耦合腔慢波线互作用阻抗测试的研究

一 引言 耦合腔慢波线是由许多大功率行波管中的关键性部件,在科学技术突飞猛进的发展中,这此大功率微波器件始终显示着强大的生命力。对耦合腔慢波线的色散和互作用阻抗特性的研究和测量被广泛地作为研制这些大功率微波器件中的重要一环。 在J.slater谐振腔微扰理论〔1〕〔2〕〔3〕基础上发展起来了漫波线互作用阻抗测试法——微扰法。即在慢波线镜象对称     

双槽型耦合腔行波管非线性注波互作用计算方法

建立了双槽型耦合腔行波管三维频域非线性注波互作用模型,推导出参与注波互作用电磁场及粒子运动方程组。根据模型与方程组编写非线性互作用计算程序,模拟注波互作用过程,得到输出功率、增益等性能参数。计算结果与X波段双槽型耦合腔行波管实测数据比较,以验证计算方法的准确性,并对互作用过程中的非线性现象进行分析,希望能够辅助行波管的设计。     

利用MAFIA软件模拟耦合腔慢波结构的冷测特性

利用MAFIA软件对休斯结构的耦合腔慢波结构的色散特性和耦合阻抗进行了模拟,同实验数据相比,其计算精度是令人满意的,从而为耦合腔行波管的生产和研发提供了一个便捷而有力的工具.     

宽带行波管高频结构和互作用区的设计和实现

计算机辅助设计对行波管的设计非常重要。本文首先利用微波管模拟器套件（MTSS）软件的高频电路模拟器模块计算得到行波管慢波结构的色散、耦合阻抗、衰减常数高频参数,然后运用其注波互作用模拟器模块仿真得到行波管输出功率,最后将仿真结果与样管实测功率进行比较,从而验证了MTSS软件的可靠性。     

基于MAFIA软件的螺旋线慢波结构冷特性仿真

利用MAFIA软件所提供的准周期边界条件,对两种不同夹持结构的螺旋线行波管一个周期结构的色散和耦合阻抗特性进行了仿真,并与国内开发的螺旋线行波管计算软件包的计算结果进行了比较,为今后进一步优化螺旋线行波管的慢波结构打下基础.     

螺旋线慢波结构冷特性自动测量系统

介绍了一种用于螺旋线慢波结构模型色散特性和耦合阻抗的自动测量系统,它以非谐振微扰法为理论基础,硬件系统包括矢量网络分析仪、PC机、电移台、机械结构、光学监测装置等,并研制了专用的测量控制和数据处理软件。该系统实现了螺旋线慢波结构测量的自动化控制,人机界面友好,测量进程控制灵活,可以直接给出2～20 GHz频率范围内的色散特性和耦合阻抗的频响曲线。测量对象为行波管研制中所用螺旋线慢波结构的1∶1模型。     

微扰用介质薄片介电常数的精确测量

本文介绍作为平面结构慢波系统耦合阻抗测量用的介质薄片(云母片,陶瓷片等)介电常数ε_r的测量方法——谐振微扰法;并考虑到测试腔耦合元件电纳对测量结果的影响,提出了修正公式。在三厘米波段,对几种介质薄片进行了实际测量,并与传输线驻波比法进行了比较。这种测量方法还适用于各种半导体材料薄膜介电特性的测量。     

W波段带状注耦合腔慢波结构行波管的设计与冷测（英文）

对W波段三槽梯形线耦合腔慢波结构(包括大功率输入输出耦合器和射频窗)的加工和冷测进行了研究。此慢波结构由一个矩形波导耦合器馈电,该耦合器由放置在输入腔短边上的三阶阶梯变换矩形波导组成。首先,利用仿真方法研究了慢波结构的色散、互作用阻抗、传输特性和注-波互作用。结果表明,采用三槽梯形线耦合腔慢波结构的行波管能够在91～96 GHz的频率范围内提供大于1 000 W的饱和输出功率,并且在94 GHz频点,饱和输出功率最大,可以达到1 125 W。其次,采用高精度数控铣床加工出三槽梯形线慢波结构,并将其固定在非磁性不锈钢外壳中。文中给出了带有耦合器和射频窗的三槽梯形线慢波系统的测试结果,表明在90 GHz到100 GHz的频率范围内,S_(11)-10 dB。因此,三槽梯形线慢波结构在W波段大功率行波管方面具有应用前景。     

