Gnecco L.T. Design of Shielded Enclosures: Cost-Effective Methods to Prevent EMI

Oxford (GB): Newnes, 2000. — 204 p.This book is written for the type of clients that we often see in our laboratory at TEMPEST INC.: Electrical or mechanical engineers who are faced with thorny electromagnetic compatibility problems and who need to design a shielded enclosure. Even though shielding does involve electromagnetic theory, this book makes a special effort to avoid hitting you with vectors, gradients, multiple integrals, and Maxwell's equations. Instead, this book presents practical tools such as nomographs. This book also includes a lot of illustrations. Most engineers grasp things more quickly with pictures than we do with text alone.
Shielding is both an electrical and a mechanical problem. Mechanical engineers tend to take the electrical aspects very seriously, and they should be able to get all the shielding information they need out of this book. On the other hand, we electronics engineers tend to neglect the mechanical aspects. We tend to design enclosures that are either too flimsy or too heavy, unnecessarily expensive, or hard to manufacture. Sometimes we design them with parts that simply don't fit together! If you are an electronics engineer, I strongly urge you to sit down with the owner or foreman of your machine shop and review the mechanical drawings of your enclosure before they start bending metal.
Besides finding errors, the machine shop can suggest ways to make the enclosure simpler and easier to build. This preplanning process will save you time and money when you get into production. Some companies employ draftsmen or mechanical designers to prepare the final drawings. This arrangement is fine, but don't rely on them blindly. Set up a meeting among you, the mechanical designer, and the manager of the machine shop. Let everyone understand that the purpose of the meeting is to find ways to save time and money, not just to criticize the mechanical designer.List of Illustrations.
List of Tables xvii Preface.Mechanical Help for Electronic Engineers.
A Crash Course in Mechanical Drawing.
Chapter 1 Problems.
Chapter 1 Answers.Terms.
Electromagnetic Interference.
Electromagnetic Compatibility.
Attenuation.
Decibels.
Measurement Accuracy.
Electric Fields.
Magnetic Fields.
Plane Waves.
Power Line and Signal Line Conduction.
Equipment Under Test (Unit Under Test).
Emissions.
Susceptibility and “Immunity”.Chapter 2 Problems.
Chapter 2 Answers.How Shielding Is Accomplished.
Reflection.
Absorption.
Electric and Magnetic Fields.
Air Gaps.
Slot Radiators.
Joints.
Doors, Lids, and Openings.
Corrosion.
Selection of Materials.
Finishes.
Vents and Cooling.
Penetrations.
Controlling Internal Reflections.
Magnetic Shielding.
Shielding at Ultra High Frequencies and Beyond.
Shielding Cables.
Ferrite Beads.
A Word About Welding.
Latches.
Doors.
Access Panels.
Setup Panels.
Signal Line Filters.
Power Line Filters.
Sprinklers and Halon.Types of Shielded Enclosures.
Shielded Rooms.
Shielded Racks.
Tabletop Enclosures.
Hand-Held Enclosures.
Tiny and Printed Circuit Board-Mounted Enclosures.Testing.
Basic Procedures.
Instrumentation.
Technical Terms.
Spectrum Analyzers.
Saturation.
Front Ends.
Preselectors.
The Attenuator.
Dynamic Range.
Calibration.
Linearity.
Current Shielding Effectiveness Standards.
Antennas.
Cables and Connectors.
Cables.
Signal Generators.
Testing Printed Circuit Board-Mounted Enclosures.
Power Amplifiers.
Preamplifiers.
Spectrum Analyzers.
Other Receivers.
A Testing Kit.
The “Gang Box”.
Extension Cables.
Tripods.
Reach Extenders.
Signal Cables.
Connectors and Adapters.
Batteries.
Soldering Kit.
Tools to Fix RF Leaks in Large Enclosures.
Items That Help You Get in and out of Construction Sites.
Tools for Documentation.
Items for Comfort and Safety in On-Site Tests.
Selecting Test Points.
Techniques for Testing Shielded Rooms.
Troubleshooting.
Care of Test Equipment.
The Test Report.Appendixes:
MIL-STD-285.
A Primer on Medical Device Interactions with Magnetic Resonance Imaging Systems.
Electromagnetic Compatibility Suppliers Directory.References.
Index.