Electrical dictornary


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Electrical dictornary

  1. 1. Product Manager: Karen FeinsteinProject Editor: Ibrey WoodallPackaging design: Jonathan Pennell These files shall remain the sole and exclusive property of CRC Press LLC, 2000 Corporate Blvd., N.W., Boca Raton, FL 33431.The contents are protected by copyright law and international treaty. No part of the Electrical Engineering Dictionary CRCnetBASECD-ROM product may be duplicated in hard copy or machine-readable form without prior written authorization from CRC PressLLC, except that the licensee is granted a limited, non-exclusive license to reproduce limited portions of the context for the licensee’sinternal use provided that a suitable notice of copyright is included on all copies. This CD-ROM incorporates materials from othersources reproduced with the kind permission of the copyright holder. Credit to the original sources and copyright notices are givenwith the figure or table. No materials in this CD-ROM credited to these copyright holders may be reproduced without their writtenpermission.WARRANTY The information in this product was obtained from authentic and highly regarded sources. Every reasonable effort has beenmade to give reliable data and information, but the publisher cannot assume responsibility for the validity of all materials or theconsequences of their uses.© 2000 by CRC Press LLCNo claim to original U.S. Government worksInternational Standard Book Number 0-8493-2170-0International Standard Series Number 1097-9568© 2000 by CRC Press LLC
  2. 2. Preface One can only appreciate the magnitude of effort required to develop a dictionary by actually experiencing it. Although I had written nine other books, I certainly did not know what I was getting into when in January of 1996 I agreed to serve as Editor-in- Chief for this project. Now, after 2 1/2 years I understand. Unlike other books that I have written, creating this dictionary was more a test of will and stamina and an exercise in project management than mere writing. And although I have managed organizations of up to 80 academics, nothing is more like “herding cats” than motivating an international collection of almost 200 distinguished engineers, scientists, and educators scattered around the globe almost entirely via email. Yet, I think there is no other way to undertake a project like this. I still marvel at how Noah Webster must have managed to construct his English Dictionary without the benefits of modern communication. But this project, as much as it is a monument to individual will, is really the collaborative work of many brilliant and dedicated men and women. This is their dictionary and your dictionary. Phillip A. Laplante, PE, Ph.D. Editor-in-Chief President Pennsylvania Institute of Technology Media, Pennsylvania© 2000 CRC Press LLC
  3. 3. Editorial Board E.R. Davies Andrew Kahng University of London University of California at Berkeley Associate Editor: Signal and Co-Editor: Digital electronics, VLSI, Image Processing hardware description language Mike Fiddy Mark Kinsler University of Massachusetts, Lowell Editor: Power systems Editor: Electro-optical and lightwave systems Mike Golio Lauren Laplante Rockwell Collins Public Service Electric and Gas Editor: Microwave systems Editor: Properties of materials Marco Gori Sudhakar Muddu University of Florence Silicon Graphics Associate Editor: Information Processing Co-Editor: Digital electronics, VLSI, hardware description language Ling Guan Meredith Nole University of Sydney American Efficient Lighting Editor: Communications and information Editor: Illumination processing Bob Herrick Amos Omondi Purdue University Flinders University Editor: RF, radio and television Editor: Computer engineering (I/O and storage) Jeff Honchell Ian Oppermann Purdue University University of Sydney Associate Editor: RF, radio and television Associate Editor: Communication Jin Jiang John Prince University of Western Ontario University of Arizona Editor: Circuits and systems Editor: Packaging Tadeusz Kaczorek Mark Reed Warsaw University of Technology Yale University Editor: Control systems Editor: Microelectronics and solid state devices© 2000 CRC Press LLC
  4. 4. David Shively Eugene Veklerov Shively Engineering Lawrence Berkeley Labs Editor: Electromagnetics Editor: Signal and image processing Tim Skvarenina Janusz Zalewski Purdue University University of Central Florida Editor: Electric machines and power electronics Editor: Computer engineering (processors)© 2000 CRC Press LLC
  5. 5. Foreword How was the dictionary constructed? As I knew this project would require a divide-and-conquer approach with fault- tolerance, I sought to partition the dictionary by defining areas that covered all aspects of Electrical Engineering. I then matched these up to IEEE defined interest areas to ensure that complete coverage was provided. This created a great deal of overlap, which was intentional. I knew that terms needed to be defined several different ways, depending on usage and I needed to ensure that every term would be defined at least once. The mapping of the Dictionary’s areas to the IEEE interest areas are as follows: Power systems Circuits and systems • Power Engineering • Circuits and Systems • Power Electronics • Instruments and Measurements Electric motors and machines Control systems • Power Engineering • Control Systems • Power Electronics • Robotics and Automation Digital electronics, VLSI, hardware Electromagnetics description language • Electromagnetic Compatibility •Consumer Electronics • Magnetics •Electronic Devices •Industrial Electronics •Instruments and Measurements Computer engineering (processors) • Computer Microelectronics and solid state devices • Industrial Electronics Computer engineering (I/O and storage) • Instruments and Measurements • Computer RF, radio, and television Microwave systems • Broadcast Technology • Antennas and Propagation • Microwave Theory and Techniques Communications and information processing • Communications Electro-optical and lightwave systems • Information Theory • Lasers and Electro-Optics • Systems, Man, and Cybernetics • Reliability Illumination Signal and image processing Properties of materials • Signal Processing • Dielectrics and Electrical Insulation • Systems, Man, and Cybernetics Packaging • Components, Packaging, and • Manufacturing Technology Note that Software Engineering was not included as an area, and most software terms have been omitted. Those that were included were done so because they relate to some aspect of assembly language programming or low-level control, or artificial intelligence and robotics. For those interested in software engineering terms, CRC’s© 2000 CRC Press LLC
  6. 6. forthcoming Comprehensive Dictionary of Computer Science, Engineering and Tech- nology will include those terms. Several other IEEE interest areas were not explicitly assigned to area editors. How- ever, after discussing this fact with the Editorial Board, it was decided that relevant terms of a general nature would be picked up and terms that were not tagged for the dictionary from these areas were probably too esoteric to be included. These interest areas encompass: Aerospace and Electronic Systems Geosience and Remote Sensing Education Industry Applications Engineering in Medicine and Biology Nuclear and Plasma Science Engineering Management Oceanic Engineering Professional Communications Ultrasonic, Ferroelectrics, and Frequency Control Social Implications of Technology Vehicular Technology Given the Area Editor structure, constructing the dictionary then consisted of the following steps: 1. Creating a terms list for each area 2. Defining terms 3. Cross-checking terms within areas 4. Cross-checking terms across areas 5. Compiling and proofing the terms and definitions 6. Reviewing compiled dictionary 7. Final proofreading The first and most important task undertaken by the area editors was to develop a list of terms to be defined. A terms list is a list of terms (without definitions), proper names (such as important historical figures or companies), or acronyms relating to Electrical Engineering. What went into each terms list was left to the discretion of the area editor based on the recommendations of the contributing authors. However, lists were to include all technical terms that relate to the area (and subareas). Technical terms of a historical nature were only included if it was noted in the definition that the term is “not used” in modern engineering or that the term is “historical” only. Although the number of terms in each list varied somewhat, each area’s terms list consisted of approximately 700 items. Once the terms lists were created, they were merged and scrutinized for any obvious omissions. These missing terms were then assigned to the appropriate area editor. At this point the area editors and their contributing authors (there were 5 to 20 contributing authors per area) began the painstaking task of term definition. This process took many months. Once all of the terms and their definitions were collected, the process of converting, merging, and editing began. The dictionary included contributions from almost 200 contributors from 17 coun- tries. Although authors were provided with a set of guidelines to write terms def- initions, they were free to exercise their own judgment and to use their own style.© 2000 CRC Press LLC