W波段带状注耦合腔慢波结构行波管的设计与冷测

对W波段三槽梯形线耦合腔慢波结构(包括大功率输入输出耦合器和射频窗)的加工和冷测进行了研究。此慢波结构由一个矩形波导耦合器馈电,该耦合器由放置在输入腔短边上的三阶阶梯变换矩形波导组成。首先,利用仿真方法研究了慢波结构的色散、互作用阻抗、传输特性和注-波互作用。结果表明,采用三槽梯形线耦合腔慢波结构的行波管能够在91~96 GHz的频率范围内提供大于1000 W的饱和输出功率,并且在94 GHz频点,饱和输出功率最大,可以达到1125 W。其次,采用高精度数控铣床加工出三槽梯形线慢波结构,并将其固定在非磁性不锈钢外壳中。文中给出了带有耦合器和射频窗的三槽梯形线慢波系统的测试结果,表明在90 GHz到100 GHz的频率范围内,S11<-10 dB。因此,三槽梯形线慢波结构在W波段大功率行波管方面具有应用前景。     

W波段阶梯型交错双栅慢波结构行波管的研究

为了提高传统交错双栅慢波结构行波管的性能,提出了一种阶梯型交错双栅慢波结构,并基于此新型慢波结构,提出了新型输入输出耦合结构.在此基础上,设计了一只工作在W波段的带状电子注阶梯型交错双栅慢波结构行波管.计算结果显示,阶梯型交错双栅慢波结构行波管的耦合阻抗更高,从而使行波管在更短的互作用电路长度里,实现更高的饱和增益和互作用效率.在90～100GHz频率范围内,阶梯型交错双栅慢波结构的耦合阻抗大于4Ω,高于传统交错双栅慢波结构;W波段带状电子注行波管高频结构的反射系数(S11)小于-15dB;并且行波管的饱和输入功率仅约为0.7W,可以实现最高输出功率约800W,相应的效率大于7.8%,增益大于30.6dB.     

波导本征值问题的有限元分析

本文简要讨论了波导本征值问题的有限元分析方法。给出了一个用有限元法求解波导本征值问题的标准程序。使用该程序可以获得一大类横截面周界由直线及圆弧围成的波导的各个本征值和本征函数。文中通过对十几种不同结构波导本征值问题的求解,证实了该程序的可靠性。     

程序设计基础课程教学模式研究与设计

程序设计基础课程是一门实践性很强的课程,其内容繁多,既有深度,又有广度,它的知识体系较难把握。针时初学者特点,通过对高校程序设计的教学现状进行调查,探讨了算法与语法规则在程序设计课程中的关系,采用“程序设计基础”课程的知识选取上采取“瘦身”措施,提出了采用程序设计语言语法子集进行教学的方案,通过试验,该方案能培养学生分析问题、解决问题的能力,更好地提高程序设计课程的教学效率。     

单片晶体滤波器的计算机辅助设计和分析

本文是在深入研究单片晶体滤波器理论和等效电路的基础上,首次利用单片晶体滤波器的综合设计与网络分析相结合的方法将过去人工设计和反复试验的过程全部在计算机中实现。在设计程序中,为了避免解超越方程给出了半经验公式,并对一些系数进行了修正。在分析程序中,采用了模块技术和级联矩阵方法。本程序是在PC机汉字操作系统下用BASICA编写的。最后给出了用本程序设计制作的几种单片晶体滤波器。     

