Cover
Title Page
Copyright Page
Contents
Author Biographies
Foreword
Preface to the Second Edition
Acknowledgments
Chapter 1 Overview
References
Chapter 2 Fundamental Concepts
2.1 Maxwell's Equations Demystified
2.1.1 Fundamental Terms
2.1.1.1 Electric Charge
2.1.1.2 Conservation of Charge and the Continuity Equation
2.1.1.3 Electric and Magnetic Forces and Fields
2.1.1.4 Biot–Savart Law
2.1.2 Maxwell's Equations
2.1.2.1 Gauss's Law for Electric Field
2.1.2.2 Gauss's Law for Magnetic Field
2.1.2.3 Faraday's Law of Induction
2.1.2.4 Ampere's Law
2.1.2.5 Impressed and Conduction Currents
2.1.2.6 Constitutive Relations
2.1.2.7 Divergence-Free (Solenoidal Vector) Fields
2.1.2.8 Curl-Free (Conservative) Fields
2.2 Boundary Conditions
2.3 Intrinsic Inductance of Conductors and Interconnects
2.3.1 Concept of Inductance
2.3.2 Self-Inductance
2.3.3 Mutual Inductance
2.3.4 Partial Inductance
2.3.5 External and Internal Inductance
2.3.6 Conductors as Materials
2.3.7 Skin Effect and Skin Depth
2.3.8 Proximity Effect
2.4 Nonideal Properties of Passive Circuit Components and Interconnects
2.4.1 "Real-World" Resistors
2.4.2 "Real-World" Capacitors
2.4.3 Antiresonance of Parallel (Nonideal) Capacitors
2.4.4 "Real-World" Inductors
2.4.5 Interconnects (Wires and PCB Traces)
2.5 Return Current Path Impedance
2.5.1 How Current Flows
2.5.2 What Path Should Return Currents Follow?
2.5.3 Is the Shortest Path Always the Best?
2.5.4 What If Alternate Paths Are Available?
2.5.5 Equivalent Circuit Analysis
2.5.5.1 Return Current Path at Low Frequencies
2.5.5.2 Return Current Path at High Frequencies
2.5.5.3 Return Current Flow in Inductive Return Paths
2.5.5.4 When is Inductance Minimized?
2.5.5.5 Physical Generalization of the Path of Least Impedance Principle
2.5.5.6 Return Current Path, Conclusion
2.5.5.7 Experimental Validation for the Path of Least Inductance Principle
2.5.6 Implication of the Principle
2.5.6.1 Signal Current Return Path on PCBs
2.5.6.2 Signal Current Return Path in Coaxial Cables
2.5.6.3 Signal Current Return Path in Flat (Ribbon) Cables
2.5.6.4 Signal Current Return Path in Twisted Wire Pairs
2.6 Spectral Content of Signals
2.6.1 Radiation Efficiency and Electrical Length
2.6.2 Periodic Pulsed Signals
2.6.3 Random (Aperiodic) Pulsed Signals
2.6.4 Effect of Ringing on the Spectrum of Pulsed Signals
2.6.5 Spectrum Conservation
2.7 Transmission Line Fundamentals
2.7.1 Transmission Line Definition
2.7.2 Transmission Line Equations and Intrinsic Parameters
2.7.3 The Dual View of Signals and Interconnects
2.7.4 Transmission Line Termination and Loading Conditions
2.8 Modes of Signal Propagation
2.8.1 Differential-Mode and Common-Mode Signals
2.8.2 Common-Mode Interference-Generation Mechanism and Its Mitigation
2.8.2.1 CM Generation Due to "Ground Loops"
2.8.2.2 CM Generation Due to Imbalance in Differential Drivers
2.8.2.3 CM Generation Due to Induction and Coupling
2.8.2.4 CM Generation Due to Signal Skew in Differential Conductors
2.8.2.5 Mitigation of Common-Mode Interference Generation
2.8.3 Differential Signaling and Balanced Circuits
2.8.4 Common-Mode (CM) to Differential-Mode (DM) Conversion
2.8.5 Even- and Odd-Mode Impedances
2.8.5.1 Characteristic Impedance of a Single, Isolated Line
2.8.5.2 Differential Impedance
2.8.5.3 Common Impedance
2.8.5.4 Odd- and Even-Mode Impedance
2.8.5.5 Generalizing Z0, Zodd, and Zeven Relationship
2.9 Interaction Between Sources to Radiated Fields
2.9.1 Radiation from Current-Carrying Conductors
2.9.1.1 DM Current Sources (Small Magnetic Loops)
2.9.1.2 CM Current Sources (Small Electric Dipoles)
2.9.2 Flux Cancellation, the Electromagnetics of Balancing
2.9.3 Not all Common-Mode Currents are Bad ...
2.10 Out of Band Susceptibility in Solid-state Devices
2.10.1 RFI Rectification Mechanism in p–n Junctions
2.10.2 Digital and Linear IC Interference Susceptibility
2.10.3 Susceptibility of Op-Amps to Ground-Coupled EMI
References
Chapter 3 The Grounds for Grounding
3.1 Grounding, an Introduction
3.1.1 "Grounding," One Term, Many Imports
3.1.2 The Grounding Symbol – Adding to the Confusion
3.1.3 Grounding—A Historical Perspective and the Evolution of the Term
3.1.4 Grounding-Related Myths, Misconceptions, and Misapprehensions vs Facts and Sensible Choices
3.1.4.1 Myth – Current Goes to Ground
3.1.4.2 Myth – Grounding Brings Everything to Zero Potential, Reducing Touch and Step Voltage to a Safe Value
3.1.4.3 Myth – To Be Safe, Add More Earth Electrodes
3.1.4.4 Myth – Earth Electrodes Keep Us from Getting Shocked
3.1.4.5 Myth – Transient Current in the Grounding Conductors May Introduce Errors in Data Transmission Between Interconnected Equipment
3.1.4.6 Myth – Different Currents Should Flow Through Separate Paths
3.1.4.7 Myth – Electricity (Only) Takes the Path of Least Resistance
3.1.4.8 Myth – Common, Ground, and Neutral Are Equivalent
3.1.4.9 Myth – It Is Advisable to Tie Neutral and Ground Together in Multiple Places
3.1.4.10 Myth – Single Point Ground Is Necessary
3.1.4.11 Myth – for the Sake of Best Equipment Performance, Safety Regulations May Be Compromised
3.2 Objectives of Grounding
