CONTENTSPrefacexVIntroductiontoRadioCommunicationSystemsI111.1Introduction21.2NetworkTheory31.3Modulation31.4 ReceiversAModem Communications Receiver/ Direct Conversion Receiver/ An Integrated-CircuirFMReceiver121.5 Transmitters131.6Problems141.7 Additional Reading162Small-SignalAmplifiers162.1 Introduction162.2 BipolarTransistorAmplifiersEquivalentCircuits/Common-EmitterAmplifier/Common-BaseAmplifier/Emitter-Follower272.3 Field-EffectTransistorAmplifiersEquivalent Circuits/Common-Source Amplifier/Source-Follower/Common-GateAmplifier-/InputImpedance/VotageGain/OutputImpedance362.4Multistage Amplifiers382.5Dual-Gate FET392.6 Push-PullAmplifiers412.7 DifferentialAmplifierCommon-Mode RejectionRatio/FETDifferentialAmplifier/BJTDifferentialAmplifier492.8OperationalAmplifierOp-Amp Characteristics/ Ideal Inverting Amplifier/Nonideal Inverting Amplifier:ix
xCONTENTSThe Effect of Finite LoopGain/Gain-BandwidthProduct/Effect of FiniteInputImpedance/Effect of FiniteInput and Output Impedance/Noninverting Amplifier2.9 Problems572.10 References653NetworkNoiseand IntermodulationDistortion67673.1Introduction3.2Noise67Thermal Noise/Active Device Noise/Noise in Transistor Amplifiers773.3 Noise Figure, Noise Factor, and SensitivityAverage Noise Factor/Noise Figure/Noise Factor of Cascaded Networks/ NoiseTemperature / Sensitivity853.4 Design of Low-Noise NetworksNetwork NoiseRepresentation/Network NoiseFactors/Low NoiseDesign/ALow-NoiseAmplifier/Optimizationof BJTBiasCurrent933.5IntermodulationDistortionGain Compression /Second Harmonic Distortion /Intermodulation DistortionRatio/Dynamic Range/SINAD993.6Problems3.7References1013.8 Additional Reading10141Frequency-SelectiveNetworks and Transformers1034.1 Introduction1034.2 SeriesResonant Circuits103Effectof Source Resistance/VoltageApplication4.3 Parallel Resonant Circuits112BranchCurrents4.4 Parallel Resonant Circuits Including Transformers116Transformers with Tuned Secondaries /Double-Tuned Circuits/ Autotransformers/CapacitiveTransformers1294.5ImpedanceMatching and HarmonicFilteringUsingReactiveNetworksVoltageGain4.6 Filter Delay and Signal Distortion1354.7Problems1384.8 References1434.9 Additional Reading1445High-Frequency Amplifiers and Automatic Gain Control1455.1Introduction145
xiCONTENTS1455.2High-FrequencyPerformanceof BipolarandField-EffectTransistorAmplifiersBJT High-Frequency Model /Current Gain-Bandwidth Product/FET High-Frequency Model /Miller'sTheorem/ High-Frequency Response of FETAmplifiers/High-Frequency Responseof BJTAmplifiers/Common-BaseAmplifiers/EmitterFollowers/Differential Amplifiers / High-Speed Operational Amplifiers / Cascadeof Identical Stages1785.3 BroadbandingTechniquesInput Compensation / Feedback / Current-to-Voltage Feedback / Voltage-to-CurrentFeedback/Lossless FeedbackAmplifiers/Neutralization/Cascode Amplifiers1985.4 AutomaticGainControlTheory of Automatic Gain Control/ AnotherAGC Model / AGC System Components2075.5Problems2125.6 References2125.7 Additional Reading2136HybridandTransmission-LineTransformers2136.1 Introduction2136.2Three-Winding TransformersAsymmetricThree-WindingTransformers/PowerTransfer inHybridTransformers/PhaseDistribution inHybrid Transformers/Nonideal Three-WindingTransformer2266.3 Transmission-LineTransformersStep-UpTransformer/HybridTransformer/APowerOutput Stage2366.4Problems2396.5 References2406.6Additional Reading2417Oscillators2417.1 Introduction2417.2 Conditions for OscillationNyquist StabilityCriteria/ Circuit Analysis/Another Interpretation of the OscillatorCircuit.The Pierce Oscillator2587.3 Amplitude Stability259'7.4 Phase Stability2617.5 Crystal OscillatorCharacteristicsParallel-ModeCrystal Oscillators/Series-ModeCrystal Oscillators2767.6Voltage-Controlled Oscillators and Voltage-Controlled Crystal Oscillators2837.7 Field-EffectTransistor OscillatorsTheFETPierce Oscillator2857.8 Oscillator Control Using Delay Lines