  7. 7. As a result, the entries vary widely in content from short, one-sentence definitions to rather long dissertations. While I tried to provide some homogeneity in the process of editing, I neither wanted to tread on the feet of the experts and possibly corrupt the meaning of the definitions (after all, I am not an expert in any of the representative areas of the dictionary) nor did I want to interfere with the individual styles of the authors. As a result, I think the dictionary contains a diverse and rich exposition that collectively provides good insights into the areas intended to be covered by the dictionary. Moreover, I was pleased to find the resultant collection much more lively, personal, and user-friendly than typical dictionaries. Finally, we took advantage of the rich CRC library of handbooks, including The Control Handbook, Electronics Handbook, Image Processing Handbook, Circuits and Filters Handbook, and The Electrical Engineering Handbook, to pick up any defini- tions that were missing or incomplete. About 1000 terms were take from the CRC handbooks. We also borrowed, with permission from IEEE, about 40 definitions that could not be found elsewhere or could not be improved upon. Despite the incredible support from my area editors, individual contributors, and staff at CRC Press, the final task of arbitrating conflicting definitions, rewording those that did not seem descriptive enough, and identifying missing ones was left to me. I hope that I have not failed you terribly in my task. How to use the dictionary The dictionary is organized like a standard language dictionary except that not ev- ery word used in the dictionary is defined there (this would necessitate a complete embedding of an English dictionary). However, we tried to define most non-obvious technical terms used in the definition of another term. In some cases more than one definition is given for a term. These are denoted (1), (2), (3), . . ., etc. Multiple definitions were given in cases where the term has multiple distinct meanings in differing fields, or when more than one equivalent but uniquely descriptive definition was available to help increase understanding. In a few cases, I just couldn’t decide between two definitions. Pick the definition that seems to fit your situation most closely. The notation 1., 2., etc. is used to itemize certain elements of a definition and are not to be confused with multiple definitions. Acronym terms are listed by their expanded name. Under the acronym the reader is referred to that term. For example, if you look up “RISC” you will find “See reduced instruction set computer,” where the definition can be found. The only exceptions are in the cases where the expanded acronym might not make sense, or where the acronym itself has become a word (such as “laser” or “sonar”). While I chose to include some commonly used symbols (largely upon the recom- mendations of the contributors and area editors), this was not a principle focus of the dictionary and I am sure that many have been omitted.© 2000 CRC Press LLC
  8. 8. Finally, we tried to avoid proprietary names and tradenames where possible. Some have crept in because of their importance, however. Acknowledgments A project of this scope literally requires hundreds of participants. I would like to take this moment to thank these participants both collectively and individually. I thank, in no particular order: • The editorial board members and contributors. Although not all partici- pated at an equal level, all contributed in some way to the production of this work. • Ron Powers, CRC President of Book Publishing, for conceiving this dictio- nary, believing in me, and providing incredible support and encouragement. • Frank MacCrory, Norma Trueblood, Nora Konopka, Carole Sweatman, and my wife Nancy for converting, typing, and/or entering many of the terms. • Jill Welch, Nora Konopka, Ron Powers, Susan Fox, Karen Feinstein, Joe Ganzi, Gerry Axelrod, and others from CRC for editorial support. • CRC Comprehensive Dictionary of Mathematics and CRC Comprehensive Dictionary of Physics editor Stan Gibilisco for sharing many ideas with me. • My friend Peter Gordon for many of the biographical entries. • Lisa Levine for providing excellent copy editing of the final manuscript. Finally to my wife Nancy and children Christopher and Charlotte for their incredible patience and endurance while I literally spent hundreds of hours to enable the birth of this dictionary. This achievement is as much theirs as it is mine. Please accept my apologies if anyone was left out — this was not intentional and will be remedied in future printings of this dictionary. How to Report Errors/Omissions Because of the magnitude of this undertaking and because we attempted to develop new definitions completely from scratch, we have surely omitted (though not deliber- ately) many terms. In addition, some definitions are possibly incomplete, weak, or even incorrect. But we wish to evolve and improve this dictionary in subsequent printings and editions. You are encouraged to participate in this collaborative, global process. Please send any suggested corrections, improvements, or new terms to be added (along with suggested definitions) to me at p.laplante@ieee.org or plaplante@pit.edu. If your submission is incorporated, you will be recognized as a contributor in future editions of the dictionary.© 2000 CRC Press LLC
  9. 9. Editor-in-Chief Phil Laplante is the President of Pennsylvania Institute of Technology, a two-year, private, college that focuses on technology training and re-training. Prior to this, he was the founding dean of the BCC/NJIT Technology and Engineering Center in Southern New Jersey. He was also Associate Professor of Computer Science and Chair of the Mathematics, Computer Science and Physics Department at Fairleigh Dickinson University, New Jersey. In addition to his academic career, Dr. Laplante spent almost eight years as a software engineer designing avionics systems, a microwave CAD engineer, a software systems test engineer, and a consultant. He has written dozens of articles for journals, newsletters, magazines, and confer- ences, mostly on real-time computing and image processing. He has authored 10 other technical books and edits the journal, Real-Time Imaging, as well as two book series including the CRC Press series on Image Processing. Dr. Laplante received his B.S., M.Eng., and Ph.D. in Computer Science, Electrical Engineering, and Computer Science, respectively, from Stevens Institute of Technology and an M.B.A. from the University of Colorado at Colorado Springs. He is a senior member of IEEE and a member of ACM and numerous other pro- fessional societies, program committees, and advisory boards. He is a licensed profes- sional engineer in New Jersey and Pennsylvania. Dr. Laplante is married with two children and resides in Pennsylvania.© 2000 CRC Press LLC
  10. 10. References [1] Attasi, Systemes lineaires homgenes a deux indices, IRIA Rapprot Laboria, No. 31, Sept. 1973. [2] Baxter, K., Capacitive Sensors, IEEE Press, 1997. [3] Biey and Premoli, A., Cauer and MCPER Functions for Low-Q Filter Design, St. Saphorin: Georgi, 1980. [4] Blostein, L., Some bounds on the sensitivity in RLC networks, Proceedings of the 1st Allerton Conference on Circuits and Systems Theory, 1963, pp. 488–501. [5] Boutin, A.C., The misunderstood twin-T oscillator, IEEE Circuits and Systems Magazine, Dec. 1980, pp. 8–13. [6] Chen, W.-K., Ed., The Circuits and Filters Handbook, Boca Raton, FL: CRC Press, 1995. [7] Clarke and Hess, D.T., Communication Circuits: Analysis and Design, Addison- Wesley, 1971. [8] Coultes, E. and Watson, W., Synchronous machine models by standstill frequency re- sponse tests, IEEE Transactions on Power Apparatus and Systems, PAS 100(4), 1480–1489, 1981. [9] Dorf, R.C., Ed., The Electrical Engineering Handbook, 2nd ed., Boca Raton, FL: CRC Press, 1997. [10] Enslow, H., Multiprocessor organization, Computing Surveys, 9(1), 103–129, 1977. [11] Filanovsky, M., Piskarev, V.A., and Stromsmoe, K.A., Nonsymmetric multivibrators with an auxiliary RC-circuit, Proc. IEEE, 131, 141–146, 1984. [12] Filanovsky, M. and Piskarev, V.A., Sensing and measurement of dc current using a trans- former and RL-multivibrator, IEEE Trans. Circ. Syst., 38, 1366–1370, 1991. [13] Filanovsky, M., Qiu, S.-S., and Kothapalli, G., Sinusoidal oscillator with voltage con- trolled frequency and amplitude, Intl. J. Electron., 68, 95–112, 1990. [14] Frerking, C., Oscillator Design and Temperature Compensation, Van Nostrand Reinhold, 1978. [15] Fornasini and Marchesini, G., Double-indexed dynamical systems, Mathematical Sys- tems Theory, 1978, pp. 59–72. [16] Franco, Design with Operational Amplifiers and Analog Integrated Circuits, McGraw-Hill, 1988. [17] Held, N. and Kerr, A.R., Conversion loss and noise of microwave and millimeter-wave mixers: Part 1, Theory and Part 2, Experiment, IEEE Transactions on Microwave Theory and Techniques, MTT-26, 49, 1978. [18] Hennessy, L. and Patterson, D.A., Computer Architecture: A Quantitative Ap- proach, 2nd ed., Kaufmann, 1996. [19] Huelsman, P. and Allen, P.E., Introduction to the Theory and Design of Active Filters, McGraw-Hill, 1980.© 2000 CRC Press LLC