3.2.1 Electrical Safety Grounding
3.2.1.1 Grounding for Preclusion of Power Fault Hazards
3.2.1.2 Lightning Protection System (LPS) Grounding
3.2.2 Grounding for Control of Electromagnetic Interference (EMI)
3.2.2.1 Controlled Path for EMI Current
3.2.2.2 Image Plane
3.2.3 Signal Grounding
3.2.3.1 Signal Reference Grounding
3.2.3.2 Signal Current Return Path
3.2.4 Summary of Grounding Objectives
References
Chapter 4 Fundamentals of Grounding Design
4.1 Ground-Coupled Interference and Its Preclusion
4.1.1 Grounding May Not Be the Solution; Rather, it is Part of the Problem
4.1.2 The Good Earth
4.1.3 Controlling Common-Impedance Interference Coupling
4.1.3.1 Lowering the Impedance of the Common Return Path
4.1.3.2 Precluding Common Current-Return Paths
4.1.3.3 Designing Noise-Tolerant Circuits
4.2 Fundamental Grounding Schemes
4.2.1 The Need for Different Schemes
4.2.2 Fundamental Grounding Schemes
4.2.2.1 Floating Scheme
4.2.2.2 Single-Point Grounding Scheme
4.2.2.3 Multipoint Grounding (MPG) Scheme
4.2.2.4 Composite (Hybrid) Grounding Scheme
4.2.2.5 Frequency-Selective Grounding
4.2.3 Grounding Schemes in Complex Systems
4.2.3.1 Distributed Single-Point Grounding
4.2.3.2 "Soft" Grounding
4.2.3.3 "Tree" Grounding
4.2.3.4 "Nested" Grounding
4.3 Grounding Trees
4.3.1 Objectives and Basic Design Considerations
4.3.2 Ground Tree Design Methodology
4.3.2.1 Step 1: Identify System Architecture
4.3.2.2 Step 2: Define Chassis Connections at the Circuit/Module Level
4.3.2.3 Step 3: Define Subassembly Signal Returns' (Ground) Requirements
4.3.2.4 Step 4: Identify Chassis Isolation/Connection Requirements in Subassemblies
4.3.2.5 Step 5: Define Common Grounding Point (CGP) Location
4.3.2.6 Step 6: Determine Return Conductors Connections from the Circuits to the CGP
4.3.2.7 Step 7: Identify Potential Ground Loops
4.3.2.8 Step 8: Consider "Special Cases" Potentially Leading to Violation of the Grounding Scheme
4.3.2.9 Step 9: Incorporate "Isolation Measures" for Preclusion of Undesired Ground Loops
4.3.2.10 Step 10: Sketch the "Grounding Tree"
4.3.2.11 Step 11: Consider Intra-Circuit Grounding Scheme
4.3.2.12 Step 12: Define the Power Supply Outputs' Specification
4.4 Role of Isolated Switch-Mode Power Supplies in Grounding System Design
4.4.1 Principle of Switch-Mode Power Supply Operation
4.4.2 The Need for Isolation in Switch-Mode Power Supplies
4.4.3 Isolation and Grounding in Switch-Mode Power Supplies
4.4.4 Isolation Requirements and Testing
4.5 Ground Loops
4.5.1 Definition of a "Ground Loop"
4.5.2 "Who's Afraid of the Big Bad Loop?," or - Ground Loop Consequences
4.5.2.1 Why Are Ground Loops a Problem?
4.5.2.2 When Are Ground Loops Not a Problem?
4.5.3 Ground Loop Interference Coupling Mechanisms
4.5.3.1 Coupled Ground Loop Interactions
4.5.3.2 Ground Loop Interference Due to Load Imbalance
4.5.3.3 Application of the Transfer Impedance Concept to Ground Loop Interference Coupling
4.5.4 Ground Loop Interactions: Frequency Considerations in CM to DM Interference Conversion
4.5.4.1 Case A: Totally Floating Circuit
4.5.4.2 Case B: Circuit Connected to SRS ("Grounded") at One End
4.5.4.3 Case C: Circuit Connected to SRS ("Grounded") at Both Ends
4.5.5 Resolving Ground Loop Problems
4.5.5.1 Isolation Transformers
4.5.5.2 Common-Mode Chokes (Baluns, Bifilar Chokes)
4.5.5.3 Optocouplers and Optical Isolators
4.5.5.4 Capacitive Couplers/Isolators
4.5.5.5 High-Speed Digital Isolators
4.5.5.6 Analog Differential, Instrumentation, and Isolation Amplifiers
4.5.5.7 Galvanically Isolated High-Speed Differential Transceivers
4.5.5.8 Circuit Bypassing
4.5.5.9 Summary of Interface Isolation Techniques
4.5.5.10 Example: Data Line Interface Isolation Design (10/100/1000BaseT)
4.6 Zoned Grounding
4.6.1 Electromagnetic Topology
4.6.2 The Zoning Concept as Applied to Grounding
4.6.3 Zoning Compromises and Violation
4.6.4 Impact of Zoning on Subsystem Grounding Architecture
4.7 Equipment Enclosure and Signal Grounding
4.7.1 External Signal and Safety Grounding Interconnects Between Enclosures
4.7.2 Equipment DC Power, Signal, and Safety Grounding
4.7.3 Power Distribution Grounding Schemes in Integrated Clustered Systems
4.7.3.1 Centralized Power Scheme with Secondary Power Supplies
4.7.3.2 Fully Centralized Power Distribution Scheme
4.7.3.3 Decentralized (Distributed) Power Distribution Scheme
4.7.4 Grounding of Equipment Enclosure Shield
4.8 Rack and Cabinet Subsystem Grounding Architecture
4.8.1 Grounding Ground-Rules in Racks and Cabinets
4.8.2 Ground Loops and Their Mitigation in Racks and Cabinets
4.8.3 External Grounding of Racks and Cabinets
4.9 Grounding Strategy Applied by System Size and Layout
4.9.1 One Size Fits None
4.9.2 Isolated System
4.9.3 Clustered System
4.9.4 Distributed System
4.9.5 Nested-Distributed System
4.9.6 Central System with Extensions
4.9.7 Grounding Strategy by System Size and Layout - Summary and Case Study
References
Chapter 5 Bonding Principles
5.1 Objectives of Bonding
5.2 Bond Impedance Requirements
5.3 Types of Bonds
5.3.1 Direct Bonds
5.3.1.1 Welding
5.3.1.2 Brazing
5.3.1.3 Soft Soldering
5.3.1.4 Bolts
5.3.1.5 Rivets
5.3.1.6 Conductive Adhesive
