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Analysis of nonreciprocal mode-conversion properties of magnetooptic channel waveguides using the finite element method

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electronics AND COMMUNICATIONS IN JAPAN PART II-electronics 1996年第10期79卷 32-39页

作者： Zhuang, XP Koshiba, M Tsuji, Y Faculty of Engineering Hokkaido University Sapporo Japan 060 Graduated from the Department of Communication Engineering Guellin Electronic Institute China in 1986. She received her M.S. degree from Hokkaido University in 1991 and was admitted to the doctoral program. She has been engaged in research on the optimum design of magnetooptic waveguides for nonreciprocal optical devices. Graduated in 1971 from the Department of Electronic Engineering Hokkaido University where he received his M.S. degree in 1973 and his Dr. of Eng. degree in 1976. In 1976 he became a Lecturer in the Department of Electronic Engineering Kitami Institute of Technology where he was promoted to Associate Professor in 1977. In 1979 he became an Associate Professor at Hokkaido University where he was promoted to Professor in 1987. He has been engaged in research on optical and wave electronics. In 1987 he received a Best Paper Award. He is the author ofFundamentals of Finite Element Method of Optics and Waves(Morigkata Publ.)Optical Waveguide Analysis(Asakura Publ.)Optical Waveguide Analysis(McGraw-Hill Book Co.) andOptical Waveguide Theory by the Finite Element Method(KTK Scientific Publishing/Kulwer Academic Publishers). He is also co-author of one book and has written chapters in six other books. He is a member of the Institute of Television Engineers of Japan the Institute of Electrical Engineers of Japan the Japan Society for Simulation Technology the Japan Society for Computational Methods in Engineering and the Japan Society of Applied Magnetics and Mechanics. He is also an IEEE Senior Member. Graduated in 1991 from me Department of Electronic Engineering Hokkaido University where he received his M.S. degree in 1993. He is currently in the doctoral program. He has been engaged in research on quantum wave phenomena and computer-aided design of optical and quantum effect devices.

To evaluate nonreciprocal mode conversion characteristics in a magnetooptic channel waveguide, a finite element analysis based on the scalar wave approximation is formulated for the first time. A simple iterative calculation method is conceived for solution of the nonlinear eigenvalue equations finally obtained in which the two polarizations are coupled. Specifically, the maximum isolation ratio in the mode-conversion-type magnetooptic rib guide was evaluated and the validity of the method is confirmed by comparison with published experimental results.

关键词： nonreciprocal optical devices magnetooptic waveguide nonreciprocal mode conversion finite element method numerical analysis

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Scattering parameter estimation accuracy of Root-MUSIC algorithms in electromagnetic wave scattering measurements

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electronics AND COMMUNICATIONS IN JAPAN PART II-electronics 1996年第5期79卷 106-115页

作者： Yamada, H Yamamoto, K Yamaguchi, Y Sengoku, M Faculty of Engineering Niigata University Niigata Japan 950-21 Received his B.S. M.S. and Ph.D. degrees from Hokkaido University Sapporo Japan in 1988 1990 and 1993 respectively all in Electronic Engineering. Since 1993 he has been with Niigata University where he is currently a Lecturer. His current research involves superresolution techniques electromagnetic wave measurements and radar signal processings. Dr. Yamada is a member of the IEEE. Received his B.S. degree from Niigata University Niigata Japan in 1994 in Information Engineering. He is currently in the Master's program in Information Engineering. His current research involves superresolution technique and antenna measurements. Received his B.E. degree in Electronics Engineering from Niigata University in 1976 and his M.E. and Dr. of Eng. degrees from Tokyo Institute of Technology Tokyo Japan in 1978 and 1983 respectively. In 1978 he joined the Faculty of Engineering Niigata University where at present he is a Professor. From 1988 to 1989 he was a Research Associate at the University of Illinois at Chicago. His interests are in the field of propagation characteristics of electromagnetic wave in lossy medium radar polarimetry microwave remote sensing and imaging. Dr. Yamaguchi is a senior member of IEEE and a member of the Japan Society for Snow Engineering. Received his B.E. degree in Electrical Engineering from Niigata University Japan in 1967 and his M.E. and Ph.D. degrees from Hokkaido University in 1969 and 1972 respectively. In 1972 he joined the staff at Hokkaido University as a Research Associate. In 1978 he was an Associate Professor at Niigata University where he is presently a Professor. During 1986–1987 he was a Visiting Scholar at the University of California Berkeley and at the University of Illinois Chicago. His research interests include transmission of information network theory and graph theory. He is a recipient of the Best Paper Award of I.E.I.C.E. in 1992. Dr. Sengoku is a senior member of IEE

