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

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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35-dB small-signal-gain high-power diffraction-limited tapered semiconductor amplifier

35-dB small-signal-gain high-power diffraction-limited taper...

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IEEE Photonics Conference (IPC)

作者： P.-H.S. Ych I-Fan Wu Shijun Jiang M. Dagenais Department of Electrical Engineering and Joint Program for Advanced Electronics Materials University of Maryland College Park MD USA

Summary form only given. GaAs-AlGaAs GRINSCH single quantum well tapered semiconductor optical amplifier characterisation and fabrication. We demonstrated 6 mW of coupled input power, and more than 4.5 W of pulsed out... 详细信息

关键词： Diffraction Semiconductor optical amplifiers High power amplifiers

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PERFORMANCE TESTING OF SHIPBOARD ELECTRONIC SYSTEMS

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NAVAL ENGINEERS JOURNAL 1993年第3期105卷 118-124页

作者： HARDER, G MARTIN, RA PE George Harder:is an electronics engineer for Naval Undersea Warfare Center Detachment Norfolk's Electromagnetic Engineering Branch located at the Norfolk Shipboard Electronic Systems Evaluation Facility (SESEF) site. He is responsible for fleet electromagnetic readiness (FEMR) inspections on board Navy ships and provides computer programming support to SESEF. Mr. Harder has a bachelor of science degree in electrical engineering from the University of Florida and has qualified for his professional engineering license in the state of Virginia. Robert A. Martin:is a supervisor electronics engineer employed by the Naval Undersea Warfare Center Detachment Norfolk. He functions as the branch head for the Electromagnetic Engineering Office which is responsible for the operation of the Norfolk Shipboard Electronic Systems Evaluation Facility (SESEF) and the Fleet Electromagnetic Readiness (FEMR) Program. Mr. Martin received a bachelor of science degree in electrical engineering from the University of Akron.

Performance evaluation of shipboard electronic systems entails debugging the systems in a laboratory environment, placing them in service and relving on svstem operators to provide feedback. General testing can be performed at selected sites by system designers, but each site where equipment is to be installed can offer unique problems. It is impossible to predict all the scenarios. Unique problems are more the rule than the exception when equipment is destined for Navy ships. Ship deployments make for difficult logistics when sending test teams to evaluate system failures. So, out of necessity, if newly installed equipment receives the proper inputs and generates the proper outputs, it is accepted and becomes the sailor's responsibilitv to maintain. In cases where documentation is ambiguous or incomplete, it is left to the sailor's ingenuity to continue testing and training on equipment. This is generallv obtained through computer simulations and back-to-back testing which can provide results for ideal conditions, but does not take the dynamics of interference into account. Remote site testing is the only way to get a true representation of equipment performance and training problems. Electronic system operators on board Navy vessels are fortunate, thev have help. There exists an organization available near major naval ports worldwide whose existence is to test electronic systems performance. The testing utilizes electronic systems as they would normally be configured for operations. This organization is the Shipboard Electronic Svstem Evaluation Facility (SESEF).

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VIRTUAL PROTOTYPING USING KNOWLEDGE - BASED MODELING AND SIMULATION TECHNIQUES

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NAVAL ENGINEERS JOURNAL 1993年第3期105卷 201-212页

作者： SHEA, JG The Author:holds bachelor and master of engineering degrees in mechanical engineering a M.Eng. in engineering management and is currently fulfilling requirements for the M.S. and Ph.D. degrees in computer science at the University of Louisville. He is employed as program manager Phalanx Advanced Engineering Development at the Naval Ordnance Station Crane Div. NavSurfWarCen Louisville Ky. During his tenure with Phalanx Mr. Shea has contributed to system reliability improvement system performance upgrading and the development of the Phalanx HOL (RISC) Computer. Mr. Shea is a member of ASNE the Institute of Electrical and Electronics Engineers American Institute of Aeronautics and Astronautics Society for Computer Simulation International Test & Evaluation Association and the Military Operations Research Society.

Knowledge-based modeling and simulation bridges the gap between ''conventional'' artificial intelligence implementations (such as expert systems) and more traditional computer-aided design techniques. We are currently developing software, whose primary function is to capture a user-input design specification and produce a ''virtual'' rapid prototvpe in the form of executable rule-based code. This code can then be exercised either as an interactive part of a hardware-in-the-loop testbed simulator or as a component of an object-oriented ''behavioral'' simulation environment. While the Phalanx Testbed is the immediate beneficiary of this work, the techniques described have a wide range of application in the modeling of conceptual design and performance characteristics. This paper describes the system architecture and software tools that we are applying to generate virtual rapid prototypes for use in the Phalanx Testbed. Particular attention is paid to defining the intelligent knowledge-capture mechanisms and model generation methodologies that we are using to translate design knowledge and performance requirements into rule-based simulations. The object-oriented programming approach to the merging of ''new'' data with previouslv-captured and stored data is discussed, and the issues of verifying and validating prototypes generated using such partiallv ''reengineered'' models are examined. An application currently in use as an investigative prototype for testbed development, a simple position controller servomechanism used to control the azimuth angle of a target-tracking sensor, is used to illustrate the process.