5.3.2 Indirect Bonds
5.3.3 Contact Impedance of Bonds
5.3.4 Bonding Impedance Equivalent Circuit
5.3.4.1 Bond Resistance
5.3.4.2 Bond Reactance
5.3.5 Bond Effectiveness
5.3.6 Enhancing Bonding Effectiveness
5.4 Surface Treatment
5.4.1 Roughness of Mating Surface Conditions
5.4.2 Surface Contaminants
5.4.3 Surface Hardness
5.4.4 Contact Pressure
5.4.5 Bond Area
5.5 Dissimilar Metals and Galvanic Corrosion Control
5.5.1 Thermodynamic Basis of Galvanic Corrosion
5.5.2 Electrochemical Series
5.5.3 Galvanic Series
5.5.4 Electrochemical Kinetics of Galvanic Corrosion - Blame it on Faraday
5.5.5 Galvanic Couples
5.5.6 Impact of Environment on Galvanic Corrosion
5.5.7 Effects of Corrosion on EMC Performance
5.5.7.1 Degradation of Equipment Bonding and Shielding
5.5.7.2 Collocation and RF-Coexistence in Spectrum-Dependent Systems
5.5.7.3 Electrostatic Discharge (ESD) Effects
5.5.8 Corrosion Protection and Control
5.5.8.1 Use of Similar Mating Metals
5.5.8.2 Applying Protective Conductive Coatings
5.5.8.3 Interposing Metals and Sacrificial Anodic Parts
5.5.8.4 Sacrificial Metal Coating
5.5.8.5 Minimizing Cathode to Anode Area Ratio
5.5.8.6 Breaking the Electrolytic Bridge
5.5.8.7 Protective (Nonconductive) Paint
5.5.8.8 Understand Project Particulars
5.6 Bonding Verification
References
Chapter 6 Grounding in Power Transmission and Distribution Networks
6.1 Introduction
6.2 Overhead Transmission Lines
6.3 Underground Power Cable Transmission and Distribution Networks
6.4 Earth Fault and Ground Potential Rise
6.5 Tolerable Step and Touch Voltages
6.6 Earthing for High-Voltage Substations
6.6.1 Bonding Requirements
6.6.2 Principal Design Considerations
6.7 Earthing for Power Distribution System
6.7.1 Faults in Power Distribution Systems
6.7.2 Electric Shock Hazards
6.7.2.1 Step and Touch Voltage and Transferred Potential Arising from Ground Faults
6.7.2.2 Leakage via Power Line Filter Capacitance
6.7.2.3 Shock Protection by Earthed Equipotential Bonding and Automatic Disconnection of Supply
6.7.3 Methods of Earthing in Power Distribution Systems
6.7.3.1 Solid Earthing
6.7.3.2 Impedance Earthing
6.7.4 The Ungrounded System
6.8 Earthing in Low-Voltage Distribution System
6.8.1 TN-System
6.8.1.1 TN-S System
6.8.1.2 TN-C System
6.8.1.3 TN-C-S System
6.8.2 TT System
6.8.3 IT System
6.8.4 Temporary Overvoltage in Low-Voltage Installations Due to Faults Between High-Voltage Systems and Earth
6.8.5 Earthing Systems and EMC
6.8.6 Requirements for the Installation of Equipment with High-Protective Earth Conductor Current
6.8.7 Application of Residual Current Devices for Shock Protection
6.9 Equipotential Bonding to Building Structures and Other Services
References
Chapter 7 Grounding for Generators, UPSs, VSDs, and Instrumentation
7.1 Grounding for Generators
7.1.1 Ungrounded Generator
7.1.2 Resistance Grounding
7.1.2.1 High-Resistance Grounding
7.1.2.2 NGR Grounding Transformers
7.1.3 Grounding of Generators in Parallel Operation
7.1.3.1 Multiple-Point Grounding
7.1.3.2 Single-Point Grounding
7.1.3.3 Neutral Grounding Transformer
7.1.4 Grounding and Earth Fault Protection for Generators in Parallel Operation
7.1.5 Nuisance Tripping of Generators in Parallel Operation – A Case Study
7.1.6 Transfer Switching of Alternate Power Supplies
7.2 Grounding for Uninterruptible Power Supplies
7.2.1 Grounding Scheme for Static Double-Conversion UPS
7.2.2 Grounding for Transformerless UPS
7.3 Grounding for Variable Frequency Drives
7.3.1 Stray Currents in VFDs
7.3.2 VFD Cables
7.4 Grounding Requirements for Instrumentation
7.4.1 Grounding Practices for Instrumentation
7.4.1.1 Connections to Instrument Earth
7.4.1.2 Connections to Safety Earth
7.4.2 Grounding for Fieldbus Systems
7.4.2.1 Power Supply and Isolation
7.4.2.2 Fieldbus Signals
7.4.2.3 Fieldbus Cable System
7.4.2.4 Shielding and Grounding
7.4.3 The Least You Need to Know
References
Chapter 8 Grounding for Lightning Protection Systems
8.1 An Overview of the Lightning Phenomenon
8.2 Lightning Attachment Point and Zones of Protection
8.3 The Lightning Protection System
8.3.1 The Air Termination Subsystem
8.3.2 The Down Conductors
8.3.3 The Earth Termination Network
8.4 Application of Natural Earth Electrodes
8.5 Reduction of the Transient Impedance of Earth Electrodes
8.6 Protection Against Transferred, Touch, and Step Voltages
8.7 Influence of LV Earthing Schemes on Lightning Overvoltage
8.8 Separate or Integrated Electrical and Lightning Grounds
8.9 Pitfalls in Earthing and Bonding
References
Chapter 9 Integrated Facility and Mobile/Transportable Vehicle Grounding Systems
9.1 Facility Grounding Subsystems
9.1.1 Earth Electrode Subsystem (EESS)
9.1.2 Fault Protection Subsystem (FPSS)
9.1.3 Lightning Protection Subsystem (LPSS)
9.1.4 Signal Reference Subsystem (SRSS)
9.2 Grounding Practices in Buildings and Fixed Facilities
9.2.1 Grounding of Power Distribution Systems in Buildings
9.2.2 Grounding in Industrial Facilities
9.2.3 Grounding for Information Technology Equipment
9.2.4 Grounding in Telecommunication and C4I (Command, Control, Communications, Computer, Intelligence, Surveillance, and ...