  11. 11. [20] Gibson, Jerry D., Ed., The Mobile Communications Handbook, Boca Raton, FL: CRC Press, 1996. [21] Huising, H., Van Rossum, G.A., and Van der Lee, M., Two-wire bridge-to-frequency converter, IEEE J. Solid-State Circuits, SC-22, 343–349, 1987. [22] IEEE Committee Report, Proposed excitation system definitons for synchronous ma- chines, IEEE Transactions on Power Apparatus and Systems, PAS-88(8), Au- gust 1969. [23] IEEE Standard Dictionary of Electrical Engineering, 6th ed., 1996. [24] Jouppi, N.P., The nonuniform distribution of instruction-level and machine prallelism and its effect on performance, IEEE Transactions on Computers, 38(12), 1645– 1658, Dec. 1989. [25] Kaczorek, Linear Control Systems, Vol. 2, New York: John Wiley & Sons, 1993. [26] Kaczorek, The singular general model of 2-D systems and its solution, IEEE Transac- tions on Automatic Control, AC-33(11), 1060–1061, 1988. [27] Kaczorek, Two-Dimensional Linear Systems, Springer-Verlag, 1985. [28] Kaplan, -Z., Saaroni, R., and Zuckert, B., Analytical and experimental approaches for the design of low-distortion Wien bridge oscillators, IEEE Transactions on Instru- mentation and Measurement, IM-30, 147–151, 1981. [29] Katevenis, G.H., Reduced Instruction Set Computer Architectures for VLSI, MIT Press, 1985. [30] Kurek, The general state-space model for a two-dimensional linear digital system, IEEE Transactions on Automatic Control, AC-30(6), 600–601, 1985. [31] Krause, C., Wasynczuk, O., and Sudhoff, S.D., Analysis of Electric Machinery, IEEE Press, 1995. [32] Levine, W.S., Ed., The Control Handbook, Boca Raton, FL: CRC Press, 1995. [33] Morf, Levy, B.C., and Kung, S.Y., New results in 2-D systems theory, Proc. IEEE, 65(6), 861–872, 1977. [34] Myers, J., Advances in Computer Architecture, 2nd ed., New York: John Wiley & Sons, 1982. [35] Neubert, K.P., Instrument Transducers, Clarendon Press, 1975. [36] Qiu, S.-S. and Filanovsky, I.M., Periodic solutions of the Van der Pol equation with mod- erate values of damping coefficient, IEEE Transactions on Circuits and Systems, CAS-34, 913–918, 1987. [37] Orchard, J., Loss sensitivities in singly and doubly terminated filters, IEEE Transac- tions on Circuits and Systems, CAS-26, 293–297, 1979. [38] Pallas-Ar´ ny and Webster, J.G., Sensor and Signal Conditioning, New York: John a Wiley & Sons, 1991. [39] Patterson, A. and Ditzel, D.R., The case for the RISC, Computer Architecture News, 8(6), 25–33, 1980. [40] Patterson, A. and Sequin, C.H., A VLSI RISC, IEEE Computer, 15(9), 8–21, 1982. [41] Pederson, O. and Mayaram, K., Analog Integrated Circuits for Communication, Kluwer, 1991.© 2000 CRC Press LLC
  12. 12. [42] Radin, The 801 Minicomputer, IBM J. Res. Devel., 21(3), 237–246, 1983. [43] Ramamurthi and Gersho, A., IEEE Transactions on Communications, 34(1), 1105–1115, 1986. [44] Roesser, P., A discrete state-space model for linear image processing, IEEE Transac- tions on Automatic Control, AC-20(1), 1–10, 1975. [45] Russ, J.C., Ed., The Image Processing Handbook, 2nd ed., Boca Raton, FL: CRC Press, 1994. [46] Rosenbrock, H.H., Computer-Aided Control System Design, Academic Press, 1974. [47] Smith, Modern Communication Circuits, McGraw-Hill, 1986. [48] Strauss, Wave Generation and Shaping, 2nd ed., McGraw-Hill, 1970. [49] Tabak, RISC Systems and Applications, Research Studies Press and Wiley, 1996. [50] Thomas and Clarke, C.A., Eds., Handbook of Electrical Instruments and Measur- ing Techniques, Prentice-Hall, 1967. [51] Whittaker, J.C., Ed., The Electronics Handbook, Boca Raton, FL: CRC Press, 1996. [52] Youla and Gnavi, G., Notes of n-dimensional system theory, IEEE Transactions on Circuits and Systems, 26(2), 105–111, 1979.© 2000 CRC Press LLC
  13. 13. ContributorsJames T. Aberle Partha P. BanjereeArizona State University University of AlabamaTempe, AZ Huntsville, ALGiovanni Adorni Ishmael (“Terry”) BanksUniversità di Parma American Electric Power CompanyParma, Italy Athens, OHAshfaq Ahmed Walter BanzhafPurdue University University of HartfordWest Lafayette, IN Hartford, CTA. E. A. Almaini Ottis L. BarronNapier University University of Tennessee at MartinEdinburgh, Scotland Martin, TNEarle M. Alexander IV Robert A. BartkowiakSan Rafael, CA Penn State University at Lehigh Valley Fogelsville, PAJim AndrewCISRA Richard M. BassNorth Ryde, Australia Georgia Institute of Technology Atlanta, GAJames AntonakosBroome County Community College Michael R. BastianBinghampton, NY Brigham Young University Provo, UTEduard AyguadeBarcelona, Spain Jeffrey S. Beasley New Mexico State UniversityBibhuti B. Banerjee Las Cruces, NMDexter Magnetic MaterialsFremont, CA Lars Bengtsson Halmsted University Halmsted, Sweden© 2000 by CRC Press LLC
  14. 14. Mi Bi Antonio ChellaTai Seng Industrial Estate University of PalermoSingapore Palermo, ItalyEdoardo Biagioni C. H. ChenSCS University of MassachusettsPittsburgh, PA N. Dartmouth, MADavid L. Blanchard Zheru ChiPurdue University Calumet Hong Kong Polytechnic UniversityHammond, IN Hung Hom, Kowloon, Hong KongWayne Bonzyk Shamala ChickamenahalliColman, SD Wayne State University Detroit, MIR. W. BoydUniversity of Rochester Christos ChristodoulouRochester, NY University of Central Florida Orlando, FLM. BraaeUniversity of Cape Town Badrul ChowdhuryRondebosch, South Africa University of Wyoming Laramie, WyomingDoug BurgesUniversity of Wisconsin Dominic J. CiardulloMadison, WI Nassau Community College Garden City, NYNick BurisMotorola Andrew CobbSchaumburg, IL New Albany, INJose Roberto Camacho Christopher J. ConantUniversidade Federal de Uberlindia Broome County Community CollegeUberlindia, Brazil Binghamton, NYGerard-Andre Capolino Robin CraveyUniversity of Picardie NASA Langley Research CenterAmiens, France Hampton, VALee W. Casperson George W. CrawfordPortland State University Penn State UniversityPortland, OR McKeesport, PA© 2000 by CRC Press LLC
  15. 15. John K. Daher Andrzej DzielinskiGeorgia Institute of Technology ISEPAtlanta, GA Warsaw University of Technology Warsaw, PolandFredrik DahlgrenChalmers University of Technology Jack EastGothenburg, Sweden University of Michigan Ann Arbor, MIE. R. DaviesUniversity of London Sandra EitnierSurrey, England San Diego, CARonald F. DeMara Samir El-GhazalyUniversity of Central Florida Arizona State UniversityOrlando, FL Tempe, AZWilliam E. DeWitt Irv EnglanderPurdue University Bentley CollegeWest Lafayette, IN Waltham, MAAlex Domijan Ivan FairUniversity of Florida Technical University of Nova ScotiaGainesville, FL Halifax, Nova Scotia, CanadaBob Dony Gang FengUniversity of Guelph University of New South WalesGuelph, Ontario, Canada Kensington, AustraliaTom Downs Peter M. FenwickUniversity of Queensland University of AucklandBrisbane, Australia Auckland, New ZealandMarvin Drake Paul FieguthThe MITRE Corporation University of WaterlooBedford, MA Waterloo, Ontario, CanadaLawrence P. Dunleavy Igor FilanovskyUniversity of South Florida University of AlbertaTampa, FL Edmonton, Alberta, CanadaScott C. Dunning Wladyslau FindeisenUniversity of Maine Warsaw University of TechnologyOrono, ME Warsaw, Poland© 2000 by CRC Press LLC
  16. 16. Dion Fralick P. R. HemmerNASA Langley Research Center RL/EROPHampton, VA Hanscom Air Force Base, MALawrence Fryda Vincent HeuringCentral Michigan University University of ColoradoMt. Pleasant, MI Boulder, COMumtaz B. Gawargy Andreas HirsteinConcordia University Swiss Electrotechnical AssociationMontreal, Quebec, Canada Fehraltorf, SwitzerlandFrank Gerlitz Robert J. HofingerWashtenaw College Purdue University School ofAnn Arbor, MI Technology at Columbus Columbus, INAntonio Augusto GorniCOSIPA Michael HonigCubatao, Brazil Northwestern University Evanston, ILLee GoudelockLaurel, MS Yan Hui Northern TelecomAlex Grant Nepean, Ontario, CanadaInstitut für Signal- und Informationsverarbeitung Suresh HungenahallyZurich, Switzerland Griffth University Nathan, Queensland, AustraliaThomas G. HabetlerGeorgia Tech Iqbal HusainAtlanta, GA University of Akron Akron, OHHaldun HadimiogluPolytechnic University Eoin HydenBrooklyn, NY Madison, NJDave Halchin Marija IlicRF MicroDevices MITGreensboro, NC Cambridge, MAThomas L. Harman Mark JanosUniversity of Houston Uniphase Fiber ComponentsHouston, TX Sydney, Australia© 2000 by CRC Press LLC
