提高声光偏转器空间分辨率的方法研究

由声光偏转器件（AOD）和四像限探测器（QD）组成的闭环光束跟瞄系统与以往的快速反射镜（FSM）和四像限探测器组成的跟瞄系统相比，具有带宽高、功耗低、重量轻、体积小、重复性好和控制简单可靠等优点。然而，随着控制光束偏转的超声波频率变化的加快，单声光偏转器件（SAOD）的空间分辨点数会随之下降，影响光束控制的精度。提出了一种新型的快速、非机械、高精度光束偏转方法，采用二级声光偏转器件（DAOD）进行光束控制，与一级声光控制器相比具有更快的光束控制速度，更高的空间分辨点数和更宽的扫描范围，可以显著提高光束跟踪的速度和精度。同时还提出了一种求静态和动态分辨点数的方法，并与实验数据进行了比较、分析。     

双纵模激光拍频干涉仪的研究

介绍了一种可对大尺寸工件进行无导轨精密测量的系统。以有高稳定性和强抗干扰能力(室外可达10^-7)的双纵模热稳频He-Ne激光器为光源，其拍频约为790MHz，拍频波长约376μm；以节点为对准标志，最邻近节点到被测点的间距用组合于同一光路中的分系统激光干涉仪测量，分辨率为0．08μm。采用自适应滤波和小波运算大幅度地降低了光电信号噪声，并强化波形。测试表明，测量的不确定度优于30μm／10m，整个测量系统可在0～20m范围内工作。     

Linux操作系统实时性分析及改进策略

实时操作系统要求具有速度快和可预测性的特点,必须保证实时任务在要求的时间内完成。本文在分析Linux操作系统的中断方式和进程调度等影响实时性的因素后,对Linux的实时性策略进行改进,提出了双内核解决方案。     

One high- efficiency analysis method f or high- speed circuit networks containing dist ributed parameter elements

In the field of high-speed circuits , the analysis of mixed circuit networks containing both distributed parameter elements and lumped parameter elements becomes ever important . This paper presents a new method for analyzing mixed circuit networks. It adds transmission line end currents to the circuit variables of the classical modified nodal approach and can be applied directly to the mixed circuit networks. We also introduce a frequency- domain technique without requiring decoupling for multiconductor transmission lines. The two methods are combined together to efficiently analyze high-speed circuit networks containing uniform , nonuniform ,and frequency- dependent transmission lines. Numerical experiment is presented and the results are compared with that computed by PSPICE.     

Orthogonal Transforms in Bases of Slant Step Functions. I. Constructing Complete Sets of Orthogonal Slant Step Functions

The author introduces a new class of step functions and defines them in terms of the Rademacher functions. Two complete systems of orthogonal slant step functions are constructed and their characteristics are analyzed. The relationship between the basis functions of these systems and the system of the Walsh functions is established and their orthonormality is proved. It is shown that the proposed systems of slant step functions can be efficiently used to code video signal. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 118–132, May–June 2005.     

Artificial neural networks in their simplest forms for analysis and synthesis of RF/microwave planar transmission lines

In this work, the multiplayer perceptron (MLP) and radial basis function (RBF) neural networks in their simplest forms are employed in function approximation for highly nonlinear and complex analysis and synthesis of the most commonly used planar RF/microwave transmission lines, that is, microstrip lines, coupled microstrip lines, and basic and shielded coplanar‐waveguides. Since the analysis and synthesis processes for these systems have “one‐to‐one mapping” relations with each other, a forward model is defined for the analysis process for all these types of the planar transmission lines; on the other hand, a reverse model is also considered for the synthesis of the same lines. This reverse model is realized by swapping some of the inputs/outputs in the analysis model, and training the neural networks accordingly. Both MLP and RBF types of neural models are applied to the four widely used anisotropic and isotropic dielectric materials: PTFE/microstrip glass, RT/Duroid 6006, alumina and gallium arsenide. The results are shown to agree very well with the targets. A low‐pass filter with 30‐dB attenuation frequency at 3.5 GHz on an alumina substrate is designed by the use of a neural‐network synthesis and its resulting performance agrees well with the one using analytical formulas for the synthesis. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005.     