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Educational use of a microwave electromagnetic analysis of 3-D planar structures

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Computer Applications in engineering Education 1993年第3期1卷 243-243页

作者： Rautio, J.C. Sonnet Software Inc. Suite 203 135 Old Cove Road Liverpool NY 13090 Dr. James C. Rautio:founded Sonnet Software a developer of 3-D planar electromagnetic microwave software in 1983 with support from the David Sarnoff Research Center Hewlett Packard General Electric and Syracuse University. He has served as a visiting member of the faculty at Syracuse University and as an adjunct faculty member at Cornell University teaching microwave and computer courses as well as pursuing research in electromagnetics. Dr. Rautio previously worked in General Electric's Space Division and Electronics Laboratory. He designed microwave circuits including filters for a Landsat receiver and various GaAs microwave integrated circuits. He also developed microwave and millimeter wave automated measurement equipment and wrote a large microwave circuit analysis program. Dr. Rautio holds a BS in Electrical Engineering from Cornell University an MS in Systems Engineering from the University of Pennsylvania and a PhD in Electrical Engineering from Syracuse University

The use of an electromagnetic analysis of 3-D planar structures is described with respect to the educational requirements of students from the college freshman level through the graduate level. The analysis is intended primarily for microwave use; however, there is also significant potential interest from the student of high speed digital design. The analysis is used for passive planar circuits with any number of layers. The third dimension is represented by vias. A mature graphical user interface is provided allowing rapid capture of structure geometry, color visualization, and animation of the resulting current distributions. The software is also explicitly designed to work in conjunction with popular circuit theory based microwave software and with SPICE.

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CIRCULAR OVERMODED WAVE-GUIDE FOR SHIPBOARD USE

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NAVAL ENGINEERS JOURNAL 1993年第2期105卷 39-52页

作者： HUTING, WA WARREN, JW GARNER, PN KRILL, JA William A. Huting:received the B.S.E. degree in electrical engineering from Duke University in 1981 the M.S.E.E. degree from the Georgia Institute of Technology in 1982 and the Ph.D. degree in electrical engineering (electrophysics) from the University of Maryland in 1989. From September 1981 to December 1983 he was a graduate teaching assistant with Georgia Tech. Since January 1984 he has been with The Johns Hopkins University Applied Physics Laboratory where he has principally been involved with the development of circular overmoded waveguides and tapered waveguide transitions for use in naval radar systems. Dr. Huting is a member of the Institute of Electrical and Electronics Engineers. Jeffery W. Warren:received a B.S. degree in 1982 and an M.S. degree in 1984 both in electrical engineering from the University of South Carolina. His thesis research evaluated electro-optical measurements of surface charging of insulators in low-frequency fields. He joined The Johns Hopkins University Applied Physics Laboratory in 1984. Mr. Warren's activities include development and testing of electro-optical systems and the development of high-power low-loss overmoded waveguides. Mr. Warren is a member of the Institute of Electrical and Electronics Engineers. Paul N. Garner: Jr. received the B.S. degree in mathematics and the B.S. degree in mechanical engineering from the University of Maryland in 1973 and 1980 respectively and the M.B.A. degree from the Florida Institute of Technology in 1984. Since 1987 he has been involved with the Cooperative Engagement Capability Program as the lead mechanical engineer and since 1990 he has been with The Johns Hopkins University Applied Physics Laboratory where he is now a member of the Senior Professional Staff. Jerry A. Krill:received the B.S.E.E. and M.S.E.E. degrees from Michigan State University in 1973 and 1974 respectively and a Ph.D. in electrical engineering (electrophysics) from the University of Maryland in 1978. From 1973 to the present he has been with The Johns

Several future Navy combat systems under development require efficient delivery of high power microwave energy from remote transmitters to array antennas. To achieve this requirement, a family of microwave components has been developed and tested. Progress is described in the design and testing of an overmoded circular TE01 mode waveguide applicable to special shipboard needs. Because such a waveguide had originally been developed for low power millimeter band trunkline communications between cities, new theoretical, design, and fabrication techniques had to be developed to meet our specific performance requirements. Moreover, in order to fulfill the combat system requirements, the waveguide would have to withstand harsh military requirements. Over several years the obstacles to the application of overmoded technology to Navy combat systems have been systematically eliminated. The effort has resulted in the invention of several new components, the development and validation of a new computer aided design package, and the implementation of new microwave measurement techniques. The first application of an overmoded waveguide to a combat system element was recently achieved in the successful demonstration of the prototype Cooperative Engagement Capability, and steps toward a production military version of the waveguide have been initiated.

