【作者】 邓光晟；

【导师】 吴华夏；

【作者基本信息】 合肥工业大学 ， 计算机应用技术， 2014， 博士

【摘要】 太赫兹波在宽带通信、雷达、电子对抗、天文学、医学成像、无损检测、安全检查等领域都有重大的科学研究价值与广阔的应用前景,这使得太赫兹技术成为二十一世纪最炙手可热的研究方向之一。而缺乏小型化、大功率的太赫兹辐射源,已成为太赫兹波应用研究发展的主要瓶颈。双光栅绕射辐射器件作为一种新型的真空太赫兹辐射源,具有结构紧凑、电子效率高、工作电压低等许多优点,是一类极具应用前景的太赫兹器件。由于理论的复杂性,双光栅绕射辐射器件技术还并不成熟。本文以双光栅绕射辐射THz源高频系统为研究对象,利用计算机辅助设计手段,得到的主要研究成果和创新点包括以下几个方面：1.对双光栅绕射辐射器件的高频结构进行了理论研究,得到了开放式谐振腔的模式以及场分布情况。通过对双光栅绕射辐射器件高频系统内的模式特性研究,得到了双光栅绕射辐射器件采用的工作模式并给出了其横向模式数,利用场论方法研究了双光栅绕射辐射器件的高频结构,得到其高频场表达形式。2.研究了双光栅绕射辐射器件的高频特性,包括高频系统内的电磁场强度分布规律与Q值特性。分析了结构参数对模式分布及谐振频率的影响,提出了增强互作用区域内电磁场的有效方法。采用理论分析方法得到Q值的表达式及影响因素,通过对结构参数变化对Q值的影响规律研究实现高频系统Q值的优化。给出了一种快速求解高频结构的谐振频率及场分布的方法。3.对双光栅器件高频系统内部的模式竞争特性进行了研究,得到了保证工作模式稳定运转的有效方法。研究结果为解决双光栅绕射辐射器件高频系统内模式竞争奠定了理论基础。4.采用粒子模拟方法研究了双光栅绕射辐射器件的注-波互作用这一物理过程,并对互作用时的粒子行为、功率输出等特性进行了分析,研究了双光栅绕射辐射器件的电调谐特性。5.对双光栅绕射辐射器件高频系统的大深宽比的光栅结构加工方法进行了探索,得到的研究成果为该类器件高频系统的加工提供了有效参考。6.提出了一种新的基于光栅结构的绕射辐射器件,并对其模式分布与模式竞争特性进行了数值分析,为进一步深入研究奠定了基础。双光栅绕射辐射器件作为一种新型的THz电真空器件,目前国内外对此研究较少。我们研究发现,双光栅绕射辐射器件具有工作电压低、结构紧凑等优点,同时其功率输出水平及电子效率较传统绕射辐射器件又有较大提高,因而双光栅绕射辐射器件是一种极具应用前景的THz电真空器件。本文的研究为双光栅绕射辐射器件的设计和优化提供了理论依据。更多还原

【Abstract】 The broad application prospect of Terahertz-waves in areas such as broadband communication, radar, electronic warfare, astronomy, Medical imaging, nondestructive testing and security check which makes the terahertz technology has become one of the hottest research directions in twenty-first century. Lack of miniature and high-power terahertz source is the bottleneck of development of terahertz technology. As a newly developed vacuum terahertz source, dual-grating diffraction radiation device has the advantages of compact dimensions, high efficiency and low voltage. In the dissertation, the high frequency system of dual-grating diffraction radiation device was studied, and our researches are mainly focus on the following aspects:l.The high frequency structure was studied, and the modes and distribution of field were analyzed. The working mode of dual-grating diffraction radiation device were analyzed by studing the mode characteristics of high frequency system. And the high frequency characteristics was studied by electromagnetic field method in this dissertation.2.The intensity of electromagnetic field and Q characteristics of dual-grating diffraction radiation device was studied. The influence of structure parameters on the mode distribution and resonance frequency were analyzed, and the influence of structure parameters on the Q characteristics was also studied. A newly simulation method of analyzing resonant frequency and field distribution was presented in the dissertation.3.The characteristics of mode competition in dual-grating diffraction radiation device was studied, and the effective methods to ensure stable operation on working mode was presented.4.The beam-wave interaction of dual-grating diffraction radiation device was studied. Meanwhile, the the process of bunching particles, the output characteristics and electric tuning characteristics were also simulated by particle-in-cell method.5.The processing method of high depth width ratio of grating structure in dual-grating diffraction radiation device was explored, which providing an effective reference for the processing of this structure.6.A new diffraction radiation device based on gratings structure was presented. The numerical analysis of mode competition and field distribution were carried out which was intended to lay the groundwork for future research.As a new type of THz vacuum device, the technique of dual-grating diffraction radiation device is immature. The high frequency system of dual-grating diffraction radiation device was studied in details in the dissertation, and the results show that the dual-grating diffraction radiation device is a novel promising vacuum tube with compact dimensions and high power. The studies in the dissertation can provide some guidance to the design and optimize of dual-grating diffraction radiation device.更多还原