真空电子学和微波真空电子器件的发展和技术现状

真空电子学是研究真空中与电子相关的物理现象的学科,主要研究电子的产生和运动、电子与电磁波和物质的相互作用,是各类真空电子器件和粒子加速器等真空电子装置的基础。微波真空电子器件是最重要的真空电子器件,已广泛应用于国防、国民经济和科学研究领域,是军用和民用微波电子系统的核心器件,本文将介绍真空电子学和微波真空电子器件的发展历史,技术现状和应用情况,并对其发展趋势作简要的评述。     

自由电子在平面电磁波作用下辐射的频谱分析

相对论自由电子束与平面电磁波相互作用,将产生更短波长的相干电磁辐射,这一原理已应用于近年来发展的自由电子激光嚣的研究中。本文采用了适当的运动坐标系,将平面电磁波变换成沿轴向的驻波,简化了计算。求解出自由电子在平面电磁波作用下的运动轨迹,进一步分析了电子与电磁波     

征稿通知

《电子器件》创刊于1978年,是由教育部主管、东南大学主办的学术性刊物。对国内外公开发行,并被英国科学文摘(SA)收录。本刊主要刊登真空电子学、微波电子学、光电子学、薄膜电子学、电子显示技术、激光与红外技术、半导体物理与器件、集成电路与微电子技术、光纤技术、真空物理与技术、表面分析技术、     

征稿通知

《电子器件》创刊于1978年,是由教育部主管、东南大学主办的学术性刊物。对国内外公开发行,并被英国科学文摘(SA)收录。本刊主要刊登真空电子学、微波电子学、光电子学、薄膜电子学、电子显示技术、激光与红外技术、半导体物理与器件、集成电路与微电子技术、光纤技术、真空物理与技术、表面分析技术、传感技术、电子材料     

带轴向导引场激光泵浦FEL的辐射机制分析

本文从单粒子理论出发,讨论分析了相对论电子束同时处于激光泵浦场、轴向导引磁场以及自身辐射场中的运动和辐射过程;结合对辐射波增益的计算,发现这种电磁波泵浦自由电子激光与一般静磁泵浦场中的波粒相互作用以及辐射机制类似,可以从不同角度来加以解释。通过分析计算结果,本文展现了清晰的物理图象。     

征稿通知

《电子器件》创刊于1978年,是由教育部主管、东南大学主办的学术性刊物。对国内外公开发行,并被英国科学文摘(SA)收录。本刊主要刊登真空电子学、微波电子学、光电子学、薄膜电子学、电子显示技术、激光与红外技术、半导体物理与器件、     

征稿通知

《电子器件》创刊于1978年,是由教育部主管、东南大学主办的学术性刊物。对国内外公开发行,并被英国科学文摘(SA)收录。本刊主要刊登真空电子学、微波电子学、光电子学、薄膜电子学、电子显示技术、激光与红外技术、半导体物理与器件、     

征稿通知

《电子器件》创刊于1978年,是由教育部主管、东南大学主办的学术性刊物。对国内外公开发行,并被英国科学文摘(SA)收录。本刊主要刊登真空电子学、微波电子学、光电子学、薄膜电子学、电子显示技术、激光与红外技术、半导体物理与器件、集成电路与微电子技术、光纤技术、真空物理与技术、表面分析技术、传感技术、电子材料与元器件、电光源与照明技术、电     

征稿通知

正《电子器件》创刊于1978年,是由教育部主管、东南大学主办的学术性刊物。对国内外公开发行,并被英国科学文摘(SA)收录。本刊主要刊登真空电子学、微波电子学、光电子学、薄膜电子学、电子显示技术、激光与红外技术、半导体物理与器件、集成电路与微电子技术、光纤技术、真空物理与技术、表面分析技术、传感技术、电子材料与元器件、电光源与照明技术、电子技术应用,并涉及电子科学领域内的新理论、新思想、新技术等方面的内容。欢迎有关科技人员和广大读者踊跃投稿。     

征稿通知

《电子器件》创刊于1978年,是由教育部主管、东南大学主办的学术性刊物。对国内外公开发行,并被英国科学文摘(SA)收录。本刊主要刊登真空电子学、微波电子学、光电子学、薄膜电子学、电子显示技术、激光与红外技术、半导体物理与器件、集成电路与微电子技术、光纤技术、真空物理与技术、表面分析技术、传感技术、电子材料与元器件、电光源与照明技术、电     

Vacuum electronics at the dawn of the twenty-first century

In this introduction to the Special Issue on vacuum electronics, the history, operating principles, and recent technological trends of vacuum electronic devices are reviewed. The development of microwave power tubes is described and improvements in these devices over the past quarter of a century are highlighted. These improvements have been substantial and have been driven by modern high-power applications and by advances in materials and computational science. The second part of this paper describes the advent of a new class of vacuum electronics generator as involving relativistic electron beams and interaction with fast waves (e.g., gyrotrons, free-electron lasers). These new types of generators are opening the electromagnetic spectrum beyond the microwave region (i.e., millimeter-wave, infrared, ultraviolet, and even X-ray) for applications of high-power, coherent generators of electromagnetic radiation     

