Control and Measurement of Unintentional Electromagnetic Radiation

CHAPTER 1

INTRODUCTION

This book is meant to satisfy the needs of a rather diversified audience. Therefore, if it has not been done already, the preface, “Tailor This Book to Your Needs,” should be read by anyone about to join that audience.

1.1 THE PROBLEM

The human environment of today—at work, at home, at school, and at play—contains ever-increasing numbers of electronic devices. In recent years it has become increasingly evident that many of these devices interfere with each other and otherwise contaminate the environment. They do so by radiating electromagnetic energy. Some electronic devices are designed to communicate with one another by radiating electromagnetic energy. However, the vast majority of electronic devices are not designed to radiate, yet they very often do radiate. These devices are filling the environment in rapidly increasing numbers and, at the same time, their potential to radiate electromagnetic energy is also rapidly increasing.

Unintentional electromagnetic radiation is a significant engineering problem, as well as a significant societal problem, for many reasons. The reasons can be lumped into three basic categories. (1) Unintentional electromagnetic radiation from many electronic devices often interferes with the proper operation of others of those devices. (2) Continued exposure of the human body to relatively low levels of electromagnetic radiation is suspected to be harmful, but its long-term effects are not yet well understood. And, (3) because ...