersion and coupling impedance ofphotonic crystal SWS are calculated. The analysis of the calculation results shows that,photonic crystal has an important effect on the TWT SWS in oriented selecting mode.The work of this paper lays the foundation for TWT realizing higher mode operation.Third, a kind of photonic crystal grating slow-wave circuit, cross-sectiondistributing two-dimensional photonic crystal slow-wave circuit (CD2DPhSWC), wasproposed. And the way of design for CD2DPhSWC was put forward, too. To simplythe design, the way was actualized by two steps. The two steps are the calculation ofthe photonic band gap (PBG) for the TE polarization and the dispersion of the equivalent rectangular waveguide grating. The numerical results explain that thebandwidth of the traveling wave tubes (TWTs) based on CS2DPhSWC is wider, andthe operating voltage is lower, than that of the rectangular waveguide grating.Correspondingly, the cost of the TWTs will decrease.Four, for solving the processing precision and power capacity of foldedwaveguide traveling wave tube operating in3mm band and above, a new kind offolded waveguide slow wave structure of which finite periodic structure is irregular isproposed. Firstly, we give the reason why using this structure can enhance couplingimpedance of high harmonic efficiently, and derivative the expressions of thedispersion and coupling impedance. A group of design parameters which are optimizedis obtained by the numerical calculation, and this is the authority of operating point oftraveling wave tube. Finally, the gain is obtained by MAFIA particle simulationsoftware.更多还原