9.2.5 Grounding in HA-EMP-Protected and Secure C4ISR Facilities
9.2.5.1 Grounding for Facility HA-EMP Survivability
9.2.5.2 Grounding for Facility Emanation Security (EMSEC)
9.2.5.3 EMSEC vs HA-EMP Grounding in Secure C4ISR Facilities
9.2.5.4 Grounding and Bonding Principles for C4ISR Facilities
9.2.6 Grounding Practices in Mass Rapid Transit Systems
9.2.6.1 Earthing in Stations
9.2.6.2 Stray Currents
9.2.6.3 Passenger Station and Platform
9.2.6.4 Protection Against Electrical Faults and Lightning Surges
9.2.7 Grounding Design Practices for Underground Facilities (in Rock Cavern)
9.2.7.1 Earthing and Bonding Requirements
9.2.7.2 Equipotential Bonding
9.2.7.3 Lightning Considerations
9.2.7.4 Earthing and Bonding Methodology
9.2.7.5 Guarding the Point of Entry
9.3 Grounding for Preclusion of Electrostatic Discharge (ESD) Effects in Facilities
9.3.1 Nature and Sources of Static Electricity
9.3.2 Susceptibility to ESD
9.3.3 ESD Protected Areas (EPAs) in Facilities
9.3.4 ESD Protective Tools, Materials, and Equipment
9.3.4.1 ESD Protective Workbenches and Work Surfaces
9.3.4.2 Personnel Wrist Straps
9.3.4.3 Protective Floors, Floor Mats, and Floor Finishes
9.3.5 Essentials of Grounding for ESD Control
9.3.6 Safety Considerations in ESD Grounding
9.4 Grounding Practices in Mobile Platforms and Vehicles
9.4.1 Grounding Practices in Transportable Tactical Shelters
9.4.1.1 Stand-Alone Equipment
9.4.1.2 Stand-Alone Shelters or Trailers
9.4.1.3 Collocated Transportable Equipment
9.4.1.4 Collocated Shelters
9.4.2 Grounding Practices in Aircraft
9.4.2.1 Earthing of Aircraft and Ground Services
9.4.2.2 Internal Aircraft Grounding
9.4.3 Grounding Practices in Spacecraft
9.4.3.1 Earthing and External Grounding Connections between the Spacecrafts to the Launch Facility
9.4.3.2 Spacecraft Internal Grounding Considerations
9.4.4 Grounding Practices in Ships
9.4.4.1 Ground Reference Structure
9.4.4.2 Hull-Generated EMI
9.4.4.3 Grounding at Ship Hull Penetrations
9.4.4.4 Hull (Structure) Power Current Return Scheme
9.4.4.5 Shipboard Signal Return Grounding Scheme
9.4.4.6 Grounding Architecture in Nonmetallic Hull Ships
References
Chapter 10 The Earth Connection
10.1 Introduction
10.2 Typical Features of an Earthing System for a Low-Voltage Installation
10.3 Typical Features of an Earthing System for a High-Voltage Installation
10.3.1 General Design Considerations
10.3.2 Particular Design Considerations
10.4 Resistance to Earth
10.5 Soil Resistivity
10.6 Types of Earth Electrodes
10.6.1 The Earth Rods
10.6.2 Earth Plates
10.6.3 Horizontal Strip or Round Conductor Electrode
10.6.4 The Mesh or Grid Earth Electrode
10.6.5 The Ring Earth Electrode
10.6.6 Foundation Earth Electrode
10.7 Design of Earth Electrodes and Their Layout
10.8 Selection of Material
10.9 Grounding Requirements of Power Distribution Systems
10.10 Earth Potential Rise and Surface Potential Gradients
10.10.1 Vertical Earth Rod
10.10.2 Horizontal Electrodes
10.11 Measurement of Soil Resistivity and Earth Electrode Resistance
10.11.1 Measurement of Soil Resistivity
10.11.2 Measurement of Earth Resistance
10.11.2.1 Fall-of-Potential Method
10.11.2.2 Two-Point Method
10.11.2.3 Clamp-On Earth Tester
10.11.2.4 Three-Point Method
10.11.2.5 Staged Fault Method
10.11.3 Characteristics of Earth Electrode Resistance Testers
10.12 Measurements of Earthing System Impedance, Touch and Step Voltages
10.13 Safety in Measurement and Testing Earthing System
10.14 Reducing Earth Resistance
References
Chapter 11 Grounding in Wiring Circuits and Cable Shields
11.1 Introduction: System Interface Problems
11.2 To Ground or not to Ground (Cable Shields)
11.3 Fundamentals of Cable Shielding
11.3.1 Why Shield Cables?
11.3.2 Fundamental of Shielding Mechanisms
11.3.3 Configuration of Shielded Cables
11.3.3.1 Balanced and Unbalanced Shielded Signal-Interface Cables
11.3.3.2 Transmission-Line Model of Shielded Cables
11.4 Cable Shield Termination
11.4.1 Termination of Cable Shields - A Qualitative Discussion
11.4.2 Termination of Cable Shields - A Quantitative Discussion
11.4.2.1 Shielding Against Electric Fields Interactions
11.4.2.2 Shielding for Control of Magnetic Fields Coupling onto Wiring
11.4.2.3 Shielding for Control of Magnetic Field Emissions
11.4.3 Frequency Considerations in Cable Shield Termination
11.4.3.1 Shielding and Ground Loops
11.4.3.2 Shield Termination at High Frequencies
11.4.3.3 Frequency-Selective Shield Termination
11.4.3.4 An R-L-C Lumped-Element Analysis of Shield and Its Termination
11.5 Shield Surface Transfer Impedance
11.5.1 Methods for Cable Shielding
11.5.2 Shield Surface Transfer Impedance in Coaxial Lines
11.5.3 Where Should a Shield of a Balanced Line be Terminated?
11.5.4 Shield Termination - The Key to Optimal Cable Shielding Performance
11.5.4.1 Effect of Pigtail Shield Termination
11.5.4.2 High-Performance Shield-Termination Techniques
11.5.4.3 Maintaining Cable Shield Continuity
11.5.4.4 Termination of Multiple Shields
11.5.4.5 Resistive Termination in Multiple Shields
11.5.4.6 Frequency-Selective Cable-Shield Termination
11.5.5 Twisted Cables and the Effect of Grounding
11.5.6 Strategies for Shield Termination in Common Types of Shielded Cables
11.5.6.1 Coaxial Cables
11.5.6.2 Triaxial Cables
11.5.6.3 Twinaxial Cables
11.5.6.4 Ribbon Cables
11.6 Grounding Considerations in Signal Interfaces
11.6.1 Interfacing Low-Frequency Unbalanced Signal Circuits
11.6.2 Interfacing High-Frequency Unbalanced Signal Circuits
11.6.3 Interfacing Equipment Containing both Low- and High-Frequency Signals
11.6.4 Interfacing of Broadband (Video) Signal Circuits
11.6.5 Interfacing of Balanced Signal Circuits
11.6.5.1 Differential vs Balanced Signaling - A Déjà vu
11.6.5.2 RS-422 and RS-485
11.6.5.3 Ethernet (Twisted-Pair Interface)
11.6.6 Effect of Interface Grounding Scheme on Magnetic Interference Susceptibility
11.7 Grounding of Transducers and Measurement Instrumentation Systems
11.7.1 Measurement Accuracy Concerns
11.7.1.1 Floating Measurements
11.7.1.2 Floating Measurement Apparatus
