【作者】 赖剑强；

【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】 慢波结构是线性注微波真空电子器件实现微波信号的产生或放大的最核心部件。带状电子注器件相比于传统圆形电子注器件，因为可以明显提高输出功率而成为真空电子器件的一个新的发展方向。工作在微波及毫米波低频段的真空电子器件研究相对成熟，有不少管型已成功应用于国防和民用领域。在中小功率领域的应用中很多真空器件逐渐被不断发展的微波固态器件所替代，而在毫米波的高频部分特别是3mm及以上的频段，固态器件的应用还很少。真空电子器件可以轻松地工作到这些频段，但是对工作在这些频段的器件研究还相对薄弱。随着现代工业的发展，对器件的工作频段要求越来越高，希望得到的功率也越来越大，这也成为了我们对真空电子器件的一个追求目标。因此对工作在短毫米波的大功率微波真空电子器件的研究具有较高的价值和现实意义。本论文以交错双栅慢波结构为研究出发点，从理论、模拟计算和实验等方面深入地研究了基于带状电子注工作的W波段、140GHz频段大功率行波管和返波振荡器，研究了一种适用于圆形电子注工作的交错双栅行波管。提出了这类器件的高频系统部件，提出了适用于带状电子注器件的电子光学系统。提出将虚边界元法应用于行波管多级降压收集极的计算。论文的主要工作和创新点如下：一、深入研究了交错双栅结构的模式结构、场结构、空间谐波、色散特性和耦合阻抗，将该结构应用于行波管，提出了适用于该类行波管的慢波电路过渡结构、输入输出结构，解决了基于该慢波结构的行波管高频系统衰减和反射大等难题。提出了一种既能保持电路反射系数小，又能抑制行波管振荡的集中衰减器，保证了行波管的稳定工作。构建了工作在W波段和140GHz频段的带状电子注交错双栅行波管，计算结果显示这类行波管具比较大的输出功率和比较宽的工作频带，为将来研制宽带大功率短毫米波行波管奠定了基础。二、提出将交错双栅慢波结构应用于W波段和140GHz频段带状电子注返波振荡器。分析了将交错双栅结构作为返波振荡器电路最适合的工作模式和工作谐波，从理论上预测返波振荡器的工作频带及对应的调谐电压范围。提出了振荡器的慢波电路过渡结构和输出结构，构建了工作在两个频段的返波振荡器。计算结果显示，这两只返波振荡器均能在较宽频带内得到瓦级以上的稳定功率输出。该研究为大功率短毫米波辐射源提供了一种解决方案。三、提出了一种带状注电子枪，发明了一种带状注多级降压收集极，并设计了一种PCM磁聚焦系统，构成了一套带状注器件电子光学系统。模拟计算结果显示，电子枪能够提供满足需求的电子注，聚焦系统可以实现带状注的良好聚焦，多级降压收集极中电子在电极内壁的“着陆”较均匀，电子回流率小，收集效率高。该研究提供了一套完整的带状注器件电子光学系统解决方案，为高效率带状电子注器件的研制打下了基础。四、为了解决带状注行波管的聚焦困难，通过对常规交错双栅慢波结构变形，将其应用在了W波段圆形电子注行波管。计算结果显示该行波管在88-103GHz频带内可得到大于200W的峰值功率输出。这只圆形注行波管对聚焦要求不高，工程实现相对容易，适用于不需要大功率的应用场合。五、提出将虚边界元法这种数值计算方法应用于多级降压收集极的计算，论证了该方法用于计算轴对称收集极的理论基础。它可以解决计算开敞结构时普通方法计算不准确的问题，也解决了边界元法会遇到的奇异积分的问题，这种方法具有计算速度快，计算精度高的特点。编写了基于该方法的二维多级降压收集极计算机代码，并计算了轴对称多级降压收集极，得到了良好的计算结果。该方法对于指导高效率收集极的设计具有实用价值。六、提出了W波段带状电子注交错双栅行波管高频系统的加工方案，分别加工了慢波电路及其过渡结构、输入输出结构以及与用于将系统与测量仪器连接的阻抗变换器。测试了将这些部件连接成为行波管高频系统的传输特性。该实验验证了交错双栅行波管高频系统的传输特性，为实际制管做了准备。更多还原

【Abstract】 Slow wave structure (SWS) is the core part of the linear beam vacuum electrondevices (VEDs) for generating or amplifying the microwave. The sheet beam electrondevices have become a new research direction in the vacuum devices communitybecause these devices were proved to be an effective way to provide much higher outputpower relative to traditional pencil beam counterparts. The VEDs with lower operationband in the microwave and millimeter wave spectra have been studying for a long timeand they are relatively more reliable and steady. A grate number of these devices havebeen put in the military and industrial applications. With the development of the solidstate devices (SSDs), some low power vacuum devices have been replaced by them.However, the SSDs operating in short millimeter wave band have not yet developed andmost of them are under studying. The VEDs can easily operate in the band and everhigher frequency bands, nevertheless most of these devices are still in developing. Withthe rapid advancement of modern microwave techniques, the demand for high operationband and high output power devices becomes more and more active, and it is the aimfor the researchers. In conclusion, it is the grate science value and practical significanceto study the high power short-millimeter wave vacuum electron devices.Base on the staggered double vane SWS, the W-band and140GHz band sheet beamhigh power traveling-wave tubes (TWTs) and backward wave oscillators (BWOs) werestudied in the dissertation with theory analysis, computer simulations and experiments.Some RF components for these devices and an electron optical system for this kind ofsheet beam devices were proposed. A staggered double vane TWT operate with pencilbeam and the corresponding electron gun were presented. Finally, a numericalcalculation method-virtual boundary element method was theoretically studied and itwas applied in the calculation for a multistage depressed collector. The main contentsand keys of innovation are as follows:(1) The staggered double vane structure was intensively