An application of the superresolution method for the analysis of the electromagnetic scattering data is expected to be effective for experimental verification of the geometrical optics approximation theory and the analysis of multiple paths. There exist many techniques for the superresolution method. It is desirable to select an appropriate technique based upon the characteristics of the individual algorithms. Among these techniques, the Root-MUSIC method has been proposed;this method enables treatment of the signal attenuating exponentially with respect to frequency. In the modified Root-MUSIC method, arbitrary frequency characteristics can be treated. This paper investigates the estimation accuracy of the scattering center and the attenuation coefficient when the Root-MUSIC method and the modified Root-MUSIC method are applied to the estimation of scattering. With the backscattering data of a conducting sphere, the estimation accuracy of the scattering parameters versus the signal-to-noise ratio (SNR) and the number of snapshots is investigated by computer simulation. As a result, it is found that the estimation accuracy of the modified Root-MUSIC method is much better than that of the conventional Root-MUSIC method in the case of a low SNR and a small number of snapshots. Experimental results are also reported.

关键词： super-resolution Root-MUSIC algorithm modified Root-MUSIC algorithm electromagnetic scattering scattering center creeping wave

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Performance of CDMA smart antenna systems

Performance of CDMA smart antenna systems

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Asilomar Conference on Signals, Systems & Computers

作者： M. Torlak Guanghan Xu Department of Electrical & Computer Engineering University of Texas Austin Austin TX USA Naval Research under Grant Joint Services Electronics Program Bell Technology Resources Inc. Motorola USA

Preliminary radio frequency (RF) field experiments were conducted to evaluate the performance of smart antenna systems for code-division multiple access (CDMA) systems. Besides conventional multipath fading problems, CDMA schemes are subject to near-far problems. The IS-95 CDMA system uses a 1/3 convolutional encoder and an interleaver to mitigate the fading problem and uses feedback power control schemes to equalize the powers of all the uplink co-channel signals. We evaluate the performance of the IS-95 standard implemented on a smart antenna system in a slow-fading environment. In particular, we evaluate the effects of imprecise power control, convolutional coding, and different beamforming techniques for a CDMA smart antenna system. Our results show that the smart antennas are not so sensitive to imperfect power control and that the optimal (Wiener) beamforming technique outperforms the simple beamforming approach. The most interesting result is that the effect of convolutional coding is not so significant for a smart antenna system than for an single antenna system. Based on our limited experimental results, we found that the 3 times bandwidth dedicated to the 1/3 convolutional encoding is better used to increase the spreading factor in a CDMA smart antenna system, leading to reduced cost and perhaps better performance.

关键词： Multiaccess communication Convolutional codes Convolution Power control Array signal processing Radio frequency Fading Feedback Bandwidth Encoding

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HIGH-VOLTAGE PULSE GENERATION IN NONLINEAR TRANSMISSION-LINE WITH CERAMIC CAPACITORS

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electrical engineering IN JAPAN 1995年第2期115卷 1-10页

作者： SUZUKI, H IBUKA, S MIYAZAWA, T ISHII, S Tokyo Institute of Technology Hiromitsu Suzuki received his B.S. dew in 1987 from the Department of Information Engineering Toyo University. He was an Assistant in the Department of Electrical and Electronic Engineering Tokyo Institute of Technology from 1990 to 1993. He is currently engaged in operation and management business of overall information equipment such as networks at the Information Center of Toyo University. Research areas include nonlinear physics artificial intelligence etc. He is a member of the Information Processing Society of Japan and Institute of Electronics Information and Communication Engineers. Takehim Miyazawa received his B.S. degree in 1993 from the Department of Electrical and Electronic Engineering Tokyo Institute of Technology where he is currently in the Master's program.