11.7.1.3 Guarded Measurement Apparatus
11.7.2 Guard Shields and Instrumentation Wiring Shield Interconnection
11.7.3 Grounding of Wiring Shields in Analog Data Acquisition Systems
11.7.3.1 Grounded Transducers
11.7.3.2 Ungrounded ("Floated") Transducers
11.7.3.3 Transducer Amplifiers
References
Chapter 12 Grounding of Terminal Protection Devices
12.1 Filtering and Transient-Voltage Suppression - Complementary Techniques to Shielding
12.2 Types of Conducted EMI
12.3 Overview of Filtering and Transient-Voltage Suppression
12.3.1 Fundamental EMI Filter Devices and Circuits
12.3.2 Special EMI Filter Applications
12.3.2.1 Common-Mode Chokes
12.3.2.2 Power-Line Filters
12.3.3 Transient-Voltage Surge Suppression (TVSS) Devices and Circuits
12.3.3.1 A Transient-Effects, Grounding-Related Case Study
12.3.3.2 Fundamentals of Transient-Voltage Surge Protection
12.3.3.3 Commonly Used Transient-Voltage Surge Suppression Devices (TVSS)
12.3.3.4 Hybrid Transient-Protection Circuits
12.4 Grounding and Bonding of Filters and Transient-Voltage Surge Suppression (TVSS) Devices
12.4.1 Modes of Protection
12.4.2 Modes of EMI and Transients
12.4.2.1 Common-Mode Surges
12.4.2.2 Linear and Nonlinear Conversion Loss
12.4.3 Effect of Circuit Grounding Scheme on Terminal Protection
12.4.3.1 Transient Protection in a Completely "Floating Circuit"
12.4.3.2 Transient Protection in a "Single-Point Grounded Circuit"
12.4.4 When Is Ground Not Equal to Ground?
12.4.5 Practices for Mounting and Grounding/Bonding of Terminal Protection Devices (TPDs)
12.4.5.1 Optimizing Filter Grounding - Feed-Through Capacitors and Filters
12.4.5.2 Filter Connectors
12.4.5.3 Optimizing Filter Grounding - PCB Layout Issues for Transient-Voltage Protection
12.4.5.4 Mounting Practices - "Doghouse Mounting"
References
Chapter 13 Grounding on Printed Circuit Boards
13.1 A Bird's Eye View on Signal Integrity (SI), Power Integrity (PI), and EMC
13.2 Interference Sources on the PCB
13.3 "Grounding" on PCBs
13.4 Signal Propagation on PCBs – The Dual World View of Currents, Voltages, Circuit Elements, and Electromagnetic Fields
13.4.1 Circuit Representation of Transmission Lines on PCBs
13.4.2 Electromagnetic field representation of transmission lines on PCBs
13.4.3 Equivalence of Power and Ground Planes as Return Paths for High-Speed Signal Propagation
13.4.4 Common Transmission Line Configurations on PCBs
13.4.4.1 Single-Ended Transmission Line Configurations
13.4.4.2 Differential Transmission Line Configurations
13.4.4.2 Nature of Transmission Lines at Ultrahigh Frequencies
13.4.4.1 Losses and Absorption
13.4.4.2 Conductor and Plane Losses
13.4.4.3 Dispersion
13.4.4.4 Effect of Conductor Surface Roughness
13.4.5 The Dark Side – Return of the Signal: Return Current Path on PCBs
13.4.6 Return Current Distribution
13.4.7 Crosstalk on PCBs – The Conversation We Wish Would Stop!
13.4.8 Common Impedance Coupling on PCBs
13.4.9 Consequences of Transmission Line Topology on EMI and Crosstalk Control
13.5 Return Path Discontinuities: "Mind the Gap"
13.5.1 Dreadful or Tolerable – It Depends? A Case Study
13.5.2 Undesired Effects of Traces Crossing Gaps in the Reference Planes: "Seeing is Believing"
13.5.2.1 Creation of Common-Mode Currents and Emissions
13.5.2.2 Susceptibility to Impulsive-Radiated Electromagnetic Fields
13.5.2.3 Crossing Reference Plane Breaks as a Source of Crosstalk
13.5.2.4 Crossing Reference Plane Breaks, Rise Time Effects on Signals
13.5.2.5 Radiated Emissions from a Split Plane, Verification by Simulation
13.5.3 Reference Plane Discontinuities and Mitigation Strategies
13.5.3.1 Traces Crossing Slots and Splits in Reference Planes
13.5.3.2 Mitigating the Adverse Effects of Traces Crossing Slots in Reference Planes – "Bypass (Stitching) Capacitors"
13.5.3.3 Mitigating the Adverse Effects of Traces Crossing Slots in Reference Planes – "Interdigital Slot in Reference Planes"
13.5.3.4 Excessive Pin/Hole Clearance
13.5.4 (Almost) Never Jump Layers! – Cavity Excitations by Signals
13.5.4.1 Signal Trace Traversing a Single Reference Layer
13.5.4.2 Signal Trace Traversing Multiple but Identical Reference Layers
13.5.4.3 Signal Trace Traversing Multiple and Dissimilar Reference Layers
13.5.4.4 The Layer-Jumping Dilemma – Seeing is Believing!
13.5.4.5 Improper Motherboard to Daughter Board Connections
13.5.5 Differential Lines Crossing Gaps in Reference Planes
13.5.5.1 Return Current Distribution of a Differential Pair
13.5.5.2 Differential Return Current Concerns: Return Current "U-Turn"
13.5.5.3 Differential Lines Jumping Layers are No Different
13.5.5.4 Differential Lines Crossing Defected Ground Structure (DGS): Putting Slots to Work
13.5.6 Edge Connector Discontinuities and Mitigation Strategies
13.5.7 Reference Plane Edge Effects
13.6 DELTA-I (ΔI) and Simultaneous Switching Noise (SSN) in PCBs
13.6.1 General ΔI-Noise Generation Mechanism
13.6.1.1 Drive Current Discharge into Loads' Input Capacitances
13.6.1.2 Drive Current Discharge into Loads' Input Capacitances
13.6.1.3 Core (Processing) Noise
13.6.2 Consequences of ΔI-Noise
13.6.2.1 Amplitude Type Interference (Ripple)
13.6.2.2 Temporal Type Interference (Jitter)
13.6.3 Effective Management and Control of ΔI-Noise Consequences
13.6.3.1 Reducing Load Capacitance
13.6.3.2 Increasing Transition Times of the Switching Signals
13.6.3.3 Reducing Common Impedance in Connectors and Device Packages
13.6.3.4 Reducing Circuit Overall Net Inductance ("It's Really All About Inductance")
13.6.3.5 Reducing the Impedance of the Power Distribution Network ("It's ALSO All About Inductance")
13.6.4 Decoupling Strategies
13.6.4.1 The "Brigade of Capacitors"
13.6.4.2 Decoupling Design – Selection of Capacitors
13.6.4.3 Placement and Mounting of Decoupling Capacitors (Avoid the "No-Fly Zone")
13.6.4.4 Controlling Spreading (or Interconnection) Inductance
13.6.4.5 Embedded Capacitance – The Ultimate Solution?
13.6.5 And then There Were those Pesky Rogue Waves...
13.6.6 "Before You Add Capacitors... Hold Your Horses" – Decoupling and Inrush Current