Verification Simulation Acceleration Using Code-Perturbation

We propose a simulation approach that can take a large design and swiftly cover its valid code-level operating states. The approach perturbs the program-control flow during the simulation to dynamically exhaust all branching possibilities in a verification code/program. The heuristic uses the program branching information from preprocessing the test/verification code. Using the branching information the simulation allows automatic run-time forced branching to make possible a full coverage of the instruction space spanned by the verification code/program. The aim is (1) to improve the verification simulation speed and (2) to get higher coverage rate for large core-base designs such as microprocessors or digital-signal-processing (DSP) products. A case study of a 32-bit RISC processor, used in a network system, is conducted. The application code for the processor (MCP, Myrinet control program) is used as a verification program. Despite the deviation from the valid software-reachable state of the system due to forced branching, a significant number of hard-to-reach hardware states (that can be reached only through the right mix of codes, often the code segments of an application software) are covered. Using the MCP program over 30% additional coverage is achieved with the proposed approach over ordinary code-based simulation for a fixed verification time. Further, compared to the conventional simulation approach, the proposed heuristic takes about 43% less compute-cycles to achieve same state coverage level.     

Audio Program Level, the VU Meter, and the Peak-Program Meter

The accuracies of a VU meter and a peak-program (PPG) meter (EBU meter) for measuring program levels are examined by means of dual strip-chart recordings of various types of program material. It is shown that the VU-meter measurements are highly dependent on the program material, while the PPG meter does not suffer this shortcoming. The use of a PPG meter results in a program volume that is 4-5 dB greater than when using a VU meter. The stripchart recordings also show that the PPG meter makes for much easier "riding of level" than does the VU meter, thus operator fatigue is greatly reduced.     

Simulation of the urban radio propagation channel

A simulation program for the wide-band response of the urban multipath propagation channel has been developed. The program enables the generation of a sequence of "impulse responses" of the channel that would be observed by a moving vehicle communicating with a fixed station. The program incorporates empirical parameters covering four types of urban areas and three frequencies (in the 0.5-3- GHz range) and can be used in design of urban communication systems.     

Computer techniques for the frequency analysis of linear electrical networks

A detailed exposition is presented of a computer program for evaluating frequency response characteristics in arbitrary, linear, lumped, electrical networks. The program is based on Branin's "link-at-a-time" algorithm, which is adapted for frequency domain analysis and extended to networks containing nonreciprocal elements by exploiting the close relationship between Branin's work and the reinforcement technique of matrix inversion. The program is particularly effective for carrying out sensitivity studies which are often required in tolerance analyses, optimal network design techniques, and the development of network alignment procedures. The sensitivity capability of the program also forms the basis of a novel and effective method for computing group delay data from a nodal impedance matrix. Experimental and theoretical results are presented which demonstrate the superiority of the program to those based on more traditional techniques such as Gaussian elimination or Gauss-Jordan matrix inversion.     

Investigation of Program Saturation in Scaled Interpoly Dielectric Floating-Gate Memory Devices

This paper investigates the program saturation in aggressively scaled interpoly dielectric (IPD) floating-gate (FG) cells for nand application. To describe the program saturation in IPD stacks containing thick suboxides $(geq hbox{4} hbox{nm})$ , a simple model was developed, directly yielding the maximum reachable programmed threshold voltage level for a given FG cell geometry. The presented model agrees very well to program saturation measurements carried out on a 48 nm FG nand technology with an IPD composed of $hbox{SiO}_{2}$ and $ hbox{Al}_{2}hbox{O}_{3}$. By extending the considerations to an arbitrary IPD, this paper represents the first attempt to quantify the IPD current blocking ability required for future scaled FG memory cells.      

EEPROM耐久和数据保持试验方法标准分析

介绍了存储器分类,论述非易失性存储器编程机理以及编程/擦除耐久和数据保持试验方法,分析了MIL-STD-883B中的《耐久寿命试验》和JESD22-A117《电可擦除可编程只读存储器(EEPROM)编程/擦除耐久和数据保持应力试验》等试验方法标准.     

Red laser development program

EpiWorks Inc is conducting a red laser development program. Initially focused on developing longer wavelength red lasers, the program has recently moved towards 630nm. Products are expected to be production qualified throughout 2003.This is a short news story only. Visit www.three-fives.com for the latest advanced semiconductor industry news.