【作者】 许雄；

【导师】 魏彦玉；

【作者基本信息】 电子科技大学 ， 物理电子学， 2012， 博士

【摘要】 毫米波及太赫兹波段的电磁频谱开发是当今电子学领域的热点课题，它们在军事装备、科学研究、国民经济等多个领域具有非常重要的应用价值。真空电子技术作为一种重要的技术手段被用于开发这些波段的大功率电磁辐射源。行波管和返波管是其中两种广泛应用的大功率辐射源。随着工作频段的不断提高，作为器件核心部件的慢波结构遇到了传输损耗大以及反射强两大关键科学技术难题。在寻求解决方案的过程中，作者提出了一种新型的电磁结构：正弦波导。经过分析发现，正弦波导具有损耗低、反射弱的良好射频传输特性。因此，将正弦波导作为一种慢波结构，可以显著提高现有大功率辐射源的性能。同时，它在毫米波及太赫兹无源器件领域中也具有潜在的应用价值。本论文主要是从慢波特性、射频传输特性、注波互作用特性三个方面对正弦波导进行了深入的研究，并指出了可以将其应用于毫米波及太赫兹带通滤波器、传输线、行波管和返波管中慢波结构的设计。本论文的创新点主要包括以下五点：1.提出了一种新型的电磁结构：正弦波导。该结构具有宽频带、低传输损耗、弱反射、易加工等特点，适合作为毫米波及太赫兹波段的慢波结构。2.理论预言并实验验证了正弦波导可作为一种毫米波及太赫兹传输线。W波段正弦波导传输线的测试结果显示，其在全频带内的传输损耗约为0.048dB/cm，与同波段标准矩形波导的性能相当。3.提出了具有150W峰值功率水平的220GHz频段带状注正弦波导行波管的设计方案。在20.8kV电压和150mA电流下，其在200～240GHz的频带内，具有34.7dB以上的增益，电子效率超过4.8%，最大峰值输出功率为270W。同时，还提出了具有1kW峰值功率水平的W波段行波管的设计方案。设计了该器件所需要的新型集中衰减器和输入输出结构。在21.1kV电压和400mA电流下，通过30～490mW不等幅的信号激励，可在90～98GHz的频带内，均具有1kW以上峰值功率输出。4.提出了具有瓦级峰值功率水平的220GHz频段圆形电子注正弦波导返波管的设计方案。在10mA电流下，当在17～26kV之间进行电压调谐时，该返波管可在210～230GHz的频带内产生2W以上的峰值功率输出。同时，还提出了具有瓦级峰值功率水平的1THz频段带状注正弦波导返波管的设计方案。在19.4kV电压和5mA电流下，其在995.6GHz处具有1W的峰值功率输出。并且，为了方便功率的提取，提出可以利用矩形栅结构作为太赫兹返波管的反射器。5.建立了关于正弦波导色散特性和小信号增益的基础理论。利用场论的方法，从麦克斯韦方程组出发，获得了正弦波导的“冷”、“热”色散方程，并利用数值计算方法求解该方程，再与计算机仿真方法所获得的结果进行对比验证，证实了理论的正确性。总之，正弦波导这一新型电磁结构的研究及相关应用分析将对毫米波工程及太赫兹技术的发展具有重要的科学意义，尤其为大功率毫米波及太赫兹辐射源的研究提供一种新的途径。更多还原

【Abstract】 The spectrum development of millimeter wave and terahertz band is a hot spotsubject in modern electronics field. It has great value in military equipment, scientificresearch, national economy and other fields. Vacuum electronic technology as animportant technical method is being used to develop much-needed high powerelectromagnetic radiation sources. Traveling wave tube and backward wave oscillatorare two widely applied high power radiation sources. With the increasing of operatingfrequency, the slow-wave structure as the core component of the device is encounteringtwo scientific challenges about high transmission loss and strong reflection. In seekingsolving solutions, a novel type of electromagnetic structure which is called sinewaveguide is put forword. And it is speculated that the sine waveguide has good radiofrequency transmission characteristics. Therefore, the sine waveguide, as a slow-wavestructure, is able to significantly improve device performance of the existing radiationsources. At the same time, it also has important application merit in designing passiveelectromagnetic devices.This thesis does a detailed analysis for the sine waveguide on three aspects,including slow wave characteristics, radio frequency transmission characteristics andbeam wave interaction characteristics. And it is pointed out that the sine waveguide canbe applied in design a millimeter wave and terahertz transmission bandpass filter,transmission line and slow wave structure in traveling wave tube or backward waveoscillator.The innovations of this thesis are mainly concluded as follows:1. Proposed a novel type of electromagnetic structure: sine waveguide. It possesseswide bandwidth, low transmission loss, low reflection and easy fabricationcharacteristics. Therefore, it can be considered as a slow wave structure in millimeterwave and terahertz regime.2. Theoretically indicated and experimentally verified that the sine waveguide canbe considered as a millimeter-wave and terahertz transmission line. The experimentalresults of a W-band sine waveguide transmission line show that, its transmission loss is about0.048dB/cm in the entire frequency band, which is equivalent to that of standardrectangular waveguide.3. Proposed a design scheme of the220GHz sheet beam sine waveguide travelingwave tube with a peak power of150W. The scheme has a gain of over34.7dB and anelectronic efficiency of over4.8%in the frequency range of200～240GHz under abeam voltage of20.8kV and a beam current of150mA. And the maximum peak poweris270W. At the same time, a design scheme of the W-band traveling wave tube with apeak power of1kW is put forward. A novel attenuator and an input or output structurecompatible with the device. Thus, it can deliver1kW peak power output in the entirefrequency range of90～98GHz by tuning the input signal between30mW and490mW under a beam voltage of21.1kV and a beam current of400mA.4. Proposed a design scheme of the220GHz pencil beam sine waveguide backwardwave oscillator with a watt-class peak power. The oscillator can deliver over2W peakpower output in the frequency range of210～230GHz by tuning the beam voltage from17kV to26kV under a beam current of10mA. At the same time, a design scheme of awatt-class1THz sheet beam sine waveguide backward wave oscillator is put forward. Itcan deliver1W peak power output at995.6GHz under a beam voltage of19.4kV and abeam current of5mA. In addition, in order to extract power easily, a rectangularwaveguide grating is considered as a reflector for terahertz backward wave oscillator.5. Constructed the basical theory about the dispersion characteristics and the smallsignal gain of the sine waveguide. The “cold” and “hot” dispersion equations are gainedfrom Maxwell equations by field theory. Afterwards, the numerical computation methodis used to solve those equations, and then compared with the results from softwaresimulation method for verificating our theory.In summary, the investigation of the novel sine waveguide and its applicationanalysis will favor the development of the millimeter wave engineering and terahertztechnology, especially as a novel way for study on high power millimeter wave andterahertz electromagnetic radiation sources.更多还原