13.6.6.1 What is Inrush Current?
13.6.6.2 Effects of Load Capacitance on Inrush Current
13.6.6.3 Problems Caused by Inrush Current – Why the Concern?
13.6.6.4 Methods of Reducing Inrush Current
13.7 Parallel-Plate Waveguide (PPW) Noise Mitigation
13.7.1 PDN Parallel-Plate Waveguide (PPW) Excitation
13.7.2 PDN Parallel-Plate Waveguide (PPW) Cavity Resonance
13.7.3 Parallel-Plate Waveguide (PPW) Edge Radiation
13.7.4 Parallel-Plate Waveguide (PPW) Noise Mitigation using Recessed PCB Power Planes (20-H Rule)
13.7.5 Parallel-Plate Waveguide (PPW) Noise Mitigation using PCB Edge Termination
13.7.5.1 Via Stitching
13.7.5.2 Dissipative Edge Termination
13.7.6 Parallel-Plate Waveguide (PPW) Noise Mitigation using Virtual Islands and Shorting Via Arrays
13.7.7 Parallel-Plate Waveguide (PPW) Noise Mitigation using Electromagnetic Band Gap (EBG) High-.Impedance Structures (HIS)
13.7.7.1 Electromagnetic Band-Gap (EBG) Structures as Surface Wave Filters
13.7.7.2 EMI Suppression Using Embedded EBG (E-EBG) Structures
13.7.7.3 Ultra-Wideband (UWB) EMI Suppression using EBG/HIS Structures
13.7.7.4 Low-Period Coplanar EBG (LPC-EBG) Structures
13.7.7.5 Planar Meander-Line EBG (ML-EBG) Structures
13.7.7.6 Partial EBG (P-EBG) PDN Structures using Remnants of Signal Layer
13.7.7.7 Impact of EBG Structures on SI and Radiated EMI Emissions
13.8 Return Planes and PCB Layer Stackup
13.8.1 Image Planes
13.8.2 Shielding Provided by Ground Planes – or a "Trojan Horse Effect?"
13.8.3 Frequently Used PCB Layer Stackup Configurations
13.9 Local Ground Structures
13.9.1 Micro-Islands
13.9.2 Copper Fills
13.9.3 Local Ground Structure Resonances
13.9.4 Other Local Ground Structure Concerns
13.10 Guard Traces – Love Them or Leave Them?
13.10.1 Guard and Shunt Traces
13.10.2 "Boxed Stripline"
13.10.3 Guard Rings
13.11 Intentional Cuts and Slits in Return Planes
13.11.1 Circuit Partitioning, or Why Castles Don't Have EMI Issues?
13.11.2 Circuit Isolation
13.11.3 Circuit Partitioning and Isolation – A Case Study: Ethernet Circuit Ethernet Layout and the Function of Ground Planes
13.11.4 (Draw)Bridging the Gap
13.12 Grounding in Mixed (Analog-Digital) Signal Systems
13.12.1 Origins of Noise in Mixed Digital-Analog Circuits
13.12.2 Grounding Analog Circuits
13.12.3 Grounding Digital Circuits
13.12.4 Grounding in Mixed Signal PCBs: "To Split or not to Split (the Ground Plane)?"
13.12.5 The Mystery of A/D and D/A Converters Resolved
13.12.6 Grounding Scheme for a Single ADC/DAC on a Single PCB
13.12.7 Grounding Scheme for Multiple ADCs/DACs on a Single PCB
13.12.8 Grounding Scheme for ADCs/DACs on Multiple PCBs
13.13 Chassis Connections ("Chassis Stitching")
13.13.1 Purpose of Stitching PCB Return Planes to Chassis
13.13.2 Direct Stitching of Return Planes to Chassis
13.13.3 Hybrid Techniques for Stitching of Return Planes to Chassis
13.13.4 Capacitive Stitching of Return Planes to Chassis
13.13.5 Controlling PCB-Chassis Cavity Resonances
13.13.6 Benefits of Reduced Spacing between PCB and Chassis
13.13.7 Daughter and Mezzanine Boards Ground Stitching
13.14 Grounding Considerations for PCB Heatsinks
13.14.1 The Role of Heatsinks in Generation of EMI
13.14.2 Heatsink Resonances
13.14.3 The Effect of Heatsink Grounding on EMI Control
References
Chapter 14 Testing and Troubleshooting Grounding Problems
14.1 Ground Plane Interference (GPI) Susceptibility Testing
14.1.1 Conducted Susceptibility, Ground Plane Injection, Spike/Transient
14.1.2 Conducted Susceptibility, Ground Plane Injection, Audio Frequency (AF)
14.1.3 Conducted Susceptibility, Ground Plane Injection, Radio Frequency (RF)
14.1.4 MIL-STD-461G Method CS109, Conducted Susceptibility, Structure Current
14.2 Grounding Diagnostics and Troubleshooting
14.2.1 Approaches to EMI Diagnostics
14.2.2 Troubleshooting Grounding "Situations"
14.2.2.1 A Reminder of Ground Loops Problems
14.2.2.2 Diagnosing and Identifying Ground Loops
14.2.2.3 Ground Loop Solutions
14.3 Grounding, Bonding, and Earthing Case Studies
14.3.1 Case #1: "The Grounds for Electrostatic Discharge (ESD)"
14.3.1.1 Case Description
14.3.1.2 Case Investigation
14.3.1.3 Case Resolution
14.3.1.4 Misconceptions, Fallacies, and Facts Demonstrated
14.3.2 Case #2: "The Grounds for Lightning Protection"
14.3.2.1 Case Description
14.3.2.2 Case Resolution
14.3.2.3 Misconceptions, Fallacies, and Facts Demonstrated
14.3.3 Case #3: "The Grounds for Ground Radar Grounding"
14.3.3.1 Case Description
14.3.3.2 Case Resolution
14.3.3.3 Misconceptions, Fallacies, and Facts Demonstrated
14.3.4 Case #4: "The Grounds for Differential Signaling Grounding"
14.3.4.1 Case Description
14.3.4.2 Case Resolution
14.3.4.3 Misconceptions, Fallacies, and Facts Demonstrated
14.3.5 Case #5: "The Fallacy of Lightning Protection"
14.3.5.1 Case Description
14.3.5.2 Case Resolution
14.3.5.3 Misconceptions, Fallacies, and Facts Demonstrated
14.3.6 Case #6: "The Grounds for Electrical Safety"
14.3.6.1 Case Description
14.3.6.2 Case Resolution
14.3.6.3 Misconceptions, Fallacies, and Facts Demonstrated
References
Appendix A Glossary of Grounding, Earthing, and Bonding-Related Terms and Definitions
Appendix B Acronyms
Appendix C Symbols
Appendix D Values of Fundamental Properties
Appendix E Grounding, Earthing, and Bonding-Related Standards, Specifications, and Handbooks
E.1 APTA Standards
E.1.1 PR-E-S-005-98 (February 2004)
E.2 ANSI/TIA Standards
E.2.1 ANSI/TIA-607-B-2011 (September 2011)
E.3 ASTM Standards
E.3.1 ASTM D1654-08(2016)e1 (2016)
E.4 ATIS Standards