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Influence of the pulse‐width modulation control method on the performance of frequency inverter induction motor drives

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European Transactions on electrical Power 1993年第2期3卷 151-161页

作者： Ch. Andresen, E. Haun, A. Prof. Dr.-Ing. Egon Ch. Andresen (1928) VDE received the Dipl.-Ing. degree in electrical engineering from the Technische Hochschule (University) Darmstadt/Germany in 1954 and the Dr.-Ing. degree in 1959. He joined AEG-Telefunken in Berin/Germany and worked as a Development Engineer in the field of large electrical machines. He served as a Consulting Engineer for electrical drives in Dusseldorf/Germany. Since 1961 he has been responsible for the calculation and design of the AC machine program and in 1965 he became Chief Engineer of the large machine factory of AEG-Telefunken. Berlin. He is currently Professor and head of the “Institut fiir Elektrische Energiewandlung” of the Technische Hochschule Darmstadt. His main research interests are in the field of drive systems advanced motors and power electronics. (Technische Hochschule Darmstadt Institut für Elektrische Energiewandlung Landgraf-Georg-Str. 4 W-6 100 Dnrmstadt. T +496151/162167 Fax 496151/ 165489) Dr.-Ing. Andreas Haun (1960) received his Dipl.-Ing degree in 1986 from the Technische Hochschule (University) Darmstadt/Germany and his Dr.-Ing. degree in 1991 from the same University. From 1986 to 1991 he was working as scientific assistant with the “Institut für Elektrische Energiewandlung” of the Technische Hochschule Darmstadt. He is now with engineering works Goebel Darmstadt. (Maschinenfabrik Goebel Goebelstr. 21 W-6100 Darmstadt T + 496151/88 8401 Fax + 496151/ 8885 20)

The methods of sinusoidal PWM voltage control, current hysteresis control, predictive current control and direct stator flux and torque control are briefly presented. The different operation principles are explained by block and structure diagrams. Their staiorflux and stator current trajectories are compared. The effect on the characteristic operational performance of induction squirrel cage motors is investigated. The harmonic losses of the stator and rotor winding and the torque oscillations are compared while considering the skin effect of the windings. Finally the torque response times are presented. The results are achieved by digital simulation and proved on a test stand with 22 kW induction motor and 30 kVA GTO frequency inverter. Copyright © 1993 John Wiley & Sons, Ltd.

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On-wafer phase locking of a microwave oscillator for high-speed optical waveform sampling 16

On-wafer phase locking of a microwave oscillator for high-sp...

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16th International Conference on Infrared and Millimeter Waves 1991

作者： Chauchard, Eve A. Li, Ming G. Lee, Chi H. Hung, Hing-Loi A. Joint Program for Advanced Electronics Materials Electrical Engineering Dept. University of Maryland College ParkMD20742 United States COMSAT Laboratories ClarksburgMD20871 United States

Optical techniques such as electro-optic sampling and photoconductive sampling are currently used to characterize microwave and millimeterwave devices. These techniques are extremely important to the microwave scientific community because they offer several advantages over conventional network analyzer measurements. Namely, they have broader band capability (over 100 GHz) and permit on-wafer, non-invasive measurements. Jitter-free time synchronization between the microwave signal and the laser pulse train is essential to these sampling techniques. Several approaches to realize synchronization have been reported. We developed one possible approach whereby a narrow electrical pulse (with broadband content) is generated on-wafer, using a fast photoconductive switch [1]. Measurements performed in the time domain are then converted to S-parameter measurements by Fourier transformation.

关键词： Microwave radiation Mode locking Oscillators Electro optics Pulsed laser operation Semiconducting wafers Wafer-level optics electrical engineering electronics Lithium

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Effects of aging on polyimide: a model for dielectric behavior (of relative humidity sensors)

Effects of aging on polyimide: a model for dielectric behavi...

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International Conference on Solid State Sensors and Actuators (TRANSDUCERS)

作者： A.R.K. Ralston M.C. Buncick D.D. Denton T.E. Boltshauser J.M. Funk H.P. Baltes Department of Electrical and Computer Engineering and Materials Science Program University of Wisconsin Madison Madison WI USA Physical Electronics Laboratory Swiss Federal Institute of Technology Zurich Switzerland

Quantifying the effect of moisture on the electrical properties of thin dielectric films requires the use of a model that takes into account the geometry of the test structure and the dielectric properties of the air layer above the device. Using this approach, it was found that the electrical properties of dry PI (polyimide) do not change substantially after six weeks of aging at 85 degrees C/85% RH (relative humidity). The dielectric permittivity of PI as a function of %RH increased with aging for excitation frequencies between 12 Hz and 100 kHz. This increase is correlated with observed changes in the surface chemistry of the aged PI film. Shifts in ESCA peak intensities indicate oxidation of the PI surface and deimidization with aging. Possible mechanisms for the observed changes in dielectric properties with aging include a change in the morphology of the bulk PI, resulting in a decreased surface to volume ratio, increased water absorption, a change in the interaction of absorbed water with the PI matrix, and dielectric interfacial effects.< >

关键词： Aging Polyimides Surface morphology Water Moisture Dielectric films Solid modeling Geometry Testing Dielectric devices

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