  17. 17. Albert Jelalian David KelleyJelalian Science & Engineering Penn State UniversityBedford, MA University Park, PAAnthony Johnson D. KennedyNew Jersey Institute of Technology Ryerson Polytechnic InstituteNewark, NJ Toronto, Ontario, CanadaC. Bruce Johnson Mohan KetkarPhoenix, AZ University of Houston Houston, TXBrendan JonesOptus Communications Jerzy KlamkaSydney, Australia Silesian Technical University Gliwice, PolandSuganda JutamuliaIn-Harmony Technology Corp. Krzysztof KozlowskiPetaluma, CA Technical University of Poznan Poznan, PolandRichard Y. KainUniversity of Minnesota Ron LandMinneapolis, MN Penn State University New Kensington, PADikshitulu K. KalluriUniversity of Massachusetts Robert D. LaramoreLowell, MA Cedarville College Cedarville, OHAlex KaluSavannah State University Joy LaskarSavannah, GA Georgia Institute of Technology Atlanta, GAGary KamermanFastMetrix Matti Latva-ahoHuntsville, AL University of Oulu Linannmaa, Oulu, FinlandAvishay KatzEPRI Thomas S. LaverghettaPalo Alto, CA Indiana University-Purdue University at Fort WayneWilson E. Kazibwe Fort Wayne, INTelegyr SystemsSan Jose, CA J. N. Lee Naval Research Laboratory Washington, D. C.© 2000 by CRC Press LLC
  18. 18. Fred Leonberger John A. McNeillUT Photonics Worcester Polytechnic InstituteBloomfield, CT Worcester, MAGing Li-Wang David P. MillardDexter Magnetic Materials Georgia Institute of TechnologyFremont, CA Atlanta, GAYilu Liu Monte MillerVirginia Tech Rockwell Semiconductor SystemsBlacksburg, VA Newbury Park, CAJean Jacques Loiseau Linn F. MollenauerInstitute Recherche en Cybernetique AT&T Bell LabsNantes, France Holmdel, NJHarry MacDonald Mauro MongiardoSan Diego, CA University of Perugia Perugia, ItalyChris MackFINLE Technologies Michael A. MorganAustin, TX Naval Postgraduate School Monterey, CAKrzysztov MalinowskiWarsaw University of Technology Amir MortazawiWarsaw, Poland University of Central Florida Orlando, FLS. ManoharanUniversity of Auckland Michael S. MunozAuckland, New Zealand TRW CorporationHoracio J. Marquez Paolo NesiUniversity of Alberta University of FlorenceEdmonton, Alberta, Canada Florence, ItalyFrancesco Masulli M. Nieto-VesperinasUniversity of Genoa Instituto de Ciencia de MaterialesGenoa, Italy Madrid, SpainVincent P. McGinn Kenneth V. NorenNorthern Illinois University University of IdahoDeKalb, IL Moscow, ID© 2000 by CRC Press LLC
  19. 19. Behrooz Nowrouzian Marek PerkowskiUniversity of Alberta Portland State UniversityEdmonton, Alberta, Canada Portland, ORTerrence P. O’Connor Roman PichnaPurdue University School of University of Oulu Technology at New Albany Oulu, FinlandNew Albany, IN A. H. PiersonBen O. Oni Pierson Scientific Associates, Inc.Tuskegee University Andover, MATuskegee, AL Pragasen PillayThomas H. Ortmeyer Clarkson UniversityClarkson University Potsdam, NYPotsdam, NY Agostina PoggiRon P. O’Toole Università dí ParmaCedar Rapids, IA Parma, ItalyTony Ottosson Aun Neow PooChalmers University of Technology Postgraduate School of EngineeringGöteburg, Sweden National University of Singapore SingaporeJ. R. ParkerUniversity of Calgary Ramas RamaswamiCalgary, Alberta, Canada MultiDisciplinary Research Ypsilanti, MIStefan ParkvalRoyal Institute of Technology Satiskuman J. RanadeStockholm, Sweden New Mexico State University Las Cruces, NMJoseph E. PascenteDowners Grove, IL Lars K. Rasmussen Centre for Wireless CommunicationsRussell W. Patterson SingaporeTennessee Valley AuthorityChattanooga, TN Walter Rawle Ericsson, Inc.Steven Pekarek Lynchburg, VAUniversity of MissouriRolla, MO C. J. Reddy NASA Langley Research Center Hampton, VA© 2000 by CRC Press LLC
  20. 20. Greg Reese Manfred SchindlerDayton, OH ATN Microwave North Billerica, MAJoseph M. ReinhardtUniversity of Iowa Warren SeelyIowa City, IA Motorola Scottsdale, AZNabeel RizaUniversity of Central Florida Yun ShiOrlando, FL New Jersey Institute of Technology Newark, NJJohn A. RobinsonMemorial University of Newfoundland Mikael SkoglundSt. John’s, Newfoundland, Canada Chalmers University of Technology Göteborg, SwedenEric RogersUniversity of Southampton Rodney Daryl SloneHighfield, Southampton, England University of Kentucky Lexington, KYChristian RonseUniversité Louis Pasteur Keyue M. SmedleyStrasbourg, France University of California Irvine, CAPieter van RooyenUniversity of Pretoria William SmithPretoria, South Africa University of Kentucky Lexington, KYAhmed SaifuddinCommunication Research Lab Babs SollerTokyo, Japan University of Massachusetts Medical Center Worcester, MARobert SarfiABB Power T & D Co., Inc. Y. H. SongCary, NC Brunel University Uxbridge, EnglandSimon SaundersUniversity of Surrey Janusz SosnowskiGuildford, England Institute of Computer Science Warsaw, PolandHelmut SchillingerIOQ Elvino SousaJena, Germany University of Toronto Toronto, Ontario, Canada© 2000 by CRC Press LLC
  21. 21. Philip M. Spray Pieter van RooyenAmarillo, TX University of Pretoria South AfricaJoe StaudingerMotorola Jonas VasellTempe, AZ Chalmers University of Technology Göteborg, SwedenRoman StemprokDenton, TX John L. Volakis University of MichiganDiana Stewart Ann Arbor, MIPurdue University School of Technology at New Albany Annette von JouanneNew Albany, IN Oregon State University Corvallis, ORFrancis SwartsUniversity of the Witwatersrand Liancheng WangJohannesburg, South Africa ABB Power T & D Co., Inc. Cary, NCAndrzej SwierniakSilesian Technical University Ronald W. WaynantGliwice, Poland FDA/CDRH Rockville, MDDaniel TabakGeorge Mason University Larry WearFairfax, VA Sacramento, CATadashi Takagi Wilson X. WenMitsubishi Electric Corporation AI SystemsOfuna, Kamakura, Japan Talstra Labs Clayton, AustraliaJaakko TalvitieUniversity of Oulu Barry WilkinsonOulu, Finland University of North Carolina Charlotte, NCHamid A. ToliyatTexas A&M University Robert E. WilsonCollege Station, TX Western Area Power Administration Montrose, CAAustin TruittTexas Instruments Stacy S. WilsonDallas, TX Western Kentucky University Bowling Green, KY© 2000 by CRC Press LLC
  22. 22. Denise M. Wolf Stanislaw H. ZakLawrence Berkeley National Laboratory Purdue UniversityBerkeley, CA West Lafayette, INE. Yaz Qing ZhaoUniversity of Arkansas University of Western OntarioFayetteville, Arkansas London, Ontario, CanadaPochi Yeh Jizhong ZhuUniversity of California National University of SingaporeSanta Barbara, CA SingaporeJeffrey Young Omar ZiaUniversity of Idaho Marietta, GAMoscow, ID© 2000 by CRC Press LLC
  23. 23. µ0 common symbol for permeability of free space constant. µ0 = 1.257 × 10−16 henrys/meter. Special µr ability. common symbol for relative perme- Symbols ω common symbol for radian frequency in radians/second. ω = 2 · π · frequency. θ+ common symbol for positive transitionα-level set a crisp set of elements belong- angle in degrees.ing to a fuzzy set A at least to a degree α θ− common symbol for negative transi- Aα = {x ∈ X | µA (x) ≥ α} tion angle in degrees.See also crisp set, fuzzy set. θcond common symbol for conduction an- gle in degrees. f common symbol for bandwidth, inhertz. θsat common symbol for saturation angle in degrees. rGaAs common symbol for gallium ar-senide relative dielectric constant. rGaAs = θCC common symbol for FET channel-12.8. to-case thermal resistance in ◦ C/watt. θJ C common symbol for bipolar junction- common symbol for silicon relative rSi to-case thermal resistance in ◦ C/watt.dielectric constant. rSi = 11.8. A∗ common symbol for Richardson’s 0 symbol for permitivity of free space. constant. A∗ = 8.7 amperes · cm/◦ K 0 = 8.849 × 10−12 farad/meter. BVGD See gate-to-drain breakdown r common symbol for relative dielectric voltage.constant. BVGS See gate-to-source breakdownηDC common symbol for DC to RF con- voltage.version efficiency. Expressed as a percent-age. dv/dt rate of change of voltage with- stand capability without spurious turn-on ofηa common symbol for power added ef- the device.ficiency. Expressed as a percentage. Hci See intrinsic coercive force.ηt common symbol for total or true effi-ciency. Expressed as a percentage. ne common symbol for excess noise in watts. opt common symbol for source reflec-tion coefficient for optimum noise perfor- ns h common symbol for shot noise inmance. watts.c 2000 by CRC Press LLC