E.4.1 ATIS Standard ATIS-0600321.2005 (December 2005)
E.4.2 ATIS Standard ATIS-0600332.2005 (December 2005)
E.5 British Standards
E.5.1 BS 7430: 2011+A1: 2015
E.5.2 BS 6651: 1992
E.5.3 BS 7671: 2018/A1: 2020
E.6 CENELEC and ETSI Publications
E.6.1 ETS 300 253 (January 1995)
E.6.2 CENELEC Report R044-001: 1999
E.6.3 EN 50522: 2010 (E)
E.6.4 EN 12501-1: 2003
E.6.5 EN 12502-1: 2004
E.7 ESA Standards
E.7.1 ECSS-E-HB-20-07A (September 2012)
E.8 ESDA Standards
E.8.1 ESD S20.20: 2007
E.9 FAA Standards and Reports
E.9.1 FAA-STD-019F (August 2002)
E.9.2 DOT/FAA/CT-86/8 (April 1987)
E.10 IEC Standards
E.10.1 IEC 60364-1: 2001
E.10.2 IEC60364-4-41: 2005
E.10.3 IEC 60364-4-44: 2007–2008
E.10.4 IEC 60364-5-54: 2002
E.10.5 IEC 60950-1: 2005
E.10.6 IEC 61000-5-1: 1996
E.10.7 IEC 61000-5-2
E.10.8 IEC 61024-1: 1993
E.10.9 IEC 61312-1: 1995
E.10.10 IEC 61312-2: 1999
E.10.11 IEC 61312-4: 1998
E.10.12 IEC 61643-12
E.10.13 IEC 62305-1: 2006
E.10.14 IEC 62305-3: 2006
E.10.15 IEC 62305-4: 2006
E.11 ISO Standards
E.11.1 ISO 8044: 2020
E.11.2 ISO 9223: 2012
E.11.3 ISO 9224: 2012
E.11.4 ISO 9227: 2017
E.12 IEEE Standards
E.12.1 IEEE C2 National Electrical Safety Code (2007)
E.12.2 IEEE-STD-80: 2013
E.12.3 IEEE-STD-81: 1983
E.12.4 IEEE-STD-141: 1993
E.12.5 IEEE-STD-142: 2007
E.12.6 IEEE-STD-242: 1986
E.12.7 IEEE-STD-1050: 1996
E.12.8 IEEE-STD-1100: 1992
E.13 International Space Station (ISS) Program Standards
E.13.1 SSP 30240, Revision C (22 December 1998)
E.13.2 SSP 30245, Revision E (15 October 1999)
E.14 ITU-T Recommendations
E.14.1 ITU-T Recommendation K.27 (03/15)
E.14.2 ITU-T Recommendation K.31 (03/93)
E.14.3 ITU-T Recommendation K.35 (05/96)
E.14.4 ITU-T Recommendation O.9 (03/99)
E.15 Military Standards and Handbooks
E.15.1 MIL-STD-171E (23 June 1989)
E.15.2 MIL-STD-188-114A (30 September 1985)
E.15.3 MIL-STD-188-124B (1 May 1998)
E.15.4 MIL-STD-188-125-1 (17 July 1998)
E.15.5 MIL-STD-188-125-2 (3 March 1999)
E.15.6 MIL-HDBK-232A (20 March 1987)
E.15.7 MIL-HDBK-241B (30 September 1983)
E.15.8 MIL-HDBK-263B (31 July 1994)
E.15.9 MIL-HDBK-274 (AS), Notice 1 (29 June 1990)
E.15.10 MIL-HDBK-419A (29 December 1987)
E.15.11 MIL-HDBK-411B (15 May 1990)
E.15.12 MIL-STD-461G (11 December 2015)
E.15.13 MIL-STD-464D (24 December 2020)
E.15.14 MIL-STD-889B, Notice 3 (USAF) (17 May 1993)
E.15.15 MIL-HDBK-1195 (30 September 1988)
E.15.16 MIL-STD-1250A (29 June 1992)
E.15.17 MIL-STD-1310H (Navy) (17 September 2009)
E.15.18 MIL-STD-1377 (Navy) (20 August 1971)
E.15.19 MIL-STD-1399 (Navy), Section 300A, Notice 1 (11 March 1992)
E.15.20 MIL-STD-1399 (SH), Section 406B (1 July 1995)
E.15.21 MIL-STD-1541A (USAF) (30 December 1987) (Cancelled)
E.15.22 MIL-STD-1542B (USAF) (15 November 91)
E.15.23 MIL-STD-1568B (USAF), Notice 1 (12 October 1994)
E.15.24 MIL-STD-1576 (31 July 1984)
E.15.25 MIL-HDBK-1857 (27 March 1998)
E.15.26 MIL-B-5087B Interim Amendment 3, USAF (Cancelled) (24 December 1984)
E.15.27 MIL-DTL-24749A(SH) (21 August 1997)
E.16 Other Military Documents
E.16.1 AFP 91-38 (2 October 1989)
E.16.2 AFSC Design Handbook DH 1-4 (27 March 1998)
E.16.3 Air Force Qualification Training Package 2EXXX-202D (1 October 1999)
E.16.4 Air Force Instruction (AFI) 32-1065 (14 June 2017)
E.16.5 Pacific Air Forces PACAF Instruction 33-103 (26 April 1999)
E.16.6 Air Force Air Combat Command (ACC) Instruction 33-165 (18 September 1998)
E.16.7 UFC-3-580-01 (1 June 2016)
E.16.8 MIL-I3A (February 2010)
E.16.9 TM 5-690 (15 February 2002)
E.16.10 USA-CERL Technical Report M-89/01 (October 1988)
E.16.11 TC 6-02.6 (TC 11-6) (November 2017)
E.16.12 CECOM TR-96-2 (May 1996)
E.17 NASA Standards and Handbooks
E.17.1 NASA-HDBK-4001 (17 February 1998)
E.17.2 NASA-STD-4003A (5 February 2013)
E.17.3 NASA-STD-5008A (21 January 2004)
E.17.4 NASA-STD-6012 (8 March 2012)
E.17.5 MSFC-HDBK-3697 (24 March 2014)
E.17.6 MSFC-SPEC-521, Revision C (1 July 2013)
E.17.7 NASA/CR-1998-207400 (March 1998)
E.17.8 NASA Reference Publication 1368 (June 1995)
E.17.9 NASA Practice No. PD-ED-1214
E.17.10 KSC-STD-E-0022, Change 2 (5 February 2019)
E.17.11 KSC-STD-E-0012F (10 January 2013)
E.17.12 NSTS 37330 (2 December 1999)
E.18 NFPA Codes and Standards
E.18.1 NFPA 70 (2020)
E.18.2 NFPA 780 (2004)
E.19 SAE Recommended Practices
E.19.1 ARP1870 (April 1999)
E.19.2 ARP4043, Revision A (January 1999)
E.20 Singapore Standards
E.20.1 SS 551: 2009
E.20.2 SS 555-1: 2010
E.20.3 SS 555-3: 2010
E.20.4 SS 555-4: 2010
E.21 UL Standards
E.21.1 UL 96A: 1998
E.21.2 UL 467 (22 March 2013)
E.22 Other (Miscellaneous) Standards
E.22.1 API (American Petroleum Institute) Recommended Practice 2003 (6th Edition, 1998)
E.22.2 ATT-TP-76403 (July 2006)
E.22.3 NWSPD 30-41 (25 April 2017)
Appendix F Practical Experiments for Demonstration of Grounding and Bonding-Related Principles
F.1 Introduction
F.2 Experiment #1: “Rusty Bolt” Demonstrator
F.2.1 Relevance
F.2.2 Contributor
F.2.3 Objective
F.2.4 Equipment
F.2.5 Procedure
F.2.6 Theory
F.3 Experiment #2: Ground Noise in Digital Logic
F.3.1 Relevance
F.3.2 Contributor
F.3.3 Objective
F.3.4 Equipment
F.3.5 Procedure
F.3.6 Theory
F.4 Experiment #3: Effect of Pulse Rise/Fall Time on Signal Spectra
F.4.1 Relevance
F.4.2 Contributor
F.4.3 Objective
F.4.4 Equipment
F.4.5 Procedure
F.4.6 Theory
F.5 Experiment #4: Common-Mode Currents and Radiated Emissions of Cables
F.5.1 Relevance
F.5.2 Contributor
F.5.3 Objective
F.5.4 Equipment
F.5.5 Procedure
F.5.6 Theory
References
Appendix G Grounding Verification Checklist and Procedures
Purpose
Practice
Benefits
Requirements
Applicability
Scope
How to Use this Guide?