Usual axial cables and aerial lines are distributed constant linear transmission lines which can transmit a pulse without changing its initial shape. On the other hand, a nonlinear transmission line consisting of nonlinear capacitors can sharpen the front of a propagating pulse. In this study, a transmission line with commercially available ferroelectric BaTiO3 ceramic capacitors is constructed to obtain high-voltage pulses with short rise-time. Strong dependence of their capacitance on the applied voltage has been found. The rise-time of the input pulse with 300 V in amplitude was shortened from 60 ns after propagating through the line.

关键词： NONLINEAR TRANSMISSION LINE CERAMIC CAPACITOR NONLINEAR CAPACITANCE HIGH-VOLTAGE PULSE

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PARALLEL AND DISTRIBUTED TLM COMPUTATION WITH SIGNAL-PROCESSING FOR ELECTROMAGNETIC-FIELD MODELING

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INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS 1995年第3-4期8卷 169-185页

作者： SO, PPM ESWARAPPA, C HOEFER, WJR NSERC/MPR Teltech Research Chair in RF Engineering Department of Electrical and Computer Engineering University of Victoria Victoria British Columbia V8W 3P6 Canada Poman So received his B.Sc. degree in computer science and physics from the University of Toronto Toronto Onatario Canada in 1985. He obtained his B.A. Sc. and M.A.Sc. degrees in electrical engineering (summa cum laude) from the University of Ottawa Ottawa Ontario Canada in 1987 and 1989 respectively. Mr So was a research engineer in the University of Ottawa from January 1989 to October 1991 his research interests included CAD techniques of microwave circuits and numerical methods for electromagnetic wave modelling. He specialized in the development of electromagnetic engineering CAD software and successfully implemented a number of electromagnetic wave simulators based on the two-dimensional and three-dimensional transmission-line matrix methods. From August 1990 to February 1991 he accompanied Professor W. J. R. Hoefer to Rome Italy and Sophia Antiopolas France. During that time he implemented a parallel version of the 3D-TLM simulator for the CM-2 Connection Machine using C-Star and X Windows Library. He is a research engineer and a Ph.D. student at the University of Victoria Victoria British Columbia Canada. He ported the 2D- and 3D-TLM simulators to DECmpp 1200 massively parallel computer using MPL C and C++. He also combined OSA90/hope a commercially available microwave CAD program with a 2D-TLM simulation module for geometry optimization using the Datapipe technique of OSA90/hope. Recently he has developed a distributed client-server computing technique for the TLM method this technique could accelerate the TLM simulation by more than an order of magnitude. Channabasappa Eswarappa received the M.Tech. degree in electrical engineering from the Indian Institute of Technology Kanpur India in 1983 and Ph. D. degree from the University of Ottawa Canada in 1990. He worked as an Assistant Executive Engineer and later as

This paper describes the implementation of transmission-line matrix (TLM) method algorithms on a massively parallel computer (DECmpp 12000), the technique of distributed computing in the UNIX environment, and the combination of TLM analysis with Prony's method as well as with autoregressive moving average (ARMA) digital signal processing for electromagnetic field modelling. By combining these advanced computation techniques, typical electromagnetic field modelling of microwave structures by TLM analysis can be accelerated by a few orders of magnitude.

关键词： Mathematical models

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Raman Scattering and X-Ray Diffraction Studies of Gallium Nitride Films Grown on (100) Gallium Arsenide

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MRS Online Proceedings Library 1994年第1期339卷 503-508页

作者： S. W. Brown S. C. Rand C.-H. Hong D. Pavlidis University of Michigan Applied Physics Program Ann Arbor USA Department of Electrical Engineering and Computer Science University of Michigan Solid State Electronics Laboratory Ann Arbor USA

Raman spectroscopy and x-ray diffraction are used to characterize Gallium Nitride (GaN) films grown on (100) Gallium Arsenide (GaAs) substrates. Reflection X-ray diffraction data from (200) planes of GaAs and cubic GaN are presented. The linewidth of the cubic GaN diffraction peak is shown to be a strong function of the growth temperature. Raman spectra are presented for a series of samples grown at different temperatures. Raman scattering is characterized by strong peaks at 560 cm-1 and at 736 cm-1, corresponding to TO and LO phonon modes of cubic GaN, respectively. An additional, unexplained feature at 768 cm-1 is clearly observed in Raman spectra of c-GaN samples grown at lower temperatures. The polarization dependence of the intensity of the GaN LO phonon mode is presented and compared with the GaAs LO phonon mode to establish the relative orientation of the c-GaN epitaxy on GaAs.