  24. 24. nt common symbol for thermal noise in deux indices,” IRIA Rapport Laboria, No.watts. 31, Sept. 1973.10base2 a type of coaxial cable used to 2-D Fornasini–Marchesini model a 2-Dconnect nodes on an Ethernet network. The model described by the equations10 refers to the transfer rate used on standardEthernet, 10 megabits per second. The base xi+1,j +1 = A0 xi,j + A1 xi+1,jmeans that the network uses baseband com- + A2 xi,j +1 + Buij (1a)munication rather than broadband communi- yij = Cxij + Duij (1b)cations, and the 2 stands for the maximumlength of cable segment, 185 meters (almost i, j ∈ Z+ (the set of nonnegative integers)200). This type of cable is also called “thin” here xij ∈ R n is the local state vector,Ethernet, because it is a smaller diameter ca- uij ∈ R m is the input vector, yij ∈ R p isble than the 10base5 cables. the output vector Ak (k = 0, 1, 2), B, C, D are real matrices. A 2-D model described by10base5 a type of coaxial cable used to the equationsconnect nodes on an Ethernet network. The xi+1,j +1 = A1 xi+1,j + A2 xi,j +110 refers to the transfer rate used on stan-dard Ethernet, 10 megabits per second. The + B1 ui+1,j + B2 ui,j +1 (2)base means that the network uses baseband i, j ∈ Z+ and (1b) is called the second 2-Dcommunication rather than broadband com- Fornasini–Marchesini model, where xij , uij ,munications, and the 5 stands for the max- and yij are defined in the same way as for (1),imum length of cable segment of approxi- Ak , Bk (k = 0, 1, 2) are real matrices. Themately 500 meters. This type of cable is also model (1) is a particular case of (2).called “thick” Ethernet, because it is a largerdiameter cable than the 10base2 cables. 2-D general model a 2-D model de- scribed by the equations10baseT a type of coaxial cable used toconnect nodes on an Ethernet network. The xi+1,j +1 = A0 xi,j + A1 xi+1,j10 refers to the transfer rate used on standard + A2 xi,j +1 + B0 uijEthernet, 10 megabits per second. The basemeans that the network uses baseband com- + B1 ui+1,j + B2 ui,j +1munication rather than broadband communi- yij = Cxij + Duijcations, and the T stands for twisted (wire)cable. i, j ∈ Z+ (the set of nonnegative integers) here xij ∈ R n is the local state vector, uij ∈2-D Attasi model a 2-D model described R m is the input vector, yij ∈ R p is the outputby the equations vector and Ak , Bk (k = 0, 1, 2), C, D are real matrices. In particular case for B1 = B2 = 0 xi+1,j +1 = −A1 A2 xi,j + A1 xi+1,j we obtain the first 2-D Fornasini–Marchesini model and for A0 = 0 and B0 = 0 we obtain + A2 xi,j +1 + Buij the second 2-D Fornasini–Marchesini model. yij = Cxij + Duij 2-D polynomial matrix equation a 2-Di, j ∈ Z+ (the set of nonnegative integers). equation of the formHere xij ∈ R n is the local state vector,uij ∈ R m is the input vector, yij ∈ R p is AX + BY = C (1)the output vector, and A1 , A2 , B, C, D arereal matrices. The model was introduced by where A ∈ R k×p [s], B ∈ R k×q [s], C ∈Attasi in “Systemes lineaires homogenes a R k×m [s] are given, by a solution to (1) wec 2000 by CRC Press LLC
  25. 25. mean any pair X ∈ R p×m [s], Y ∈ R q×m [s] The algorithm is based on the row compres-satisfying the equation. The equation (1) sion of suitable matrices.has a solution if and only if the matrices[A, B, C] and [A, B, 0] are column equiva- 2-D Z-transform F (z1 , z2 ) of a dis-lent or the greatest common left divisor of A crete 2-D function fij satisfying the condi-and B is a left divisor of C. The 2-D equation tion fij = 0 for i < 0 or/and j < 0 is defined by AX + Y B = C (2) ∞ ∞ −i −jA∈ R k×p[s], B ∈ R q×m [s], C∈ R k×m [s] F (z1 , z2 ) = fij z1 z2are given, is called the bilateral 2-D polyno- i=0 j =0mial matrix equation. By a solution to (2) we An 2-D discrete fij has the 2-D Z-transformmean any pair X ∈ R p×m [s], Y ∈ R k×q [s] if the sumsatisfying the equation. The equation has a ∞ ∞solution if and only if the matrices −i −j fij z1 z2 i=0 j =0 A 0 AC and 0 B 0 B exists.are equivalent. 2DEGFET See high electron mobility transistor(HEMT).2-D Roesser model a 2-D model de-scribed by the equations 2LG See double phase ground fault. h xi+1,j h A1 A2 xij B1 3-dB bandwidth for a causal low-pass = + u v xi,j +1 A3 A4 v xij B2 ij or bandpass filter with a frequency functioni, j ∈ Z+ (the set of nonnegative integers), H (j ω) the frequency at which | H (j ω) |dB is less than 3 dB down from the peak value h xij | H (ωP ) |. yij = C v + Duij xij 3-level laser a laser in which the most h vHere xij ∈ R n1 and xij ∈ R n2 are the hori- important transitions involve only three en-zontal and vertical local state vectors, respec- ergy states; usually refers to a laser in whichtively, uij ∈ R m is the input vector, yij ∈ R p the lower level of the laser transition is sepa-is the output vector and A1 , A2 , A3 , A4 , B1 , rated from the ground state by much less thanB2 , C, D are real matrices. The model was the thermal energy kT. Contrast with 4-levelintroduced by R.P. Roesser in “A discrete laser.state-space model for linear image process-ing,” IEEE Trans. Autom. Contr., AC-20, 3-level system a quantum mechanicalNo. 1, 1975, pp. 1-10. system whose interaction with one or more electromagnetic fields can be described by2-D shuffle algorithm an extension of the considering primarily three energy levels.Luenberger shuffle algorithm for 1-D case. For example, the cascade, vee, and lambdaThe 2-D shuffle algorithm can be used for systems are 3-level systems.checking the regularity condition 4-level laser a laser in which the most det [Ez1 z2 − A0 − A1 z1 − A2 z2 ] = 0 important transitions involve only four en- ergy states; usually refers to a laser in whichfor some (z1 , z2 ) ∈ C×C of the singular gen- the lower level of the laser transition is sep-eral model ( See singular 2-D general model). arated from the ground state by much morec 2000 by CRC Press LLC
  26. 26. than the thermal energy kT . Contrast with ty of the image. For example a leak factor of 313-level laser. 32 the prediction decay is maintained at the center of the dynamic range.45 Mbs DPCM for NTSC color videoa codec wherein a subjectively pleasing pic- − 31 −ture is required at the receiver. This does XL = 128 + X − 128 .not require transparent coding quality typical 32of TV signals. The output bit-rate for video Finally, a clipper at the coder and decodermatches the DS3 44.736 Megabits per second is employed to prevent quantization errors.rate. The coding is done by PCM coding theNTSC composite video signal at three times 90% withstand voltage a measure ofthe color subcarrier frequency using 8 bit per the practical lightning or switching-surge im-pixel. Prediction of current pixel is obtained pulse withstand capability of a piece of powerby averaging the pixel three after current and equipment. This voltage withstand level is681 pixels before next to maintain the sub- two standard deviations above the BIL of thecarrier phase. A leak factor is chosen before equipment.computing prediction error to main the quali-c 2000 by CRC Press LLC
  27. 27. two-port networks. Sometimes referred to as chain parameters. ABCD parameters are A widely used to model cascaded connections of two-port microwave networks, in which case the ABCD matrix is defined for each two-port network. ABCD parameters can also be used in analytic formalisms for prop-a posteriori probability See posterior agating Gaussian beams and light rays. Raystatistics. matrices and beam matrices are similar but are often regarded as distinct.a priori probability See prior statistics. ABC parameters have a particularly use- ful property in circuit analysis where theA-mode display returned ultrasound composite ABCD parameters of two cas-echoes displayed as amplitude versus depth caded networks are the matrix products ofinto the body. the ABCD parameters of the two individual circuits. ABCD parameters are defined asA-site in a ferroelectric material with thechemical formula ABO3 , the crystalline lo- v1 AB v2 =cation of the A atom. i1 CD i2A/D See analog-to-digital converter. where v1 and v2 are the voltages on ports one and two, and i1 and i2 are the branch currentsAAL See ATM adaptation layer. into ports one and two.ABC See absorbing boundary condition. aberration an imperfection of an optical system that leads to a blurred or a distortedABCD propagation of an optical ray image.through a system can be described by a sim-ple 2×2 matrix. In ray optics, the character- abnormal event any external or program-istic of a system is given by the correspond- generated event that makes further normaling ray matrix relating the ray’s position from program execution impossible or undesir-the axis and slope at the input to those at the able, resulting in a system interrupt. Exam-output. ples of abnormal events include system de- tection of power failure; attempt to divide byABCD formalism analytic method using 0; attempt to execute privileged instructiontwo-by-two ABCD matrices for propagating without privileged status; memory parity er-Gaussian beams and light rays in a wide va- ror.riety of optical systems. abort (1) in computer systems, to termi-ABCD law analytic formula for trans- nate the attempt to complete the transaction,forming a Gaussian beam parameter from usually because there is a deadlock or be-one reference plane to another in paraxial op- cause completing the transaction would re-tics, sometimes called the Kogelnik transfor- sult in a system state that is not compati-mation. ABCD refers to the ABCD matrix. ble with “correct” behavior, as defined by a consistency model, such as sequential con-ABCD matrix the matrix containing sistency.ABCD parameters. See ABCD parameters. (2) in an accelerator, terminating the ac- celeration process prematurely, either by in-ABCD parameters a convenient mathe- hibiting the injection mechanism or by re-matical form that can be used to characterize moving circulating beam to some sort ofc 2000 by CRC Press LLC
