The Electromagnetic environment is an integral part of the world in which we live. Various apparatus such as radio and television broadcast stations, communication transmitters, and other radar and navigational aids radiate electromagnetic energy during their normal operation. These are intent6ional radiations of electromagnetic energy into the environment. Many appliances, such as automobile ignition systems anmd industrial control equipment used in everyday life also emit electromagnetic energy although these emissions are not an essential part of normal operation. The electromagnetic environment created by these intentional and unintentional sources, when sufficiently strong, interference with the operation of many electrical and electronics equiptment and systems.