xiiCONTENTS7.9RelaxationOscillator2872887.10Integrated-CircuitOscillatorsNE6027.11Problems3023087.12 References3097.13 AdditionalReading8311Phase-Locked Loops3118.1 Introduction3138.2 Linear Modelof thePhase-LockedLoop3178.3 Phase Detectors (PDs)Digital Phase Detectors / Exclusive-OR Detectors / Flip-Flop Detectors / Dual-DFlip-Flops/Phase-FrequencyDetectors/Mixers/Sampling Detectors/PhaseDetector Comparisons3308.4 Voltage-Controlled Oscillators3318.5LoopFilters3328.6 Linear and Nonlinear PLL Simulations Using SPICEA Sinusoidal Phase Detector Model /Voltage-Controlled OscillatorSimulations/LinearandNonlinearPLLSimulations3408.7Phase-LockedLoopApplicationsTracking Filters / Angle Modulation/Frequency Demodulation/ AmplitudeDemodulation/PhaseShifiers/Signal Synchronizers and CarrierRecovery3468.8 Digital Phase-Locked Loops3488.9 Integrated-Circuit Phase-Locked LoopsACMOS PLL3518.10 Problems3538.11 References3538.12 Additional Reading0354Phase-Locked LoopAnalysis3549.1 Introduction3549.2 Steady-State Error Analysis3569.3 Stability AnalysisTypeI Systems/Pole-Zero Filter/Control of Loop Bandwidth/ Type Il Systems/TypellThird-OrderSystems/Loops Including aTimeDelay/Loops ContainingaSample-and-Hoid Phase Detector3829.4 PLLTransient PerformanceTransientAnalysis of the Linearized PLL/ TypeI Systems: Phase Step Response/Type/ Systems:FrequencyStep Response/Type II Loop/ Ramp Inputs/Comparison of Type I and Type Il Loops / Large-Signal Behavior/ Digital PhaseDetectors/First-OrderSystems/ TypeI Loop Including a Low-Pass Filter/Sinusoidal Phase Detection/ Numerical Example
xiliCONTENTS4049.5Problems4069.6References4069.7 Additional Reading40710Frequency Synthesizers40710.1 Introduction40810.2DirectFrequency Synthesis41110.3 Frequency Synthesis byPhase LockEffectsofReferenceFrequencyonLoopPerformance/Variable-ModulusDividers/PLLFrequency SynthesizerICs / Down Conversion/ Methods for ReducingSwitching Time and/orwidening theLoop Bandwidth/Multiple-LoopFrequencySyn-thesizers /Fractional-N Loops43110.4 Direct Digital Synthesis43610.5 SynthesizerDesignExample43910.6 Phase NoiseA Model forOscillatorPhaseNoise/PhaseNoise in Phase-Locked Loops /EffectofFrequencyDivisionandMultiplicationonPhaseNoise44710.7Problems44910.8 References45010.9 AdditionalReading45211PowerAmplifiers45211.1 Introduction45311.2 Class AAmplifiersTransformer-Coupled ClassAAmplifiers/Class APush-PullAmplifiers/Square-Wave Input46311.3ClassBAmplifiersPush-Pull AmplificationwithComplementaryTransistors/PowerRelations intheDirect-CoupledClassBPush-PullAmplifier46911.4ClassCAmplifiersClass CPowerAmplifierDesign/FrequencyMultiplicationn47711.5 ClassDAmplifiersNonideal Performance48111.6ClassSPowerAmplifiersPulse-Width Modulators48311.7 Class ETuned PowerAmplifiers48311.8Problems48611.9 References48611.10AdditionalReading48712ModulatorsandDemodulators
xivCONTENTS48712.1Introduction48812.2FrequencyMixersSwitching-Type Mixers/ Conversion Loss / Distortion / Intermodulation DistortioninDiode-RingMixers/Square-LawMixers/BJTMixers/FETMixers50712.3AmplitudeandPhaseModulationandDemodulationAmplitude Modulation/ AmplitudeModulators:Standard AM/Demodulators/AverageEnvelopeDetectors /Synchronous Detection/Angle Modulation/AngleModulators/FMDemodulators/FMDetectors/PulseDiscriminators52112.4 Digital ModulationDigital Modulation and Demodulation of Analog Data / Amplitude Modulation/FrequencyModulation/PhaseModulation52712.5Integrated-CircuitTechniques53012.6 Problems53212.7 References53212.8AdditionalReading535Appendixes1.MotorolaNPNTransistorP2N2222A/2.U310JFETSiliconix/3.MotorolaMRF177RFPowerFET/4.ComlinearCLC430CurrentFeedbackOp-amp/5.BurrBrown35541.7-GHzOpAmp/6.Texas InstrumentsSN54LS297Digital Phase-Locked LoopFilters/7.Motorola MC14046BPhase-Locked Loop573Index