  28. 28. dump. This is generally done to prevent in- absolute sensitivity denoted S(y, x), isjury to some personnel or damage to acceler- simply the partial derivative of y with respectator components. to x, i.e., S(y, x) = ∂y/∂x, and is used to establish the relationships between absoluteABR See available bit rate. changes. See sensitivity, sensitivity measure, relative sensitivity, semi-relative sensitivity.absolute address an address within aninstruction that directly indicates a location in absolute stability occurs when the net-the program’s address space. Compare with work function H (s) has only left half-planerelative addressing. poles.absolute addressing an addressing mode absorber generic term used to describewhere the address of the instruction operand material used to absorb electromagnetic en-in memory is a part of the instruction so that ergy. Generally made of polyurethaneno calculation of an effective address by the foam and impregnated with carbon (and fire-CPU is necessary. retardant salts), it is most frequently used to For example, in the Motorola M68000 ar- line the walls, floors and ceilings of anechoicchitecture instruction ADD 5000,D1, a 16-bit chambers to reduce or eliminate reflectionsword operand, stored in memory at the word from these surfaces.address 5000, is added to the lower word inregister D1. The address “5000” is an exam- absorbing boundary condition (ABC) aple of using the absolute addressing mode. fictitious boundary introduced in differentialSee also addressing mode. equation methods to truncate the computa- tional space at a finite distance without, inabsolute encoder an optical device principle, creating any reflections.mounted to the shaft of a motor consistingof a disc with a pattern and light sources and absorption (1) process that dissipates en-detectors. The combination of light detectors ergy and causes a decrease in the amplitudereceiving light depends on the position of the and intensity of a propagating wave betweenrotor and the pattern employed (typically the an input and output reference plane.Gray code). Thus, absolute position infor- (2) reduction in the number of photons of amation is obtained. The higher the resolution specific wavelength or energy incident uponrequired, the larger the number of detectors a material. Energy transferred to the materialneeded. See also encoder. may result in a change in the electronic struc- ture, or in the relative movement of atoms inabsolute moment The pth order absolute the material (vibration or rotation).moment µp of a random variable X is the (3) process by which atoms or moleculesexpectation of the absolute value of X raised stick to a surface. If a bond is formed, it isto the pth power: termed chemisorption, while the normal case is physisorption. The absorption process pro- µp = E[|X|]p . ceeds due to, and is supported by, the fact that this is a lower energy state.See also central moment, central absolutemoment. See also expectation. absorption coefficient (1) in a passive de- vice, the negative ratio of the power absorbedabsolute pressure units to measure gas (pabsorbed = pin −pout ) ratioed to the power inpressure in a vacuum chamber with zero be- (pin = pincident − preflected ) per unit length (l),ing a perfect vacuum. Normally referred to usually expressed in units of 1/wavelength oras psia (pounds per square inch absolute). 1/meter.c 2000 by CRC Press LLC
  29. 29. (2) factor describing the fractional atten- rameter are closest to the parameters of anuation of light with distance traversed in a ideal capacitor. Hence, not only a capaci-medium, generally expressed as an exponen- tance is measured in terms of capacitance (intial factor, such as k in the function e−kx , resistive ratio arms bridges), but the induc-with units of (length)-1. Also called attenu- tance as well is measured in terms of capac-ation coefficient. itance (Hay and Owen bridges). The AC bridges with ratio arms that areabsorption cross section energy ab- tightly coupled inductances allow measure-sorbed by the scattering medium, normal- ment of a very small difference between cur-ized to the wavenumber. It has dimensions rents in these inductances, and this fact isof area. used in very sensitive capacitance transduc- ers.absorption edge the optical wavelengthor photon energy corresponding to the sep- AC circuit electrical network in which thearation of valence and conduction bands in voltage polarity and directions of current flowsolids; at shorter wavelengths, or higher pho- change continuously, and often periodically.ton energies than the absorption edge, the ab- Thus, such networks contain alternating cur-sorption increases strongly. rents as opposed to direct currents, thereby giving rise to the term.absorption grating (1) a diffractiongrating where alternate grating periods are AC coupling a method of connecting twoopaque. circuits that allows displacement current to (2) an optical grating characterized by flow while preventing conductive currents.spatially periodic variation in the absorption Reactive impedance devices (e.g., capacitorsof light. Absorption gratings are generally and inductive transformers) are used to pro-less efficient than phase gratings. vide continuity of alternating current flow between two circuits while simultaneouslyabsorption optical fiber the amount of blocking the flow of direct current.optical power in an optical fiber capturedby defect and impurity centers in the energy AC motor an electromechanical sys-bandgap of the fiber material and lost in the tem that converts alternating current electri-form of longwave infrared radiation. cal power into mechanical power.AC See alternating current. AC plasma display a display that em-AC bridge one of a wide group of ploys an internal capacitive dielectric layerbridge circuits used for measurements of re- to limit the gas discharge current.sistances, inductances, and capacitances, andto provide AC signal in the bridge transducers AC steady-state power the averageincluding resistors, inductors, and capacitors. power delivered by a sinusoidal source to a The Wheatstone bridge can be used with network, expressed asa sinusoidal power supply, and with an ACdetector (headphones, oscilloscope), one can P =| V | · | I | cos(θ )use essentially the same procedure for mea- √ √surement of resistors as in DC applications. where 2· | V | and 2· | I | are the peakOnly a small number of other AC bridges are values, respectively, of the AC steady-stateused in modern electric and electronic equip- voltage and current at the terminals. θ rep-ment. A strong selection factor was the fact resents the phase angle by which the voltagethat in a standard capacitor the electrical pa- leads the current.c 2000 by CRC Press LLC
  30. 30. AC/AC converter a power electronics ation error to a constraint on the gain of thedevice in which an AC input voltage of some open loop system. The relevant equationsmagnitude, frequency, and number of phases are ea = Ka and Ka = lims→inf ty s 2 q(s), 1is changed to an AC output with changes to where q(s) is the transfer function modelany of the previously mentioned parameters. of the open loop system, including the con-AC/AC converters usually rectify the input troller and the process in cascade, and s issource to a DC voltage and then invert the the Laplace variable. See also position errorDC voltage to the desired AC voltage. constant, velocity error constant.AC/DC converter See rectifier. accelerator (1) a positive electrode in a vacuum tube to accelerate emitted electronsAC-DC integrated system a power sys- from its cathode by coulomb force in a de-tem containing both AC and DC transmission sired direction.lines. (2) a machine used to impart large kinetic energies to charged particles such as elec-ACARS aircraft communications ad- trons, protons, and atomic nuclei. The ac-dressing and reporting. A digital commu- celerated particles are used to probe nuclearnications link using the VHF spectrum for or subnuclear phenomena in industrial andtwo-way transmission of data between an air- medical applications.craft and ground. It is used primarily in civilaviation applications. acceptable delay the voice signal de- lay that results in inconvenience in the voiceACC See automatic chroma control. communication. A typically quoted value is 300 ms.accelerated testing tests conducted athigher stress levels than normal operation but acceptance in an accelerator, it definesin a shorter period of time for the specific how "large" a beam will fit without scrap-purpose to induce failure