Structure of the Guide?
Impact of Nonpractice
Purpose
Verification Methods
Purpose
Before Equipment is Installed
Installed Equipment
Fault Protection Subsystem
Bonding
Other Observations
References
Appendix H Grounding Documentation Content
H.1 Approach for Grounding/Power Distribution Schemes
H.2 Content of Power and Grounding Schemes
Appendix I On the Equivalence Between Ohm’s Law and Fermat’s Least Time Principle
I.1 Origin of the LT/MP Principle
I.2 Statement of the LT/MP Principle
I.3 Derivation of the Equivalence Between Ohm’s Law and Fermat’s Least Time Principle
I.4 Equivalence of Ohm’s Law and the LT/MP Theory
Reference
Appendix J Thoughts on the Low-Frequency Return Current Distribution
J.1 Introduction
J.2 Current Flow and Ohm’s Law
J.3 Duality Between J and D
J.4 Application to Return Current Flow in a Ground Plane on a PCB
J.5 Conclusions
J.6 Simulation and Results
References
Appendix K Overview of S Parameters
K.1 Background
K.2 Ports and Interaction Matrices
K.3 The Scattering Matrix and S Parameters
K.3.1 The Scattering (S) Matrix
K.3.2 S21 or “Forward Transmission Gain/Loss”
K.3.3 S11 or “Input Return Loss”
K.3.4 S22 or “Output Return Loss”
K.3.5 S12 or “Reverse Gain and Reverse Isolation”
K.3.6 Effect of Reference Impedance
K.4 Characteristic Values of S Parameters
K.5 S Parameters in Loss-Free and Lossy Networks
K.5.1 The Loss-Free Network
K.5.2 Lossy Networks
K.5.3 Insertion Loss
K.5.4 Radi/Figure/ciation Loss
K.5.5 Mismatch Loss
K.5.6 Loss Factor
K.5.7 Efficiency Factor
K.6 Mixed Mode S Parameters
K.6.1 Mode Conversion on a Differential Pair
References
Appendix L Sample Practical Analysis of “Common-Impedance Coupling”
L.1 Scenario
L.2 Conducted Susceptibility, Ground Plane Injection, Spike/Transient Requirement
L.3 Analysis
L.3.1 Potential Interference Mechanism
L.3.1.1 Coupling Through the DC Power Circuits, Supplied Directly from a Primary, Grounded DC Power Source
L.3.1.2 Coupling by Leakage Through Line-to-Ground Capacitors (or Other Parasitic Capacitance), into the DC Supply Input to Victim Equipment
L.3.1.3 Coupling Through the Ground/Reference Circuits of the Secondary Voltages (e.g. DGND and AGND), When (as Often) Grounded to Equipment Enclosure and Chassis
L.3.2 Summary and Conclusions
References
Appendix M Grounding, Bonding, and Earthing Check Yourself Quiz
M.1 Introduction
M.2 Grounding
M.2.1 Which of the following statements best defines Grounding?
M.2.2 Common-mode current flows on all
M.2.3 For controlling high-frequency radiated emissions earthing of equipment
M.2.4 Multipoint grounding is particularly useful in order to
M.2.5 Current, if not obstructed, will always follow the path of
M.2.6 If resistance of the grounding conductor in the figure shown below is negligible, the grounding path’s characteristic impedance (Z0) is approximately …
M.2.7 Ground loops are
M.2.8 An equipotential ground structure should have
M.2.9 What grounding scheme is best for high frequencies?
M.2.10 Multipoint grounding is not the cure for all grounding problems because its greatest drawback is …
M.2.11 Frequency-selective grounding is necessary for …
M.2.12 The “grounding tree” concept is …
M.2.13 Optical isolators (opto-couplers) are …
M.2.14 Ground loops can be “broken” by …
M.2.15 In distributed systems, the most important method to ensure EMI-free performance is …
M.2.16 The greatest benefit of differential signaling is that it …
M.2.17 In order to preclude magnetic field emissions from a high-frequency coaxial cable connected to a grounded circuit, the cable shield should be …
M.2.18 The term “AC Ground” implies …
M.2.19 Inductance in high-frequency circuits …
M.2.20 Multiple, unequal parallel decoupling capacitors produce …
M.2.21 Interplane capacitance on multilayer PCBs …
M.2.22 High-speed transmission lines jumping across the VCC (power) and GND (return) planes is OK …
M.2.23 The grounding scheme in circuits with an embedded A/D converter depends primarily on …
M.2.24 Chassis stitching is useful to …
M.2.25 Indirect bonds …
M.2.26 Corrosion reactions primarily result from …
M.2.27 Ground-coupled interference in a differential system occurs primarily due to …
M.2.28 A practical ground is …
M.2.29 Single-point grounding is …
M.2.30 Cable shield should not serve as a signal return path except in …
M.2.31 A ground fault circuit interrupter (GFCI) monitors the …
M.2.32 Flat straps are preferred over round wires with equal cross section for high-frequency conductors because they …
M.2.33 The impedance of a bonding strap at 50 Hz power frequency is primarily determined by its …
M.2.34 Directly bonding a copper conductor to an aluminum surface will result in …
M.2.35 The preferred ratio for a flat bonding strap’s length to width is …
M.2.36 Why is bonding typically specified in terms of DC resistance?
M.3 Earthing
M.3.1 The ground fault loop impedance of a single-phase supply circuit has a measured value of 0.65 Ω, and the value is indicative that the grounding scheme is likely to be
M.3.2 In a low-voltage electrical installation, electrocution is primarily due to
M.3.3 An isolation transformer is commonly installed at the output side of a static UPS because it provides
M.3.4 The most suitable earth electrode system for a telecommunication base station to be erected on a rocky hilltop is
M.3.5 The resistance to earth of a 3 m copper earth rod of 25 mm diameter installed at a site of uniform soil resistivity of 50 Ω-m is about
M.3.6 The armor/sheath of a single-core transmission power cable may be grounded by
M.3.7 The neutral of a generator is connected to ground through a resistor
M.3.8 The ring earth electrode preferably should be buried at a depth below ground of
M.3.9 Bonding of lightning conductor to metallic enclosure of electrical equipment installed at the rooftop should be carefully evaluated to avoid
M.3.10 The earthing and bonding practice to prevent dangerous lightning-induced sparking inside a structure may include
M.4 Answer Key
Index
EULA