相对论电子在高斯激光场中的加速

为了研究激光电磁场对真空中电子的作用,从洛伦兹方程出发,得出了电子运动轨迹,实现了激光场对电子的加速。继而由运动电子产生的流密度,得到了电子的辐射能量谱,分析了相对论电子的辐射特点。结果表明,高斯激光场对真空中电子有很好的加速效果,最大轴向速度可达0.9c。     

微波真空电子器件的发展与应用

根据真空电子器件的工作原理,其百年发展史可分为三个阶段:以静电控制的普通电子管阶段、以动态控制原理工作的微波真空电子器件阶段、基于相对论效应的新型器件阶段,每个阶段的代表管型在各自的应用领域都发挥了重要的作用。随着电磁波谱的开发利用,微波真空电子器件的技术水平向高频率、高功率、高效率方向发展,推动着军用装备和工业应用的不断拓展,特别在航天领域有长足发展。本文综述微波真空电子器件在厘米波段、毫米波段和太赫兹波段技术发展和装备应用概况,探讨未来的发展方向。     

Efficiency enhancement in a Cherenkov laser loaded with a Kerr-likemedium

Efficiency enhancement in energy conversion for a Cherenkov free elctron laser loaded with a Kerr-like medium is discussed with the aid of particle simulation. For the analysis of the problem, a two-dimensional model for the Cherenkov free electron laser is considered which is composed of a planar relativistic electron beam and a parallel plate waveguide one plate of which is loaded with a nonlinear dielectric sheet exhibiting a Kerr-like effect. To follow the growth of an electromagnetic wave and the decrease in the kinetic energy of the electron beam in the specified model of the Cherenkov free electron laser, a particular segment of the electron beam with the longitudinal length of one guide wavelength is picked out. In that segment, as it travels down the waveguide, the interaction between the electromagnetic wave and a group of electrons is analyzed with the use of the finite-difference time-domain (FDTD) method. The result of numerical simulation shows that the efficiency of energy transfer from the electron beam to the electromagnetic wave is greatly enhanced by the proper choice of the nonlinear parameter for a Kerr-like medium. The enhanced efficiency is due to the improved velocity matching between the electron beam and the electromagnetic wave, and to the self-focusing effect of a Kerr-like medium     

Applications of advanced materials technologies to vacuumelectronic devices

The applications of advanced engineering materials in modern vacuum electronic devices are reviewed. Unique materials with desirable thermal, mechanical, electrical, and magnetic properties are playing a crucial role in raising the average power capability, bandwidth, and efficiency of microwave and millimeter wave amplifiers and oscillators. Five major materials-related topics and technologies are covered in this article: diamond electromagnetic windows and electrode supports; electromagnetically lossy composite ceramics for control of instabilities; methods of cooling metal structures; pyrolytic graphite beam collectors and electron-gun modulation grids; and rare-earth permanent magnets for confining electron beams. For each topic, this article reviews the background physics. describes the importance of the technology to vacuum electronics, presents illustrative examples of how such technologies perform, and reviews current results from the literature     

折叠波导慢波结构太赫兹真空器件研究

简要介绍了利用折叠波导慢波结构的太赫兹真空辐射源的发展现状,重点对折叠波导慢波结构的特点进行了研究,并利用这种慢波结构开展了W、D波段行波管,W波段和650GHz返波振荡器,560GHz反馈振荡放大器的设计、计算和模拟优化,分别得到了较好的结果,并实际研制出W波段连续波行波管,输出功率达到8W。对太赫兹真空辐射源的部件技术、微细加工技术进行了研究和分析。     

Mode analysis of a dielectric-loaded Raman-type free-electron laser

The Raman-type free-electron laser consists of a relativistic electron beam contained in a dielectric-induced parallel plate waveguide and an array of permanent magnets for the wiggler. Under the influence of the periodic magnetostatic field, the coupling between the scattered electromagnetic wave of the TE mode (positive-energy wave) and the electron plasma wave of the TM mode (negative-energy wave) is investigated in detail. The following results are obtained. First, when a dielectric sheet is loaded on the waveguide, the maximum growth rate and the oscillation frequency can be greater than those for the vacuum Raman-type free-electron laser. Second, by choosing proper values for the relative permittivity of the dielectric sheet and the ratio of the beam guide, the beam energy can be greatly lowered without degrading the oscillation characteristics. Third, the growth rate decays exponentially with the oscillation frequency kept almost constant as the beam-dielectric gap increases     

Powering Implantable and Ingestible Electronics

Implantable and ingestible biomedical electronic devices can be useful tools for detecting physiological and pathophysiological signals, and providing treatments that cannot be done externally. However, one major challenge in the development of these devices is the limited lifetime of their power sources. The state-of-the-art of powering technologies for implantable and ingestible electronics is reviewed here. The structure and power requirements of implantable and ingestible biomedical electronics are described to guide the development of powering technologies. These powering technologies include novel batteries that can be used as both power sources and for energy storage, devices that can harvest energy from the human body, and devices that can receive and operate with energy transferred from exogenous sources. Furthermore, potential sources of mechanical, chemical, and electromagnetic energy present around common target locations of implantable and ingestible electronics are thoroughly analyzed; energy harvesting and transfer methods befitting each energy source are also discussed. Developing power sources that are safe, compact, and have high volumetric energy densities is essential for realizing long-term in-body biomedical electronics and for enabling a new era of personalized healthcare.