faster. ing into the limiting aperture of a transport line. The acceptance is the phase-space vol-accelerating power the excess electric ume within which the beam must lie to bepower at a synchronous machine unit which transmitted through an optical system with-cannot be transmitted to the load because of out losses. From an experimenters pointa short circuit near its terminals. This energy of view acceptance is the phase-space vol-gives rise to increasing rotor angle. ume intercepted by an experimenter’s detec- tor system.acceleration error the final steady dif-ference between a parabolic setpoint and theprocess output in a unity feedback control acceptor (1) an impurity in a semicon-system. Thus it is the asymptotic error in po- ductor that donates a free hole to the valencesition that arises in a closed loop system that band.is commanded to move with constant acceler- (2) a dopant species that traps electrons,ation. See also position error, velocity error. especially with regard to semiconductors.acceleration error constant a gain Ka access channel a channel in a communi-from which acceleration error ea is read- cations network that is typically allocated forily determined. The acceleration error con- the purpose of setting up calls or communi-stant is a concept that is useful in the design cation sessions. Typically the users share theof unity feedback control systems, since it access channel using some multiple accesstransforms a constraint on the final acceler- algorithm such as ALOHA or CSMA.c 2000 by CRC Press LLC
  31. 31. access control a means of allowing ac- time until the desired data rotates under thecess to an object based on the type of ac- head. (LW)cess sought, the accessor’s privileges, and theowner’s policy. accidental rate the rate of false coinci- dences in the electronic counter experimentaccess control list a list of items associ- produced by products of the reactions of moreated with a file or other object; the list con- than one beam particle within the time reso-tains the identities of users that are permitted lution of the apparatus.access to the associated file. There is infor-mation (usually in the form of a set of bits)about the types of access (such as read, write, accumulation (1) an increase in the ma-or delete) permitted to the user. jority carrier concentration of a region of semiconductor due to an externally appliedaccess control matrix a tabular repre- electric field.sentation of the modes of access permittedfrom active entities (programs or processes) accumulator (1) a register in the CPUto passive entities (objects, files, or devices). (processor) that stores one of the operandsA typical format associates a row with an ac- prior to the execution of an operation, andtive entity or subject and a column with an into which the result of the operation isobject; the modes of access permitted from stored. An accumulator serves as an implicitthat active entity to the associated passive en- source and destination of many of the pro-tity are listed in the table entry. cessor instructions. For example, register A of the Intel 8085 is an accumulator. See alsoaccess line a communication line that CPU .connects a user’s terminal equipment to aswitching node. (2) the storage ring in which successive pulses of particles are collected to create aaccess mechanism a circuit board or an particle beam of reasonable intensity for col-integrated chip that allows a given part of a liding beams.computer system to access another part. Thisis typically performed by using a specific ac- achievable rate region for a multiplecess protocol. terminal communications system, a set of rate-vectors for which there exist codes suchaccess protocol a set of rules that estab- that the probability of making a decoding er-lishes communication among different parts. ror can be made arbitrarily small. See alsoThese can involve both hardware and soft- capacity region, multiple access channel.ware specifications.access right permission to perform an achromatic the quality of a transport lineoperation on an object, usually specified as or optical system where particle momentumthe type of operation that is permitted, such has no effect on its trajectory through the sys-as read, write, or delete. Access rights can tem. In an achromatic device or system, thebe included in access control lists, capability output beam displacement or divergence (orlists, or in an overall access control matrix. both) is independent of the input beam’s mo- mentum. If a system of lenses is achromatic,access time the total time needed to re- all particles of the same momentum will havetrieve data from memory. For a disk drive equal path lengths through the system.this is the sum of the time to position theread/write head over the desired track and the ACI See adjacent channel interference.c 2000 by CRC Press LLC
  32. 32. acknowledge (1) a signal which indicates another signal in a second cell, or with fixedthat some operation, such as a data transfer, signals on a mask.has successfully been completed. (2) to detect the successful completion of acousto-optic deflector device devicean operation and produce a signal indicating where acousto-optic interaction deflects thethe success. incident beam linearly as a function of the input frequency of the RF signal driving theacoustic attenuation the degree of am- device.plitude suppression suffered by the acous-tic wave traveling along the acousto-optic acousto-optic device descriptor ofmedium. acousto-optic cells of any design; generally describes a cell plus its transducer struc-acoustic laser a laser (or maser) in which ture(s), and may encompass either bulk,the amplified field consists of soundwaves or guided-wave, or fiber-optic devices.phonons rather than electromagnetic waves;phonon laser or phaser. acousto-optic effect the interaction of light with sound waves and in particular theacoustic memory a form of circulating modification of the properties of a light wavememory in which information is encoded in by its interactions with an electrically con-acoustic waves, typically propagated through trollable sound wave. See also Brillouina trough of mercury. Now obsolete. scattering.acoustic velocity the velocity of the acousto-optic frequency excisor similaracoustic signal traveling along the acousto- to an acousto-optic spectrum analyzer whereoptic medium. the RF temporal spectrum is spatially and se- lectively blocked to filter the RF signal feed-acoustic wave a propagating periodic ing the Bragg cell.pressure wave with amplitude representingeither longitudinal or shear particle displace-ment within the wave medium; shear waves acousto-optic instantaneous spectrum an-are prohibited in gaseous and liquid media. alyzer in Bragg mode device in which the temporal spectrum of a radio frequency sig-acousto-optic cell a device consisting of nal is instantaneously and spatially resolveda photo-elastic medium in which a propa- in the optical domain using a Fourier trans-gating acoustic wave causes refractive-index form lens and a RF signal-fed Bragg cell.changes, proportional to acoustic wave am-plitude, that act as a phase grating for diffrac- acousto-optic modulator a device thattion of light. See also Bragg cell. modifies the amplitude or phase of a light wave by means of the acousto-optic effect.acousto-optic channelized radiometerSee acousto-optic instantaneous spectrum acousto-optic processor an optical sys-analyzer in Bragg mode. tem that incorporates acousto-optic cells con- figured to perform any of a number of math-acousto-optic correlator an optical sys- ematical functions such as Fourier trans-tem that consists of at least one acousto- form, ambiguity transforms, and other time-optic cell, imaging optics between cells and frequency transforms.fixed masks, and photodetectors whose out-puts correspond to the correlation function of acousto-optic scanner a device that usesthe acoustic wave signal within one cell with an acoustic wave in a photoelastic mediumc 2000 by CRC Press LLC