analyzed from its modestructure, field structure, spatial harmonic, dispersion characteristics and interactionimpedance, and it was proposed to apply on W-band and140GHz-band sheet beam TWTs. The corresponding transaction structures for circuit and the input and outputcouplers were proposed which keep a low attenuation and reflection parameters of theRF system for the tubes. A concentrated attenuator which can eliminate the oscillationbut maintain a low circuit reflection was proposed and such attenuator guarantee asteady operation. Particle-in-cell (PIC) simulation revealed that the W-band TWT canproduce very high power in a broad band. This study laid a solid foundation fordeveloping broad band high power short-millimeter wave amplifiers.(2) The application of staggered double vane to W-band and140GHz-band sheetbeam BWOs were proposed after analyzing the feature of BWO. The operation modeand spatial harmonic which are best fit for BWO were selected and the operation bandsand the corresponding tuning voltage scopes were predicted. The two sheet beamstaggered double vane BWO were constructed after presenting its circuit transitionstructure and output coupler. The simulation results show that the W-band and140GHz-band BWO can offer watt-class steady average power in a relative wide band.These studies offered a solution for large power short-millimeter wave radiationsources.(3) After the studying of the sheet beam devices, a sheet beam electron gun wasproposed, a sheet beam multi-stage depressed collector were invented and a periodicalcusped magnet focus stack was designed. Finally an electron-optical system wasestablished. Numerical calculation results demonstrated that the gun can produce therequired sheet beam, the focus stack can achieve a good-quality sheet beam focus, theelectrons can uniformly land on the electrodes of the collector and the collectorefficiency was high but with low backflow rate. Such study provides a completeelectron-optical system solution for sheet beam devices and laid a foundation fordeveloping high efficiency sheet beam vacuum devices.(4) The staggered double vane SWS was applied to W band pencil beam TWTthrough which can greatly alleviate the focus problem relative to sheet beam TWT.Calculation results show that it can produce over200W peak power in the band of88-103GHz providing a constant input power of0.1W. The beam focus was easy forsuch TWT therefore it is suitable for the application in the situation that the low ormiddle power is needed.(5) A computer numerical calculation method named virtual boundary element method was proposed for multistage depressed collector design. The theoreticalfoundation of such method for calculating the axial symmetry collector was discussed.This method can solve the problem of bigger error when calculation open structure withtraditional method and it also avoid the singular integral which the boundary elementmethod can not deal. It is fast and accurate in calculation. Accordingly, atwo-dimensional simulation code for collector calculation was written and anaxial-symmetric four-stage depressed collector was calculated and a good result wasobtained. Such method has a high practical value in designing high efficiency collector.(6) The processing scheme of the RF system for the W-band sheet beam staggereddoubled vane TWT was designed. The SWS and transition structure, input/outputcoupler and an impedance converter were fabricated, respectively. These componentswere combined to a RF system with the complete signal path and its transmissionperformance was tested. This experiment examined the transmission characteristics ofthe W-band staggered double vane TWT RF system and it is useful for futureinvestigation.更多还原