Fundamentals

Unlike so many technologies in use today, horn antenna history actually started more than a hundred years ago. This short article introduces the reader to the history of horns from the early experiments of radio pioneers to the “horn boom” during the 1940s and 1950s. The article ends with the latest evolution of horn antennas.

Your static control program is up and running. How do you determine whether it is effective? How do you make sure your employees follow it? In Part 3, we suggested that there were at least nine critical elements to successfully developing and implementing an effective ESD control program. In Part 4, we will focus on two more of these elements: training and auditing.

Here are the most likely reasons why, along with the forgotten available 5 GHz band.

Wireless networks offer the convenience of not worrying about being tied to various cables, switches, etc., but they also need to be understood according to their limitations.

Most manufacturers of electrical and electronic equipment have some sort of a regulatory compliance program. These may be part of the company’s internal procedures, a subscription to a compliance related database or various bits and pieces of information held by key people within the organization. No matter how complex or simple, it is imperative that management involved in global regulatory compliance issues have the right information needed to make their programs work efficiently.

Product liability has created problems for manufacturers and product sellers for many decades. These problems have been exacerbated by the expansion of product liability laws throughout the world. In addition, there has been a proliferation of safety regulatory requirements, starting in the United States and then moving to the European Union. In addition, countries such as Japan, China, Australia, Canada, Brazil and South Africa have all recently established or strengthened their product safety regulatory regimes and requirements.

The science of electromagnetic compatibility has been in exis­tence for several decades. As an art, it goes back much further, perhaps to the time of Edison when he was just beginning to experiment with practical electrical devices. I am sure that with some of his more sophisticated devices undesired interac­tions took place because of inadequate shielding or filtering. Certainly, with the advent of radio, incompatibility problems occurred as a result of the poor quality of transmitters and receivers. Perhaps the first formal recognition of electromag­netic compatibility problems occurred when the telephone and power companies found they had mutual coupling problems when their lines were carried on the same utility poles. Later on, the increasing use of the radio spectrum called for formal controls administered by departments in the post, telephone, and telegraph offices in many countries, or through the Feder­al Communications Commission in the United States.