This second edition of PHASELOCKTECHNIQUES promises to be-as wasthe first-the standard reference on thesubject.Now greatly expanded andlargely rewritten to reflect a betterunderstanding of the subject,the bookpresents much recent material,somepublished here for the first time.Ex-planation of fundamentals is improvedand expanded,and description of appli-cations is greatly increased.The first portion of the book is a well-organized review of the fundamentals ofphaselock,as well as a discussion of theunderlying problems faced by de-signers.Most of this material has beenrewritten from the first edition.The ma-About the authorterial that follows deals with practical as-FLOYD M.GARDNER has been workpects of component circuits and with ra-with phaselock loops since 1955.Hetional procedures for deciding uponphaselock loop parameters.This all-engaged in basic phaselock resealin circuit design,in debugging of phanew examination of loop components islock hardware,and in the teachingfound nowhere else in today's literature.phaselock courses.He brings longThe remaining chapters provide engi-perience to the writing of this seceneering descriptions and analyses ofedition of PHASELOCK TECHNIQUEapplications of phaselock.Most of thisDr.Gardner has been an indepencmaterial is unique.Included are discus-sions of phaselocked modulators andconsulting engineer since 1960.Intime he spent 1%years consultdemodulators,synthesizers,receivers,abroad by invitation of AEG-Telefuntransponders,oscillator stabilizers,andin Germany and the European Spdata synchronizers.Agency in the Netherlands.Besisuch diverse topics as digital commcations(especially synchronization),lemetry,electronic tracking and navtion systems,and design of radioceivers.He received his education at lllinoisstitute of Technology (BSEE 1950),Siford University (MSEE 1951),andPrefaceThis book was written for practicing engineers:for system engineers whomust know the capabilities and limitations of phaselock,for equipmentdesign engineers who build phaselock circuits,and for equipment userswho must understand the operation of their equipment.For these readersthe book discusses basic principles of phaselock operation,typical prac-tices of phaselock engineering,and selected applications of phaselock tovarious problems.Long mathematical derivations have been avoided on the premise thatthey are of little interest to the practicing engineer.Instead,I have tried tooutline the underlying assumptions and methods employed in derivationsand have stressed practical results.For those readers who may be inter-ested in further details,I have listed numerous references.On the other hand,I have avoided producing a circuits cookbook.Specific circuits quickly become obsolete;furthermore,very little funda-mental understanding can be gained from a collection of circuit recipes.Ihave tried to stress physical understanding of basic phenomena as much aspossible.Nonetheless,because many aspects of phaselock can be expressed onlyin mathematical terms,the largest part of the material is presented here inthat form.As a consequence,the reader must have some mathematicalbackground.For fullest understanding of the subject some familiarity withtransfer functions in the Laplace transform notation,a background infeedback or servo theory,and a nodding acquaintance with noise andspectral analysis of stochastic processes are needed.The results andapplications are presented so that a less well-prepared reader can under-stand them,but the minimum prerequisites are necessary for a full under-standing of the detailed basic principles.This philosophy underlay the first edition of this book,which was wellreceived by its intended audience.In the years since its publication muchhas happened in the phaselock world.Better analyses have been per-formed,new circuits have arisen (and old ones have faded away),moreiPrefaceapplications have appeared,and my own understanding of phaselock hasimproved substantially.Thus the time seems ripe for a new edition.The reader will find additional analytical tools and improved explana-tions of the fundamentals of the subject.Moreover,the material onapplications has been expanded greatly.I hope the profession finds thisbook to be as useful as its predecessor.I have benefited from the wise counsel of J.L.Dautremont,Jr.,W.C.Lindsey,A.J.Mallinckrodt,L.Eaton,L.M.Hershey,J.J.Spilker,Jr.,J.F.Heck,C.E.Krehbiel,K.Wong,and F.Chethik,each of whomreviewed one or more chapters.Their expert critiques have made this bookbetter than it would have been through my unaided efforts.FLOYD M.GARDNERPalo Alto,CaliforniaApril 1979