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Angled-facet high-power diffraction-limited tapered semiconductor amplifier

Angled-facet high-power diffraction-limited tapered semicond...

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IEEE Photonics Conference (IPC)

作者： P.S. Yeh C.C. Lu S. Merritt P. Heim S.H. Cho C. Dauga S. Fox C.E.C. Wood M. Dagenais Department of Electrical Engineering and Joint Program for Advanced Electronics Materials University of Maryland College Park MD USA Laboratory of Physical Science MD USA

Summary form only given. Tapered semiconductor amplifiers have successfully demonstrated high-power diffraction-limited emission. So far, all these amplifiers had normal incidence facets coated with antireflection (AR) coating to prevent self-oscillation. In this work, an angled-facet high-power diffraction-limited tapered GaAs-AlGaAs QW semiconductor amplifier operating at 809-nm was realized. Due to the angled facet structure, any residual reflection from the facets is fed back at a small angle with the signal propagation direction.

关键词： Diffraction Semiconductor optical amplifiers High power amplifiers Pulse amplifiers Power amplifiers Optical amplifiers Power generation Educational institutions Coatings Optical propagation

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TECHNICAL ISSUES REGARDING SATELLITE PACKET-SWITCHING

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INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第3期12卷 257-267页

作者： IVANCIC, WD CHU, P SHYY, DJ National Aeronautics and Space Administration Lewis Research Center Cleveland Ohio 44135 USA. A design engineer in the Digital Technology Branch of the Space Electronics Division. He has extensive experience in satellite communications systems modulation and coding on-board switching and routeing and high speed digital design. Since joining NASA in 1982 Mr. Ivancic has been responsible for the development of a variety of matrix switch controllers ground terminal equipment numerous pieces of special test equipment a beacon controller for the SARSAT program (Search and Rescue Satellite) and a time-shared decoder for a processing satellite. In addition Mr. Ivancic has been technical contract monitor on a number of advanced communications technology contracts including the Advanced Modulation Technology Development a 5 GHz fibre-optic link and multi-programmable modem study. He was awarded the B.S.E.E. and M.S.E.E. degrees by Cleveland State University in 1982 and 1986 respectively. Cleveland State University Cleveland Ohio 44115 USA. Currently an assistant professor of Electrical Engineering Department at Cleveland State University. He obtained the M.S. and Ph.D. degrees from Iowa State University majoring in Electrical and Computer Engineering. His research interests include high-speed computer networks digital systems and neural networks applications. He is a member of Sigma Xi Phi Kappa Phi as well as the IEEE and ACM. ComSearch Reston Virginia 22091 USA. Received the B.S. degree in electrical engineering from National Chiao-Tung University Hsin-Chu Taiwan in 1983 and the M.S. and Ph.D. degrees in electrical engineering from Georgia Institute of Technology Atlanta GA in 1986 and 1990 respectively. From June 1987 to October 1987 he worked for the Department of Neurology Emory University Atlanta as a Programmer. From September 1989 to December 1989 he worked for the Advanced Development Laboratory. AMP Inc. Atlanta as a Test Engineer. From February 1990 to August 1993 he wor

Many concepts for advanced communication satellite networks have recently been proposed. Critical technical issues relating to satellite packet switching for meshed very small aperture terminal networks and broadband ... 详细信息

关键词： FAST PACKET SWITCH BISDN MESHED VSAT ON-BOARD PROCESSING

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THE CALLING(SM) NETWORK - A GLOBAL WIRELESS COMMUNICATION-SYSTEM

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INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第1期12卷 45-61页

