TY - BOOK AU - ROBERT J. SCHOENBECK TI - ELECTRONIC COMMUNICATIONS: MODULATION AND TRANSMISION SECOND EDITION SN - 0029465524 AV - TK51025S362 S362 PY - 1992/// CY - REPUBLICA DE SINGAPUR N1 - CONTENIDOS CAPÍTULO UNO PRINCIPIOS DE MODULACIÓN DE AMPLITUD 1.1 Introducción ................................................... 1 1.2 Modulación ................................................... 1 1.2.1 Necesidad de Modular ............................. 2 1.2.2 Formas de Modulación ............................. 2 1.2.3 Conceptos Visuales ................................... 3 1.2.4 Frecuencias Laterales ................................ 4 1.2.5 Factor de Modulación y Porcentaje de Modulación ........ 6 1.2.6 La Matemática de la Onda AM ..................... 9 1.2.7 Resumen ................................................ 10 1.2.8 Relaciones de Voltaje de Modulación ............ 10 1.3 Relaciones de Potencia ................................ 12 1.4 Fasores Componentes de la Onda AM ............... 14 1.5 Espectro de Frecuencia Asignable .................. 15 1.6 Selección de Banda ....................................... 17 1.6.1 Banda Comercial de Radiodifusión AM ........... 17 1.6.2 Interferencia de Canal ................................ 17 1.6.3 Definiciones ............................................. 19 1.6.4 Potencia Radiada Efectiva ........................... 20 1.6.5 Código de Emisión .................................... 21 CAPÍTULO DOS TRANSMISORES AM 2.1 Introducción ................................................. 27 2.2 Circuitos ....................................................... 27 2.2.1 Formación de la Señal Modulada ................. 28 2.2.2 Excitador .................................................. 29 2.2.3 Amplificador de Potencia ........................... 31 2.2.4 Amplificador de Conducción ....................... 31 2.2.5 Modulador ................................................ 32 2.2.6 Procesador de Audio ................................ 32 CONTENTS xvii 4.2.1 RF Amplifier 105 4.2.2 The Mixer/Oscillator 106 4.2.3 Intermediate Frequency (IF) Amplifiers 107 4.2.4 Detector 107 4.2.5 Automatic Gain Control (AGC) 107 4.2.6 Output Reproducer 108 4.3 Double-Conversion Receivers 108 4.3.1 Image Frequency Rejection 109 4.3.2 Signal-to-Noise Ratio (S/N) 110 4.3.3 Sensitivity 111 4.3.4 Selectivity 111 4.3.5 Dynamic Range 112 4.4 Receiver Circuits: The Front End 113 4.4.1 The RF Amplifier 113 4.4.2 Mixer 115 4.4.3 The Local Oscillator 118 4.4.4 Tuning Capacitors 119 4.4.5 High- or Low-Frequency Oscillator? 122 4.4.6 Front-End Circuits 122 4.5 Intermediate-Frequency Amplifiers 125 4.6 AM Detectors 132 4.7 Automatic Gain Control (AGC) 136 4.8 Audio Amplifiers 137 4.9 Squelch 141 4.10 Receiver Schematics 142 4.11 Loudspeakers 146 4.12 Pilot Carrier Receivers 148 4.13 Independent Sideband Receivers 149 4.13.1 Frequency Synthesis 150 4.13.2 Product Detectors 152 4.14 AM Stereo 152 4.15 AM Receiver Testing 155 4.15.1 Test Setup 156 4.15.2 Alignment 158 4.15.3 Noise Measurements 159 4.15.4 Receiver Sensitivity Measurements 161 4.15.5 Selectivity Measurements 162 4.15.6 Dynamic Range Measurements 162 CHAPTER FIVE FREQUENCY MODULATION PRINCIPLES 169 5.1 Introduction 169 5.2 Modulated Wave 170 5.2.1 Frequency Deviation 171 5.2.2 Percentage of Modulation 172 5.3 FM Radio Frequency Band 173 5.3.1 Radiation Standards 174 CONTENTS 5.4 Direct Frequency Modulation 175 5.4.1 Deviation Sensitivity 178 5.4.2 Carrier Frequency Tolerances 178 5.4.3 The Effects and Limits of the Audio Frequency 179 5.4.4 Modulation Index 181 5.4.5 FM Wave Equation 181 5.4.6 Bandwidth of the FM Wave 186 5.4.7 Deviation Ratio 186 5.4.8 The Voltage Distribution in the FM Wave 187 5.4.9 Power in the Modulated FM Wave 188 5.4.10 Narrowband FM 189 5.4.11 