  33. 33. to deflect light to different angular positions acousto-optics the area of study of in-based on the frequency of the acoustic wave. teraction of light and sound in media, and its utilization in applications such as signalacousto-optic space integrating convolver processing and filtering. device that is the same as an acousto-opticspace integrating convolver except that it im- ACP See adjacent channel power.plements the convolution operation. acquisition (1) in digital communica-acousto-optic space integrating correlator tions systems, the process of acquiring syn- an acousto-optic implementation of the cor- chronism with the received signal. Thererelation function where two RF signals are are several levels of acquisitions, and for aspatially impressed on two diffracted beams given communication system several of themfrom Bragg cells, and a Fourier transform have to be performed in the process of settinglens spatially integrates these beams onto a up a communication link: frequency, phase,point sensor that generates a photo current spreading code, symbol, frame, etc.representing the correlation function. (2) in analog communications systems, the process of initially estimating signal pa-acousto-optic spectrum analyzer an rameters (for example carrier frequency off-acousto-optic processor that produces at a set, phase offset) required in order to beginphotodetector output array the Fourier de- demodulation of the received signal.composition of the electrical drive signal of (3) in vision processing, the process byan acousto-optic device. which a scene (physical phenomenon) is converted into a suitable format that al- lows for its storage or retrieval. See alsoacousto-optic time integrating convolver synchronization. same as the acousto-optic time integratingcorrelator, except implements the signal con- across the line starter a motor starter thatvolution operation. See acousto-optic time applies full line voltage to the motor to start.integrating correlator. This is also referred to as “hard starting” be- cause it causes high starting currents. Largeracousto-optic time integrating correlator motors require reduced voltage or “soft start- an acousto-optic implementation of the cor- ing.”relation function where two RF signals arespatially impressed on two diffracted beams ACRR See adjacent channel reuse ratio.from Bragg cells, and a time integrating sen-sor generates the spatially distributed corre- ACSR aluminum cable, steel-reinforced.lation results. A kind of overhead electric power conduc- tor made up of a central stranded steel cableacousto-optic triple product processor overlaid with strands of aluminum.signal processor that implements a triple inte-gration operation using generally both space ACT See anticomet tail.and time dimensions. action potential a propagating change inacousto-optic tunable filter (AOTF) an the conductivity and potential across a nerveacousto-optic device that selects specific op- cell’s membrane; a nerve impulse in commontical frequencies from a broadband optical parlance.beam, depending on the number and frequen-cies of acoustic waves generated in the de- activation function in an artificial neuralvice. network, a function that maps the net outputc 2000 by CRC Press LLC
  34. 34. of a neuron to a smaller set of values. This active load a transistor connected so as toset is usually [0, 1]. Typical functions are the replace a function that would conventionallysigmoid function or singularity functions like be performed by a passive component suchthe step or ramp. as a resistor, capacitor, or inductor.active contour a deformable template active load-pull measurement a mea-matching method that, by minimizing the surement method where transfer characteris-energy function associated with a specific tics of a device can be measured by electri-model (i.e., a specific characterization of the cally changing the load impedance seen fromshape of an object), deforms the model in the device. In an active load-pull measure-conformation to salient image features. ment, the load impedance is defined by using an output signal from the device and an in- jected signal from the output of the device.active device a device that can convertenergy from a DC bias source to a signal at active logic a digital logic that operatesan RF frequency. Active devices are required all of the time in the active, dissipative regionin oscillators and amplifiers. of the electronic amplifiers from which it is constructed. The output of such a gate isactive filter (1) a filter that has an en- determined primarily by the gate and not byergy gain greater than one, that is, a filter that the load.outputs more energy than it absorbs. (2) a form of power electronic converter active magnetic bearing a magneticdesigned to effectively cancel harmonic cur- bearing that requires input energy for stablerents by injecting currents that are equal and support during operation. Generally imple-opposite to, or 180◦ out of phase with, the tar- mented with one or more electromagnets andget harmonics. Active filters allow the out- controllers.put current to be controlled and provide sta-ble operation against AC source impedance active mixer a mixer that uses three termi-variations without interfering with the system nal devices such as FET rather than diodes asimpedance. nonlinear element. One advantage of active The main type of active filter is the series mixers is that they can provide conversiontype in which a voltage is added in series with gain.an existing bus voltage. The other type is theparallel type in which a current is injected active network an electrical networkinto the bus and cancels the line current har- that contains some solid state devices such asmonics. bipolar junction transistors (BJTs) or metal- oxide-silicon field effect transistors (FETs) operating in their active region of the volt-active impedance the impedance at the age vs. current characteristic. To ensure thatinput of a single antenna element of an ar- these devices are operating in the active re-ray with all the other elements of the array gion, they must be supplied with proper DCexcited. biasing.active layer See active region. active neuron a neuron with a non-zero output. Most neurons have an activationactive learning a form of machine learn- threshold. The output of such a neuron hasing where the learning system is able to in- zero output until this threshold is reached.teract with its environment so as to affect thegeneration of training data. active power See real power.c 2000 by CRC Press LLC
  35. 35. active power line conditioner a device ACTV See advanced compatible tele-which senses disturbances on a power line vision.and injects compensating voltages or currentsto restore the line’s proper waveform. acuity sharpness. The ability of the eye to discern between two small objects closelyactive RC filter an electronic circuit spaced, as on a display.made up of resistors, capacitors, and opera-tional amplifiers that provide well-controlled adaptability the capability of a system tolinear frequency-dependent functions, e.g., change to suit the prevailing conditions, espe-low-, high-, and bandpass filters. cially by automatic adjustment of parameters through some initialization procedure or byactive redundancy a circuit redundancy training.technique that assures fault-tolerance by de- adaptation layer control layer of a mul-tecting the existence of faults and performing tilayer controller, situated above the directsome action to remove the faulty hardware, control layer and — usually — also above thee.g., by standby sparing. optimizing control layer, required to intro- duce changes into the decision mechanismsactive region semiconductor material of the layer (or layers) below this adaptationdoped such that electrons and/or holes are layer; for example adaptation layer of the in-free to move when the material is biased. In dustrial controller may be responsible for ad-the final fabricated device, the active regions justing the model used by the optimizing con-are usually confined to very small portions of trol and the decision rules used by the directthe wafer material. (regulation) control mechanisms.active-high (1) a logic signal having its adapter a typical term from personalasserted state as the logic ONE state. computers. A circuit board containing the (2) a logic signal having the logic ONE interface toward an additional peripheral de-state as the higher voltage of the two states. vice. For example, a graphic adapter (inter- face boards like EGA, VGA, CGA), a gameactive-low (1) a logic signal having its controller, a SCSI controller, a PCMCI inter-asserted state as the logic ZERO state. face, etc. (2) a logic signal having its logic ONE adaptive algorithm (1) a method for ad-state as the lower voltage of the two states; justing the parameters of a filter to satisfy aninverted logic. objective (e.g., minimize a cost function). (2) an algorithm whose properties are ad-actuator (1) a transducer that converts justed continuously during execution withelectrical, hydraulic, or pneumatic energy to the objective of optimizing some criterion.effective motion. For example in robots, ac-tuators set the manipulator in motion through adaptive antenna antenna, or array ofactuation of the joints. Industrial robots antennas, whose performance characteristicsare equipped with motors that are typically can be adapted by some means; e.g., theelectric, hydraulic, or pneumatic. See also pattern of an array can be changed whenindustrial robot. the phasing of each of the array elements is (2) in computers, a device, usually me- changed.chanical in nature, that is controlled by acomputer, e.g., a printer paper mechanism or adaptive array an array that adapts itselfa disk drive head positioning mechanism. to maximize the reception of a desired sig-c 2000 by CRC Press LLC