PREFACEThere have been many advances in communication circuits since the publica-tion of the first edition of this book.Yet most of the communication circuit funda-mentals remain intact. Amplifiers, oscillators, tuned circuits, transformers, mixers,andpoweramplifiersarestillamongthefundamentalbuildingblocksofcommuni-cationcircuits.Thereis a shifttoward the useofmorebroadbandcircuitry,butafewnarrowband circuits are still required,particularly in oscillators.It is still not possi-bletorealizean inductor in an integrated circuit,and inductors remain a necessarycomponent of many communication circuits.The many new integrated circuitshavemarkedly expanded the frequency range over which the material in this bookis applicable. While the approach of the first edition has not changed, the secondedition incorporates changes suggested by the advances in technology as well thetremendous improvements in,and availability of, computer simulation,particularlySPICE.Computer projects have been added to every chapter.This book presents fundamental analysis and design techniques for moderncommunication circuits covering the frequency range up to several hundred mega-hertz.The coveragereflects the practice of modern communication systems designto use integrated circuits, to minimize tuning operations by using broadband cir-cuits,andto use more field-effecttransistors in high-frequencycircuits.Much oftheinformation presented here appears inbookformfor thefirst time.Some of it isoriginal,much of ithas been gathered from adiverse literature on communicationelectronics,and some has been adapted from earlypublications on vacuum-tubeelectronics.Practical approximations areemphasized ratherthan theoreticalderiva-tions based on complex circuit models.The approximations provide more insightinto the design process than do lengthy derivations. Computer simulation is fre-quently used to establish the accuracy of the approximations.The"book is intended for use as a textbook in senior-level and beginninggraduate-level courses in electrical engineering and as a reference book for practi-cing engineers. It is assumed that the reader has the basic background in linear tran-sistor circuit theory obtained from a junior-level electrical engineering course,butnot necessarily in the subjects which arebecoming restricted to specialized coursesin high-frequency electronics, such as tuned-circuit analysis. Chapter 2 presents areview ofthenecessaryelectronic circuit background.A characteristic of almost all realistic communication circuits is that they aretoo complex for a complete analysis, and approximations must bemade.The
xviPREFACEjudicious use of approximations is also required in the design process.A goal ofthis book is to illustrate many of the approximations convenient and effectivefor the analysis and design of communication circuits. The circuit models areoften incomplete,but more accurate and complex models areusually best treatedwithcomputer-aided analysis methods availableto most electrical engineering stu-dents and electrical engineers. Computer-aided analysis is frequently used in theexamples.Most,ifnot all,communication circuits are availableas integrated circuits,butthere are several reasons why designers must still be familiar with the discrete cir-cuit techniques.First, there are many communication systems that cannot yet berealized in integrated-circuitform, because circuitfexibility is compromised and aninductor-capacitor tuned circuit cannot be fabricated on a chip. Second, the perfor-mance of discrete communication circuits is superior.It is necessary for the com-munication circuit designer to consider the tradeoffs among size, cost, outputpower, power consumption, noise, and distortion.Third, even when integrated cir-cuits are used, a basic understanding of communication circuitry is required. Also,monolithic power amplifiers create many additional problems,which result in thecomplete amplifier's occupying more space than would be required of adiscretepower amplifier. This book incorporates the impact that integrated circuits are hav-ing on thedesign of communication systems.Two chapters are devoted to thephase-locked loop. The importance of this device in modern systems is largely dueto its realization as an integrated circuit. Phase-locked loop applications are dis-cussed in Chap.8, and the analysis of phase-locked loops is presented in detail inChap.9.It is not possible to completely cover a subject as broad as communication elec-tronics in a single text. Much of the methodology presented here is applicable tocommunication