Preemphasis (Deemphasis) 189 5.5 Indirect Frequency Modulation (Phase Modulation) 192 5.6 Carrier Phase in the Frequency-Modulated Wave 196 CHAPTER SIX FREQUENCY-MODULATED TRANSMITTERS 6.1 Introduction 201 6.2 Carrier Oscillator 201 6.2.1 Reactance Modulator 205 6.3 Frequency Changers 209 6.3.1 Mixers 209 6.3.2 Modulators 209 6.3.3 Converters or Translators 209 6.3.4 Dividers 211 6.3.5 Multipliers 211 6.4 Power Amplifiers 214 6.5 Feedback Frequency Control 216 6.6 Phase Modulator 218 6.7 Carrier Null 219 6.8 Transmitter Adjustments 220 CHAPTER SEVEN FM RECEIVERS 7.1 Introduction 225 7.2 RF Amplifier 226 7.2.1 Noise in RF Amplifiers 227 7.3 Local Oscillator 233 7.4 Mixer Amplifier 234 7.5 IF Amplifiers 235 7.6 Limiters 236 7.7 FM Detectors 237 7.7.1 Slope Detector 237 7.7.2 Dual Slope Detector 238 7.7.3 The Discriminator 239 CONTENTS 9.2.1 Pure Resistance Line 301 9.2.2 Resistance Circle Sets 302 9.2.3 Reactance Circles (Arcs) 302 9.2.4 Wavelength Scales 305 9.2.5 Reflection Coefficient 305 9.2.6 Reflection Magnitude 306 9.3 Normalized Impedances 306 9.3.1 Standing Wave Ratio Circle 307 9.3.2 Load Line 307 9.4 Matching Load Impedances 309 9.5 Problem Solving Procedures 310 9.5.1 Explanation of the Procedures 312 9.6 Directional Couplers 314 9.6.1 VSWR Meter 314 9.7 Slotted Lines 315 9.7.1 Matching with a Slotted Line 318 9.7.2 Unknown Z, with a Slotted Line 319 9.7.3 Matching Transformers for Complex Load Impedances 320 9.7.4 Reflection Coefficient, Magnitude, and Angle 320 9.7.5 Line Input Impedance 321 9.8 Lossy Lines 322 9.9 Multiple-Stub Tuning 325 9.10 Other Uses of the Smith Chart 330 9.11 Carter Chart 330 CHAPTER TEN ANTENNAS 333 10.1 Introduction 333 10.1.1 Reciprocity Theorem 334 10.2 Half-Wave Dipole Antenna 334 10.2.1 The Radiated Wave 335 10.2.2 Polarization 336 10.2.3 Radiation Patterns 337 10.2.4 Antenna Impedance 339 10.2.5 Antenna Size 340 10.3 Folded Dipole 341 10.4 Conical Antenna 343 10.5 Turnstile Antenna 345 10.6 Parasitic Array Antennas 345 10.6.1 Driven Arrays 351 10.6.2 Log-Periodic Array 355 10.7 Antenna Stacking 358 10.8 Multiband Antennas 361 10.9 Quad Antennas 362 10.10 Helical Beam Antennas 363 10.11 Marconi Antenna 365 10.12 Impedance Matching to Antennas 370 CONTENTS 10.12.1 Transformer Matching 370 10.12.2 Matching Stubs 371 10.12.3 "T" Match and Delta Match 372 10.12.4 Gamma Match 374 Parabolic and Corner Reflectors 375 Circular Polarization 376 10.15 Model Antennas 378 CHAPTER ELEVEN WAVE PROPAGATION 11.1 Introduction 383 11.2 Ground Waves 383 11.3 Sky Waves 385 11.3.1 Radio Horizon 386 11.3.2 Ionospheric Layers 387 11.3.3 Power Density 389 11.3.4 Electric Field Strength 390 11.3.5 Skip Wave 391 11.4 Space Waves 394 CHAPTER TWELVE MICROWAVE SYSTEMS AND DEVICES 12.1 Introduction 399 12.2 Microwave System 399 12.3 Waveguide 403 12.3.1 Attenuation 406 12.3.2 Waveguide Selection 407 12.3.3 Coupling Methods 408 12.3.4 Modes 409 12.3.5 Slots in Waveguides 412 12.3.6 Working Factors of Waveguide 413 12.3.7 Input Impedance to the Guide 415 12.3.8 Power Limits of Waveguide 415 12.3.9 Corners, Bends, and Tees 416 12.3.10 Directional Couplers 419 12.3.11 Planned Waveguide Obstructions 422 12.4 Horn Antennas 423 12.5 Parabolic Reflectors 428 12.6 The Dielectric Rod Antenna 435 12.7 Resonant Cavities 438 12.7.1 Transit Time 439 12.7.2 Electron Bunching 440 12.7.3 Klystron 440 12.7.4 Magnetrons 443 12.7.5 Traveling Wave Tube (TWT) 446 CONTENTS 12.8 Parametric Amplifiers ........................................ 449 12.9 Circulators. Magic Tees, and Hybrid Rings .......... 451 12.10 Gas Discharge Tubes ........................................ 452 12.11 Bolometers ......................................................... 453 12.12 Microwave Diodes ................................................ 