The most important use of RF energy may be to provide telecommunications services. Radio and television broadcasting, cellular telephones, radio communications in the police and fire departments, amateur radio, microwave point-to-point links and satellite communications are just a few of the many telecommunications applications. There are also many non-communication applications that use RF energy. Microwave ovens are a good example of the non-communication use of RF energy. Other important non-communication uses of RF energy are radar and industrial heating and sealing. Radar is a valuable tool for many applications from traffic enforcement to air traffic control and military applications. Industrial heaters and sealants generate RF radiation to rapidly heat the material being processed in the same manner as microwave ovens. These devices have many uses in the industry, including molding plastic materials, bonding wood products, sealing articles such as shoes and wallets, and processed foods. Other industrial applications include testing RF components and measuring material density.
RF energy is also used in medical applications. It is used in medical treatments such as beauty treatments to tighten the skin, reduce fat or promote healing. MRI, magnetic resonance imaging uses RF waves to generate human images. RF is also used to destroy cancer cells.
Because of the large number of RF applications in the world, products and systems must be able to operate in their electromagnetic environment and must not introduce unacceptable electromagnetic interference into the environment. Therefore, RF immunity and radiation testing must be performed before the product or system enters the market. For RF immunity testing, the device is exposed to RF interference and fields with field strength and frequency range, representing its operating environment. On the other hand, when testing the RF emissions of a piece of equipment, the device will monitor the RF interference and the field under normal operation.