Design metal-dot based QCA circuits using SPICE model

This paper proposes a SPICE model development methodology for quantum-dot cellular automata (QCA) cells and presents a SPICE model for QCA cells. The model is validated by simulating the basic logic gates such as inverter and majority voter. The proposed model makes it possible to design and simulate QCA combinational circuits and hybrid circuits of QCA and other NANO devices using SPICE. In the second half part of the paper, SET and QCA co-design methodology is proposed and SET is used as a readout interface of the QCA cell array. The SET and QCA hybrid circuit is a promising nano-scale solution.     

Statistical Tensile Strength for High Strain Rate of Aramid and UHMWPE Fibers

Technora,madefromaramidfibersandsome whatsimilartothecommonlyknowKevlar,and Ultrahighlyorientedhighmolecularweightpolyeth ylene UHMWPEfibersarealloftenusedinflexible armourapplicationsandhencesubjectedtohighrates ofloading.Theutilizationoftheirreinforcedcom positesarmourincertainballisticapplicationsisin creasinglypreferredoverconventionalrigidmetalar moursystemsbecauseofitssuperiorstrength to weightratioandflexibility.Todate,thedesignand developmentofsuchfabricarmoursystemshave largelybeen…     

A Broadband Quadrature-Modulator in Standard 0.13 μm CMOS

A polyphase filtering topology is proposed which uses parallel switchable RC-networks for accurate broadband 90^∘ phasing. A 0.13μm CMOS prototype using the quadrature-generation network in a direct-conversion quadrature-modulator achieves a measured image-rejection ratio of −39 dBc or better in 0.6–2.5 GHz while consuming only 66 mW from a 2.2 V single supply. Esa Tiiliharjuwas born in Rovaniemi, Finland, in 1966. He received the M.Sc. degree in Information Technology in 1995, and the Lic.Tech degree in electrical engineering in 1998, both from Helsinki University of Technology, Finland. From 1996 to July 1997 he was employed as an assistant at Helsinki University of Technology. He has held a position as a research assistant since 1997, and he is currently working towards his Ph.D. degree in the Electronic Circuit Design Laboratory at Helsinki University of Technology. His research interests include the design of integrated low-power circuits for portable telecommunication applications. He has designed and measured several integrated circuits for this application area. He is the author or co-author of several internationally-refereed conference and journal publications on analog integrated circuits. Kari A.I. Halonenwas born in Helsinki, Finland, on May 23, 1958. He received the M.Sc. degree in electrical engineering from the Helsinki University of Technology (HUT) in 1982 and the Ph.D. degree in electrical engineering from the Katholieke Universiteit Leuven, Heverlee, Belgium, in 1987. From 1982 to 1984, he was with HUT as an Assistant and with the Technical Research Center of Finland as a Research Assistant. From 1984 to 1987, he was a Research Assistant with the E.S.A.T. Laboratory, Katholieke Universiteit Leuven, with a temporary grant from the Academy of Finland. Since 1988, he has been with the Electronic Circuit Design Laboratory, HUT, as a Senior Assistant from 1988 to 1990, and as the Director of the Integrated Circuit Design Unit of the Microelectronics Center from 1990 to 1993. He was on leave of absence during the academic year 1992–1993, acting as Research and Development Manager with Fincitec Inc., Finland. From 1993 to 1996, he was an Associate Professor, and since 1997, he has been a full Professor with the Faculty of Electrical Engineering and Telecommunications, HUT. He became the Head of Electronic Circuit Design Laboratory year 1998. He was the Technical Program Committee Chairman for the European Solid-State Circuits Conference in 2000. He is the author or coauthor of over 150 international and national conference and journal publications on analog integrated circuits, and holds several patents on analog integrated circuits. His research interests are in CMOS and BiCMOS analog integrated circuits, particularly for telecommunication applications. Dr. Halonen was an Associate Editor of the IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS–PART I: FUNDAMENTAL THEORY AND APPLICATIONS from 1997 to 1999. He has been a Guest Editor for the IEEE JOURNAL OF SOLID-STATE CIRCUITS. He received the BeatriceWinner Award from the IEEE International Solid-State Circuits Conference in 2002.[c-halonen.eps]