作者： TUCK, EF PATTERSON, DP STUART, JR LAWRENCE, MH Calling Communications Corporation. 1900 West Garvey Ave South. Suite 200 West Covina CA 91790 USA. Chairman of Calling Communications Corporation. He is also the Managing Director of Kinship Venture Management Inc. the general partner of Kinship Partners 11 and a General Partner of Boundary the general partner of The Boundary Fund. As a venture capitalist he has founded or participated in founding several telecommunications companies including Calling Communications Corporation Magellan Systems Corporation manufactures of Global Positioning System receivers Applied Digital Access manufacturer of DS-3 test access and network performance monitoring equipment Endgate Technology Corporation specialists in satellite phased array antennas and Poynting Systems Corporation. now a division of Reliance Corporation manufacturers of fibre optic transport equipment. He was a founder of Kebby Microwave Corporation where he invented the first solid-state. frequency-modulated commercial microwave link system. The company was acquired by ITT Corporation where he rose to the position of V.P. and Technical Director of ITT North America Telecommunications Inc. Subsequently he was V.P. of Marketing and Engineering at American Telecommunications Inc. (ATC). He was founding Director of American Telecom Inc. a joint venture between ATC and Fujitsu and has served on more than 20 boards of directors including those of three public companies. He has authored articles on microwave engineering and telephone signalling and was a contributor to Reference Data For Radio Engineers. He is a graduate of the University of Missouri at Rolla where he was later awarded an honorary Professional degree and serves on its Academy of Electrical Engineering. Mr Tuck is a Senior Member of the IEEE a Fellow of the Institution of Engineers (Australia) a Professional Member of the AIAA and a registered professional engineer in three states. More than 25 years of experience in the telecommunications industry where he has been responsibl

There is a very large demand for basic telephone service in developing nations, and remote parts of industrialized nations, which cannot be met by conventional wireline and cellular systems. This is the world's largest unserved market. We describe a system which uses recent advances in active phased arrays, fast-packet switching technology, adaptive routeing, and light spacecraft technology, in part based on the work of the Jet Propulsion Laboratory and on recently-declassified work done on the Strategic Defense Initiative, to make it possible to address this market with a global telephone network based on a large low-Earth-orbit constellation of identical satellites. A telephone utility can use such a network to provide the same modern basic and enhanced telephone services offered by telephone utilities in the urban centres of fully-industrialized nations. Economies of scale permit capital and operating costs per subscriber low enough to provide a service to all subscribers, regardless of location, at prices comparable to the same services in urban areas of industrialized nations, while generating operating profits great enough to attract the capital needed for its construction. The bandwidth needed to support the capacity needed to gain these economies of scale requires that the system use K(alpha)-band frequencies. This choice of frequencies places unusual constraints on the network design, and in particular forces the use of a large number of satellites. Global demand for basic and enhanced telephone service is great enough to support at least three networks of the size described herein. The volume of advanced components, and services such as launch services, required to construct and replace these networks is sufficient to propel certain industries to market leadership positions in the early 21st Century.

关键词： LOW EARTH ORBIT SATELLITE COMMUNICATIONS FAST PACKET SWITCHING EARTH FIXED CELLS ADAPTIVE ROUTEING LIGHT SPACECRAFT K(A) BAND PHASED-ARRAY ANTENNAS

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EFFECT OF THE SPATIAL GAIN AND INTENSITY VARIATIONS ON A 2-SECTION FABRY-PEROT SEMICONDUCTOR-LASER - AN ANALYTICAL STUDY

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IEEE JOURNAL OF QUANTUM electronics 1993年第3期29卷 864-876页

作者： THEDREZ, BJ LEE, CH Joint Program of Advanced Electronics Materials Electrical Engineering Department University of Maryland College Park MD USA

An analytical static model for two-section Fabry-Perot semiconductor lasers is presented. The spatial dependence of both the field and the gain is fully taken into account. The cases of either a loss or a gain segment coupled to a main gain section are both considered. The bistable and linear behaviors above threshold are analytically described. Models with no spatial dependence are also discussed. The validity of the model extends to any homogeneously broadened laser.

关键词： Fabry-Perot Semiconductor lasers Equations Laser modes Pump lasers Laser noise Laser theory Analytical models Bandwidth Energy consumption

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