systems in all frequency ranges, but distributed-parameter circuitanalysis techniques,not covered in this book,are usuallymore accurate at frequen-cies above 100 MHz.Digital circuits are playing an increasingly important role incommunication systems.Many applications of digital circuits are described in thistext, but conventional logic circuits are not considered, as the subject is well cov-eredinmanytexts.Chapter 1 presents an introduction to communication circuits and discussesrecent trends in receiver design. Chapter 2 reviews linear small-signal analysis ofbipolarand field-effecttransistoramplifiers.Operational amplifiers are included,since there are now devices available with gain-bandwidth products suffcientlylarge that they can be used in high-frequency communication circuits.Chapter 3defines thenoiseand distortion specificationsusedto describecommunication sys-tems.Thefundamentals of low-noise amplifierdesign are included in this chapter.The simple parallel and series tuned circuits still so important in modern communi-cation systems are discussed in Chap. 4, Methods for analyzing the high-frequencyperformance of transistor amplifiers are given in Chap. 5, together with models forautomatic gain control systems.Thetransformers, which are widely used in moderncommunication systems, are discussed in Chap. 6. The transmission-line trans-formeris stilla suitablelumped impedance-matchingnetworkfor therealizationofuntuned,broadband, interstage,and output-matching networks.Chapter7contains
xviiPREFACEan in-depth treatment of the analysis and design of high-performance transistoroscillator circuits,including crystal and voltage-controlled oscillators.Chapter 8 isdevoted to applications of the phase-locked loop, and Chap.9 to its analysis.Thephase-locked loop is one of the most versatile and widely applied circuits in com-munication systems.Its availability as an inexpensive integrated circuit impliesthat it will continue to find application in virtually all communication systems.Integrated circuits have also resulted in the design of frequency synthesizers, whichhave altered the design of most new communication systems using frequency tuning.The frequency synthesizer has also allowed the practical implementation ofmoderncommunicationtechniquessuchasfrequencyhopping.Chapter10providesa detailed treatment of frequency synthesizers. Methods for frequency shifting,modulation,and demodulation are discussed in Chap.11,including methods forfrequency-and phase-shift keying and other methods for handling digital signals.Chapter 12 discusses the design and analysis of power amplifiers and includesseveral curves useful for the design of class C power amplifiers.The book contains enough material for a two-semester course, provided it issupplemented with articles from the current literature.Chapters 1,3 through 8, and10 have been used for a one-semester course at the University of Florida.Eachchapter contains probiems that emphasize particular points; several chapters in-cludeproblems that extend the material covered.Component and integrated specification sheets contained in the appendixes are used in some of the problems.Thewriting ofthefirstedition of this book resulted from manydiscussions withmyfriend Dr.UlrichRohde,president of Compact Software.RobBruckner, nowofIntel Corporation,assisted withthe writing of this edition.The suggestions,correc-tions, and circuit designs of my students have also markedly improved the qualityofthisbook.JackSmith
ABOUTTHEAUTHORJACKR.SMITH is Professor Emeritus of Electrical Engineering at the University ofFlorida. He is founder and president of Neurotronics Incorporated.He also foundedMicrotronics Incorporated and served as its president until its saleto Oxford Instru-ments,Ltd.Dr.Smithhasbeen a visiting scientistat theFrenchNational Centerfor Sci-entific Research, the Medical School of Geneva Switzerland,and the TokyoMetro-politan Center for Neurological Research.He continues to consult for industry,mostrecently assisting the Land Mobile Productions Division of Motorola Incorporated