Introduction To Radio

Wireless communication products, such as cell phones and satellite radio, have become as much a part of today's everyday life as the microwave did two decades ago. During the next few years, this technology will spread from consumer products onto the shop floor. Automation and process engineers and managers need to understand wireless — or radio frequency (RF) — technology to properly assess and deploy the many wireless automation products that soon will become available to them.

Working with wireless products, which use the air as the medium of communication, offers challenges different from their more familiar wired product counterparts. Early incarnations of wireless automation products often left the buyer feeling mystified and shortchanged. They offered spotty performance and were difficult to install, configure and maintain. Fortunately, the new generation of wireless products is easier to use. In addition to consuming much less power, these new products are easy to configure and install, offer built-in tools for monitoring the reliability of the wireless connection and can easily be integrated with existing wired infrastructure.

But before deploying an RF instrumentation control system in a facility, it is important to understand the basics of the technology, its advantages and its limitations. This article describes the major elements of a RF system and how they work together to move sensor data from point to point:

• Basic RF components
• Frequencies commonly used in RF product design
• Different modulation techniques for RF signals
• The effect of environment and interference on radio