454 12.13 Microwave Field-Effect Transistors ...................... 455 12.14 Stripline and Microstrip Circuits ........................ 456 CHAPTER THIRTEEN THE COMMUNICATIONS SATELLITE 13.1 Introduction .......................................................... 463 13.2 Satellite Orbit ....................................................... 465 13.3 Satellite Position ................................................... 465 13.4 Linkages ............................................................... 466 13.4.1 Up-Link ........................................................... 466 13.4.2 Down-Link ....................................................... 467 13.4.3 Cross-Link ....................................................... 468 13.5 Assignable Satellite Frequencies ............................ 469 13.6 Inside the Satellite .................................................. 469 13.6.1 Transponder ..................................................... 470 13.6.2 Antenna Systems ............................................... 474 13.6.3 Power Package .................................................. 475 13.6.4 Station Keeping ................................................ 476 13.7 Forms of Modulation .............................................. 477 13.8 Free-Path Space Losses ........................................... 478 13.9 Ground Station ...................................................... 480 13.9.1 Aligning the Satellite Dish ................................ 482 13.10 Some Future Trends ............................................... 484 CHAPTER FOURTEEN FIBER OPTICS 14.1 Introduction .......................................................... 487 14.2 Modulation Techniques ........................................... 487 14.3 Frequencies ............................................................ 488 14.4 Fiber Optic Cables ................................................... 490 14.4.1 Refraction ....................................................... 491 14.4.2 Numerical Aperture ........................................... 493 14.4.3 Graded Index Cables ........................................ 494 14.4.4 Single Mode versus Multimode .......................... 495 14.4.5 Pulse Dispersion ................................................ 496 14.4.6 Cable Construction ............................................. 497 14.4.7 Cable Losses ...................................................... 500 14.5 Connectors ............................................................ 503 14.6 Advantages/Disadvantages ...................................... 507 CONTENTS 14.7 Bit Error Rate 509 14.7.1 Minimum Input Signal 509 14.8 Flux Budget 510 14.9 Rise Time Budget 513 14.10 Light Sources 515 14.10.1 Lasers 520 14.11 Light Detectors 524 14.6.1 Pin Diodes 526 14.6.2 Avalanche Diodes 528 14.12 System Components 530 CHAPTER FIFTEEN DIGITAL MODULATION 535 15.1 Introduction 535 15.1.1 Codes 535 15.2 Data Forms 536 15.3 Transmission Modes between Stations 538 15.4 Networks 539 15.4.1 Point-to-Point 539 15.4.2 Star 540 15.4.3 Ring 540 15.4.4 Bus 540 15.5 Telephone Lines 541 15.6 Dial Up Lines 543 15.7 Dedicated Lines 545 15.8 Acoustical Couplers 546 15.9 Data Communications Systems 546 15.10 Parity 548 15.11 Asynchronous and Synchronous Transmission 548 15.12 UARTS and ACIAS 550 15.13 RS232C Interconnect Cable (CCIT V.24 and V.28) 555 15.13.1 Drivers/Terminators 558 15.13.2 System Status 559 15.14 Modems 560 15.14.1 Low-Speed Modems 560 15.14.2 Medium-Speed Modems 563 15.14.3 High-Speed Modems: 8 PSK 567 15.15 Dual Four-Level Converters 572 15.16 Hybrid Devices 574 15.17 Loopback Testing 576 15.18 Protocol 577 15.18.1 Select 578 15.18.2 Polling 578 15.18.3 Responses 578 15.18.4 Asynchronous 579 15.18.5 Synchronous (Bisync or BSC) 579 15.18.6 High-Level Data Link Control (HDLC) 581 CONTENTS 15.19 Analog to Digital Conversion .......................................................... 586 15.19.1 Pulse Amplitude Modulation (PAM) ........................................ 587 15.19.2 Time-Division Multiplexing (TDM) ............................................ 589 15.19.3 Pulse Width Modulation (PWM) .................................................. 593 15.19.4 Pulse Position Modulation (PPM) ............................................... 594 15.20 Frequency Division Multiplexing (FDM) ....................................... 593 15.20.1 Decoding the FDM Signals ........................................................ 598 15.21 Cellular Communications .................................................................. 599 CHAPTER SIXTEEN TELEVISION 16.1 Introduction ...................................................................................... 607 16.2 Scanning Principles .......................................................................... 607 16.3 Deflection Systems .......................................................................... 610 16.3.1 High Voltage .................................................................................. 613 16.4 Video Picture Signal .......................................................................... 614 16.4.1 Blanking and Synchronizing Pulses .......................................... 615 16.4.2 Positive/Negative Picture Phase ................................................ 617 16.5 Vestigial Sideband Transmission .................................................. 618 16.5.1 Sound Carrier ................................................................................. 619 16.5.2 Channel Assignments .................................................................. 620 16.6 Receiver Block Diagram .................................................................. 620 16.6.1 Tuner ............................................................................................... 620 16.6.2 IF Amplifiers .................................................................................. 622 16.6.3 Automatic Gain Control ................................................................ 623 16.6.4 Video Amplifiers ............................................................................ 624 16.6.5 Sound Carrier ................................................................................. 625 16.6.6 Synchronizing Circuit .................................................................. 625 16.7 Color .................................................................................................. 626 16.7.1 Subcarrier Modulation .................................................................. 627 16.8 Multichannel Television Sound (MTS): TV Stereo ......................... 628 SMITH CHARTS .................................................................................. 635 ; Ingeniería Eléctrica N2 - ADDITIONAL MAXWELL MACMILLAN INTERNATIONAL EDITIONS IN ENGINEERING Astus PRINCIPLES OF BIOMEDICAL INSTRUMENTATION & MEASUREMENT Bugat ELECTRONIC DEVICES & CIRCUITS/2e DeGanno ENGINEERING ECONOMY/5e Floyd ELECTRONIC DEVICES/2e Floyd ELECTRONICS FUNDAMENTALS/2e Floyd PRINCIPLES OF ELECTRIC CIRCUITS/3e Floyd PRINCIPLES OF ELECTRIC CIRCUITS, ELECTRON FLOW VERSION/2e Mayer ELECTRONIC MATERIALS SCIENCE Proakis INTRODUCTION TO DIGITAL SIGNAL PROCESSING Shackelford INTRODUCTION TO MATERIALS SCIENCE FOR ENGINEERS/2e Taha OPERATIONS RESEARCH/4e Tocci FUNDAMENTALS OF ELECTRONIC DEVICES/4e Shearer DYNAMIC MODELING & CONTROL OF ENGINEERING SYSTEMS Webb INDUSTRIAL CONTROL ELECTRONICS Wolf STATICS & STRENGTH OF MATERIALS Young ELECTRONIC COMMUNICATION TECHNIQUES/2e Ziemer SIGNALS & SYSTEMS CONTINUOUS & DISCRETE/2e DING EN ER -